6:33 WRONG! The counterweight will only raise to a higher orbit. It will still be locked to Earth's gravity as a rotation per day at that altitude is not fast enough to escape earth's gravity; it will stay in geostationary orbit, just higher. We could just grab it again without much trouble.
I don't know about balloons, but there have been some companies that have used jet aircraft (typically old strategic bombers like the B-52 or airliners with special modifications) to lift rockets to about 40 000 feet before launching them. Upsides: "Re-usable 1st stage" i.e. the jet platform > lower costs Caveats: 1000lb payload capacity Examples: Orbital Sciences, which has the Pegasus platform
Weave the Kevlar strands into long cables. Then weave the cables together. Use the moon as a counter weight. Construct tracks on both the moon and earth so as the moon rotates it doesn't snap the cables. Also construct carbon nanotube sheilding to stop the space debris.
Something I've always wondered why they've never tried: using electromagnetic mass drivers to assist the rockets during the initial phase of their acceleration so that less of their payload has to be fuel. If I remember right, these large railguns can't achieve escape velocity on their own, but we could significantly reduce the required fuel. Also, if you miniaturized it enough, you could install it in a 747 and launch stuff from 10,000 ft to cut that distance out as well; useful for small stuff
2:11 if you didn't know, those building blocks are called "KEVA Planks". they're lightweight but very strong and well-balanced. you can't build into orbit with them, but if you're careful, you can actually build them to massive heights.
Something like that IS actually possible at this point in time; and with only one power station at that. The concept was actually fairly well flushed out in a game called "Ace Combat 5" and people are still debating it. The theory, as I understand it, would use large capacitors to store electricity over time. Once a sufficient amount of energy was stored, it was channeled into an electromagnetic mass driver, like a rail gun, to propel a single stage craft into orbit.
Haven't been "Squozen" since it became Brit Lab. Used to tune in because of vids like this from Capt. Slow. Space Lift is a fun "May" look at things. His humor still resonates.
It baffles me that most people seem to ignore the fact that geostationary orbits happen at approx. 3Km/second speed. Climbing (or descending) such a structure (even if it could be built) is no "trivial task". You still have to gain that orbital speed and it ain't free. Newton's laws still apply (ie: F=ma). So supposing such an elevator were built and the climb began, where would that force come from ? If viewed from the rotating earth/elevator's frame of reference, the climbing elevator would experience a HUGE Coriolis force "pulling" in the direction opposite the rotation, and this force would have to be "countered". Of course Coriolis is an "apparent force", and can be explained by plain inertia if the system is observed from an "outside" inetrtial frame of reference. But either way, the elevator still has to reach orbital speed, which is why "ordinary" rockets need so much fuel to begin with. It's not so much about the "hight".
Im not fully confident i understood the concept but i think that at the point you reach geostationary altitude you are moving with orbital velocity (3km/s) in reference to the earth. In other words, if the earth had a 35k radius, its surfacevelocity would be 3km/s. Correct me if im wrong
You're more than welcome. I also think the method proposed in Big Ideas was decent. That solar powered lift would be great if we can develop a newer carbon-based strength material similar to carbon fiber to act as the chain. - Loyal Top Gear, Man Lab, Big Ideas, and Head Squeeze fan. And Redditor.
Building a space elevator is what the Tower of Babel was meant to accomplish. We could greatly increase the efficiency of launching things into orbit by building a very large gun, I don't know if a magnetic rail gun a few miles long could ever safely put humans into orbit. But we could launch all the necessary equipment for constructing an elevator for fractions of the cost of traditional rocket powered vehicles.
I suppose that in the event that the cable was somehow snapped, we could design a complex rocket powered (yes, rockets) system to automatically put the counterweight into orbit with the earth, thereby avoiding it's fond farewell into the cosmos and giving us a chance to budge it back into place and repair the cable. :)
6:34 if the cable snapped, the counterweight wouldn't be in a hurry to "fly off" into eternity. It's in geo-stationary orbit, it would (more or less) sit there waiting to be re-attached to a new cable.
There is a solution which solves vitually all of these problems. It is called an orbital ring. Basically it's a ring constructed just a few hundred kilometers up (so out of the way of 99.9% of meteorites and junk), wouldn't need a super strong cable, and, by my calculations, could be contructed in such a way that it lifts itself into space. It would be nothing more complecated than a lightweight pipeline with magnetic particles inside and two meglev engines on either end with cables attached.
I once had a looong discussion with a very experienced NASA engineer on the prospect of building space elevators. He saw no future in the concept at all because of the difficulties in engineering such a device.
