I had two TA's, one spoke only Japanese, the other Italian. Neither could speak with the other or the small class, duplicating balls rolling down an incline, incredible precision and good data being the point not the learned lesson. This is how research is done. This is how peer review is done. This was back in the 60's. Today with pressures, many studies are spread out. Being immersed and expected to learn the math at the same time as the physics as the computer was daunting. Throw in 1 credit hour courses in Fortran ( turn in your punch cards and wait for the error stack from the one and only main frame ), and mandatory Saturday quiz sections we were immersed. Our failure rate freshman year soared to 60%. It was also an engineering school. Later taking computer science classes the cheating was rampant, my professor dealing with irate parents asking about bad grades. It became a party school. All games all the way up and down. Sad sad sad.
Calculus... Lol is awesome... It is just find the acceleration at any point of velocity at any point... Meaning... Let's do what any mortar or artillery or tank crew does.. lol
@@mikedubovs1574 each time I struggle with Calculus I am like "a XIX century prussian artillery dude with one set of pants whose entire education ended in 7th grade did it under fire, stop whinning"
I‘ve listened to too many Well There’s Your Problem episodes to ever believe a space elevator wouldn’t result in the worst engineering disaster in a century.
my first and only thought every time the concept of a space elevator comes up is "yknow what happens when you accidentally hit your leg with a weedwhacker, but with like half of the planet"
I zoned out to a talk about space elevators and when i zoned back in, you were all of a sudden ranting about terabytes of fridge data. This is what im here for
The best bit about this channel is how the videos start calm and normal and end up with a really entertaining rant, but only the people that make it through the first 30 mins get to the rant part.
"So there's this RUclips channel called Cracking the Cryptic and I watch them to sudoku puzzles." She's just like me fr fr "I have absolutely no positive feelings towards any human achievement. Ever." Oh.
For context on the Hyatt disaster, it was caused by a smalll cost saving change made AFTER the engineering was done. They had two walkways. The engineer had them both anchored to the ceiling. They made the cost saving decision to anchor the bottom one to the top one. The anchors for the top one could not hold the weight of both and they failed.
The engineers had rods anchored to the roof and it ran through the beams that held up the walkways. But they hadn't designed a way to hold the upper beams to the rods (edit)that was constructible.. I am not assigning blame here. We do so far too easily these days. Ultimately it was small errors by a number of companies that lead to tragedy which is often the case. (end of edit)
@@indetigersscifireview4360 No, that's not correct, the upper beams were secured to the rods by nuts. OP is correct. Your comment only adds misinformation and confusion.
@@indetigersscifireview4360they had a way to do this, the complication was that because they would attach the it via nuts, the rods would have to be threaded their whole length. They were very long, and manufacturing a rod with that long of a thread and installing it without somehow damaging the threads was considered infeasible. So, they split the rod in two. This effectively meant that then nuts for the upper platform were supporting both the upper platform and the lower platform, which they were not designed to do.
@@aidanwarren4980the issue with the threads seems like a callback to the video talking about making a rope for the elevator so long without breaking it. it’s an even more apt comparison than it already was, lol
1. A space elevator would block off a whole class of orbits for satellites. Imagine the lawyer fights over this territory. 2. If the tether is in any way conductive, imagine a Carrington event with massive induced current running up/down the tether. That would be fun. 3. Is Angela turning into "old man yells at clouds"? If so, welcome to the club.
#1 is completely solvable, #2 is the first thing I've heard that gave me a pause for a moment, but that's why we have civil, electrical, mechanical, and materials engineers to solve those hurdles and I think that we actually might be able to make that Carrington event a selling feature with a little thought. #3. yes.
And probably wouldn't be good if a hurricane when through it either. I assume these elevators would need to be at the equator if they are to be stationary.
@@qsquared8833 Go with enough of them, you'd not need those LEO birds, just put small stations at those orbital altitudes on the elevator "cable". A conductive cable with extremely low resistance would likely happily carry that current to ground. Don't recall any wires being reported destroyed during the Carrington event. But, a ride on a space elevator reminds me of a candy bar commercial, "Gonna be a while?", only with a *lot* of candy bars needed...
@@spvillano I literally almost came back here and edited this comment to basically say the charge should go to ground and be no big deal like any building being struck my lightening, but decided to leave it thinking someone will surely realize it's not a big deal and write a reply. Looks like that would be you, and thanks for that. Also fully agree a space elevator isn't about LEO, it's to get things well and truly up high enough that they'd be useful
She’s made a video with no edits? Not a criticism, I like collier’s sense of comedic timing in the edits, I’m just yet to see her go all Goodfellas club scene in any of her vids
My favorite structural engineering channel is "Building Integrity." Space elevators were a lot more attractive an idea when we were only using rockets once. If we had to build a new ship or airplane every time we wanted to cross the ocean, we'd be talking seriously about building a bridge.
The most appealing part to me is using them to sling stuff off into higher solar orbits. Making a trip to mars last a couple of months rather than a six month trip.
@@atashgallagher5139you can just use a rotating tether, but for any reasonable taper you're still only going to get 3km/s. Reasonable for TLI but for Mars it's not a great deal when you consider the mass ratio and the size of a Mars lander and the need to reboost between launches and the long time between windows.
Naw, space elevators are more appealing now that we can actually lift lots of stuff into orbit because now it's actually economically possible to build one.
33:42 I'm so happy to see when there's people outside of tech industry/open source activists who are voicing their dismay at the state of tech. Granted you're in STEM so that's tech industry adjacent, but all too often I spoke to professors who were blissfully ignorant of this softcore dystopia we ended up in. The more awareness we raise the better shot we have at changing things. Thank you!
One note about helicopters: they're actually pretty damn safe. More dangerous than commercial planes, sure, but safer than private ones, and *much* safer than cars. Considering they are typically used in risky rescue operations, this is actually really impressive. One common misconception is that you die if the engines fails, which is simply not true. Helicopters can safely come down if you turn off the engine thanks to autorotation, as the air causes the unpowered blades to rotate
helicopter has to fly high to achieve autorotation, but intuition says you should go closer to the ground to quickly land, as well as you are ascending from low height while taking-off. In short, autorotation didn't provide safety when helicopter is flying low.
Well yes, but no. Helicopters are safer than cars because there isn't the equivalent volume of traffic going through them. Couple that with the bell curve spreading out on safety checks, helicopters are dangerous as fuck as "flying cars."
@@Pho7onper hour spent in them helicopters are about 50 times as dangeorus as cars, how that translates to per kilometer or per flight/drive dependso n how fast/where/how far you go in each motorcycles are comparable to helicopters in deaths per gigahour though also depends on who's flyign it and how and why, etc just like with general aviation you get a lot of crashes from private owners with lax safety standards and a you can really bump up the safety by sticking to a few rules
I love cracking the cryptic! It's always such a chill time, but I do get a little stressed whenever he flies off the handle and says "bobbins". Also strong recommend for their The Witness playthrough.
@@excrubulent Yeah it's why I can't watch him anymore. I live next door to an English man and it fucking sucks. Like people think it's funny that some people can't handle that shit but it's really not and I wish they'd just stop.
A subscripiton to a live stream of the night sky for only 10€ a month, and a night sky+ to look at the nothern lights There's a reason rent seeking is a sin, this is hell on earth.
I was surprised that the video was over 200 hours long and took 6 me hours to buffer, but then when it got the section of the video that was the footage of her playing factorio (real and true) it all made sense and added so much to the overall viewing experience.
@@najawin8348GTNH space elevator... In my case it is currently in a state of "possible after a week of crafting, during which power will definitely die at some point"
One of the worst and/or best structural failure stories I can think of is the Erfurt latrine disastrer from the late 12th century, where 60 nobles fell through a fortress floor and drowned in poo. en.wikipedia.org/wiki/Erfurt_latrine_disaster
I love it every time I find someone who enjoys watching two middle-aged British former accountants solve Sudoku puzzles because there's no way to explain it to anyone else. Great idea for a video, as always. Can't wait to watch it.
I think the idea that a lot of people have with a space elevator is that they know they're never going to ride a rocket to space. going to space as a normal person sounds a lot more attainable in an elevator than a rocket
Probably should give it a more descriptive technical name in that case, like Tethered Ascension Vehicle or something, so people don't think it's actually like just stepping into an elevator and popping out in space
Traditionally the way to maximise the likelihood for an individual to win a seat in a space craft involved dedication and study. Astronauts tended to be genuinely humbled and excited by the experience. Coming soon is the era of anti social media influencers. Won't be long before we are avoiding watching the likes of Logan Paul do his thing in orbit. O wonder... ...O brave new world. That has such people in it.
Maybe it is a function of when your childhood is. I grew up in the 70s and 80s, expecting to die in a nuclear holocaust. Instead I live in a world with astounding access to information.
While not strictly a structural failures channel, "Practical Engineering" does cover a number of disasters from time to time (among other equally excellent videos about various aspects of civ-eng). He actually does cover the Hyatt disaster in a shorter sub-video for Tom Scott's channel. It goes by the title 'The Disaster That Changed Engineering: The Hyatt Regency Collapse'. He also covers the Tacoma Narrows Bridge collapse in an earlier video.
You would love the channel "Building Integrity". The channel started after the surfside condo collapse, the creator is a licensed structural engineer and he does an *amazing* job of analyzing the evidence collected from engineering disasters.
I went to a presentation about 15 years ago on space elevators (80% for entertainment, and 20% because I want to live in Star Trek even though I know I can't). Honestly, a little bit of the talk was about the idea and the promise of it, but most of the discussion was about the issues that they haven't solved so at least at that time, so at least it wasn't all sunshine, rainbows, and tricorders. So these are some of the ideas that they had at the time (at least what I remember of what they said) ... posted as my time capsule of space elevator BS: THE CABLE: The cable would be a carbon nanotube ribbon. According to them a ribbon would actually be stronger than a round cable and more resilient to damage (don't remember exactly how now). But they did mention that the longest pieces of carbon nanotubes were measured in centimeters (reminder ... 15 years ago) POWER: Their idea was that if they could use carbon nanotube ribbons, they could actually transmit the power through the ribbon at low resistance saving them any power generation or storage on the elevator itself. SLOW RIDE: While they did say that the payload would be less than the shuttle (it was still running back then), the turnaround for an elevator trip would still have been far less than the many weeks of cycle time to inspect and prep a returned shuttle for another flight, making the space elevator total throughput greater than the shuttle. DYNAMIC COMPENSATION: As far as balancing for the changes in the physical system as the elevator takes mass up and down the ribbon to space, the counterweight could be reeled in and out to adjust for the mass and position of the elevator. Basically reel it out when the elevator is low and reel it in as the elevator pulls itself up so that the center mass remains in the geosynchronous range. SAFETY: I believe they said that if the ribbon broke, the elevator itself would act as a reentry vehicle and have a deployable parachute system. The geosynchronous station could essentially cut the tie to the counterweight and remain in orbit. At that point you would have to go through the whole process of replacing the counterweight and lowering and attaching a new ribbon. WHY: There were a few reasons they gave. One was for lowered cost. . Beyond that was holy grail of space tourism ... basically making it cheaper for people to go to space and, um ... do space things ... space selfies? idk. Part of the lowered cost idea was to make human exploration of other planets easier, as well as asteroid mining ... and I think He3 from the moon (though I might be conflating that with something else). There was no mention of billboards ... but also no mention of banning them ... OTHER PROBLEMS: In addition to all the issues you already mentioned, they did mention one thing that you didn't. That was the geopolitics problem. Essentially that the elevator has to be somewhere that is near the equator and if you look at the countries that are near the equator usually aren't the most stable of places. And it's something that could potentially become a target, which is a bad combo. So I hope this is, um ... useful doesn't seem to be the right word ... but I hope it's ... something ...
This is informative, and I think genuinely starts to answer Collier's main questions of "why, and is it worth it to try". My followup question is under SAFETY: what about the part of the ribbon below the break? How do you stop that from impacting the ground at high velocity?
Was that the group from the Keck Institute? I remember reading their feasibility study some years ago and these were pretty much the same ideas they floated. Re: the damage resistance I think they calculated (or 'calculated', I don't recall) that the ribbon should retain structural integrity even with numerous holes from micrometeorites and the like until patching up. Although, in all honesty, they were speculating about the management of a non-existing material. In hindsight, all of it sounds like a slightly more prestidigitative handwaving. Still, fun to think about.
1) Cables: Still not sure the "one long cable" notion is anything but retro-futurism as for as design is concerned. 2) Billboards: Space billboards are pretty much inevitable. They might not look like we imagine, but commercial advertising is almost certain.
lol. Clarke solved the geography problem by moving his adopted home south to the equator. Great book. Also proposed carbon nano tubes as structure going on 40 years ago. He wove a great story around the physics
I love the way this starts out as a straightforward classical-mechanics problem, worked out nice and clearly, then blossoms into a righteous rant against outer-space hype and pop-science nonsense. We never saw it coming! Great video
The basic idea to my understanding is generally that if you have a space elevator then the cost of getting stuff into space goes down. This allows you to do stuff in space that requires large amounts of stuff from earth like moon and mars colonies or enormous space stations for far less resources than using rockets. That is the dream of the space elevator after you hand wave away all the things that make it impossible, that it will allow for a space based future, not in a Star Trek instersteller way but in a neo-colonial solar system way. And depending on your views that’s either inspiring, troubling or both.
Also, what would happen before colonies, mining materials from space objects more cheaply and more easily getting it back to the ground to be turned into more things to mine shit in space. So basically capitalism again. Basically the only way to get capital interested in space development, other than as a pet project for someone unimaginably wealthy. Get one rock mostly made of incredibly rare metal here on Earth, tow or mine it on site and bring it back here. Then watch as quite a few countries IMPLODE as their economies are ANNHILATED because their economies were before forced to exclusively just mine this material. At least till the operations up there are developed enough to be mostly based on space based labour. IF we can transfer most of our production processes to work in near zero G.
