One thing that has always bothered me since watching the upward bound series is how do you actually build things like an orbital ring, loftstrom loop, and active support structures since all three are inherently unstable during construction or have great changes in length while raising if you could do a video on the logistics of building early mega projects or address it in your monthly livestream that would be great thank you!
You could start with self supporting arches. Build them under the oceans surface. Float it when complete. Then start the support system while pushing the ends closer together. You would get a giant arch, maybe from San Diego to Hawaii. Build more, then connect them at various levels and extend them in stages.
You might rely on lifting gasses to get it to an altitude where you could functionally connect all the pieces, then build it accordion-style, able to expand as the active support raises it. Once at the desired altitude, balance out the speed of the active support to maintain altitude. Lifting gasses would probably be a rather expensive option, and you'd need some active engines for station keeping, but it allows you to stay up there for long enough to get all the pieces up, connected, and powering an active support system. It would also be advisable to ensure all the pieces are structurally complete and ready to go before lifting any one piece, so as to minimize the time you need to keep them suspended. With one highly coordinated lift, you could get all the pieces into position in relatively short order, then couple them all together, evacuate anything you need to evacuate, triple-validate that everything's good, and power your active lifting system. I'd still budget a day minimum for that, and the potential that anything might go wrong is high.
I recall that Isaac mentioned that an orbital ring could be built by assembling the stationary and hype-orbital velocity portions both at orbital velocity initially. The hyper-orbital velocity portion could then be accelerated to its functional speed by magnetically pushing off the stationary portion, thus slowing the stationary portion (any action creates an equal and opposite reaction) to a speed that makes it actually stationary relative to the ground.
Isn't the idea to put individual sections into orbit, then connect them until there's enough to complete the loop. The loop will not be stationary, it will be rotating at orbit speed.
This seems like a very hard problem. The issue with the down from orbit method is that you need to get the pieces of the ring down to the right altitude in a circular orbit before you can connect them. That means a fair bit of time using enough propulsion to overcome air resistance. Lifting seems more plausible to me. Maybe you can start with quite a small (in cross section) ring and use it to help anchor the pieces for a larger ring...tho I guess if it's already robust enough for that you may not need the bigger version. I think hot air balloons might be the best options but then it's a harder problem to accelerate the ring but yes he should do an episode!
@13:43 The main reason that we don't put cell towers up high is that we need to "re-use" the frequencies from 1 cell in another cell that is located only a few cells away. Thus because of frequency re-use, we often want cell towers to be very low to the ground, thus making each cell very small. The size of each cell has been constantly getting smaller with each version cellular technology. The latest 5G cell size within a crowded city is often less than 1km in radius, with the height of the cell tower being about as high as the street lights that illuminate the roadways at night, often times street lights have cellular antennas added to create new cells.
I was going to post this same point. The cellular system is based on the concept of "cells" that use discrete sets of frequencies which are different between adjacent cells, but are repeated on cells far enough from each other to not cause interference. Transmission power is intentionally limited for this reason. The system is designed with "handoff" features to switch the frequency a phone is using as it moves between cells, usually so seamlessly as to be unnoticeable by the user. If something like dirigibles or ultra low satellites were used, something more similar to the technology used in Starlink would be needed (phased array antennas, etc), which would greatly complicate service and probably make a phone difficult to carry.
the concept isn't new to me, I remember seeing it in "battle angel Alita" years ago, but I do enjoy hearing about it in greater detail, I loved the episode
Love your videos. I should be studying instead, so I often imagine you'll be disappointed that I'm not, to motivate myself to study. Thanks for the quality content
One thing I miss from the video are High Altitude Pseudo Satellites - stuff like Airbus'es Zephyr. UAVs got mentioned, but HAPS are sufficiently unique to make a segment in this sort of content.
If you have a teather reaching into the atmosphere by using a tube for the teather you can pump air to the top to use as propellant in a ion rocket to maintain altitude.
I really like the idea of structures like these holding up a thin film , reflecting all the direct sunlight away from major cities. To give context, I'm from India where we just experienced an insanely hot summer. We don't have much of a spring. April, May and June are our summer months. If we could shade our cities, even for a limited time around the peak of sun, we should be able to have cooler cities and a double benefit regarding global warming. The double benefit would be the direct reflection away of some sunlight and the decreased drawdown of power due to lower air conditioning costs. There could be social and economic benefits too, with the time of the peak sun becoming useful in urban areas as opposed to just being used for naps and siestas. During times other than summer, the films could be tilted to allow the light through and of course, communication, surveillance and advertising services would continue. The big question in an Indian context would be how these structures react to the power of the monsoon winds. But i do believe that it is worth an experiment.
Great episode. It reminds me of skydiving; there's a moment at the end where you're still held aloft by 'nothing,' even though the ground is so close you can practically reach out and touch it. That is, the thought of major structures just hanging from the sky is kinda surreal / cool.