The earth is a rotating mass, and as such, the tower rotates with it. The farther away from the centre of rotation, the faster the rotation is. At that height, the speed that the tower rotates at the top is equal to an object's orbital speed at that altitude, so that's why stepping off the tower would be suffice to enter orbit.
He would be at geostationary orbit HEIGHT, but to be "in orbit" (in any orbit, not only the geostationary one) he would also need some speed perpendicular to the geodetic. Otherwise, like already said, he would fall down. In the video it is clearly specified that to 'escape' gravity w/o entering a stable orbit you would need to go much higher (6:55)
Rockets are actually very efficient. The reason they need so much fuel to get into orbit is that the rocket needs to go really fast. It's called the rocket equation. You need to put in so much energy to accelerate to orbital speeds. Even if you have a space elevator you are still using energy just to lift yourself into space. As one wise man said about life "there is not such thing as a free lunch". You get nothing for free.
Can you really call anything efficient if there’s literally nothing to compare it to? I’m not disagreeing I’m just saying that we really don’t know just how efficient it is to blast rockets into space compared to other methods because no other methods exist yet You might be confusing efficiency with practicality. For example, it has ALWAYS been more efficient to own an electric vehicle, ever since the early 1900’s. But despite technically being more efficient, they weren’t practical at all and were burdensome due to low mileage and long charging times. With rockets I don’t think they would be considered “efficient” because they’re just simply not, from a weight standpoint alone. Burning off that much weight in fuel isn’t efficient, even if we can manage it. However they ARE convenient, because we don’t have any other methods of going into space and any that we do have are impractical which makes rocketry the superior option at this point in time (Funny how making literal tons of rocket fuel is the most practical way we have at the moment of getting shit into orbit) Using rockets could turn out to be one of the least efficient ways for all we know. Or it could be the very best, I don’t think we can really say either or yet
If you make the inside of the space elevator shaft a near vaccum, then the elevator itself doesn't have to fight against air resistance like a rocket would have to, which would make it use less energy. And more importantly, a space elevator could use electricity instead of fuel for it's energy, which is cheaper and renewable.
You don't have to launch all 5000 tons of the counterweight via rocket. You can launch a skinnier ribbon with a smaller counterweight via rockets (say, two launches of the Falcon Heavy), then have climbers add to the ribbon and counterweight in a bootstrapping process. The quest for the necessary material is quite a challenge. It's driven me into a career in materials engineering so I can help in the creation of such a material and therefore make the space elevator a reality.
simple physics. go iceskating and start spinning, like the earth, then extend one arm, like the space rope and the weight, and you will slow down. if we model the rope as an ideal rope we will have two bodies orbiting each other and, ignoring every other body in the universe, using the equation of universal gravitation we can find the the speed of earth+weight will be a bit smaller than the speed of only the earth, and the rotation axis will be shifted a bit towards the weight
You're right there is no centrifugal force (or a normal force in this situation). If you construct the freebody (a force) diagram in this case you just have two forces - the centripetal force provided by the cable tension and the weight of the elevator. Both these forces are directed towards the centre of rotation. I jump on my students for labelling a centrifugal force on a freebody diagram
By climbing the cable you are actually doing that already. Think of it like holding a rope with a rock and the end and spinning, and a spider walking along the rope as its spinning toward the rock. GEO, or gestational orbit, is important because it is the distance away the the orbital velocity is exactly the same as the spinning of the earth. (which is why people put satellites there because they can constantly be above the same spot on earth). So there is no work to be done once you get there,
Imagine when we've figured it out. We have our Graphene cables that can be magnetized for power (or the solar lift version). Then we take this technology to another planet and eventually have these systems running from local planets to each other. Like a Solar system train route. Amazing thought.
That... wouldn't exactly... work... at all. Tying a rope to two planets is impossible because all the planets have their own orbital periods which are different from earth's, and in addition, different rotational periods. Even if their rotational periods were the same... it still wouldn't work because both objects being tethered would rip the rope/structure apart once either object turns around. Also there would be the theoretical time it would take to get there. A space elevator or whatever, doesn't make the trip any faster, it just makes it easier to get into space more cost effectively. You'd be on that space train for years getting to another planet, or months to the moon. Not to mention all the debris that would bombard it all to hell. HOWEVER! It would be pretty sick if there was a train to Mars or something, but it would only work if all the planets didn't rotate, and if they all orbited the sun at exactly the same pace (wrong choice of word, they all need to be in a straight line, so their speeds would have to be at a pace that each planet orbits the sun in the same number of days), and if the elevator went straight through the core of each planet as a short cut of going around them :P
@@johnmichaelchase8530 Four years late I know, but it would kind of work. If you can get to escape velocity on an elevator it would then take relatively little energy in a conventional rocket to go from the top of one elevator to another, even if that second elevator is another planet, since in open space you need energy only to accelerate and decelerate. So your "affordable" interplanetary public transport network is just elevator up, rocket between planets, elevator down. Simple!