@@cancermcaids7688 if you think "neo-colonial" is an absurd concept think about the Beltalowda from The Expanse series. That's what we'll get if people like Bezos and Musk have it their way
Also if your country wins the "build the space elevator race" it become the next super power because you can basically controll the economic flow of people/things to space
oh, it would be a colonial project eitehr way because you need at least three major places along the equator in the right spacing and the countries or companies most likely to build one currently have 0 land at the equator so someones gonna tell everyone near the equator to die except in a very friendly, brand safe way but still thats basically gonna be the message
Being a depressed old man, I'd like to thank influencer Dr. Collier for consistently raising my spirits. She is the future as I imagined it. Oh brave new world...
@@facingup1624 whether you like it or not, both pronunciations are *very* well-attested in English. It would be unreasonable to consider "suduko" to be incorrect in English when nearly half of English speakers (according to my personal experience) say it that way. Go be a grammar Nazi somewhere else.
I am a 60+ physicist. I envy your ability to work on formulas on a tablet. I need pen and paper for that. And this is actually the only thing I need a notebook for.
I am 64, and I have a similar dependence on paper. Though the other day I was using a paper map and tried to zoom in on it. I am very disappointed that I now have no fluency with both paper and electronic maps.
@@marymegrant1130 That's hilarious. You're still probably pretty good on pen and paper tho. It's just now that you like your maps of a digital variety. Back then they need reading glasses to do that
I think that difficulty may point toward aspects of human learning, memory, and thought which are tied to embodiment. That is to say, there are unconscious processes that are tied to, even utilizing or built upon, things like tactile sensation and proprioceptive feedback. Where I notice it most in myself is a pronounced difference in retention and ability to apply concepts when reading the same textbook from a tablet versus from the printed hardcover. My son reports the opposite effect I experience. He has trouble retaining from a printed book and is better when using a tablet, but then he has been using a tablet since before he could walk. That’s a pretty small _n_ to be sure (heh!) but it’s fascinating to me.
I liked the idea of space elevators and really thought they were an interesting solution to a lot of problems with putting stuff in orbit. And now I just remembered that I first heard about them from Michio Kako and now my day is ruined and my disappointment is immesurable
@@halcyonacoustic7366 Kako is very likely a nice fellow and a gentleman, but he's also a credentialed Ivy League Physics Professor who makes endless TV and internet appearances as a "science communicator" presenting wildly speculative prognostications about sci-fi technologies and sensational unfounded takes on theoretical topics outside his field.
They want a space elevator to escape the rocket equation. If the elevator could be powered by electricity from the ground, then the energy needed to lift something would be proportional to the mass.
Most of the engineering papers about a space elevator I've read suggest a kind of solar-panel powered elevator car being energized by high-power ground-based lasers or microwave beams, which is only slightly less hand-wavey than the materials tech they need to engineer a cable capable of withstanding the tensile forces in play, and honestly I don't recall any of them ever addressing the oscillation issue.
Not only that, but using regenerative braking, you can use the potential energy of stuff going down to power stuff going up. If the masses balance, you only have to provide power to overcome friction, and other losses in the system.
She addresses the reasons. She doesn't mention the rocket equation, but I'm pretty confident that someone with a PhD in astrophysics is aware of it. The real question is: what would you use a space elevator *for?* It's useless for putting stuff in Earth orbit, and interstellar travel is even more impossible than space elevators. That leaves missions within the solar system, and there aren't enough of those for a space elevator to ever pay for itself.
@@MarianneExJohnson The reason usually used in science fiction is to bring people and cargo up to a huge station at the top, and then shuttle things from the station to wherever they are needed. It's feasible, kinda, but the level of infrastructure needed to make it practical is a lot more than just the elevator itself.
Two thoughts: 1. The fact that Philip K. Dick predicted the idea of needing to pay a subscription service in order to open the door to your house. Like. Goddamn. 2. The first company to put a giant glowing billboard in the night sky is going to get [PARODY REDACTED] and I still don't think that would be enough to stop them from doing it.
That would be a fun follow up, if you were to assume that the space escalator travels at a 45 degree angle, how much sorry material would be required to reach space?
I understand almost none of the science/math, but I find extreme comfort in knowing there are people passionate about this stuff. Makes me feel safer knowing there are tons of smarter people than me out in the world.
I love hearing you say. “It’s sooner than you think.” The first video i ever saw of yours was about space elevators. That alone was worth a subscription. You never disappoint.
Seconded, he is absolutely incredible! I can credit Khan Academy for getting me from "confused math-illiterate adult going back to college" to Calc III-ish, and then 3Blue1Brown helped me finish the Calc IV and linear algebra for my EE degree. I'm so grateful for all the work these guys put into making math more accessible.
@@lixxark47 It depends; for some schools on the quarter system, it's Calc 3, more or less, since the calculus sequence gets sliced up into four parts instead of three. For others, especially those on semesters, it's just another name for what's more commonly called Ordinary Differential Equations (a.k.a. ODEs or DiffEq). None of the universities or colleges I've taught at had a course named Calc 4, though; names vary, check the descriptions/syllabi.
22:07 pulling a vibrating string taught would actually make it worse, because if you force a vibration to decrease in amplitude without dissipating its energy, it increases its frequency. That could easily cause the cable to experience forces outside its tolerances. You'd need to have some kind of harmonic negation device that pumps an opposing wave into the vibrating cable to cancel it out. And you'd need them all along the cable because the speed of sound (aka the speed of wave motion in the object) would be waaaay too slow for a cable of that size to stop an out of control oscillation in time. But all of this is moot! Because the MAIN problem with space elevators that I never see talked about is the actual building part. Not material building, mind you. Leave aside materials, since we could always make one on a friendlier planet like Mars, which I *think* has requirements within the limits of steel. The Moon is also technically possible, but because of its slow rotation it'd be way too long (relative to things that are already WAY too long for us to make right now!) But forget all that, here's the bigger problem: orbital mechanics! People talk about going up and unravelling this cable from space, but you're not stationary up there, you're going in circles and - guess what? - so is that cable! Not only that, but that cable, you can't just "lower" it. Anything in your orbital plane wants to stay there. To drop or rise requires energy, and dropping is harder, because to go literally "down" relative to a gravity well, you need to match the speed of your current orbital velocity in the opposite direction. But not the orbital velocity of the thing you're leaving, YOUR orbital velocity, which INCREASES as you lower your orbit, meaning you need to accelerate. But not just accelerate, you need to accelerate exponentially, by the factor of gravity's increasing strength as you near the surface of the body. AND, because we're talking about a cable and not a single object, you ALSO have to take into account that this needs to remain true for every segment above you! This entire cable line would need to be covered in thrusters with their own fuel reserves, and a LOT of it because they'll need to burn hard to stay under control. You could very easily wind up making a thing that spirals into the planet and it useless and horribly dangerous, or worst case it turns into an enormous whip and you accidentally invent the most inefficient yet also most devastating superweapon in human history
A mitigation method would be to make sections of the cable have different resonant frequencies through variations in stiffness. This would make it difficult for standing waves to arise.
@@TheAntibozo Firstly, the 300 word ramble is hardly worth a comment, he's joined the circus. Then you propose how to "mitigate" the vibration something of unknown geometry, under unknown forcing functions, that doesn't exist, and never will. Removing "Anti" from your handle would be a good plan for some mitigation.
@@Andriastravels Did you watch the video? Poster is correctly responding to acollierastro's proposal. You can't damp a vibration by tightening the cable. Energy needs to be shed. As for my comment, your quick turn to a laughably lame attempt at insult suggests that you simply don't understand it, which is fine.
@@TheAntibozo Firstly, a string or cable would be a small part of a "space elevator" design. The "cable" would have to be part of an integrated, impossible, complex structure with unknown resonance, stiffness and geometry. These terms you learn in elementary theory of vibrations. In the video, all external effects are assumed to be absent in her initial stick model. You are in over your head. Come back when you have 20 years of mechanical design engineering experience.
@@emperorbailey Call it what you want, it is education, well deserved. If crybabies want to talk fantasy and not learn anything, they are part of the problem.
Not a space elevator fan, but since you asked, here's why I would want a space elevator: Assuming one exists that would also mean we more than likely have the technology to make asteroid mining plausible. Having a central facility to process and move all of that material makes sense.
Also shout out to my favorite podcast, Well There's Your Problem, which makes episodes about engineering disasters and the causes leading up to them with a leftist comedic take. They actually covered the Hyatt walkway disaster in an early episode. Edit: after the last quarter of the video I DOUBLY recommend WTYP. They love talking about the same issues you are discussing here about how capitalism results in all these scam startups and such. Also Trashfuture is another great one on similar topics but less focused on any one thing.
So, I work for a company that is making a satellite constellation to provide internet services, in fact I design the guidance and control system. I’m a big fan btw, love your content. The time it takes to de orbit a Leo satellite (roughly 600 km altitude) is roughly 10 years. At 800 km it’s more like 100 years. Go higher and it gets really long. This is because at this low altitude, there’s a pretty significant atmospheric density. In effect, if a vehicle is low enough, the altitude is “self-cleaning “. I know maybe you think everyone in this industry is an irresponsible ass, and it’s generally a pretty safe assumption, particularly with an x-fascist, but the problem of accumulating space debris is considered and dealt with. Fly low, use a really efficient electric thruster to restore the energy loss from drag, and it’s possible to not ruin space forever. Worst case, you fuck up a decade. Finally, these vehicles are really really flimsy. Not a lot of ceramic or quartz or hard steel. Aluminum and composite and thin silicon solar arrays. They burn up in the atmosphere, so nobody is going to be hit by anything. Now, is it great to oblate thousands of kg of this stuff? I don’t know, but no one is going to be hit by this stuff directly.
'Don't worry, we only ruined access to space for a decade and also destroyed all vital communications and meteorological satellites. Good thing we were so responsible.'
Literally every time someone steps up to try and defend space bro bullshit, it just really makes it clear how dangerous the industry is & how entitled the industry feels it is to LEO. Like it just owns the place and if they ruin it for 10~ years or so, eh, what's a lost decade here or there?
Fully agree with you, I wanted to mention this too. 99% of the debris burns in high atmosphere, the rest has 70% chances to land in ocean. Biggest chunks are the only ones that can survive reentry and those are tracked. Still, we should consider the probabilities of a Kessler syndrome when deploying large fleets of satellites with an appropriate risk analysis.
@@ItWasSaucerShapedI would imagine that having a debris field at 400km does not impede sattelite communication and metreology satellites at all. it might not be worth the risk to send a sattelite up to space because theres so much debris, but it will only cover a very small area of the earth so imaging and communication through that layer should be alright.
This was wonderful for me. My grandfather was an amazingly smart, but basically uneducated man. His capacity for wonder amazed me. He was completely OBSESSED with the concept of Space Elevators for 20+ years and I had countless arguments with him about how completely unfeasible the concept was. He always came back to "it's not that we CAN'T do it, its that we MUST do it". Ok grandpa. Thanks for this video!
Some notes about solving the practical issues with space elevators (other than the tether material) - impact shielding from micrometeorites is probably feasible when you can also create the tether material. For larger objects like satellites, tracking them and predicting a collision, then sending out a satellite-hunting satellite to change thier course if the object cannot itself maneuver could be reasonably practical. The tether itself, like modern ropeways on earth, could likely have multiple redundant cables, allowing one to be damaged and repaired while the other(s) held the load. For what it's worth, modern ropeways on earth have possibly the best safety record of any form of transit, with well-maintained systems that aren't hit by a plane having a flawless record. - similar to some of the buildings you mention, the tether could have active mass dampers at regular intervals ro counter vibrations. - the car could be hauled or powered by the cable, from the ground, which is sort of the main advantage of the cable system. - finally, i think the best practical use case in the nearish term for a space elevator would be resource gathering from space. Not sure if it would ever be competitive, but if equipment can be brought to space and raw materials available in asteroids and the moon can be brought down for a small fraction of what that would currently cost in terms of money, pollution, and land, it could be worth it, especially in a future world where we incresingly care about the impacts of resouce extraction on earth.
@@matthewjohnson3656 yep, that's why 'hauled by' the cable probably makes more sense. if you can make the cable, you can also make another cable that can pull the car up. that can be powered from whichever stationary end is more practical.
@@rancidmarshmallow4468 even if we had some magic indestructible cable- it doesn’t solve the rotational inertia problem. To get an object from the surface of earth to a satellite space station thingy you need to apply tangential force to accelerate it. On earth at the equator it’s moving at 1000 mph by a geostationary satellite is moving at tens of thousands of miles per hour. A cable can’t provide the sideways force needed to do this.
A car climbing up the cable is equivalent to it PULLING DOWN on the cable. The dynamics would be incredibly difficult. And it takes a certain amount of energy to lift a mass up a few thousand miles, whether it is lifted by a rocket or by a cable or by a magical electric motor.
Don't worry about the Factorio bit. I've played the mod you're referencing for ~250 hours and I still don't have the space elevator. Granted I'm not the fastest but still I would say 100-150 hours would be blazingly fast to get there.
Love it. As an engineer whose has worked with many physicists (I have a masters in Physics), there comes a time when you have to take the project away from the physicists and give it to the engineers. Yeah, we know we don't know everything about the problem, but we also know there are things we have no idea about just waiting for us around the corner and until we start stumbling our way down the path, we will never find out what problems we don't know exists.
Plenty of people stumbling down the path already. We're going to need to see lots of radical changes in technology before a space elevator or tethered ring is considered feasible, and it will likely *never* be considered safe enough to actually build.
The author of the book seemed to have a space hook and a space elevator confused. Space elevators are what you described in this video. A space hook does something similar but between two orbits, which facilitates Hohmann transfers. Isaac Arthur has an excellent video on both.
From Robert Forward who wrote on this back in the 80s, the expense analysis was that the cost of electricity to power it would be about 10% of the cost of a rocket (on a per kg basis). Time to orbit would be about 5-7 days, compared to 7-8 hours by rocket. I like your point about vibrations - which has _not_ anywhere I have seen - been addressed. I think pulling it more taught would be a bad idea, as that would increase the frequency, right? Assuming you could - because increasing the tension might cause the thing to break. Two things I think about are (1) how much potential energy is stored in that cable? If it breaks towards the counterweight, how much energy will be released onto the Earth as it falls? (2) what is the tension in that cable? It's easy to talk about getting some unobtanium - sure, spun diamond carbon fiber, whatever. How strong does it actually need to be? What are the vibration modes of the cable? (to get to your point). Ignoring the accidental failure (SpaceX satellite hitting it, Musk's car loops back, whatever), what is the risk of sabotage or terrorist attack? How could that be mitigated?