To me this is one of the most impressive youtube channels around. The way you create insightful, funny and well researched scientific and philosophical content on such a regular basis is way beyond me
Happy to see JP Aerospace get mentioned. I first heard about them a little over 10 years ago, and have been keeping up with their progress ever since. Would love to see a Dark Sky Station built in real life.
i know you probably won't see this Mr Arthur. but when i need a good dose of science mixed with science fiction or future science i think is more accurate i come here. but you are the master of your craft much appreciated friend
If we ever manage to solve this problem, hopefully instead of naming the "Cloud City" - Stratos, like in Star Trek. ;P They name the city after Isaac Arthur.
Loved the episode as always, but especially interesting were these out of the box ideas about the degree to which planets are suitable for solar powered objects.
I've had a striking mental image of a post apocalyptic sci fi setting with orbital structures visible from the surface. In my mind it's always been a cool visual that probably wouldn't be practical, as it'd need to be huge objects to be visible from the surface. The idea that these structures could actually be in super low orbits is awesome.
Want thousands of satellites that don't need to be in orbit and cost very little to opperate? We just need the equivalent to a starlink satellite that are installed on all commercial aircraft and on all cargo ships. The military already does this with its vehicles to expand the coverage of their networks.
The army had something like this a few years back. There was an airborne radar station that used to float above the Virginia-DC-Maryland area. I think it was called JLENS. Unfortunately the floating radar idea had some severe issues. Most notably the blimp would break loose from its tether. This happened several times when the radar was deployed overseas. It also happened once while floating over DC. The tether wound up being dragged across three states knocking out power lines in the process.
The stratotram or DSS options sound feasible now with refueling and refilling via drones but you would need to filter out humidity on a regular basis. The Goodyear blimp has to do this. Maybe with mylar film or carbon films this is not required. What you would need is radiation shielding and protection from high speed particles that would degrade the device over time.
I remember an April Fools skit on the radio back in the 70s about a satellite launch failing to reach altitude, and that people should watch out for it now whizzing around the planet 6 feet above the surface. I also recall some... lesser enlightened people took that warning seriously. In practice though I do love playing KSP and putting things in silly orbits. If it doesn't have an atmosphere, the only thing stopping me is terrain variation.
remind me of the sf book "Spin" by Robert C Wilson, in which humanity is forced to rely on stratospherics satellites since spaces satellites don't work anymore ('coz aliens shenanigans)
A tethered high altitude balloon sounds like a fun idea to do all sorts of interesting things. Communications, high altitude launches, and power generation all in one! Heck, you could probably have a string of systems running down the tether at different altitudes if needed.
Deployed since 1980, the US uses the Tethered Aerostat Radar System, which are helium balloons that have a look-down radar set to detect low flying aircraft, especially in rugged terrain such as the US-Mexico border.
Everything leaks - it is a matter of degree. So there is always a trade-off between weight of lifting gas and weight of the tanks needed to compensate for leaks.
I read somewhere that some dirigibles used something like methane for both lifting gas and fuel. It saved them the trouble of condensing and holding the steam from the exhaust to maintain weight and thus stabilize altitude.
Anything tethered to the ground is highly vulnerable when extreme weather hits. Power lines are frequently brought down by the weight of ice accumulating.
We do have balloon cell towers, or had. Lookup project loon, it was in service over Puerto Rico for a while. They found that they can keep a balloon stationary enough just by varying the height and taking advantage of different wind directions.
It amazed me as it disappointed me. Looking up while in the Northern Wisconsin National forests. My watch running Glonass and Galileo independent from cellular. Watching the train of Starlink stuns me each time. I apologize for punctuation. Semper Fi, it's been a wonderful 6 years. Thank you so much
this is the first time I've ever heard why helium always leaks. I'd always idly wondered why you can't just seal it in an airtight tank. Makes so much sense in hindsight. Atoms literally smaller than the gaps in the material you'd be sealing it in.
Could we put a propellor on the poles? Before you click me away, let's get serious. What if we take a double wing structure and spin it up on the south pole. Both wings are at 180 degrees to one another, and turn around a very big structure on the south pole. The structures are aerodynamic wings and they are set with propellors. The wings rotate and are gradually expended. Power is supplied by a reactor and all the time the wings maintain a direct connection to the spoke structure. You can easily attach three or four or more wingtethers. Centrifugal pull will pull the wings taught so they angle from the polar structure and the longer the wings are extended the more the pull will yank them higher into the arctic atmosphere. As you slide wing extensions down the wing tether the structures that rotate in the higher atmosphere will "dynamically deploy" different types of ways of pushing it through the stratospheric atmosphere, and by making the wing partially filled with helium would also serve to create bouyancy. At some point you start deploy cable where they no longer is much in the way of air friction. I really think this could work quite well to deploy a launch system that can dump large amounts of asteroids in orbit quite cheaply. I call this a Khannea Skyhook.
I might need a diagram to make sure I'm picturing what you have in mind Khannea but I think that should work, though I think that static polar stations is really mostly helpful for above small and fast rotating objects and most of those you could just build a tower, especially with the lack of air.
You really ought to make a video about photon powered space travel, like using a vast network of lasers on a planet to heat propellant to extreme temperatures and those then expand out of rocket nozzles on ships.