@@georgebateman3876 well sure, that all makes sense, but the original comment must've seemed to me back then to imply making a space elevator ALL the way to a different planetary body. For obvious reasons, that just wouldn't work lol
If you didn't know, those building blocks are called "JENGA Blocks". they're lightweight but not well-balanced. you can't build into orbit with them because they are simply blocks of wood used to play a game for amusement.
Well there's a bit of a compromise solution. An Earth based mass driver, built into a mountain could launch a payload at fairly high speed and altitude. But it wouldn't get into space on its own, it would still need a rocket. But on the plus side, the construction would be cheaper than a space elevator (still enormous, on the scale of the LHC), cost less than rockets, use existing tech, and it would need significantly less fuel than a conventional rocket launch.
The same side of the moon is always facing us, anchor the space elevator to the moon. I heard something about the number of plastic bottles that we use and so I'm sure we can make enough material to get to the moon and leave it. And we only need to have it reach down far enough to where those giant Red Bull balloons can reach. Remember Red Bull Stratos and the dude jumping from the edge of space? Have a balloon powered vehicle reach up and 'dock' with the space cable.
The main challenge in building tall buildings is not how much weight the base has to support but rather the shear modulus of the building. For any cylindrical or cone shaped building, whether the building will topple over can be determined by whether (density * height^3)/(shear modulus * diameter^2) exceeds a certain amount. That amount is larger for cone shaped buildings than cylindrical buildings.
Small maneuver rockets could be attached to the projectile to stabilize its orbit, but they would be much lighter than what is needed to punch from the ground through the atmosphere, and a supercomputer could compute the necessary muzzle velocity so that the payload is only a little bit off from the trajectory it needs.
how about this; a cylindrical tower with cables fastened at the base running up the interior in cyclone pattern fastened to the interior walls to maintain the pattern but allowing the cable to converge until at geo stationary orbit, where the cables will meet some sort of space buoy the entire structure will act as an anchor and the weight on the base would be countered by the cable's upward pull.
if the rope ever snaps, then the space counter gets flinged across like a discus being thrown. Throwing a high speed projective over space that probably wont stop until it hit something is always fun. It may even smash into some alien ships that are really really far away, and start a intergalactic war.
Uh no the rope would fall back to earth. The counter weight would be in geostationary orbit and won't be affected. When in geostationary orbit you are orbiting earth every 24hours, from the ground it would look like the satellite is stationary. The satellite would of course be in zero g while falling even while attached to a huge space elevator.
Centrifugal force is an apparent force that causes an object to leave its centre of rotation. This is caused by inertia. In other words, centrifugal force is inertia, and in that sense, centrifugal force does exist (as inertia).
You forgot to mention Sir Arthur C. Clarke, who in 1979 wrote a Sci-Fi novel about a space elevator rising from Sri Lanka to a satellite in geosync orbit.
No, in the case of the video, the centripetal force would be the earth's gravity curving the path of the object and thus keeping the object in orbit. Centrifugal force does not exist as a force on its own, but is presented in this case as inertia, which would cause the object to fly out of orbit into space.
you could keep going straight up, but you would never reach orbit. only two outcomes are really possible if you launch straight up. either 1, you shut off the engines before reaching escape velocity, and your rocket goes up, then stops, then falls right back down. or 2, you keep firing until you reach escape velocity, at which point our trajectory would never bring us back to earth, and you fly of into space. all this is also true if you launch in the other direction as well.
It makes it sound like one of those platform games. You have to go to the further away bit, before you can even think about jumping on the nearer stuff.
How will the elevator rotate earth? In order to secure it well enough, the support has to be very strong, and that would mean it'll have to be stationary. We can't really put a strong enough guiderail around earth either, because of tectonic plates, oceans and seasons. That means that there will be a pull on one side of the earth all the time using the earth's rotation. I can only assume that'll slow it down to a standstill, and that will be bad for us all.
It should have been mentioned in this video! His detailed depiction of the space elevator is pretty much blueprint how it would be build. A must read for people who are interested!
I have a question if its possible to answer. Rockets and other space equipment always go left or right after they leave Earth but if we launched a rocket into space and it had the fuel to keep going indefinitely so that the earth was always directly below the rocket (it went up in a straight line and didn't curve at all), how far straight up could it theoretically go? Same for the opposite, if we launched it into space and turned it straight down so it went below earth and kept going downwards.