The channel “Plainly Difficult” is probably my favourite (for lack of a better term) youtuber that takes a very fact based approach to structural failures and general engineering incompetence. They do a lot of UK based things, but cover some larger north american events too
I went to a mid-tier university (NIU) for my PhD and we did the 4 exams thing. The grad students all studied for the qualifiers together. One of us had that book, and we were shocked to find that it was basically undergrad problems. We had previous semester exams from our university to practice on and they were all upper level grad problems. The EM section was 4 homework problems from Jackson. The passing bar was fairly low though. You needed 50% on every exam, or any one exam with a 75% meant you passed the whole thing. I liked that system, because I feel like that was the only time I ever really learned to solve high level problems in a general sense. Even the classes that had those same problems on tests, you always went in knowing fairly narrowly what the test would be on. I know the environment is totally different and now that I'm a post-doc at a higher tier university, I can see that the students are held to a higher standard in other ways, but I'll always be proud that I passed a test that was harder than the one at an Ivy league school.
I think in a different video she talks about finding that series boring. For those interested, the ending of Red Mars includes a vivid description of a space elevator collapse.
I actually prefer sky hooks to the space elevator concept. Big rotating hooks in the upper atmosphere. Fly up your ship, dock, and get flung up to a higher energy level!
Thank you for motivating me to doing a physics problem. I got it completely wrong. Looking back, what I ended up calculating is just what the geosynchronous orbit is... which is not what the question was, but hey... at least I got that part right. Considering I haven't done this in like a decade that's not bad.
@Exactly! Also strings, as the elementary constituents of matter, are unbreakable, so all the problems related with the resistance of the cable are automatically solved. We just need to wait ten more years XD
Well eventually Earth plus space elevator will spontaneously glitch itself into existence somewhere but, given that will take approximately 10^10^ludicrous number of years, maybe it's actually 10^10^(ludicrous-1) and you're technically correct.
She is great at physics, but her practical engineering skills are not on display at all in this video. Or she like presenting strawmen and refuses to look up how some of these challenges are faced today in other projects. Every one of here engineering problems have solutions right now. The one caveat I have is that we cannot make carbon nanotubes currently at a high enough quality, quantity and length to do this project. Everything else she mentioned is covered and has been covered and isnt the issue she makes it out to be.
To answer 'why space elevator?' from what I've always understood, I think the point was we're generally better at converting energy into mechanical motion than we are at using the rocket formula. Sure a trip by rocket is pretty quick, but the fuel is always gonna be nasty stuff, and dangerous, and there are pretty hard limits on the amount of stuff you can lift at once (not to mention when you factor in the time it takes to stack, fuel, and load a rocket the time savings isn't that great). So for space elevator however it works it's a pretty simple transfer of electricity into climb/descent motion. It may take a while but it's efficient. Additionally, if designed correctly nothing would stop you from making it like a ski lift, just running car after car up one side and down the other as fast as you can slot them onto the cable. I absolutely agree from a materials standpoint it's impossible, but I never had trouble understanding why you'd want one.
@@fernandoterra4108 the materials needed to handle the stresses involved over the distances required don't exist and aren't even hinted at from what we know about chemistry and physics. Existing manufacturing isn't close to the scale required. So yes, impossible in any timescale less than centuries.
Came here looking for kinda this comment. To me the most obvious answer is - burning fuel is bad, we have to stop. At the rate we're going space elevators will be impossible because we will have starved and flooded ourselves to death by burning so many petrochemicals. If we're dreaming of some bright future where it's important to maximise the efficiency of getting people and goods to/from space, then it is a necessary condition that we have solved climate change in order even to reach that future alive. That means part of the point of the elevator is to get to space without rocket fuel. (But realistically an elevator is impossible, so probably if we want to keep going to space, using rocket fuel will have to be one of the few irreplaceable carbon burns we keep doing, which only makes turning the rest of the economy carbon negative more important.)
Come on. The fridge will not steal your data. It's just some totally innocuous IOT thing you totally need. Trust me I am fridge engineer and need job security. I promise I will put nice RGB light on the next model and you will feel like you are totally in Star Trek on Tatooine.
I always thought that the main conceptual advantage of a space elevator is that you can use it to overcome the energy potential barrier using counterweights descending/ascending reciprocally. You can avoid using lossy energy conversion (like chemical rockets) and instead just work with conservative gravitational potential. It seems like it's just trying to harvest the gravitational and rotational potential intelligently. You'd still need to initially add enough potential energy to the system to overcome the gravitational potential but if it's all just weights the energy can be conserved. I think, based on the conservation of energy, you'd probably be pulling energy out of the rotational momentum of the earth, which is a weird thought. Though the engineering /materials concerns alone still seem absolutely prohibitively difficult, and the motivation seems unclear, it seems like people wanting SciFi utilities without thinking about the actual utilities people need.
The main engineering obstacle here is how do you move the energy around. Not obvious at all. You need to efficiently move energy around on a 100 megametres length of cable. Run a superconductor along it? Yeah sure.
@@ioresultWhat do you mean move energy around? If material technology is advanced enough that we can build this elevator, then it's logical to assume that we have the ability to create a strong enough cable that can span the whole height of it. If so, then the motor can just be on Earth surface, controlling the car through a pulley system similar to today's elevator. Use the traditional elevator system of counterweight and braking system and it becomes very practical. No superconductor or rockets necessary.
@@iruns1246 attaching it to the ground brings extra issues. Putting it on the ocean instead might help offset them. But the more complex we make it the more prone it is to a catastrophic failure, and a lot of the issues would add a ton of complexity to remedy.
This is the fun of discussing it, which I've been doing since I was a kid. The cable itself would develop quite a charge from multiple sources including being a giant thermocouple.
@@seasidescott it's really interesting trying to think of all of the details of the environment that are left out in the simple pictures of it. Temperature differences and changes, charge build up and other interactions with electromagnetic waves, let alone impacts and sound waves. Just so much stuff to think about! :D
33:43 -- "When I was a child the future seemed really exciting, and now everything's just the worst possible version." I feel the same, and I couldn't have said it better myself. //Rick
This feeling, everything is getting worse/will only get worse is a constant going back to the earliest records we have... taking a look at the Egyptian early failed pyramid shows is they tried it before they found out their slope was too steep and they had to build the later pyramids less steep so the darn things wouldn't fall over before their building was done...
@@DavidRayBurroughs The old adage "a broken clock is right twice per day" comes to mind. Quality of life is decreasing for huge swathes of the population, even if the metrics used to measure it are being redefined to pretend it's not.
@@mallninja9805 - as in all True Sayings, these are subject to more than one description often outlining the defined reality, or more nearly so, or nearly more complete. That is, for example, huge medical advances leading to far fewer infant deaths and its increased population and feeding problems and perhaps too many people alive at one time - yet, still and all, we all eventually die. No wonder true believers rely on ginning up god beliefs and immortality of the soul and the reincarnation crap, etc. People love to say, "just this one thing more, and all our problems are solved!" but it is always "welllllll, not quite..."
I like the concept of a space elevator, in like, a Science Fiction type way. The moment you start thinking about the practicalities of it in real life, even if the physics are theoretically possible (BIG IF), there are so many stumbling blocks that we're just not anywhere close to ready for. Like you mention in the video; space debris & maintenance, tectonic activity and any kind of wobbling in the structure, and just the simple issue of... how do you start constructing it? This isn't like a videogame, where you gather the materials and the structure just materializes, this thing will have to be built over several decades. And how do you coordinate actually setting this thing up, either from Earth or from space?
some thoughts: from space. start with a pilot-tether. unspool it to both directions to keep center of gravity. add to it over time. iirc even the nasa paper from 2000 mentions to wobble the tether to avoid space debris. (the bottom part doesn't need a fixed connection to earth it could for example be attached to a swimming rig that can induce the necessary oscillations by moving around) Have the tethers redundant and big enough they don't fail by getting hit by debris that's too small for being tracked. And fix it after an impact. Repairing cables is a solved problem. fun fact: in theory and given the correct tapering any material would suffice to build such a tether. Practicality is another thing of course. tldr: many of this problems have (at least in concept) solutions as people have thought about this stuff for a while now. Then again there are things that are (afaik) still questionable like: In the upper atmosphere there's atomic oxygen which is pretty reactive and thus unhealthy for the tether...
the US chemical safety board is not exactly about structural failures but *super* interesting if a bit grim, after major incidents they often release videos to accompany their reports. lots of engineering youtube channels dabble in structural failure post mortems though. looking forward to the leaf blower essay!
I think every science interested teenager has this moment where they learn why rockets are so expensive (need to go crazy fast and carry their own fuel), but also learning that technically space isn't that far away, and next thing you know they're dreaming about space elevators. I think the people who are into space elevators as adults have still not thought about it harder than this teenager.
I'm an engineer, and while a space elevator might not be feasible, I'm accustomed to naysayers being completely incorrect. Challenges like "megastructure terrorist attacks" are there to be overcome.
@@Kestrel-lp8ho TBH the problem with the space elevator is not just that it is difficult, but also that there are better options. Atmosphere-skimming skyhooks combined with hypersonic planes are a much lower-investment method, while for the full non-rocket approach a launch loop or an orbital ring is going to give you more utility (can easily boost payloads up to escape velocity if the rotor is rotating fast enough), without getting in the way of most Earth orbits. And both could be built with materials that are currently available in bulk amounts, rather than requiring nanomaterials like a space elevator.
> I think the people who are into space elevators as adults have still not thought about it harder than this teenager. If by "this teenager" you meant the creator of this video, I would be surprised if she is a teenager considering she has a doctorate.
I'll bite on a couple of these points. * How to power it: I feel like you didn't think very hard about this one because here's 2 reasonable solutions: 1. electrical cables running along the elevator, like trams, or any other electrified rail type thing. Am I missing something? This one feels very obvious. 2. a laser emitter at the base of the elevator aimed at the bottom of the space wagon, which has a laser receiver (sci-fi technology, but fairly reasonable, I think). * Why? We don't live in star trek: But it's kind of a chicken and the egg problem. The egg being the ability to climb out of the gravity well. If there was a reasonably cheap shuttle to space every week or month, maybe we would then... become star trek. No?
A transmission cable that goes those sorts of distances has massive issues in terms of loss and efficiency. A laser as you describe would need extreme levels of accuracy and would also probably set fire to anything that flew into its path, or would lose effectiveness by the next cloud passing by. These aren't bad ideas at the speculation phase, but everything gets harder when you have to factor in the chaotic environment of the real world.
The other issue is that like... the cable has to be super strong and stuff, and now it also has to carry power extremely effectively. This puts even more restrictions on the material used - it has to be conductive itself, or somehow has to have supports for the cables, which are also undergoing their own gravity
@@RhettAultman I would expect if we ever start to build a space elevator we would also have a proper super conductor to build the cable out of. It's just one more unobtanium we will have to obtain, easy stuff
@@tillschlothauer5377 Ah, yes. I forgot about the unobtanium ductile superconductor. Granted, once we have unobtanium, surely we could hypothesize something better than a space elevator anyway?
electricity seems obvious. two adjacent cables is the same physics as one cable. presumably the voltage is as large as necessary to make the resistance negligible, bearing in mind that you can be extremely inefficient when you don't have to carry enough fuel to carry fuel into orbit. but i think solar is a good option too. a major point of the space elevator is that there's no extra energy cost for moving slowly, unlike rockets which have to pump through fuel just to hover
I fricken love these videos. You should do this full time. I know selling your soul to the man for a paycheck is...unavoidable...this is your calling for sure.
I absolutely appreciate your content. These are the types of questions I would ask as a child but no one could answer them, now as an adult I love learning all this stuff and letting my inner child get excited to learn.
@@bejanbosc3695 Twitter valuation is also random, stock crashes anytime Musk opens his mouth. If he has a cold then he may be able to purchase a space elevator company. He sure is dumb enough to at least.
Dr Collier - I hate you just a little bit for this video :P. I'm a mature student in my final year of forensic chemistry as an undergraduate, currently applying to masters programs abroad writing thesis proposals, and teaching myself a new language because half of the courses I've applied to are in French...and now...after watching this...I have to go learn calculus and integrals because of the wizardry you just performed! Absolutely awe inspiring! Loved it!
Excellent video! I'm an engineer myself and thank you for bringing some more insight into what we do into the greater "stem limelight" I guess, for lack of a better term. The Hyatt Regency fiasco is infamous at least in Canadian engineering circles, and there isn't one undergrad who will escape the field without understanding the importance of the lessons that must be learned from, honestly, criminal negligence. Safety, ethics and integrity are absolutely paramount in engineering. It can be easy to sidestep these principles for profit.
I'm an old engineering physics grad (working in spacecraft engineering) and you completely nailed the difference in how physicists and engineers see this problem 😂 (and really I don't think physicists believe it either, science media loves to sensationalize) like yes! We can do the equations and get all the numbers we want to "solve" the basic problem, but engineers are still gonna look at those answers and giggle and then go do practical things instead because there's SO MUCH that goes into making physical structures not kill everyone building or using them. Also I love hearing you rant about late stage capitalism, I feel so seen 💜
I'm an old jack-of-all-trades facility construction, startup, operation, maintenance, modification, and retirement engineer. I've also had to work with hazardous materials and the required risk management involved at the overall level down to the industrial safety with how to ground equipment to make sure it is energy-safe. The stake through the heart is the project management, risk management, financial management, and regulatory oversight/management. How many airplanes take a crash or two to 'get it right'? Now, imagine that involves a structure that will cause mayhem in Earth orbit and on the ground, involving all the energy, kinetic/potential/electrical/vibrational/invisible pink unicorn, locked up in this system and just looking for a way to leak out!
@@AzaleaJaneStarship troopers was genuinely the most disappointing science fiction book I ever read. I thought it would be a fun adventure romp with power armor and aliens, and it was like 80% an argument for fascism
@@aidanwarren4980 not an argument for, but a 'realistic' depiction of how society works under it. its more of a "how would the world work under these conditions" less "this is how the world ought to be".