While vacuum airship are more buoyant the structure required to prevent implosion and the energy needed to maintain the vacuum would probably negate all benefits if not make it harder.
I agree. But it is a futurism channel so it might be worth a mention even if it is a partial vacuum. There are a few people, Andrey Akhmeteli, and Andy Gavrilin to name a couple who have pursued the idea.
So, as a gamer from the Buckeye State, have you attended the Origins fame fair in Columbus? they are the ONLY game convention that gives a decent discounts for AD, Guard/Reserve and military veterans...
8:30 How about a recharge ship flies in at the centre of several vehicles and charges them wirelessly and once done, flies up to the solar recharging stations to get ready for the next round
Would it be possible to create a rigid balloon like structure in orbit with "nothing" inside and then lower it into the upper atmosphere to act as a balloon without imploding. I say this because a rigid balloon like structure with very little gas or an almost complete vacuum inside is lighter than a helium or hydrogen filled balloon. Since it is created in orbit, the structure would not have to hold up to anything close to 1 bar of pressure, but maybe only 5 to 15 millibars of outside pressure and still be buoyant in the upper atmosphere.
I'm under the impression that (ultra, extreme) high vacumn conditions - while obviously less massive on its own - require enough additional structure to remain rigid that the average difference in density would be negligible. You'd need negative mass to make the numbers work. Also gassing is still an issue. Pumps, more mass.
If you want a system that can hang 2,000 lbs of telcom gear 60,000 feet over a city check out Burt Rutan's Proteus. Basically a jet powed autonomous glider.
What about vacuum balloons? They can be refilled at a higher elevation. Provide more lift than hydrogen or helium. And you aren't losing out on power by filling your balloon with gas.
however with satellite orbiting the continent it's got a major problem, the limitations of signalling, yes we do have a solution now, especially with 5G's VoIP and especially the voice over WiFi, that tends to be the part that really helps increase the capacity however there is still a range of frequencies available. Voice over Wifi has saved carriers millions alone in operational costs because they don't need to increase capacity so much but having one or 5 satellites doing our comms would be disastrous.
I have seen an amateur self published SciFi story about such a transport system (a mass driver that starts from the earths surface but terminates in the upper atmosphere - supported by constellations of very large balloons - but unfortunately, I cannot remember the name of the author or where I read it - it was a compelling read, though)
Although your logic is sound, the structure needed to maintain that vacuum outweigh the benefits gained. You would just want to use hydrogen, but it is flammable, so you might want to use helium.
One problem with maintaining such long term is the material needs to overcome the pressure pushing inwards even if you can compensate for that however you still have to account for quantum tunneling the same mechanism hydrogen and helium can leak through in fact it is also the cause of alpha decay as helium subnuclei can tunnel outside the nucleus scaping from the range of the strong nuclear force which binds atoms together. This means that even a strong rigid dirigible ultralight weight to maintain buoyancy with a vacuum has a time limit
The problem is the huge pressure difference. And it gets worse as you scale up, because the walls have to resist force, not pressure, and force increases with the area. And on top of that, the wall's ability to resist forces decreases with it's size. So the required wall thickness goes up with like the cube of the smallest diameter of the vehicle. Which means the weight of the walls go up with the fifth power. That makes this practically impossible, unless I made some big mistake somewhere. The advantage of positive internal pressure is that you can rely on tension, instead of compression, which is way way much stronger. Think about what you need to hang a one ton weight, compared to supporting it from below. Maybe it could work with active support. A big sphere, inside weights going around on magnetic tracks at very high speeds. The tricky part is that the tracks have to intersect. You want to go as big as you can, due to the square-cube law. The lift it generates grows faster then the weight. But you also need more tracks with more intersections. Maybe with good timing collisions can be avoided, I can't do that math in my head. Or maybe you can offset the tracks a bit and let them go under and over each other. Could work with flat but wide tracks. Or use a torus. That makes the intersection design so much easier, in exchange for higher surface area, and therefore weight. Added bonus is that it looks so much more cool than a stupid sphere. And more practical too. You would have to use multiple spheres to get a practical shape, so maybe it turns out to be more optimal anyway. And the hole in the middle would be a perfect place for the cargo bay. A big plus is that you only need air and vacuum, and both are abundant and free, anywhere you want to be.
You would need to constantly create charge separation on that balloon as the charge will cancel out with the atmosphere. That would complicate things, add weight, etc. Seems like a vacuum ship with extra steps
Yeah because floating stuff this low in the atmosphere never could go horribly horribly wrong... At least you aren't looking at a colony drop level disaster...
Speaking of shipping air, I am pretty sure that if there was bulk interplanetary trade in food one would have to have freighters of CO2 going the other way. Based of how much CO2 is consumed by the amount of plant matter a human consumes in a year, taking Coroscant with its cannon population of 3 trillion and 10 agricultural supply worlds as an example, assuming humans eat an average amount among all species and that those planets started like modern earth, the loss of carbon from shipping all that food to Coroscant without replacement would drive all those worlds Into an ice age in around a century. With a more realistic population of 49 quadrillion, it would take only five years. Obviously these are rough calculations, but I think I am on to something.