The majority of cost in a rocket launch is the hardware that you throw away when you drop a stage, the fuel for a average orbital launch is the same amount that you would have in a transatlantic flight in a 747. if we had only fuel costs it could be a mere 25 dollars per kilogram to low earth orbit.
I remember seeing a concept design for electromagnetic slingshots to launch things into orbit. The g-forces meant it wouldn't work (yet) for humans, but for cargo it seemed feasible to my lamemind.
I had the same basic idea several years ago as way to deal garbage. A giant mass if is sent up the tube, collected and when enough is collected, the mass is launched towards the sun and it burns up before it gets there. Problem is, New Jersey would run out of usefulness.
Obviously, the ship itself would need to take some of the load about 2/3rds up the tower... and by then, the force of the launching system would be immense. The power of the rockets, with the power of the steam catapult from an aircraft carrier (multiple of them if possible), and the magnetic launch system, much like that currently found in a Mag-Lev train.
Well yes, we know that Gravity doesn't really exist. I mean, it is not a "force" like the nuclear force(s) or electromagnetism, it's a phenomenon related to the shape of the spacetime and its interaction w/ massive particles. So the real question would be "why do some kind of particles bend the spacetime"?
The materials for a six stage progressive diameter rotorvator exists already. It's not quite as cheap as a space elevator, but it's in the same ballpark.
well even if you shot straight up, it would look as though it was curling. as you go farther up the great you would have to move sideways to stay right above. how far can they go, you would have to pose that to NASA or Spacex (i would assume once you hit escape velocity you could go on as far as you would like)
Now yes but like I said time and resources are the two main problems. To prevent an economic crash when it is finished the structure would be built over 400 years to a millennium. With the population rising the way it is a similar structures; even if it's city's in artificial caverns will be necessary if we don't start moving people to other planets and space stations. This way we get an orbital elevator and delay the time in which it is needed
You'd think someone would come up with a good solution to two issues at once. Figure out a way to collect all that space debris and use IT as the counter-weight.
An easier and much cheaper way of sending things to space would be using nuclear bombs . You only need to put such a bomb at the bottom of a very long vertical underground tunnel filled with water , place the stuff you want to send to space on top of the water , then detonate the bomb . The powerful explosion will create shockwaves that will travel through the water and push the objects on top with such strength that they will be able to escape Earth's gravity .
They said the "PROJECT" starts in 2020, they didn't predict it would happen 2020, by project meaning that they'll start designing, making parts, looking at it politically etc.
The correct answer is yes, but it is unlikely anyone born before 1990 will see it. I imagine something like a maglev would be the most feasible. The only hard part would be assembly, but once we see the rise of automated building systems it would be possible.
perhaps not by a significant margin. Again, we still need something sent up to collect the debris, and then we need to move it in place. Satellites have been proposed that will fish for debris, but their goal is to send debris into a deteriorating orbit, rather than a giant counterweight. Still, it doesn't seem like a bad approach...
No, he would actually enter orbit if the rope was going relative to the earth, at 1000 mph. which a space elevator would do. Having the rope anchored in space would make it so that the middle is spinning at earth's rotational velocity, and so stepping off would just make you be in orbit.
If someone was to lower a rope from orbitable space, and the rope being (optimistically) 20 cm in diameter, the amount of space volume needed for it to reach the earth and space would already be well over 1 million cubic meters. The weight of it depends on the material it is made of.
The biggest hurdle to space elevator construction is that we don't have a material strong and light enough to build something that's several hundred or thousand kilometres tall. Carbon nanotubes or some modified grafite material could work well. Though we've yet to make something more than a meter long with carbon nanotubes and similar materials.
The only force acting on the mass would be the centripetal force going down towards the center of the earth. If you're going past earth's gravitational field, correct me if I'm wrong, the centripetal force would simply be the tension force in the rope.
it would produce tension, yes. My issue with this concept though is that the Earth is rotating on its axis, as well as revolving around the Sun. It's not as easy as James puts it.
I don’t know why, but I laughed out loud at the idea of dropping a rope from space. That would either be a disaster if it fell into a populated area. Or the craziest amusement park ride if it worked.
Just wondering. If we had a counterweight at one end of the rope and tie the other end to the Earth. Would this have any effect on slowing down the Earth's rotation? I bet it'd be minuscule but still...
So. The highest mountains have 8 km. We can surely add the 2km tall building to form 10km high structure. Maybe in the next century, we can get at least to the ISS.
When was this discussion? For a long time the materials problem was seemingly insurmountable, as no material known to us had anywhere near the strength required. This has changed in recent years, with the advent of extremely strong artificial materials, such as the various new types of carbon.