@@aidanwarren4980 dude, you should have paid more attention in English class if you can't identify the satire in Starship Troopers. Heinlein's stories are intended to be provocative and morally ambiguous. If anything, Starship Troopers is a *criticism* of militarism and the unholy union of corporate and government interests.
After Angela mentioned leaving links to videos about Hyatt in the comments, now I just badly need her as a guest on Well There's Your Problem. That episode would go crazy
We're just physicists who multiply our results by this unitless constant that cannot be derived from physics and math fundamentals called a "Safety Factor".
Unobtanium and “you have to pay gravity” are the two most awesome words and phrases I’ve heard this week. OK, it’s only Monday, but I’m pretty sure the week will end with nothing better.
You must have not seen the film "Avatar". The term unobtanium is actually decades older than that and was a running joke in film/ science fiction criticism.
@@iankrasnow5383 Adamantium in Gulliver's Travels is what keeps the floating island levitating. At some point, people just replaced Adamantium with Unobtanium.
@@iankrasnow5383 Fun fact, the unobtanium in Avatar was actually a room temperature superconductor, which is the reason why the mountains on Pandora float.
@@Jackissimus Room temperature superconductors, space elevators, hyper loops,... Is it just me or does it feel like the frequency of big funding scams is increasing rapidly?
I think part of the appeal of space elevators is that it’s more fun to imagine a Big Thing than a Good Process. Like, the current system of using rockets works fine and is sensible and all that, but you can’t *look* at it the way you’d be able to look at a big macro-engineering project that reaches all the way into space, and I think that affects how people react to it emotionally
I first heard about that as a potential cost effective solution to getting stuff off the surface of a planet. But if I'm being honest the reason space elevators excited me is because it's the first mega "space age" construction I could conceive of. It's kind of like building a big pyramid but in SPACE.
Some kind of active support structure makes more sense, once there's enough demand for traffic in and out of space for the economies of scale to make sense... Like a launch loop or something like that at first, eventually an orbital ring -- but we have a long way to go towards setting up proper industry in space before we get there.
Yes! Launch loops (even smaller ones that might be used to replace first stages or intercontinental flights) seem much more sensible. I just think it's something the avereage decision maker is unlikely to wrap their heads around. Also, i think we don't need demand first- basically having a conveyor belt will make it so cheap that demand will come on its own. Also, i don't think we should ever make any of those big decisions purely by asking "will it earn money".
@@nos9784 Every sort of big sea-change in industry faces this same kind of chicken and egg problem. You have to bootstrap with small proofs of concept and build the demand as you go. I dislike framing things in capitalist terms, but the principle is the same even if you just look at allocating raw resources. We don't currently have enough things going on in space for it to make sense to allocate so much into building orbital rings and such, but as we inch our way forward and find out more things we can do in space (fabricating better optic fibers, collecting solar power, mining asteroids, moving polluting stuff out there where it's already an irradiated hellscape instead of our biosphere, whatever), slowly there'll be more and more reason to build bigger and leverage economies of scale. Basically, with or without money, you have to move in smaller increments, have pilot projects and trials and small scale experiments, get your foot in the door first and then slowly lever it open.
I've always wondered... what if this structure fails? Will the tether just start falling and coiling around the earth, destroying everything in its path like a giant whip from heaven?
A space elevator is meant to be in equilibrium, the part that experiences more gravity than needed as centripetal force is held up by the part that has less gravity than needed. If it snaps, the upper part will drift off into space and the lower part will come slashing down to earth.
In Kim Stanley Robinson’s Mars trilogy this happens… also in the TV adaptation of Foundation (I don’t think it happens in the books though but I don’t know for sure.) In both it’s as bad as you can imagine, I would not want to live anywhere in the path of where it might come down.
My favorite structural failure channel is Practical Engineering. They don't have a Hyatt walkway video, but they do have a video on space elevators and a lot of other disasters. Ok I lied, it's more of an infrastructure channel that talks about failures in dams, bridges, and buildings from time to time.
"You might have seen the trick where people fill a bucket with water and then spin it" - In undergrad physics 1 we had a new grad student lecturer that was very gung ho about using all the demos that had been gathering dust. After some practice he did this demo in lecture and it worked! We all applauded! ...then he launched the cup, hitting the head of someone in the first row and splashing someone's leg in the second row.
Well, but that;s only true because we assume "magical never breaking strength". If strength is finite, then the density matters A LOT. In fact, the ratio of strength to density is why we can't build this, and probably never will be able to.
@@oschonrockyou can build it from steel if you want. Just the tensile strength to weight ratio decides the shape and top vs bottom diameter ratio. The steel one will be probably hyperboloid with thousand kilometer base :)
@@ladislavseps4801According to Real Engineering's 2020 video on space elevators, a steel tapered tether with a 5 mm base on earth would need to expand to 1.76×10⁵⁴ metres at GEO - a number so absurd that it's 2×10²⁷ times wider than the known universe :) Kevlar fares better at "only" 81.3 m, and carbon nanotubes require it to be just 6.37 _millimetres,_ apparently - albeit with _a LOT of assumptions_ and optimistic values. And all of this was with zero safety margin: “I'm designing it riiiiiiight on the edge of breaking” 👍😹
Well the problem is that I'm not a physicist or an engineer. So I WAS into the idea of space elevators, because I didn't realize all the problems that would happen trying to build one. From my perspective a lot of inventions and technology are crazy things that work due to really complicated math and laws of physics, so I just figured that someone smart had proposed a space elevator as a concept a long time ago and done the math to say it is possible, why else would everyone be assuming it would work? I thought now we were just waiting on strong cables to make it actually happen. But you going into detail about how it's impossible to make that rope and why rockets are actually just better clears that up. I've never heard the opposing argument and a physicist saying "NO. It won't work."
An interesting way of looking at the problem is to translate the various tensile-strength/weight ratio of different materials into "How long can a cable get before it snaps under its own weight?"
given the proper tapering any material would do. in theory. Consider the tether only needs the full strength at the point of the most stress. The bottom part (and the upper part if you use the tether itself as a counterweight which has benefits) can be way less strong.
@@MegaHarko This kind of tapering requires an exponentially wider cable as the length increases. It does expand the range of materials a bit, but saying that "any material would do" is just factually wrong. It is impossible to build an Earth-serving space elevator out of steel, for example. The wide end of the "cable" would need to be thicker than the entire solar system, and it would collapse into itself under its own gravity.
@@PizzasgoodYo there's no reason why the cable has to support itself unassisted. There needs to be propulsion all along the cable for station-keeping anyway, why not point those propulsion systems toward the ground and use them as active support when they aren't being used for finely adjusting the position of various parts of the cable? It cuts into your energy savings but "possible and expensive" is a world away from "impossible".
@@tissuepaper9962 That wouldn't just "cut into" the energy savings. It would annihilate them. If the elevator can't even support *itself* without assistance, then that means whatever means of active support you use is going to be bearing 100% of the downward force caused by the payload's climb plus whatever portion of the elevator's own weight it's supporting. Considering that *at least* 99.7% of a space elevator would be above the Karman line, the overwhelming bulk of that active support would have to involve throwing reaction mass. That means you'd have to *lift* reaction mass up to the thrusters which are providing the thrust to perform the lifting, thereby necessitating even more reaction mass to lift the reaction mass... and that's just the Rocket Equation with extra steps, plus you have to keep it running 24/7 or millions die.
@@PizzasgoodYo You're right. That's why I wrote 'in theory' as in mathematically. Most materials aren't strong enough in practice. And those that are can't be produced in sufficient quality and quantity yet. Point being: One can construct cables that won't snap with any material yet it's not feasible to use them in practice for different reasons (as the one you pointed out)
What's wild about the sky hook concept (aside from normal space elevator stuff) is that it's not only orbiting the Earth, but also is rotating at just the right angular velocity such that the hook at the lower end will remain horizontally stationary. So it's essentially a planet-sized trebuchet.
I think that the Hyatt Regency thing is one of the central examples in the book "To Engineer is Human" about engineering failures. I remember looking at the diagram that explained the error and being shocked that something so seemingly unimportant could be deadly. Engineering is hard stuff, man.
I love that book. I think it should be a mandatory read for all high school students. It illustrates to any lay reader how and why experts can make major mistakes and to always double check everything and don't be complacent.
![BLACK BAG - Official Trailer [HD] - Only in Theaters March 14](http://i.ytimg.com/vi/Du0Xp8WX_7I/mqdefault.jpg)
"calculus isn't that scary, just learn it, then this is fun" This is a woman who had to TA freshman. I applaud you
I had two TA's, one spoke only Japanese, the other Italian. Neither could speak with the other or the small class, duplicating balls rolling down an incline, incredible precision and good data being the point not the learned lesson. This is how research is done. This is how peer review is done. This was back in the 60's. Today with pressures, many studies are spread out. Being immersed and expected to learn the math at the same time as the physics as the computer was daunting. Throw in 1 credit hour courses in Fortran ( turn in your punch cards and wait for the error stack from the one and only main frame ), and mandatory Saturday quiz sections we were immersed. Our failure rate freshman year soared to 60%. It was also an engineering school. Later taking computer science classes the cheating was rampant, my professor dealing with irate parents asking about bad grades. It became a party school. All games all the way up and down. Sad sad sad.
Calculus... Lol is awesome... It is just find the acceleration at any point of velocity at any point... Meaning... Let's do what any mortar or artillery or tank crew does.. lol
@@mikedubovs1574 each time I struggle with Calculus I am like "a XIX century prussian artillery dude with one set of pants whose entire education ended in 7th grade did it under fire, stop whinning"
I would watch the crap out of a 7 hour video on why leaf blowers shouldn't exist.
Right? Leaf blower video coming when?
i want to see it too
#LeafBlowersHate
x10
i would hook my laptop to a PA and put it outside and play the video at max decibels so everyone could hear it.
I‘ve listened to too many Well There’s Your Problem episodes to ever believe a space elevator wouldn’t result in the worst engineering disaster in a century.
More like the worst engineering disaster in human history
@@PatheticApatheticidk man the boston molasses flood was pretty bad
my first and only thought every time the concept of a space elevator comes up is "yknow what happens when you accidentally hit your leg with a weedwhacker, but with like half of the planet"
speaking of which, here is their hyatt regency walkway collapse episode:
ruclips.net/video/Hw2t0MOGnVc/видео.html
honestly angela would be a great guest on it
I zoned out to a talk about space elevators and when i zoned back in, you were all of a sudden ranting about terabytes of fridge data. This is what im here for
fridge data rant was a highlight for me
The best bit about this channel is how the videos start calm and normal and end up with a really entertaining rant, but only the people that make it through the first 30 mins get to the rant part.
It's almost or exactly like Marvel Post Credit Scenes
Only that Acolierastro Cinematic Universe post credit scenes are relevant to the plot
"So there's this RUclips channel called Cracking the Cryptic and I watch them to sudoku puzzles."
She's just like me fr fr
"I have absolutely no positive feelings towards any human achievement. Ever."
Oh.
@@SeanMcPseudonymbobbins!! 😂
Truly the prog rock of science channels
If we built a space escalator instead, then when it breaks down, it will simply be space stairs.
Really makes me wonder
It would be a litteral stairway to heaven !
"... sorry for the convenience"
I miss Mitch. The good thing is that he hasn't done hard drugs in 18 years. He used to do hard drugs, but he don't do them no more.
Thank you Barack Lesnar
For context on the Hyatt disaster, it was caused by a smalll cost saving change made AFTER the engineering was done. They had two walkways. The engineer had them both anchored to the ceiling. They made the cost saving decision to anchor the bottom one to the top one. The anchors for the top one could not hold the weight of both and they failed.
The engineers had rods anchored to the roof and it ran through the beams that held up the walkways. But they hadn't designed a way to hold the upper beams to the rods (edit)that was constructible.. I am not assigning blame here. We do so far too easily these days. Ultimately it was small errors by a number of companies that lead to tragedy which is often the case. (end of edit)
@@indetigersscifireview4360 No, that's not correct, the upper beams were secured to the rods by nuts. OP is correct. Your comment only adds misinformation and confusion.
@@indetigersscifireview4360they had a way to do this, the complication was that because they would attach the it via nuts, the rods would have to be threaded their whole length. They were very long, and manufacturing a rod with that long of a thread and installing it without somehow damaging the threads was considered infeasible. So, they split the rod in two. This effectively meant that then nuts for the upper platform were supporting both the upper platform and the lower platform, which they were not designed to do.
@@aidanwarren4980the issue with the threads seems like a callback to the video talking about making a rope for the elevator so long without breaking it. it’s an even more apt comparison than it already was, lol
Here's a >5min explanation with diagrams if anyone's interested
ruclips.net/video/VnvGwFegbC8/видео.htmlsi=PGFmnM4QIm26kPAT
1. A space elevator would block off a whole class of orbits for satellites. Imagine the lawyer fights over this territory.
2. If the tether is in any way conductive, imagine a Carrington event with massive induced current running up/down the tether. That would be fun.
3. Is Angela turning into "old man yells at clouds"? If so, welcome to the club.
#1 is completely solvable,
#2 is the first thing I've heard that gave me a pause for a moment, but that's why we have civil, electrical, mechanical, and materials engineers to solve those hurdles and I think that we actually might be able to make that Carrington event a selling feature with a little thought.
#3. yes.
@@qsquared8833I agree, we have a single intercontinental internet cable between Europe and america
And probably wouldn't be good if a hurricane when through it either. I assume these elevators would need to be at the equator if they are to be stationary.
@@qsquared8833 Go with enough of them, you'd not need those LEO birds, just put small stations at those orbital altitudes on the elevator "cable".
A conductive cable with extremely low resistance would likely happily carry that current to ground. Don't recall any wires being reported destroyed during the Carrington event.
But, a ride on a space elevator reminds me of a candy bar commercial, "Gonna be a while?", only with a *lot* of candy bars needed...
@@spvillano I literally almost came back here and edited this comment to basically say the charge should go to ground and be no big deal like any building being struck my lightening, but decided to leave it thinking someone will surely realize it's not a big deal and write a reply. Looks like that would be you, and thanks for that.