Probably not just carbon. Remember the phosphorus scarcity in the universe. ruclips.net/video/oPU9jeQbTOU/видео.html I'm reminded of The Hitchhiker's Guide to the Galaxy: "For years, the fabulously beautiful planet of Bethselamin increased its booming tourist industry without any worries at all. Alas, as is often the case, this was an act of utter stupidity, as it led to a colossal cumulative erosion problem. Of course, what else could one expect with ten billion tourists per annum? Thus today the net balance between the amount you eat and the amount you excrete while on the planet is surgically removed from your body weight when you leave; so every time you go to the lavatory there, it is vitally important to get a receipt..."
You know Isaac, Mark Meer, the voice of the male Commander Shepard in Mass Effect is an avid D+Der, and part of a group called "The Black Dice Society" he's on twitter and announces his D+D events there. Ya know, just saying.
4:21 if this image is meant to illustrate various orbits with same perigee but different apogee, then it's completely wrong. I mean, you can _see_ it's wrong because perigee is supposed to be the lowest point of the orbit but here the orbit intersects the earth at two different points. If the perigee of different orbits is equal then the orbits with lower apogee will be contained in its entirety _inside_ the lower perigee orbits, they will not intersect, because the planet will always remain at the focus of the ellipse.
How does one start building an orbital-loop? I understand how they would work when built but it's the jump to fully built I can't imagine beyond a huge number of active support towers and building the orbital loop across the top like a bridge until it's switched on and then removing the towers or most of them.
"So, the balloon is covered in graphene solar cells, which power its propellers and crack hydrogen from water vapor in the atmosphere to replenish the hydrogen in the gas bag, which holds its hydrogen in by being surrounded by graphene solar cells."
if only we would have similar motivations as guys on Pradise -island in Attack on Titan...we would be there already. But "titans" are not attacking from space...yet
Douglas Adams said that flying is the art of throwing yourself at the ground and missing. This is as good a definition of orbit as I can think of.
As a teacher, I genuinely wish Isaac taught either, or both, physics lessons and Sci-Fi creative writing on RUclips. This is so fascinating!
To me every single video is exactly both of those things 👍🏽
He kind of does.
I’m learning and enjoying . Win Win.
like he isnt
Doesn't he have content on curiosity stream or another learning platform?
One thing that has always bothered me since watching the upward bound series is how do you actually build things like an orbital ring, loftstrom loop, and active support structures since all three are inherently unstable during construction or have great changes in length while raising if you could do a video on the logistics of building early mega projects or address it in your monthly livestream that would be great thank you!
You could start with self supporting arches. Build them under the oceans surface. Float it when complete. Then start the support system while pushing the ends closer together. You would get a giant arch, maybe from San Diego to Hawaii. Build more, then connect them at various levels and extend them in stages.
You might rely on lifting gasses to get it to an altitude where you could functionally connect all the pieces, then build it accordion-style, able to expand as the active support raises it. Once at the desired altitude, balance out the speed of the active support to maintain altitude.
Lifting gasses would probably be a rather expensive option, and you'd need some active engines for station keeping, but it allows you to stay up there for long enough to get all the pieces up, connected, and powering an active support system. It would also be advisable to ensure all the pieces are structurally complete and ready to go before lifting any one piece, so as to minimize the time you need to keep them suspended. With one highly coordinated lift, you could get all the pieces into position in relatively short order, then couple them all together, evacuate anything you need to evacuate, triple-validate that everything's good, and power your active lifting system. I'd still budget a day minimum for that, and the potential that anything might go wrong is high.
I recall that Isaac mentioned that an orbital ring could be built by assembling the stationary and hype-orbital velocity portions both at orbital velocity initially. The hyper-orbital velocity portion could then be accelerated to its functional speed by magnetically pushing off the stationary portion, thus slowing the stationary portion (any action creates an equal and opposite reaction) to a speed that makes it actually stationary relative to the ground.
Isn't the idea to put individual sections into orbit, then connect them until there's enough to complete the loop. The loop will not be stationary, it will be rotating at orbit speed.
This seems like a very hard problem. The issue with the down from orbit method is that you need to get the pieces of the ring down to the right altitude in a circular orbit before you can connect them. That means a fair bit of time using enough propulsion to overcome air resistance. Lifting seems more plausible to me. Maybe you can start with quite a small (in cross section) ring and use it to help anchor the pieces for a larger ring...tho I guess if it's already robust enough for that you may not need the bigger version. I think hot air balloons might be the best options but then it's a harder problem to accelerate the ring but yes he should do an episode!
I love Thursdays with Isaac! Better than any other day of the week!
@13:43 The main reason that we don't put cell towers up high is that we need to "re-use" the frequencies from 1 cell in another cell that is located only a few cells away. Thus because of frequency re-use, we often want cell towers to be very low to the ground, thus making each cell very small. The size of each cell has been constantly getting smaller with each version cellular technology. The latest 5G cell size within a crowded city is often less than 1km in radius, with the height of the cell tower being about as high as the street lights that illuminate the roadways at night, often times street lights have cellular antennas added to create new cells.