Sorry elevators broken, take the stairs
ShadowVyrus
Damn you... Damn you all to hell
Imagine hearing that 3 days into your trip up the elevator...
NOOOOOOOOOOOOOOOOO 😢😢😢
Stair time: 10 weeks
ShadowVyrus. 😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂
Im just here because I miss Top Gear
Sander Salumets I'm here because I miss the grand tour
252Scooby we still dont even have a trailer for season 2 yet
I come from the future to tell you that season 2 is live and seasons 3 will begin shortly.
I’m here because I miss top gear, and have watch all the grand tour episodes till fridays next. Which you all need to watch if you don’t.
Fel Hammer
And sadly season 3 is almost done probably.
6:33 WRONG! The counterweight will only raise to a higher orbit. It will still be locked to Earth's gravity as a rotation per day at that altitude is not fast enough to escape earth's gravity; it will stay in geostationary orbit, just higher. We could just grab it again without much trouble.
I don't know about balloons, but there have been some companies that have used jet aircraft (typically old strategic bombers like the B-52 or airliners with special modifications) to lift rockets to about 40 000 feet before launching them.
Upsides: "Re-usable 1st stage" i.e. the jet platform > lower costs
Caveats: 1000lb payload capacity
Examples: Orbital Sciences, which has the Pegasus platform
Mmmm we're working on it!
Really!!
Weave the Kevlar strands into long cables. Then weave the cables together. Use the moon as a counter weight. Construct tracks on both the moon and earth so as the moon rotates it doesn't snap the cables. Also construct carbon nanotube sheilding to stop the space debris.
I'm getting flashbacks of the New Mombasa Space Elevator from Halo
I also have flashbacks to that day
Same here
Same i came here from halo
Something I've always wondered why they've never tried: using electromagnetic mass drivers to assist the rockets during the initial phase of their acceleration so that less of their payload has to be fuel. If I remember right, these large railguns can't achieve escape velocity on their own, but we could significantly reduce the required fuel. Also, if you miniaturized it enough, you could install it in a 747 and launch stuff from 10,000 ft to cut that distance out as well; useful for small stuff
2:11 if you didn't know, those building blocks are called "KEVA Planks". they're lightweight but very strong and well-balanced. you can't build into orbit with them, but if you're careful, you can actually build them to massive heights.
Something like that IS actually possible at this point in time; and with only one power station at that. The concept was actually fairly well flushed out in a game called "Ace Combat 5" and people are still debating it. The theory, as I understand it, would use large capacitors to store electricity over time. Once a sufficient amount of energy was stored, it was channeled into an electromagnetic mass driver, like a rail gun, to propel a single stage craft into orbit.
Haven't been "Squozen" since it became Brit Lab. Used to tune in because of vids like this from Capt. Slow. Space Lift is a fun "May" look at things. His humor still resonates.
make a nightclub in orbit with a space elevator. partying in zero gravity hell yeah.
Funny enough as I watch this video I am reading (yet again) Arthur C Clarke's "Fountains of Paradise" which is about this very concept.
thank you for support
It baffles me that most people seem to ignore the fact that geostationary orbits happen at approx. 3Km/second speed. Climbing (or descending) such a structure (even if it could be built) is no "trivial task". You still have to gain that orbital speed and it ain't free. Newton's laws still apply (ie: F=ma). So supposing such an elevator were built and the climb began, where would that force come from ? If viewed from the rotating earth/elevator's frame of reference, the climbing elevator would experience a HUGE Coriolis force "pulling" in the direction opposite the rotation, and this force would have to be "countered". Of course Coriolis is an "apparent force", and can be explained by plain inertia if the system is observed from an "outside" inetrtial frame of reference. But either way, the elevator still has to reach orbital speed, which is why "ordinary" rockets need so much fuel to begin with. It's not so much about the "hight".
Im not fully confident i understood the concept but i think that at the point you reach geostationary altitude you are moving with orbital velocity (3km/s) in reference to the earth. In other words, if the earth had a 35k radius, its surfacevelocity would be 3km/s. Correct me if im wrong
James shirt looks absolutely mesmerizing when you press the POW! button!
You're more than welcome. I also think the method proposed in Big Ideas was decent. That solar powered lift would be great if we can develop a newer carbon-based strength material similar to carbon fiber to act as the chain.
- Loyal Top Gear, Man Lab, Big Ideas, and Head Squeeze fan. And Redditor.
Building a space elevator is what the Tower of Babel was meant to accomplish. We could greatly increase the efficiency of launching things into orbit by building a very large gun, I don't know if a magnetic rail gun a few miles long could ever safely put humans into orbit. But we could launch all the necessary equipment for constructing an elevator for fractions of the cost of traditional rocket powered vehicles.