Also fully agree a space elevator isn't about LEO, it's to get things well and truly up high enough that they'd be useful
"I suck at video games"
*shreds through Isaac casually in 40 minutes while explaining science history without a script, no edits"
She’s made a video with no edits? Not a criticism, I like collier’s sense of comedic timing in the edits, I’m just yet to see her go all Goodfellas club scene in any of her vids
@@smsivit's the string theory one
My favorite structural engineering channel is "Building Integrity."
Space elevators were a lot more attractive an idea when we were only using rockets once. If we had to build a new ship or airplane every time we wanted to cross the ocean, we'd be talking seriously about building a bridge.
The most appealing part to me is using them to sling stuff off into higher solar orbits. Making a trip to mars last a couple of months rather than a six month trip.
@@atashgallagher5139 You'd need an even longer, and tougher, rope for that!
@@atashgallagher5139you can just use a rotating tether, but for any reasonable taper you're still only going to get 3km/s. Reasonable for TLI but for Mars it's not a great deal when you consider the mass ratio and the size of a Mars lander and the need to reboost between launches and the long time between windows.
Naw, space elevators are more appealing now that we can actually lift lots of stuff into orbit because now it's actually economically possible to build one.
@j.f.fisher5318 good point.
Well I enjoyed watching that! Simon 🙂
Ahhh, thanks for watching!
33:42 I'm so happy to see when there's people outside of tech industry/open source activists who are voicing their dismay at the state of tech. Granted you're in STEM so that's tech industry adjacent, but all too often I spoke to professors who were blissfully ignorant of this softcore dystopia we ended up in. The more awareness we raise the better shot we have at changing things. Thank you!
babe wake up, new acollierastro video just dropped
I love acollierastro videos
I'm up, babe.
"We are going to be late for church c'mon what are you doing" "watching Physics Mom solve math word problems obviously"
Just did that. Fiance not impressed
Already up. I guess Dr. Collier is conspiring to make my insomnia worse because these videos come up only at ungodly hours.
This video made me realize how lucky we are to live in a time when the sky hasn't been turned into a giant endless stream of advertisements.
yet
@@OnisanTbeat me to it lol
And you can actually go see a living giraffe!!!
I mean if you live in a densely populated city it pretty much is. I struggled to put my eyes somewhere there wasn't an ad in New York City.
@@chicken29843 this is why I’ve only been, twice. And not for long, and not for literally any other reason than a couple hardcore/punk/metal shows.
One note about helicopters: they're actually pretty damn safe. More dangerous than commercial planes, sure, but safer than private ones, and *much* safer than cars. Considering they are typically used in risky rescue operations, this is actually really impressive. One common misconception is that you die if the engines fails, which is simply not true. Helicopters can safely come down if you turn off the engine thanks to autorotation, as the air causes the unpowered blades to rotate
helicopter has to fly high to achieve autorotation, but intuition says you should go closer to the ground to quickly land, as well as you are ascending from low height while taking-off. In short, autorotation didn't provide safety when helicopter is flying low.
@@xponensame goes fro gliding a plane
you generally should not go low forl ogner than ecessary if your goal is safe air transportation
well, they're a LOT safer than a rocket
Well yes, but no. Helicopters are safer than cars because there isn't the equivalent volume of traffic going through them. Couple that with the bell curve spreading out on safety checks, helicopters are dangerous as fuck as "flying cars."
@@Pho7onper hour spent in them helicopters are about 50 times as dangeorus as cars, how that translates to per kilometer or per flight/drive dependso n how fast/where/how far you go in each
motorcycles are comparable to helicopters in deaths per gigahour though
also depends on who's flyign it and how and why, etc
just like with general aviation you get a lot of crashes from private owners with lax safety standards and a you can really bump up the safety by sticking to a few rules
We need space elevators because I think it’s cool. Why doesn’t the world revolve around what I think looks cool?
Ok Elon
this is obviously the only reason physics exists
I love cracking the cryptic! It's always such a chill time, but I do get a little stressed whenever he flies off the handle and says "bobbins". Also strong recommend for their The Witness playthrough.
🎤 That’s 3 in the corner! 🕺
I hate it when he says bobbins, sends shiver down my spine
@@TerkanTyr That's when he truly shows his monstrous, violent side.
@@excrubulent Yeah it's why I can't watch him anymore. I live next door to an English man and it fucking sucks. Like people think it's funny that some people can't handle that shit but it's really not and I wish they'd just stop.
We'll need the space elevator to get past the billboards in space in order to do astronomy. It'll cost $500/kg to look at the stars
surface-to-space adblock
Well, that's one way to sell diet plans.
@@Adam_Stoke promising alternative: surface-to-air missiles
A subscripiton to a live stream of the night sky for only 10€ a month, and a night sky+ to look at the nothern lights
There's a reason rent seeking is a sin, this is hell on earth.
Good Luck saving the world chinas already buying stars
It was so funny how you learned to play factorio and spent so many hours building a space elevator, definitely cool and worth it.
I was surprised that the video was over 200 hours long and took 6 me hours to buffer, but then when it got the section of the video that was the footage of her playing factorio (real and true) it all made sense and added so much to the overall viewing experience.
Satisfactory would've been a good candidate, you can get one there in a few hours easy.
The factory must grow. (acollierastro plays gregtech when?)
@@najawin8348greg
@@najawin8348GTNH space elevator... In my case it is currently in a state of "possible after a week of crafting, during which power will definitely die at some point"
One of the worst and/or best structural failure stories I can think of is the Erfurt latrine disastrer from the late 12th century, where 60 nobles fell through a fortress floor and drowned in poo. en.wikipedia.org/wiki/Erfurt_latrine_disaster
This is exactly why I need to read the comments on this channel.
I love it every time I find someone who enjoys watching two middle-aged British former accountants solve Sudoku puzzles because there's no way to explain it to anyone else.
Great idea for a video, as always. Can't wait to watch it.
I think the idea that a lot of people have with a space elevator is that they know they're never going to ride a rocket to space.
going to space as a normal person sounds a lot more attainable in an elevator than a rocket
Probably should give it a more descriptive technical name in that case, like Tethered Ascension Vehicle or something, so people don't think it's actually like just stepping into an elevator and popping out in space
Traditionally the way to maximise the likelihood for an individual to win a seat in a space craft involved dedication and study.
Astronauts tended to be genuinely humbled and excited by the experience.
Coming soon is the era of anti social media influencers.
Won't be long before we are avoiding watching the likes of Logan Paul do his thing in orbit.
O wonder...
...O brave new world. That has such people in it.
What is elevator?
Should we elevator?
If so, how much?
Should we do it should we do it should we do it should we do it?
Tick-ticky-tick-ticky-tick-ticky-ticky-ticky-tick
What is this referencing? I remember this songs rythm but cannot remember the original and it's killing me
@@IdeoLogs The dark matter rap
It is not a moon. It is a list of scientific observations.
Throw the Pentagon budget at it. Convince them it's for Space Force logistics lol. Build the sky screen!!
33:44 "When I was a child the future seemed really exciting and now everything's just the worst possible version" I can relate so much omg
Maybe it is a function of when your childhood is. I grew up in the 70s and 80s, expecting to die in a nuclear holocaust. Instead I live in a world with astounding access to information.
While not strictly a structural failures channel, "Practical Engineering" does cover a number of disasters from time to time (among other equally excellent videos about various aspects of civ-eng). He actually does cover the Hyatt disaster in a shorter sub-video for Tom Scott's channel. It goes by the title 'The Disaster That Changed Engineering: The Hyatt Regency Collapse'. He also covers the Tacoma Narrows Bridge collapse in an earlier video.
You would love the channel "Building Integrity". The channel started after the surfside condo collapse, the creator is a licensed structural engineer and he does an *amazing* job of analyzing the evidence collected from engineering disasters.
I went to a presentation about 15 years ago on space elevators (80% for entertainment, and 20% because I want to live in Star Trek even though I know I can't). Honestly, a little bit of the talk was about the idea and the promise of it, but most of the discussion was about the issues that they haven't solved so at least at that time, so at least it wasn't all sunshine, rainbows, and tricorders. So these are some of the ideas that they had at the time (at least what I remember of what they said) ... posted as my time capsule of space elevator BS:
THE CABLE: The cable would be a carbon nanotube ribbon. According to them a ribbon would actually be stronger than a round cable and more resilient to damage (don't remember exactly how now). But they did mention that the longest pieces of carbon nanotubes were measured in centimeters (reminder ... 15 years ago)
POWER: Their idea was that if they could use carbon nanotube ribbons, they could actually transmit the power through the ribbon at low resistance saving them any power generation or storage on the elevator itself.
SLOW RIDE: While they did say that the payload would be less than the shuttle (it was still running back then), the turnaround for an elevator trip would still have been far less than the many weeks of cycle time to inspect and prep a returned shuttle for another flight, making the space elevator total throughput greater than the shuttle.
DYNAMIC COMPENSATION: As far as balancing for the changes in the physical system as the elevator takes mass up and down the ribbon to space, the counterweight could be reeled in and out to adjust for the mass and position of the elevator. Basically reel it out when the elevator is low and reel it in as the elevator pulls itself up so that the center mass remains in the geosynchronous range.
SAFETY: I believe they said that if the ribbon broke, the elevator itself would act as a reentry vehicle and have a deployable parachute system. The geosynchronous station could essentially cut the tie to the counterweight and remain in orbit. At that point you would have to go through the whole process of replacing the counterweight and lowering and attaching a new ribbon.
WHY: There were a few reasons they gave. One was for lowered cost. . Beyond that was holy grail of space tourism ... basically making it cheaper for people to go to space and, um ... do space things ... space selfies? idk. Part of the lowered cost idea was to make human exploration of other planets easier, as well as asteroid mining ... and I think He3 from the moon (though I might be conflating that with something else). There was no mention of billboards ... but also no mention of banning them ...
OTHER PROBLEMS: In addition to all the issues you already mentioned, they did mention one thing that you didn't. That was the geopolitics problem. Essentially that the elevator has to be somewhere that is near the equator and if you look at the countries that are near the equator usually aren't the most stable of places. And it's something that could potentially become a target, which is a bad combo.
So I hope this is, um ... useful doesn't seem to be the right word ... but I hope it's ... something ...
This is informative, and I think genuinely starts to answer Collier's main questions of "why, and is it worth it to try". My followup question is under SAFETY: what about the part of the ribbon below the break? How do you stop that from impacting the ground at high velocity?
Was that the group from the Keck Institute? I remember reading their feasibility study some years ago and these were pretty much the same ideas they floated.
Re: the damage resistance I think they calculated (or 'calculated', I don't recall) that the ribbon should retain structural integrity even with numerous holes from micrometeorites and the like until patching up. Although, in all honesty, they were speculating about the management of a non-existing material. In hindsight, all of it sounds like a slightly more prestidigitative handwaving.
Still, fun to think about.
1) Cables: Still not sure the "one long cable" notion is anything but retro-futurism as for as design is concerned.
2) Billboards: Space billboards are pretty much inevitable. They might not look like we imagine, but commercial advertising is almost certain.
Skyhook better
lol. Clarke solved the geography problem by moving his adopted home south to the equator.
Great book. Also proposed carbon nano tubes as structure going on 40 years ago. He wove a great story around the physics
Impressive run of Factorio! Less then 30 mins to space elevator is impressive.
Meanwhile my K2SE play through at 500 hours still hasn’t unlocked them.
I love the way this starts out as a straightforward classical-mechanics problem, worked out nice and clearly, then blossoms into a righteous rant against outer-space hype and pop-science nonsense. We never saw it coming! Great video
The basic idea to my understanding is generally that if you have a space elevator then the cost of getting stuff into space goes down. This allows you to do stuff in space that requires large amounts of stuff from earth like moon and mars colonies or enormous space stations for far less resources than using rockets.
That is the dream of the space elevator after you hand wave away all the things that make it impossible, that it will allow for a space based future, not in a Star Trek instersteller way but in a neo-colonial solar system way. And depending on your views that’s either inspiring, troubling or both.
Also, what would happen before colonies, mining materials from space objects more cheaply and more easily getting it back to the ground to be turned into more things to mine shit in space. So basically capitalism again. Basically the only way to get capital interested in space development, other than as a pet project for someone unimaginably wealthy.
Get one rock mostly made of incredibly rare metal here on Earth, tow or mine it on site and bring it back here. Then watch as quite a few countries IMPLODE as their economies are ANNHILATED because their economies were before forced to exclusively just mine this material.
At least till the operations up there are developed enough to be mostly based on space based labour. IF we can transfer most of our production processes to work in near zero G.
You really are a cancer man hug a tree and realize your whole worlds upside down idiot
@@cancermcaids7688 if you think "neo-colonial" is an absurd concept think about the Beltalowda from The Expanse series. That's what we'll get if people like Bezos and Musk have it their way
Also if your country wins the "build the space elevator race" it become the next super power because you can basically controll the economic flow of people/things to space
oh, it would be a colonial project eitehr way because you need at least three major places along the equator in the right spacing and the countries or companies most likely to build one currently have 0 land at the equator so someones gonna tell everyone near the equator to die except in a very friendly, brand safe way but still thats basically gonna be the message
Being a depressed old man, I'd like to thank influencer Dr. Collier for consistently raising my spirits. She is the future as I imagined it. Oh brave new world...
That guy's a genius, I've seen him solve Sudoku that I previously would have considered impossible
right?! Dude is B A N A N A S at sudoku
Both of the guys in that channel are insane, it's such an amazing watch everytime
Simon hates doing sudoku in his sudoku puzzles.@@facingup1624
@@facingup1624 whether you like it or not, both pronunciations are *very* well-attested in English. It would be unreasonable to consider "suduko" to be incorrect in English when nearly half of English speakers (according to my personal experience) say it that way. Go be a grammar Nazi somewhere else.
My new favourite RUclips channel. Smart AF and completely hilarious.
I am a 60+ physicist. I envy your ability to work on formulas on a tablet. I need pen and paper for that. And this is actually the only thing I need a notebook for.
I am 64, and I have a similar dependence on paper. Though the other day I was using a paper map and tried to zoom in on it. I am very disappointed that I now have no fluency with both paper and electronic maps.
@@marymegrant1130 That's hilarious. You're still probably pretty good on pen and paper tho. It's just now that you like your maps of a digital variety. Back then they need reading glasses to do that
I’m 42 and I still prefer math on paper, and I still prefer physical books when I’m doing serious work. Quick stuff I use tablets.