I was going to post this same point. The cellular system is based on the concept of "cells" that use discrete sets of frequencies which are different between adjacent cells, but are repeated on cells far enough from each other to not cause interference. Transmission power is intentionally limited for this reason. The system is designed with "handoff" features to switch the frequency a phone is using as it moves between cells, usually so seamlessly as to be unnoticeable by the user. If something like dirigibles or ultra low satellites were used, something more similar to the technology used in Starlink would be needed (phased array antennas, etc), which would greatly complicate service and probably make a phone difficult to carry.
I was literally in a meeting proposing light weight floating infrastructure like this to my boss as the RUclips alert came up for this
which company do you work for?
What’s your job and how do I take it from you
Your hiring?
"Dark Sky Stations" sounds incredibly cool lol
I love the idea of skyhooks. Space elevators are cool too, but skyhooks sound easier to build.
I like them both. Skyhooks for their flexibility, space elevators for their utility. No reason why they couldn't coexist.
the concept isn't new to me, I remember seeing it in "battle angel Alita" years ago, but I do enjoy hearing about it in greater detail, I loved the episode
Love your videos. I should be studying instead, so I often imagine you'll be disappointed that I'm not, to motivate myself to study. Thanks for the quality content
"My orbit intersected with the surface" is my new term of choice for stubbing my toe
So, I hope that someone tries to help me figure out my ideas by 3D design. It would be so excited !😂
One thing I miss from the video are High Altitude Pseudo Satellites - stuff like Airbus'es Zephyr.
UAVs got mentioned, but HAPS are sufficiently unique to make a segment in this sort of content.
what's unique about them?
If you have a teather reaching into the atmosphere by using a tube for the teather you can pump air to the top to use as propellant in a ion rocket to maintain altitude.
Good point, though I'm thinking a car of air tanks is going to work better than a pipeline here.
@@isaacarthurSFIA
15psi supports a column if air up to space. It really doesn't take much pressure.
I thought you said teacher at first.
@@dibbidydoo4318 I saw that too
If the tube reaches past geostationary orbit you can siphon as well
I really like the idea of structures like these holding up a thin film , reflecting all the direct sunlight away from major cities.
To give context, I'm from India where we just experienced an insanely hot summer. We don't have much of a spring. April, May and June are our summer months.
If we could shade our cities, even for a limited time around the peak of sun, we should be able to have cooler cities and a double benefit regarding global warming. The double benefit would be the direct reflection away of some sunlight and the decreased drawdown of power due to lower air conditioning costs.
There could be social and economic benefits too, with the time of the peak sun becoming useful in urban areas as opposed to just being used for naps and siestas. During times other than summer, the films could be tilted to allow the light through and of course, communication, surveillance and advertising services would continue. The big question in an Indian context would be how these structures react to the power of the monsoon winds. But i do believe that it is worth an experiment.
time for my weekly drink and snack with issac Arthur. been looking forward to this. love the work man.
Great episode. It reminds me of skydiving; there's a moment at the end where you're still held aloft by 'nothing,' even though the ground is so close you can practically reach out and touch it. That is, the thought of major structures just hanging from the sky is kinda surreal / cool.
To me this is one of the most impressive youtube channels around. The way you create insightful, funny and well researched scientific and philosophical content on such a regular basis is way beyond me
Happy to see JP Aerospace get mentioned. I first heard about them a little over 10 years ago, and have been keeping up with their progress ever since. Would love to see a Dark Sky Station built in real life.
i know you probably won't see this Mr Arthur. but when i need a good dose of science mixed with science fiction or future science i think is more accurate i come here. but you are the master of your craft much appreciated friend
Thanks for your supporting ! You explain very clearly what I need to show > Many thanks.
If we ever manage to solve this problem, hopefully instead of naming the "Cloud City" - Stratos, like in Star Trek. ;P
They name the city after Isaac Arthur.
I tihnk they'd find 'cloud city' sold more condos though :)
Hm naaaah cloud city fits better. Maybe name a district of the city after Isaac Arthur tho :D
Loved the episode as always, but especially interesting were these out of the box ideas about the degree to which planets are suitable for solar powered objects.
Ahh yes an isaac Arthur video .
I should probably not study for my test tomorrow to watch this video
I'd probably suggest studying though :)
@@isaacarthurSFIA I was able to do both now let's see how much marks do I get
Edit : I got a 10/10
I've had a striking mental image of a post apocalyptic sci fi setting with orbital structures visible from the surface. In my mind it's always been a cool visual that probably wouldn't be practical, as it'd need to be huge objects to be visible from the surface. The idea that these structures could actually be in super low orbits is awesome.
Thank you Isaac! Good thinking!
Want thousands of satellites that don't need to be in orbit and cost very little to opperate? We just need the equivalent to a starlink satellite that are installed on all commercial aircraft and on all cargo ships. The military already does this with its vehicles to expand the coverage of their networks.
You had me at genealogies, I’ve been playing since ‘76 ish, and keeping that stuff straight has always been my nemesis. Great show by the way.
TBS
I knew half of the material on my Nanotechnology final just from watching your videos, haha happy Arthursday!