I suppose that in the event that the cable was somehow snapped, we could design a complex rocket powered (yes, rockets) system to automatically put the counterweight into orbit with the earth, thereby avoiding it's fond farewell into the cosmos and giving us a chance to budge it back into place and repair the cable. :)
When in the UK did we start using Dollars James?
+WhitwellMike B Soon, baby!
lol
+WhitwellMike B The US dollar is the standard international measurement for 'money'
WhitwellMike B they will after Brexit LOL
Why Saber?
James is definitely my favorite Top Gear host. Probably my favorite television host in general.
6:34 if the cable snapped, the counterweight wouldn't be in a hurry to "fly off" into eternity. It's in geo-stationary orbit, it would (more or less) sit there waiting to be re-attached to a new cable.
There is a solution which solves vitually all of these problems. It is called an orbital ring. Basically it's a ring constructed just a few hundred kilometers up (so out of the way of 99.9% of meteorites and junk), wouldn't need a super strong cable, and, by my calculations, could be contructed in such a way that it lifts itself into space. It would be nothing more complecated than a lightweight pipeline with magnetic particles inside and two meglev engines on either end with cables attached.
I once had a looong discussion with a very experienced NASA engineer on the prospect of building space elevators. He saw no future in the concept at all because of the difficulties in engineering such a device.
One of the most interesting channels on youtube!
The earth is a rotating mass, and as such, the tower rotates with it. The farther away from the centre of rotation, the faster the rotation is. At that height, the speed that the tower rotates at the top is equal to an object's orbital speed at that altitude, so that's why stepping off the tower would be suffice to enter orbit.
He would be at geostationary orbit HEIGHT, but to be "in orbit" (in any orbit, not only the geostationary one) he would also need some speed perpendicular to the geodetic. Otherwise, like already said, he would fall down.
In the video it is clearly specified that to 'escape' gravity w/o entering a stable orbit you would need to go much higher (6:55)
Rockets are actually very efficient.
The reason they need so much fuel to get into orbit is that the rocket needs to go really fast.
It's called the rocket equation.
You need to put in so much energy to accelerate to orbital speeds.
Even if you have a space elevator you are still using energy just to lift yourself into space.
As one wise man said about life "there is not such thing as a free lunch".
You get nothing for free.
Can you really call anything efficient if there’s literally nothing to compare it to? I’m not disagreeing I’m just saying that we really don’t know just how efficient it is to blast rockets into space compared to other methods because no other methods exist yet
You might be confusing efficiency with practicality. For example, it has ALWAYS been more efficient to own an electric vehicle, ever since the early 1900’s. But despite technically being more efficient, they weren’t practical at all and were burdensome due to low mileage and long charging times.
With rockets I don’t think they would be considered “efficient” because they’re just simply not, from a weight standpoint alone. Burning off that much weight in fuel isn’t efficient, even if we can manage it.
However they ARE convenient, because we don’t have any other methods of going into space and any that we do have are impractical which makes rocketry the superior option at this point in time
(Funny how making literal tons of rocket fuel is the most practical way we have at the moment of getting shit into orbit)
Using rockets could turn out to be one of the least efficient ways for all we know. Or it could be the very best, I don’t think we can really say either or yet
If you make the inside of the space elevator shaft a near vaccum, then the elevator itself doesn't have to fight against air resistance like a rocket would have to, which would make it use less energy.
And more importantly, a space elevator could use electricity instead of fuel for it's energy, which is cheaper and renewable.
You don't have to launch all 5000 tons of the counterweight via rocket. You can launch a skinnier ribbon with a smaller counterweight via rockets (say, two launches of the Falcon Heavy), then have climbers add to the ribbon and counterweight in a bootstrapping process.
The quest for the necessary material is quite a challenge. It's driven me into a career in materials engineering so I can help in the creation of such a material and therefore make the space elevator a reality.
I love how he always finds a way to tell us to subscribe!
simple physics. go iceskating and start spinning, like the earth, then extend one arm, like the space rope and the weight, and you will slow down.
if we model the rope as an ideal rope we will have two bodies orbiting each other and, ignoring every other body in the universe, using the equation of universal gravitation we can find the the speed of earth+weight will be a bit smaller than the speed of only the earth, and the rotation axis will be shifted a bit towards the weight
Centrifugal means center-fleeing, or pointing away from. Centripetal is center-seeking; meaning the rope always points towards the center.
You're right there is no centrifugal force (or a normal force in this situation). If you construct the freebody (a force) diagram in this case you just have two forces - the centripetal force provided by the cable tension and the weight of the elevator. Both these forces are directed towards the centre of rotation. I jump on my students for labelling a centrifugal force on a freebody diagram
By climbing the cable you are actually doing that already. Think of it like holding a rope with a rock and the end and spinning, and a spider walking along the rope as its spinning toward the rock.