I think that difficulty may point toward aspects of human learning, memory, and thought which are tied to embodiment. That is to say, there are unconscious processes that are tied to, even utilizing or built upon, things like tactile sensation and proprioceptive feedback.
Where I notice it most in myself is a pronounced difference in retention and ability to apply concepts when reading the same textbook from a tablet versus from the printed hardcover. My son reports the opposite effect I experience. He has trouble retaining from a printed book and is better when using a tablet, but then he has been using a tablet since before he could walk. That’s a pretty small _n_ to be sure (heh!) but it’s fascinating to me.
I liked the idea of space elevators and really thought they were an interesting solution to a lot of problems with putting stuff in orbit. And now I just remembered that I first heard about them from Michio Kako and now my day is ruined and my disappointment is immesurable
Is there something wrong with Michio Kaku?
@@halcyonacoustic7366 You mean besides the fact that he is an idiot peddling nonsensical string theory as well as other ridiculous sci fi fantasies?
Who is that?
@@ruinmasters You're better off not knowing.
@@halcyonacoustic7366 Kako is very likely a nice fellow and a gentleman, but he's also a credentialed Ivy League Physics Professor who makes endless TV and internet appearances as a "science communicator" presenting wildly speculative prognostications about sci-fi technologies and sensational unfounded takes on theoretical topics outside his field.
They want a space elevator to escape the rocket equation. If the elevator could be powered by electricity from the ground, then the energy needed to lift something would be proportional to the mass.
Thank you. It's literally referred to as "the tyranny of the rocket equation". I felt like I was taking crazy pills watching this.
Most of the engineering papers about a space elevator I've read suggest a kind of solar-panel powered elevator car being energized by high-power ground-based lasers or microwave beams, which is only slightly less hand-wavey than the materials tech they need to engineer a cable capable of withstanding the tensile forces in play, and honestly I don't recall any of them ever addressing the oscillation issue.
Not only that, but using regenerative braking, you can use the potential energy of stuff going down to power stuff going up. If the masses balance, you only have to provide power to overcome friction, and other losses in the system.
She addresses the reasons. She doesn't mention the rocket equation, but I'm pretty confident that someone with a PhD in astrophysics is aware of it. The real question is: what would you use a space elevator *for?* It's useless for putting stuff in Earth orbit, and interstellar travel is even more impossible than space elevators. That leaves missions within the solar system, and there aren't enough of those for a space elevator to ever pay for itself.
@@MarianneExJohnson The reason usually used in science fiction is to bring people and cargo up to a huge station at the top, and then shuttle things from the station to wherever they are needed. It's feasible, kinda, but the level of infrastructure needed to make it practical is a lot more than just the elevator itself.
Two thoughts:
1. The fact that Philip K. Dick predicted the idea of needing to pay a subscription service in order to open the door to your house. Like. Goddamn.
2. The first company to put a giant glowing billboard in the night sky is going to get [PARODY REDACTED] and I still don't think that would be enough to stop them from doing it.
I would like a space escalator.
Honestly take the space stairs if you are physically able, it's good exercise.
Space escalator can never break, it just becomes space stairs.
And he’s buuuying a motorized staaaairway to heaaaaven
@@nefariousyawn also, the further up you are, the easier it becomes 😂😂
That would be a fun follow up, if you were to assume that the space escalator travels at a 45 degree angle, how much sorry material would be required to reach space?
I understand almost none of the science/math, but I find extreme comfort in knowing there are people passionate about this stuff. Makes me feel safer knowing there are tons of smarter people than me out in the world.
I know none of the science/math, but I'm passionate about learning the science/math
I often find myself saying, I like your funny words magic man
They always ask or "Can we space elevator?" but never "How is space elevator?", which saddens me greatly.
I'll do you one better: Why is space elevator?
Who is space elevator?
When is space elevator
@@personzorz Never
I love hearing you say. “It’s sooner than you think.” The first video i ever saw of yours was about space elevators. That alone was worth a subscription. You never disappoint.
Grant (3Blue1Brown) is pretty awesome. I wished all math was taught in his style--would take so much stigma out of it.
Seconded, he is absolutely incredible! I can credit Khan Academy for getting me from "confused math-illiterate adult going back to college" to Calc III-ish, and then 3Blue1Brown helped me finish the Calc IV and linear algebra for my EE degree. I'm so grateful for all the work these guys put into making math more accessible.
@@registeredjademarkI didnt know calc went all the way to four 😢 what is calc 4?
@@lixxark47 It depends; for some schools on the quarter system, it's Calc 3, more or less, since the calculus sequence gets sliced up into four parts instead of three. For others, especially those on semesters, it's just another name for what's more commonly called Ordinary Differential Equations (a.k.a. ODEs or DiffEq). None of the universities or colleges I've taught at had a course named Calc 4, though; names vary, check the descriptions/syllabi.
I love cracking the cryptic. I love it when he gets that childlike joy when finding a trick to the problem. Just wholesome.
I've started saying "Bobbins!" at work.
22:07 pulling a vibrating string taught would actually make it worse, because if you force a vibration to decrease in amplitude without dissipating its energy, it increases its frequency. That could easily cause the cable to experience forces outside its tolerances. You'd need to have some kind of harmonic negation device that pumps an opposing wave into the vibrating cable to cancel it out. And you'd need them all along the cable because the speed of sound (aka the speed of wave motion in the object) would be waaaay too slow for a cable of that size to stop an out of control oscillation in time.
But all of this is moot! Because the MAIN problem with space elevators that I never see talked about is the actual building part. Not material building, mind you. Leave aside materials, since we could always make one on a friendlier planet like Mars, which I *think* has requirements within the limits of steel. The Moon is also technically possible, but because of its slow rotation it'd be way too long (relative to things that are already WAY too long for us to make right now!) But forget all that, here's the bigger problem: orbital mechanics! People talk about going up and unravelling this cable from space, but you're not stationary up there, you're going in circles and - guess what? - so is that cable! Not only that, but that cable, you can't just "lower" it. Anything in your orbital plane wants to stay there. To drop or rise requires energy, and dropping is harder, because to go literally "down" relative to a gravity well, you need to match the speed of your current orbital velocity in the opposite direction. But not the orbital velocity of the thing you're leaving, YOUR orbital velocity, which INCREASES as you lower your orbit, meaning you need to accelerate. But not just accelerate, you need to accelerate exponentially, by the factor of gravity's increasing strength as you near the surface of the body. AND, because we're talking about a cable and not a single object, you ALSO have to take into account that this needs to remain true for every segment above you! This entire cable line would need to be covered in thrusters with their own fuel reserves, and a LOT of it because they'll need to burn hard to stay under control. You could very easily wind up making a thing that spirals into the planet and it useless and horribly dangerous, or worst case it turns into an enormous whip and you accidentally invent the most inefficient yet also most devastating superweapon in human history
A mitigation method would be to make sections of the cable have different resonant frequencies through variations in stiffness. This would make it difficult for standing waves to arise.
@@TheAntibozo Firstly, the 300 word ramble is hardly worth a comment, he's joined the circus. Then you propose how to "mitigate" the vibration something of unknown geometry, under unknown forcing functions, that doesn't exist, and never will. Removing "Anti" from your handle would be a good plan for some mitigation.
@@Andriastravels Did you watch the video? Poster is correctly responding to acollierastro's proposal. You can't damp a vibration by tightening the cable. Energy needs to be shed. As for my comment, your quick turn to a laughably lame attempt at insult suggests that you simply don't understand it, which is fine.
@@TheAntibozo Firstly, a string or cable would be a small part of a "space elevator" design. The "cable" would have to be part of an integrated, impossible, complex structure with unknown resonance, stiffness and geometry. These terms you learn in elementary theory of vibrations. In the video, all external effects are assumed to be absent in her initial stick model. You are in over your head. Come back when you have 20 years of mechanical design engineering experience.
@@emperorbailey Call it what you want, it is education, well deserved. If crybabies want to talk fantasy and not learn anything, they are part of the problem.
Not a space elevator fan, but since you asked, here's why I would want a space elevator:
Assuming one exists that would also mean we more than likely have the technology to make asteroid mining plausible. Having a central facility to process and move all of that material makes sense.
Gravity would work just fine for getting things down to earth, no elevator is necessary.
Asteroid mining with transportation back to earth will never be profitable. Physics are against it.
Also shout out to my favorite podcast, Well There's Your Problem, which makes episodes about engineering disasters and the causes leading up to them with a leftist comedic take. They actually covered the Hyatt walkway disaster in an early episode.
Edit: after the last quarter of the video I DOUBLY recommend WTYP. They love talking about the same issues you are discussing here about how capitalism results in all these scam startups and such. Also Trashfuture is another great one on similar topics but less focused on any one thing.
Came here to post this! She would be an awesome guest
If only their conversational style wasn't so unbearable.
@@mju135 if only YOU weren't so unbearable.
@@iamjustkiwiLiam would be proud of you!
So, I work for a company that is making a satellite constellation to provide internet services, in fact I design the guidance and control system. I’m a big fan btw, love your content. The time it takes to de orbit a Leo satellite (roughly 600 km altitude) is roughly 10 years. At 800 km it’s more like 100 years. Go higher and it gets really long. This is because at this low altitude, there’s a pretty significant atmospheric density. In effect, if a vehicle is low enough, the altitude is “self-cleaning “. I know maybe you think everyone in this industry is an irresponsible ass, and it’s generally a pretty safe assumption, particularly with an x-fascist, but the problem of accumulating space debris is considered and dealt with. Fly low, use a really efficient electric thruster to restore the energy loss from drag, and it’s possible to not ruin space forever. Worst case, you fuck up a decade. Finally, these vehicles are really really flimsy. Not a lot of ceramic or quartz or hard steel. Aluminum and composite and thin silicon solar arrays. They burn up in the atmosphere, so nobody is going to be hit by anything. Now, is it great to oblate thousands of kg of this stuff? I don’t know, but no one is going to be hit by this stuff directly.
'Don't worry, we only ruined access to space for a decade and also destroyed all vital communications and meteorological satellites. Good thing we were so responsible.'
Literally every time someone steps up to try and defend space bro bullshit, it just really makes it clear how dangerous the industry is & how entitled the industry feels it is to LEO. Like it just owns the place and if they ruin it for 10~ years or so, eh, what's a lost decade here or there?
Fully agree with you, I wanted to mention this too. 99% of the debris burns in high atmosphere, the rest has 70% chances to land in ocean. Biggest chunks are the only ones that can survive reentry and those are tracked. Still, we should consider the probabilities of a Kessler syndrome when deploying large fleets of satellites with an appropriate risk analysis.
@@ItWasSaucerShapedI would imagine that having a debris field at 400km does not impede sattelite communication and metreology satellites at all. it might not be worth the risk to send a sattelite up to space because theres so much debris, but it will only cover a very small area of the earth so imaging and communication through that layer should be alright.
I worked on GOES-R, it's a geo, not a leo, but keep tryin! If snark were an argument you win!@@ItWasSaucerShaped
This was wonderful for me. My grandfather was an amazingly smart, but basically uneducated man. His capacity for wonder amazed me. He was completely OBSESSED with the concept of Space Elevators for 20+ years and I had countless arguments with him about how completely unfeasible the concept was. He always came back to "it's not that we CAN'T do it, its that we MUST do it". Ok grandpa. Thanks for this video!
Some notes about solving the practical issues with space elevators (other than the tether material)
- impact shielding from micrometeorites is probably feasible when you can also create the tether material. For larger objects like satellites, tracking them and predicting a collision, then sending out a satellite-hunting satellite to change thier course if the object cannot itself maneuver could be reasonably practical. The tether itself, like modern ropeways on earth, could likely have multiple redundant cables, allowing one to be damaged and repaired while the other(s) held the load. For what it's worth, modern ropeways on earth have possibly the best safety record of any form of transit, with well-maintained systems that aren't hit by a plane having a flawless record.
- similar to some of the buildings you mention, the tether could have active mass dampers at regular intervals ro counter vibrations.
- the car could be hauled or powered by the cable, from the ground, which is sort of the main advantage of the cable system.
- finally, i think the best practical use case in the nearish term for a space elevator would be resource gathering from space. Not sure if it would ever be competitive, but if equipment can be brought to space and raw materials available in asteroids and the moon can be brought down for a small fraction of what that would currently cost in terms of money, pollution, and land, it could be worth it, especially in a future world where we incresingly care about the impacts of resouce extraction on earth.
Problem with powering stuff via cable is that electricity has transmission loss over a distance
@@matthewjohnson3656 yep, that's why 'hauled by' the cable probably makes more sense. if you can make the cable, you can also make another cable that can pull the car up. that can be powered from whichever stationary end is more practical.
@@rancidmarshmallow4468 even if we had some magic indestructible cable- it doesn’t solve the rotational inertia problem. To get an object from the surface of earth to a satellite space station thingy you need to apply tangential force to accelerate it. On earth at the equator it’s moving at 1000 mph by a geostationary satellite is moving at tens of thousands of miles per hour. A cable can’t provide the sideways force needed to do this.
@@rancidmarshmallow4468 This haul cable is going to have to be as long and strong as the space elevator cable. That's not a solution
A car climbing up the cable is equivalent to it PULLING DOWN on the cable. The dynamics would be incredibly difficult. And it takes a certain amount of energy to lift a mass up a few thousand miles, whether it is lifted by a rocket or by a cable or by a magical electric motor.
Don't worry about the Factorio bit. I've played the mod you're referencing for ~250 hours and I still don't have the space elevator. Granted I'm not the fastest but still I would say 100-150 hours would be blazingly fast to get there.
Love it. As an engineer whose has worked with many physicists (I have a masters in Physics), there comes a time when you have to take the project away from the physicists and give it to the engineers. Yeah, we know we don't know everything about the problem, but we also know there are things we have no idea about just waiting for us around the corner and until we start stumbling our way down the path, we will never find out what problems we don't know exists.
Plenty of people stumbling down the path already. We're going to need to see lots of radical changes in technology before a space elevator or tethered ring is considered feasible, and it will likely *never* be considered safe enough to actually build.