Always worth watching Isaac content on RUclips, When you find it anyhow.
Only one of the orbits at 4:18 is physically plausible (the one that doesn't have two perigees).
Yeah, I saw that too
I’m going to start saying I intersected with a surface instead of I stumbled or tripped
The army had something like this a few years back. There was an airborne radar station that used to float above the Virginia-DC-Maryland area. I think it was called JLENS. Unfortunately the floating radar idea had some severe issues. Most notably the blimp would break loose from its tether. This happened several times when the radar was deployed overseas. It also happened once while floating over DC. The tether wound up being dragged across three states knocking out power lines in the process.
The UK used balloons to annoy the Germans in WW2. They towed steel cables which brought down power lines and started a fire in a sub station.
Omg, i haven't watched any of your videos in a while, your speaking has improved dramatically.
The stratotram or DSS options sound feasible now with refueling and refilling via drones but you would need to filter out humidity on a regular basis. The Goodyear blimp has to do this. Maybe with mylar film or carbon films this is not required. What you would need is radiation shielding and protection from high speed particles that would degrade the device over time.
I remember an April Fools skit on the radio back in the 70s about a satellite launch failing to reach altitude, and that people should watch out for it now whizzing around the planet 6 feet above the surface. I also recall some... lesser enlightened people took that warning seriously.
In practice though I do love playing KSP and putting things in silly orbits. If it doesn't have an atmosphere, the only thing stopping me is terrain variation.
remind me of the sf book "Spin" by Robert C Wilson, in which humanity is forced to rely on stratospherics satellites since spaces satellites don't work anymore ('coz aliens shenanigans)
Very cool.
Sir Isaac is my hero.
Keep in mind COVID is not drawing to a close, the US has gone from 20k cases per day in early April to 100k cases per day in late May...
Watching this while playing Hardspace: Shipbreaker is pretty darn immersive!
Got a kick from the "Raptor" Thanks Isaac!
A tethered high altitude balloon sounds like a fun idea to do all sorts of interesting things. Communications, high altitude launches, and power generation all in one! Heck, you could probably have a string of systems running down the tether at different altitudes if needed.
i find this ultra low orbit infrastructure stuff interesting it would be nice to see more talk of various orbital infrastructure
Deployed since 1980, the US uses the Tethered Aerostat Radar System, which are helium balloons that have a look-down radar set to detect low flying aircraft, especially in rugged terrain such as the US-Mexico border.
Excellent stuff bro
Isaac Arthur the only futurist that presents things that could actually be plossibl in the future
The leakiness of hydrogen and helium is why I prefer methane or ammonia as lifting gas despite providing less lift per volume.
Everything leaks - it is a matter of degree. So there is always a trade-off between weight of lifting gas and weight of the tanks needed to compensate for leaks.
I read somewhere that some dirigibles used something like methane for both lifting gas and fuel. It saved them the trouble of condensing and holding the steam from the exhaust to maintain weight and thus stabilize altitude.
Math and megastructures - the reason I fiend for Arthursdays. Thanks again dude for all the great work you do
Anything tethered to the ground is highly vulnerable when extreme weather hits. Power lines are frequently brought down by the weight of ice accumulating.
I love your "hard science" vids ... learning so much! Answers to all the questions I place bets on... look up on Google, and LOSE... lol!
We do have balloon cell towers, or had. Lookup project loon, it was in service over Puerto Rico for a while. They found that they can keep a balloon stationary enough just by varying the height and taking advantage of different wind directions.
It amazed me as it disappointed me. Looking up while in the Northern Wisconsin National forests. My watch running Glonass and Galileo independent from cellular. Watching the train of Starlink stuns me each time. I apologize for punctuation. Semper Fi, it's been a wonderful 6 years. Thank you so much
Your videos are such a great escape from this world...in more ways than one haha
An orbit is the same as what's described in the Hitchhiker's Guide to the Galaxy, "throwing yourself at the ground, and missing".
this is the first time I've ever heard why helium always leaks. I'd always idly wondered why you can't just seal it in an airtight tank. Makes so much sense in hindsight. Atoms literally smaller than the gaps in the material you'd be sealing it in.
Could you do (if you didn't already) an episode about vacuum balloons ?
Could we put a propellor on the poles?
Before you click me away, let's get serious. What if we take a double wing structure and spin it up on the south pole. Both wings are at 180 degrees to one another, and turn around a very big structure on the south pole. The structures are aerodynamic wings and they are set with propellors. The wings rotate and are gradually expended. Power is supplied by a reactor and all the time the wings maintain a direct connection to the spoke structure. You can easily attach three or four or more wingtethers. Centrifugal pull will pull the wings taught so they angle from the polar structure and the longer the wings are extended the more the pull will yank them higher into the arctic atmosphere. As you slide wing extensions down the wing tether the structures that rotate in the higher atmosphere will "dynamically deploy" different types of ways of pushing it through the stratospheric atmosphere, and by making the wing partially filled with helium would also serve to create bouyancy. At some point you start deploy cable where they no longer is much in the way of air friction. I really think this could work quite well to deploy a launch system that can dump large amounts of asteroids in orbit quite cheaply.