GEO, or gestational orbit, is important because it is the distance away the the orbital velocity is exactly the same as the spinning of the earth. (which is why people put satellites there because they can constantly be above the same spot on earth). So there is no work to be done once you get there,
Imagine when we've figured it out. We have our Graphene cables that can be magnetized for power (or the solar lift version). Then we take this technology to another planet and eventually have these systems running from local planets to each other. Like a Solar system train route. Amazing thought.
Imagine the delays on those bad boys.
That... wouldn't exactly... work... at all.
Tying a rope to two planets is impossible because all the planets have their own orbital periods which are different from earth's, and in addition, different rotational periods. Even if their rotational periods were the same... it still wouldn't work because both objects being tethered would rip the rope/structure apart once either object turns around.
Also there would be the theoretical time it would take to get there. A space elevator or whatever, doesn't make the trip any faster, it just makes it easier to get into space more cost effectively. You'd be on that space train for years getting to another planet, or months to the moon.
Not to mention all the debris that would bombard it all to hell.
HOWEVER! It would be pretty sick if there was a train to Mars or something, but it would only work if all the planets didn't rotate, and if they all orbited the sun at exactly the same pace (wrong choice of word, they all need to be in a straight line, so their speeds would have to be at a pace that each planet orbits the sun in the same number of days), and if the elevator went straight through the core of each planet as a short cut of going around them :P
@@johnmichaelchase8530 Four years late I know, but it would kind of work. If you can get to escape velocity on an elevator it would then take relatively little energy in a conventional rocket to go from the top of one elevator to another, even if that second elevator is another planet, since in open space you need energy only to accelerate and decelerate. So your "affordable" interplanetary public transport network is just elevator up, rocket between planets, elevator down. Simple!
@@georgebateman3876 well sure, that all makes sense, but the original comment must've seemed to me back then to imply making a space elevator ALL the way to a different planetary body. For obvious reasons, that just wouldn't work lol
If you didn't know, those building blocks are called "JENGA Blocks". they're lightweight but not well-balanced. you can't build into orbit with them because they are simply blocks of wood used to play a game for amusement.
Well there's a bit of a compromise solution. An Earth based mass driver, built into a mountain could launch a payload at fairly high speed and altitude. But it wouldn't get into space on its own, it would still need a rocket. But on the plus side, the construction would be cheaper than a space elevator (still enormous, on the scale of the LHC), cost less than rockets, use existing tech, and it would need significantly less fuel than a conventional rocket launch.
The same side of the moon is always facing us, anchor the space elevator to the moon. I heard something about the number of plastic bottles that we use and so I'm sure we can make enough material to get to the moon and leave it. And we only need to have it reach down far enough to where those giant Red Bull balloons can reach. Remember Red Bull Stratos and the dude jumping from the edge of space? Have a balloon powered vehicle reach up and 'dock' with the space cable.
Fantastic episode.
2024? End of GT, thanks James for over two decades of enjoyment.
The main challenge in building tall buildings is not how much weight the base has to support but rather the shear modulus of the building. For any cylindrical or cone shaped building, whether the building will topple over can be determined by whether (density * height^3)/(shear modulus * diameter^2) exceeds a certain amount. That amount is larger for cone shaped buildings than cylindrical buildings.
Love your videos. Sure wish they were captioned for us who have hearing loss.
Damn james may saluting redditors, im surprised he isn't with the keanu chungus wholesome 100 gang
Small maneuver rockets could be attached to the projectile to stabilize its orbit, but they would be much lighter than what is needed to punch from the ground through the atmosphere, and a supercomputer could compute the necessary muzzle velocity so that the payload is only a little bit off from the trajectory it needs.
how about this; a cylindrical tower with cables fastened at the base running up the interior in cyclone pattern fastened to the interior walls to maintain the pattern but allowing the cable to converge until at geo stationary orbit, where the cables will meet some sort of space buoy the entire structure will act as an anchor and the weight on the base would be countered by the cable's upward pull.
if the rope ever snaps, then the space counter gets flinged across like a discus being thrown. Throwing a high speed projective over space that probably wont stop until it hit something is always fun. It may even smash into some alien ships that are really really far away, and start a intergalactic war.
Uh no the rope would fall back to earth. The counter weight would be in geostationary orbit and won't be affected. When in geostationary orbit you are orbiting earth every 24hours, from the ground it would look like the satellite is stationary. The satellite would of course be in zero g while falling even while attached to a huge space elevator.