The author of the book seemed to have a space hook and a space elevator confused. Space elevators are what you described in this video. A space hook does something similar but between two orbits, which facilitates Hohmann transfers. Isaac Arthur has an excellent video on both.
From Robert Forward who wrote on this back in the 80s, the expense analysis was that the cost of electricity to power it would be about 10% of the cost of a rocket (on a per kg basis). Time to orbit would be about 5-7 days, compared to 7-8 hours by rocket.
I like your point about vibrations - which has _not_ anywhere I have seen - been addressed. I think pulling it more taught would be a bad idea, as that would increase the frequency, right? Assuming you could - because increasing the tension might cause the thing to break.
Two things I think about are (1) how much potential energy is stored in that cable? If it breaks towards the counterweight, how much energy will be released onto the Earth as it falls? (2) what is the tension in that cable? It's easy to talk about getting some unobtanium - sure, spun diamond carbon fiber, whatever. How strong does it actually need to be? What are the vibration modes of the cable? (to get to your point).
Ignoring the accidental failure (SpaceX satellite hitting it, Musk's car loops back, whatever), what is the risk of sabotage or terrorist attack? How could that be mitigated?
Cracking the Cryptic representation!!! Simon's videos carried my sanity through the pandemic
The channel “Plainly Difficult” is probably my favourite (for lack of a better term) youtuber that takes a very fact based approach to structural failures and general engineering incompetence. They do a lot of UK based things, but cover some larger north american events too
I went to a mid-tier university (NIU) for my PhD and we did the 4 exams thing. The grad students all studied for the qualifiers together. One of us had that book, and we were shocked to find that it was basically undergrad problems. We had previous semester exams from our university to practice on and they were all upper level grad problems. The EM section was 4 homework problems from Jackson. The passing bar was fairly low though. You needed 50% on every exam, or any one exam with a 75% meant you passed the whole thing. I liked that system, because I feel like that was the only time I ever really learned to solve high level problems in a general sense. Even the classes that had those same problems on tests, you always went in knowing fairly narrowly what the test would be on. I know the environment is totally different and now that I'm a post-doc at a higher tier university, I can see that the students are held to a higher standard in other ways, but I'll always be proud that I passed a test that was harder than the one at an Ivy league school.
I'm surprised the Red, Geen, Blue Mars book series wasn't mentioned. It has a pretty strong case against (and kinda for) space elevators.
I think in a different video she talks about finding that series boring. For those interested, the ending of Red Mars includes a vivid description of a space elevator collapse.
Cracking The Cryptic & acollierastro is the crossover I didn't know I needed
I actually prefer sky hooks to the space elevator concept. Big rotating hooks in the upper atmosphere. Fly up your ship, dock, and get flung up to a higher energy level!
I think we will see them on the Moon. Can't imagine how they could survive Earth's atmosphere and strong gravity.
Complete science fiction, never going to happen.
And they're so cheap. I'd imagine there's no will to build one because they look so janky and cheap.
I would be curious which fundamental problems also apply to sky hooks.
@@markotriesteThat one's simple: by being outside of the atmosphere - you'd still need generally need other forms of transportation to get to one.
Thank you for motivating me to doing a physics problem. I got it completely wrong. Looking back, what I ended up calculating is just what the geosynchronous orbit is... which is not what the question was, but hey... at least I got that part right. Considering I haven't done this in like a decade that's not bad.
New to your channel and have been binging your content for a week. Literally jumped at the Cracking the Cryptic reference. I watch them every day!
By the sixth time you said “It’s feasible. It’s gonna happen sooner than you think!” I was literally laughing out loud. Thanks for this fun video!
Space elevators are the string theory of engineering. They even look like strings.
@Exactly! Also strings, as the elementary constituents of matter, are unbreakable, so all the problems related with the resistance of the cable are automatically solved. We just need to wait ten more years XD
Well eventually Earth plus space elevator will spontaneously glitch itself into existence somewhere but, given that will take approximately 10^10^ludicrous number of years, maybe it's actually 10^10^(ludicrous-1) and you're technically correct.
I love how you explain physics. The only person who never made advanced physics seem scary.
She is great at physics, but her practical engineering skills are not on display at all in this video. Or she like presenting strawmen and refuses to look up how some of these challenges are faced today in other projects. Every one of here engineering problems have solutions right now. The one caveat I have is that we cannot make carbon nanotubes currently at a high enough quality, quantity and length to do this project. Everything else she mentioned is covered and has been covered and isnt the issue she makes it out to be.
@@krisspkriss{{cn}}
@@krisspkrissnow we need @Practical Engineering to make a video KEK
It's still scary, just for engineering reasons!
@@krisspkriss I think she was pretty spot on - we will never have a space elevator.
To answer 'why space elevator?' from what I've always understood, I think the point was we're generally better at converting energy into mechanical motion than we are at using the rocket formula. Sure a trip by rocket is pretty quick, but the fuel is always gonna be nasty stuff, and dangerous, and there are pretty hard limits on the amount of stuff you can lift at once (not to mention when you factor in the time it takes to stack, fuel, and load a rocket the time savings isn't that great). So for space elevator however it works it's a pretty simple transfer of electricity into climb/descent motion. It may take a while but it's efficient. Additionally, if designed correctly nothing would stop you from making it like a ski lift, just running car after car up one side and down the other as fast as you can slot them onto the cable.
I absolutely agree from a materials standpoint it's impossible, but I never had trouble understanding why you'd want one.
Impossible is too much, no?
@@fernandoterra4108 the materials needed to handle the stresses involved over the distances required don't exist and aren't even hinted at from what we know about chemistry and physics. Existing manufacturing isn't close to the scale required. So yes, impossible in any timescale less than centuries.
"Impossible in any time scale less than centuries". Better said.
Came here looking for kinda this comment. To me the most obvious answer is - burning fuel is bad, we have to stop. At the rate we're going space elevators will be impossible because we will have starved and flooded ourselves to death by burning so many petrochemicals. If we're dreaming of some bright future where it's important to maximise the efficiency of getting people and goods to/from space, then it is a necessary condition that we have solved climate change in order even to reach that future alive. That means part of the point of the elevator is to get to space without rocket fuel.
(But realistically an elevator is impossible, so probably if we want to keep going to space, using rocket fuel will have to be one of the few irreplaceable carbon burns we keep doing, which only makes turning the rest of the economy carbon negative more important.)
Come on. The fridge will not steal your data. It's just some totally innocuous IOT thing you totally need. Trust me I am fridge engineer and need job security. I promise I will put nice RGB light on the next model and you will feel like you are totally in Star Trek on Tatooine.
I always thought that the main conceptual advantage of a space elevator is that you can use it to overcome the energy potential barrier using counterweights descending/ascending reciprocally. You can avoid using lossy energy conversion (like chemical rockets) and instead just work with conservative gravitational potential. It seems like it's just trying to harvest the gravitational and rotational potential intelligently. You'd still need to initially add enough potential energy to the system to overcome the gravitational potential but if it's all just weights the energy can be conserved. I think, based on the conservation of energy, you'd probably be pulling energy out of the rotational momentum of the earth, which is a weird thought.
Though the engineering /materials concerns alone still seem absolutely prohibitively difficult, and the motivation seems unclear, it seems like people wanting SciFi utilities without thinking about the actual utilities people need.
The main engineering obstacle here is how do you move the energy around. Not obvious at all. You need to efficiently move energy around on a 100 megametres length of cable. Run a superconductor along it? Yeah sure.
@@ioresultWhat do you mean move energy around? If material technology is advanced enough that we can build this elevator, then it's logical to assume that we have the ability to create a strong enough cable that can span the whole height of it. If so, then the motor can just be on Earth surface, controlling the car through a pulley system similar to today's elevator. Use the traditional elevator system of counterweight and braking system and it becomes very practical. No superconductor or rockets necessary.
@@iruns1246 attaching it to the ground brings extra issues. Putting it on the ocean instead might help offset them. But the more complex we make it the more prone it is to a catastrophic failure, and a lot of the issues would add a ton of complexity to remedy.
This is the fun of discussing it, which I've been doing since I was a kid. The cable itself would develop quite a charge from multiple sources including being a giant thermocouple.
@@seasidescott it's really interesting trying to think of all of the details of the environment that are left out in the simple pictures of it. Temperature differences and changes, charge build up and other interactions with electromagnetic waves, let alone impacts and sound waves. Just so much stuff to think about! :D
33:43 -- "When I was a child the future seemed really exciting, and now everything's just the worst possible version." I feel the same, and I couldn't have said it better myself. //Rick
Same here 😕
This feeling, everything is getting worse/will only get worse is a constant going back to the earliest records we have... taking a look at the Egyptian early failed pyramid shows is they tried it before they found out their slope was too steep and they had to build the later pyramids less steep so the darn things wouldn't fall over before their building was done...
@@DavidRayBurroughs The old adage "a broken clock is right twice per day" comes to mind. Quality of life is decreasing for huge swathes of the population, even if the metrics used to measure it are being redefined to pretend it's not.
@@mallninja9805 - as in all True Sayings, these are subject to more than one description often outlining the defined reality, or more nearly so, or nearly more complete. That is, for example, huge medical advances leading to far fewer infant deaths and its increased population and feeding problems and perhaps too many people alive at one time - yet, still and all, we all eventually die. No wonder true believers rely on ginning up god beliefs and immortality of the soul and the reincarnation crap, etc.
People love to say, "just this one thing more, and all our problems are solved!" but it is always "welllllll, not quite..."
I like the concept of a space elevator, in like, a Science Fiction type way. The moment you start thinking about the practicalities of it in real life, even if the physics are theoretically possible (BIG IF), there are so many stumbling blocks that we're just not anywhere close to ready for. Like you mention in the video; space debris & maintenance, tectonic activity and any kind of wobbling in the structure, and just the simple issue of... how do you start constructing it? This isn't like a videogame, where you gather the materials and the structure just materializes, this thing will have to be built over several decades. And how do you coordinate actually setting this thing up, either from Earth or from space?
some thoughts:
from space. start with a pilot-tether. unspool it to both directions to keep center of gravity. add to it over time.
iirc even the nasa paper from 2000 mentions to wobble the tether to avoid space debris. (the bottom part doesn't need a fixed connection to earth it could for example be attached to a swimming rig that can induce the necessary oscillations by moving around) Have the tethers redundant and big enough they don't fail by getting hit by debris that's too small for being tracked. And fix it after an impact. Repairing cables is a solved problem.
fun fact: in theory and given the correct tapering any material would suffice to build such a tether. Practicality is another thing of course.
tldr: many of this problems have (at least in concept) solutions as people have thought about this stuff for a while now. Then again there are things that are (afaik) still questionable like: In the upper atmosphere there's atomic oxygen which is pretty reactive and thus unhealthy for the tether...
8:42 *Thank you so much* for not using implicit multiplication. So many people on the internet don't seem to understand it. :)
the US chemical safety board is not exactly about structural failures but *super* interesting if a bit grim, after major incidents they often release videos to accompany their reports. lots of engineering youtube channels dabble in structural failure post mortems though. looking forward to the leaf blower essay!
I think every science interested teenager has this moment where they learn why rockets are so expensive (need to go crazy fast and carry their own fuel), but also learning that technically space isn't that far away, and next thing you know they're dreaming about space elevators. I think the people who are into space elevators as adults have still not thought about it harder than this teenager.
This, and also a lifetime of safe and effiecient elevators leading non-engineers to think "the elevator part" would be trivial.
I'm an engineer, and while a space elevator might not be feasible, I'm accustomed to naysayers being completely incorrect. Challenges like "megastructure terrorist attacks" are there to be overcome.
@@Kestrel-lp8ho TBH the problem with the space elevator is not just that it is difficult, but also that there are better options. Atmosphere-skimming skyhooks combined with hypersonic planes are a much lower-investment method, while for the full non-rocket approach a launch loop or an orbital ring is going to give you more utility (can easily boost payloads up to escape velocity if the rotor is rotating fast enough), without getting in the way of most Earth orbits. And both could be built with materials that are currently available in bulk amounts, rather than requiring nanomaterials like a space elevator.
> I think the people who are into space elevators as adults have still not thought about it harder than this teenager.
If by "this teenager" you meant the creator of this video, I would be surprised if she is a teenager considering she has a doctorate.
@@3N4N"this teenager" seems to be referring to the hypothetical teenager referenced at the beginning of OP's comment
I'll bite on a couple of these points.
* How to power it: I feel like you didn't think very hard about this one because here's 2 reasonable solutions: 1. electrical cables running along the elevator, like trams, or any other electrified rail type thing. Am I missing something? This one feels very obvious. 2. a laser emitter at the base of the elevator aimed at the bottom of the space wagon, which has a laser receiver (sci-fi technology, but fairly reasonable, I think).
* Why? We don't live in star trek: But it's kind of a chicken and the egg problem. The egg being the ability to climb out of the gravity well. If there was a reasonably cheap shuttle to space every week or month, maybe we would then... become star trek. No?
A transmission cable that goes those sorts of distances has massive issues in terms of loss and efficiency. A laser as you describe would need extreme levels of accuracy and would also probably set fire to anything that flew into its path, or would lose effectiveness by the next cloud passing by.
These aren't bad ideas at the speculation phase, but everything gets harder when you have to factor in the chaotic environment of the real world.
The other issue is that like... the cable has to be super strong and stuff, and now it also has to carry power extremely effectively. This puts even more restrictions on the material used - it has to be conductive itself, or somehow has to have supports for the cables, which are also undergoing their own gravity
@@RhettAultman I would expect if we ever start to build a space elevator we would also have a proper super conductor to build the cable out of. It's just one more unobtanium we will have to obtain, easy stuff
@@tillschlothauer5377 Ah, yes. I forgot about the unobtanium ductile superconductor.
Granted, once we have unobtanium, surely we could hypothesize something better than a space elevator anyway?
electricity seems obvious. two adjacent cables is the same physics as one cable. presumably the voltage is as large as necessary to make the resistance negligible, bearing in mind that you can be extremely inefficient when you don't have to carry enough fuel to carry fuel into orbit. but i think solar is a good option too. a major point of the space elevator is that there's no extra energy cost for moving slowly, unlike rockets which have to pump through fuel just to hover
I fricken love these videos. You should do this full time. I know selling your soul to the man for a paycheck is...unavoidable...this is your calling for sure.
as requested ;)
Well There's Your Problem | Episode 4: Hyatt Regency Walkway Collapse:
ruclips.net/video/Hw2t0MOGnVc/видео.html
I absolutely appreciate your content. These are the types of questions I would ask as a child but no one could answer them, now as an adult I love learning all this stuff and letting my inner child get excited to learn.