I call this a Khannea Skyhook.
I might need a diagram to make sure I'm picturing what you have in mind Khannea but I think that should work, though I think that static polar stations is really mostly helpful for above small and fast rotating objects and most of those you could just build a tower, especially with the lack of air.
"Did we crash? "
"No, we just intersected with the surface."
Thanks man for all you do👍🏿
😁😁😁😁😁😆😆😆😆😆😆
Yooooo a StratoTram sounds gr8 ta me🤙🏿
You really ought to make a video about photon powered space travel, like using a vast network of lasers on a planet to heat propellant to extreme temperatures and those then expand out of rocket nozzles on ships.
There is a Beam-Powered Spaceships ep
7:40 Objection! It is common knowledge that helicopters stay in the air because they are so ugly, the earth repels them :P
thank you for a way to teach orbital dynamics without triggering someone's scientific ignorance defense!
You might look at Vacuum Airships as opposed to Hydrogen or Helium Airships.
While vacuum airship are more buoyant the structure required to prevent implosion and the energy needed to maintain the vacuum would probably negate all benefits if not make it harder.
I agree. But it is a futurism channel so it might be worth a mention even if it is a partial vacuum. There are a few people, Andrey Akhmeteli, and Andy Gavrilin to name a couple who have pursued the idea.
Notification gang!!
Right?!
Nice.
I suppose lightning strikes could be an issue with a graphene tether.
I wonder if someday people will look back at isach Arthur's stuff and stuff like it and call it "space punk" or something like that
Imagine the roller coasters you could build.
So, as a gamer from the Buckeye State, have you attended the Origins fame fair in Columbus? they are the ONLY game convention that gives a decent discounts for AD, Guard/Reserve and military veterans...
8:30 How about a recharge ship flies in at the centre of several vehicles and charges them wirelessly and once done, flies up to the solar recharging stations to get ready for the next round
Douglas Adams once said. If you want to fly you have to jump and miss the ground accidentally. And he was not completly wrong with that. :)
What would remain if we suddenly disappeared? Sounds like an episode of "Life After People".
I was wondering if you ever watch the cartoon G I Joe resolute this is how cobra tried to take over lol love it thank you for your work
Would it be possible to create a rigid balloon like structure in orbit with "nothing" inside and then lower it into the upper atmosphere to act as a balloon without imploding. I say this because a rigid balloon like structure with very little gas or an almost complete vacuum inside is lighter than a helium or hydrogen filled balloon. Since it is created in orbit, the structure would not have to hold up to anything close to 1 bar of pressure, but maybe only 5 to 15 millibars of outside pressure and still be buoyant in the upper atmosphere.
I'm under the impression that (ultra, extreme) high vacumn conditions - while obviously less massive on its own - require enough additional structure to remain rigid that the average difference in density would be negligible. You'd need negative mass to make the numbers work.
Also gassing is still an issue. Pumps, more mass.
If you want a system that can hang 2,000 lbs of telcom gear 60,000 feet over a city check out Burt Rutan's Proteus. Basically a jet powed autonomous glider.
could you do a video on colonizing ocean planets. by ocean planets i mean ones that are entirely covered in water with no land
I heard that hydrogen is less prone prone to leaking then helium because hydrogen is in molecules of two atoms while helium is in lone atoms
Arguably the best way to get stratelites is to use buoyancy. Weather balloons would do best.
What about vacuum balloons? They can be refilled at a higher elevation. Provide more lift than hydrogen or helium. And you aren't losing out on power by filling your balloon with gas.
You forgot nothing... as in vacuum balloons. It's becoming a possibility.
however with satellite orbiting the continent it's got a major problem, the limitations of signalling, yes we do have a solution now, especially with 5G's VoIP and especially the voice over WiFi, that tends to be the part that really helps increase the capacity however there is still a range of frequencies available.
Voice over Wifi has saved carriers millions alone in operational costs because they don't need to increase capacity so much but having one or 5 satellites doing our comms would be disastrous.
I have seen an amateur self published SciFi story about such a transport system (a mass driver that starts from the earths surface but terminates in the upper atmosphere - supported by constellations of very large balloons - but unfortunately, I cannot remember the name of the author or where I read it - it was a compelling read, though)
Instead of a balloon filled with helium or hydrogen why not a dirigible containing vacuum, after all nothing weighs less than anything.
Although your logic is sound, the structure needed to maintain that vacuum outweigh the benefits gained. You would just want to use hydrogen, but it is flammable, so you might want to use helium.
One problem with maintaining such long term is the material needs to overcome the pressure pushing inwards even if you can compensate for that however you still have to account for quantum tunneling the same mechanism hydrogen and helium can leak through in fact it is also the cause of alpha decay as helium subnuclei can tunnel outside the nucleus scaping from the range of the strong nuclear force which binds atoms together. This means that even a strong rigid dirigible ultralight weight to maintain buoyancy with a vacuum has a time limit
The problem is the huge pressure difference. And it gets worse as you scale up, because the walls have to resist force, not pressure, and force increases with the area. And on top of that, the wall's ability to resist forces decreases with it's size. So the required wall thickness goes up with like the cube of the smallest diameter of the vehicle. Which means the weight of the walls go up with the fifth power. That makes this practically impossible, unless I made some big mistake somewhere.