Wait, would it cost only 17 billion dollars? So, less than half a Twitter? That sounds cheap actually!
i think she just chose a random number, it'd more likely be in the trillions
@@bejanbosc3695 Imagine starting a New New Deal planned around a space elevator to jump start the US economy should it crash due to the debt.
@@DaLiJeIOvoImeZauzetoGreat way to make a couple real estate moguls rich and accomplish nothing else
@@bejanbosc3695 Twitter valuation is also random, stock crashes anytime Musk opens his mouth. If he has a cold then he may be able to purchase a space elevator company. He sure is dumb enough to at least.
@@personzorz That's idea behind the comment. Cynical to the end.
Dr Collier - I hate you just a little bit for this video :P.
I'm a mature student in my final year of forensic chemistry as an undergraduate, currently applying to masters programs abroad writing thesis proposals, and teaching myself a new language because half of the courses I've applied to are in French...and now...after watching this...I have to go learn calculus and integrals because of the wizardry you just performed! Absolutely awe inspiring! Loved it!
Your videos elevate my standard of living to levels beyond my own comprehension
what if our hands brushed while we were in the space elevator together
@@vermis0161 lewd!
@@vermis0161 im blushing
Excellent video! I'm an engineer myself and thank you for bringing some more insight into what we do into the greater "stem limelight" I guess, for lack of a better term.
The Hyatt Regency fiasco is infamous at least in Canadian engineering circles, and there isn't one undergrad who will escape the field without understanding the importance of the lessons that must be learned from, honestly, criminal negligence.
Safety, ethics and integrity are absolutely paramount in engineering. It can be easy to sidestep these principles for profit.
I love your choice of words sometimes. Verbing "space elevator" is really funny to me in a way that I'm baffled to describe.
I'm an old engineering physics grad (working in spacecraft engineering) and you completely nailed the difference in how physicists and engineers see this problem 😂 (and really I don't think physicists believe it either, science media loves to sensationalize) like yes! We can do the equations and get all the numbers we want to "solve" the basic problem, but engineers are still gonna look at those answers and giggle and then go do practical things instead because there's SO MUCH that goes into making physical structures not kill everyone building or using them.
Also I love hearing you rant about late stage capitalism, I feel so seen 💜
Point well taken. But not so many good applied physicists, and good engineers, see it so differently. This content creator is a good example.
This is also known as AM/FM thinking, aka actual mechanics / fucking magic
I'm an old jack-of-all-trades facility construction, startup, operation, maintenance, modification, and retirement engineer.
I've also had to work with hazardous materials and the required risk management involved at the overall level down to the industrial safety with how to ground equipment to make sure it is energy-safe.
The stake through the heart is the project management, risk management, financial management, and regulatory oversight/management.
How many airplanes take a crash or two to 'get it right'?
Now, imagine that involves a structure that will cause mayhem in Earth orbit and on the ground, involving all the energy, kinetic/potential/electrical/vibrational/invisible pink unicorn, locked up in this system and just looking for a way to leak out!
Of all the cool ideas that Robert Heinlein had,lets be honest, Power Armor is the most likely to actually ever work like it does in his books
His description of power armor is one of the things I remember most from Starship Troopers
@@AzaleaJaneStarship troopers was genuinely the most disappointing science fiction book I ever read. I thought it would be a fun adventure romp with power armor and aliens, and it was like 80% an argument for fascism
@@aidanwarren4980 Thanks for telling us you don't know what fascism actually entails but you do you...
@@aidanwarren4980 not an argument for, but a 'realistic' depiction of how society works under it. its more of a "how would the world work under these conditions" less "this is how the world ought to be".
@@aidanwarren4980 dude, you should have paid more attention in English class if you can't identify the satire in Starship Troopers. Heinlein's stories are intended to be provocative and morally ambiguous. If anything, Starship Troopers is a *criticism* of militarism and the unholy union of corporate and government interests.
That story about refrigerators at 32:20 reminded me of how LG is planning to do subscriptions for their connected appliances.
I wonder if the frig that "broke" was an LG. I know ours sure was. Linear compressors are junk.
After Angela mentioned leaving links to videos about Hyatt in the comments, now I just badly need her as a guest on Well There's Your Problem. That episode would go crazy
This video brings the total number of times a physicist has said “we gotta get the engineers in here” to…
…one.
Let’s be real - I’m surprised the physicists actually knew the engineers existed in the first place.
@@tomkelley4119oh they knew, but it was easier to just assume they rounded to zero
We're just physicists who multiply our results by this unitless constant that cannot be derived from physics and math fundamentals called a "Safety Factor".
Dr. Collier is not your everyday Physicist
Unobtanium and “you have to pay gravity” are the two most awesome words and phrases I’ve heard this week. OK, it’s only Monday, but I’m pretty sure the week will end with nothing better.
I loved "we have flying cars: they're called helicopters, and they crash all the time"
You must have not seen the film "Avatar". The term unobtanium is actually decades older than that and was a running joke in film/ science fiction criticism.
@@iankrasnow5383 Adamantium in Gulliver's Travels is what keeps the floating island levitating. At some point, people just replaced Adamantium with Unobtanium.
@@iankrasnow5383 Fun fact, the unobtanium in Avatar was actually a room temperature superconductor, which is the reason why the mountains on Pandora float.
@@Jackissimus Room temperature superconductors, space elevators, hyper loops,... Is it just me or does it feel like the frequency of big funding scams is increasing rapidly?
I think part of the appeal of space elevators is that it’s more fun to imagine a Big Thing than a Good Process. Like, the current system of using rockets works fine and is sensible and all that, but you can’t *look* at it the way you’d be able to look at a big macro-engineering project that reaches all the way into space, and I think that affects how people react to it emotionally
Of course, almost no-one reacts emotionally to how unsustainable chemical rocketry is, ESPECIALLY on Earth, but it is, EVERYWHERE.
@@ticthak yeah... with all that rocket money, we could propably build a launch loop. (something that actually works with current materials)
I first heard about that as a potential cost effective solution to getting stuff off the surface of a planet. But if I'm being honest the reason space elevators excited me is because it's the first mega "space age" construction I could conceive of. It's kind of like building a big pyramid but in SPACE.
Some kind of active support structure makes more sense, once there's enough demand for traffic in and out of space for the economies of scale to make sense...
Like a launch loop or something like that at first, eventually an orbital ring -- but we have a long way to go towards setting up proper industry in space before we get there.
Yes! Launch loops (even smaller ones that might be used to replace first stages or intercontinental flights) seem much more sensible.
I just think it's something the avereage decision maker is unlikely to wrap their heads around.
Also, i think we don't need demand first-
basically having a conveyor belt will make it so cheap that demand will come on its own.
Also, i don't think we should ever make any of those big decisions purely by asking "will it earn money".
@@nos9784 Every sort of big sea-change in industry faces this same kind of chicken and egg problem. You have to bootstrap with small proofs of concept and build the demand as you go. I dislike framing things in capitalist terms, but the principle is the same even if you just look at allocating raw resources. We don't currently have enough things going on in space for it to make sense to allocate so much into building orbital rings and such, but as we inch our way forward and find out more things we can do in space (fabricating better optic fibers, collecting solar power, mining asteroids, moving polluting stuff out there where it's already an irradiated hellscape instead of our biosphere, whatever), slowly there'll be more and more reason to build bigger and leverage economies of scale.
Basically, with or without money, you have to move in smaller increments, have pilot projects and trials and small scale experiments, get your foot in the door first and then slowly lever it open.
I've always wondered... what if this structure fails? Will the tether just start falling and coiling around the earth, destroying everything in its path like a giant whip from heaven?
Depends on failure points.
A space elevator is meant to be in equilibrium, the part that experiences more gravity than needed as centripetal force is held up by the part that has less gravity than needed. If it snaps, the upper part will drift off into space and the lower part will come slashing down to earth.
Oh boy kids, time to practice our duck and cover because the space whip is here to punish us for our hubris!
Would you *want* to be whipped by a giant whip from heaven?
In Kim Stanley Robinson’s Mars trilogy this happens… also in the TV adaptation of Foundation (I don’t think it happens in the books though but I don’t know for sure.) In both it’s as bad as you can imagine, I would not want to live anywhere in the path of where it might come down.
My favorite structural failure channel is Practical Engineering. They don't have a Hyatt walkway video, but they do have a video on space elevators and a lot of other disasters.
Ok I lied, it's more of an infrastructure channel that talks about failures in dams, bridges, and buildings from time to time.
Practical Engineering actually covered the Hyatt disaster in a guest video on Tom Scott’s channel.
@@w13storageroomB Ok, I thought I remembered seeing it but couldn't find it on his channel.
He has a great playlist with structural failure (and adjacent topics): ruclips.net/p/PLTZM4MrZKfW_kLNg2HZxzCBEF-2AuR_vP
"You might have seen the trick where people fill a bucket with water and then spin it" - In undergrad physics 1 we had a new grad student lecturer that was very gung ho about using all the demos that had been gathering dust. After some practice he did this demo in lecture and it worked! We all applauded!
...then he launched the cup, hitting the head of someone in the first row and splashing someone's leg in the second row.
Oh. My. God. The better help on the orb bit ripped straight out of my nightmares.
One of the most distressing things about playing Starfield is how often when you jump into a settled system, there is space crap everywhere.
Better than every other turn dying of dysentery?
The first time I came across this in school, I thought it was really cool that the result was entirely independent of the density.
Well, but that;s only true because we assume "magical never breaking strength". If strength is finite, then the density matters A LOT. In fact, the ratio of strength to density is why we can't build this, and probably never will be able to.
@@oschonrockyou can build it from steel if you want. Just the tensile strength to weight ratio decides the shape and top vs bottom diameter ratio. The steel one will be probably hyperboloid with thousand kilometer base :)
@@ladislavseps4801 LOL, sure...
@@ladislavseps4801According to Real Engineering's 2020 video on space elevators, a steel tapered tether with a 5 mm base on earth would need to expand to 1.76×10⁵⁴ metres at GEO - a number so absurd that it's 2×10²⁷ times wider than the known universe :)
Kevlar fares better at "only" 81.3 m, and carbon nanotubes require it to be just 6.37 _millimetres,_ apparently - albeit with _a LOT of assumptions_ and optimistic values.
And all of this was with zero safety margin: “I'm designing it riiiiiiight on the edge of breaking” 👍😹
Well the problem is that I'm not a physicist or an engineer. So I WAS into the idea of space elevators, because I didn't realize all the problems that would happen trying to build one. From my perspective a lot of inventions and technology are crazy things that work due to really complicated math and laws of physics, so I just figured that someone smart had proposed a space elevator as a concept a long time ago and done the math to say it is possible, why else would everyone be assuming it would work? I thought now we were just waiting on strong cables to make it actually happen. But you going into detail about how it's impossible to make that rope and why rockets are actually just better clears that up. I've never heard the opposing argument and a physicist saying "NO. It won't work."
An interesting way of looking at the problem is to translate the various tensile-strength/weight ratio of different materials into "How long can a cable get before it snaps under its own weight?"
given the proper tapering any material would do. in theory. Consider the tether only needs the full strength at the point of the most stress. The bottom part (and the upper part if you use the tether itself as a counterweight which has benefits) can be way less strong.
@@MegaHarko This kind of tapering requires an exponentially wider cable as the length increases. It does expand the range of materials a bit, but saying that "any material would do" is just factually wrong. It is impossible to build an Earth-serving space elevator out of steel, for example. The wide end of the "cable" would need to be thicker than the entire solar system, and it would collapse into itself under its own gravity.
@@PizzasgoodYo there's no reason why the cable has to support itself unassisted. There needs to be propulsion all along the cable for station-keeping anyway, why not point those propulsion systems toward the ground and use them as active support when they aren't being used for finely adjusting the position of various parts of the cable? It cuts into your energy savings but "possible and expensive" is a world away from "impossible".
@@tissuepaper9962 That wouldn't just "cut into" the energy savings. It would annihilate them. If the elevator can't even support *itself* without assistance, then that means whatever means of active support you use is going to be bearing 100% of the downward force caused by the payload's climb plus whatever portion of the elevator's own weight it's supporting. Considering that *at least* 99.7% of a space elevator would be above the Karman line, the overwhelming bulk of that active support would have to involve throwing reaction mass. That means you'd have to *lift* reaction mass up to the thrusters which are providing the thrust to perform the lifting, thereby necessitating even more reaction mass to lift the reaction mass... and that's just the Rocket Equation with extra steps, plus you have to keep it running 24/7 or millions die.
@@PizzasgoodYo
You're right.
That's why I wrote 'in theory' as in mathematically.
Most materials aren't strong enough in practice.
And those that are can't be produced in sufficient quality and quantity yet.
Point being: One can construct cables that won't snap with any material yet it's not feasible to use them in practice for different reasons (as the one you pointed out)
What's wild about the sky hook concept (aside from normal space elevator stuff) is that it's not only orbiting the Earth, but also is rotating at just the right angular velocity such that the hook at the lower end will remain horizontally stationary. So it's essentially a planet-sized trebuchet.
Eternal trebuchet… 😅
That's actually the entire point of a skyhook!
Maybe that's why people want them. People in 2023 are building supersonic trebuchets on RUclips.
Who's behind this? Are trebuchets numinous?
So grateful the algorithm recommended your channel to me last week. Traveling abroad and your back catalogue is keeping me sane on transit.
Only there's one of those old-timey elevator attendants
I think that the Hyatt Regency thing is one of the central examples in the book "To Engineer is Human" about engineering failures. I remember looking at the diagram that explained the error and being shocked that something so seemingly unimportant could be deadly.
Engineering is hard stuff, man.
I love that book. I think it should be a mandatory read for all high school students. It illustrates to any lay reader how and why experts can make major mistakes and to always double check everything and don't be complacent.