The advantage of positive internal pressure is that you can rely on tension, instead of compression, which is way way much stronger. Think about what you need to hang a one ton weight, compared to supporting it from below.
Maybe it could work with active support. A big sphere, inside weights going around on magnetic tracks at very high speeds. The tricky part is that the tracks have to intersect. You want to go as big as you can, due to the square-cube law. The lift it generates grows faster then the weight. But you also need more tracks with more intersections. Maybe with good timing collisions can be avoided, I can't do that math in my head. Or maybe you can offset the tracks a bit and let them go under and over each other. Could work with flat but wide tracks.
Or use a torus. That makes the intersection design so much easier, in exchange for higher surface area, and therefore weight. Added bonus is that it looks so much more cool than a stupid sphere. And more practical too. You would have to use multiple spheres to get a practical shape, so maybe it turns out to be more optimal anyway. And the hole in the middle would be a perfect place for the cargo bay.
A big plus is that you only need air and vacuum, and both are abundant and free, anywhere you want to be.
Would an ion gas balloon work? Basically fill the balloon with ions that repel each other and charge the inner skin of the balloon to contain them.
You would need to constantly create charge separation on that balloon as the charge will cancel out with the atmosphere. That would complicate things, add weight, etc. Seems like a vacuum ship with extra steps
Yeah because floating stuff this low in the atmosphere never could go horribly horribly wrong...
At least you aren't looking at a colony drop level disaster...
I wonder what path and altitude the lowest possible Earth orbit would be, just high enough to skip over any mountains and ignoring air resistence.
Speaking of shipping air, I am pretty sure that if there was bulk interplanetary trade in food one would have to have freighters of CO2 going the other way. Based of how much CO2 is consumed by the amount of plant matter a human consumes in a year, taking Coroscant with its cannon population of 3 trillion and 10 agricultural supply worlds as an example, assuming humans eat an average amount among all species and that those planets started like modern earth, the loss of carbon from shipping all that food to Coroscant without replacement would drive all those worlds Into an ice age in around a century. With a more realistic population of 49 quadrillion, it would take only five years. Obviously these are rough calculations, but I think I am on to something.
Hahaha an ice age, you consume too much global warming propaganda
I come the comments for ones like this. I hadnt considered the carbon problem with agriculture worlds feeding a world city. Thanks!
Probably not just carbon. Remember the phosphorus scarcity in the universe. ruclips.net/video/oPU9jeQbTOU/видео.html
I'm reminded of The Hitchhiker's Guide to the Galaxy: "For years, the fabulously beautiful planet of Bethselamin increased its booming tourist industry without any worries at all. Alas, as is often the case, this was an act of utter stupidity, as it led to a colossal cumulative erosion problem. Of course, what else could one expect with ten billion tourists per annum? Thus today the net balance between the amount you eat and the amount you excrete while on the planet is surgically removed from your body weight when you leave; so every time you go to the lavatory there, it is vitally important to get a receipt..."
I still don't under specific impulse. Specific impulse is a characteristic of a fuel. But how long a ship can hover depends on much fuel you have...
i would like to see carman line competitions sponsored by redbull
You know Isaac, Mark Meer, the voice of the male Commander Shepard in Mass Effect is an avid D+Der, and part of a group called "The Black Dice Society" he's on twitter and announces his D+D events there. Ya know, just saying.
4:21 if this image is meant to illustrate various orbits with same perigee but different apogee, then it's completely wrong. I mean, you can _see_ it's wrong because perigee is supposed to be the lowest point of the orbit but here the orbit intersects the earth at two different points. If the perigee of different orbits is equal then the orbits with lower apogee will be contained in its entirety _inside_ the lower perigee orbits, they will not intersect, because the planet will always remain at the focus of the ellipse.
drink and a snack, acquired
Can you make a video on space relay gates/accelerators. Kinda like the love/death/robots episode or the stellaris hyper relays!
Maybe, I tihnk our wormholes episode covered that but it could use an extended look
How does one start building an orbital-loop? I understand how they would work when built but it's the jump to fully built I can't imagine beyond a huge number of active support towers and building the orbital loop across the top like a bridge until it's switched on and then removing the towers or most of them.
The Bolt doesn't use ultium platform. Osborne effect.
"So, the balloon is covered in graphene solar cells, which power its propellers and crack hydrogen from water vapor in the atmosphere to replenish the hydrogen in the gas bag, which holds its hydrogen in by being surrounded by graphene solar cells."
Orbital rings?!?! In this economy???
If we shifted our focus towards actually helping humanity instead of the woke mind virus that is trying to destroy it, I think we could do very well.
@@semidhimmi3184 couldn’t agree more
Hydrogen, Helium, what ever happened to good 'ol vacuum?
have you guys talked about cloud nine tensegrity spheres before?
if only we would have similar motivations as guys on Pradise -island in Attack on Titan...we would be there already. But "titans" are not attacking from space...yet