Centrifugal force is an apparent force that causes an object to leave its centre of rotation. This is caused by inertia. In other words, centrifugal force is inertia, and in that sense, centrifugal force does exist (as inertia).
You forgot to mention Sir Arthur C. Clarke, who in 1979 wrote a Sci-Fi novel about a space elevator rising from Sri Lanka to a satellite in geosync orbit.
No, in the case of the video, the centripetal force would be the earth's gravity curving the path of the object and thus keeping the object in orbit.
Centrifugal force does not exist as a force on its own, but is presented in this case as inertia, which would cause the object to fly out of orbit into space.
you could keep going straight up, but you would never reach orbit. only two outcomes are really possible if you launch straight up. either 1, you shut off the engines before reaching escape velocity, and your rocket goes up, then stops, then falls right back down. or 2, you keep firing until you reach escape velocity, at which point our trajectory would never bring us back to earth, and you fly of into space. all this is also true if you launch in the other direction as well.
It makes it sound like one of those platform games. You have to go to the further away bit, before you can even think about jumping on the nearer stuff.
Anybody Viewing this from Ace Combat 7: Skies Unknown?
ah yes. ISEV
A man of culture
James did a segment on space elevators in Big Ideas. Worth checking out.
Wonderful series Mr. May, thank you. Have you read red mars trilogy? The Marian colonies use a space elevator in the novels.
THANK YOU FOR DOING THIS!
I have always wondered this...Thanks for answering.
:)
How would you change the orbital velocity of the items including the crawler as you raie or lower them along the cable?
How will the elevator rotate earth? In order to secure it well enough, the support has to be very strong, and that would mean it'll have to be stationary. We can't really put a strong enough guiderail around earth either, because of tectonic plates, oceans and seasons. That means that there will be a pull on one side of the earth all the time using the earth's rotation. I can only assume that'll slow it down to a standstill, and that will be bad for us all.
Meteorite is a meteor that makes it to the surface of the earth so tieing a rope to it would be useless
Many years ago I read Arthur C Clarke's book The Fountains of Paradise. It's about space elevators. Clever man Mr Clarke
It should have been mentioned in this video! His detailed depiction of the space elevator is pretty much blueprint how it would be build. A must read for people who are interested!
Time to start harvesting the 5000 tons of debris & junk already in orbit. Smelt it down for counterweight or materials for the waypoint.
I have a question if its possible to answer. Rockets and other space equipment always go left or right after they leave Earth but if we launched a rocket into space and it had the fuel to keep going indefinitely so that the earth was always directly below the rocket (it went up in a straight line and didn't curve at all), how far straight up could it theoretically go? Same for the opposite, if we launched it into space and turned it straight down so it went below earth and kept going downwards.
"oh no, we've become tangled in the space rope"
The "space elevator" actualized in a novel...
Arthur C. Clarke: "The Fountains of Paradise"
Excellent!
The majority of cost in a rocket launch is the hardware that you throw away when you drop a stage, the fuel for a average orbital launch is the same amount that you would have in a transatlantic flight in a 747. if we had only fuel costs it could be a mere 25 dollars per kilogram to low earth orbit.
That baby crab thing freaked me out. Kinda like the initial vampire scene in From Dusk Till Dawn...
6:00 you don't mean Meteorite James ... you mean Meteoroid. By the time it becomes a Meteorite it means you failed to catch it and it's too late.
I remember seeing a concept design for electromagnetic slingshots to launch things into orbit. The g-forces meant it wouldn't work (yet) for humans, but for cargo it seemed feasible to my lamemind.
I had the same basic idea several years ago as way to deal garbage. A giant mass if is sent up the tube, collected and when enough is collected, the mass is launched towards the sun and it burns up before it gets there. Problem is, New Jersey would run out of usefulness.
Obviously, the ship itself would need to take some of the load about 2/3rds up the tower... and by then, the force of the launching system would be immense. The power of the rockets, with the power of the steam catapult from an aircraft carrier (multiple of them if possible), and the magnetic launch system, much like that currently found in a Mag-Lev train.
Well yes, we know that Gravity doesn't really exist. I mean, it is not a "force" like the nuclear force(s) or electromagnetism, it's a phenomenon related to the shape of the spacetime and its interaction w/ massive particles. So the real question would be "why do some kind of particles bend the spacetime"?
The materials for a six stage progressive diameter rotorvator exists already. It's not quite as cheap as a space elevator, but it's in the same ballpark.
Read Kenneth Oppel's 'Starclimber'!
Any time the word Centrifugal Force is used, what is really being described is a Lack of Centripetal Force. (from a mechanical engineering student)
well even if you shot straight up, it would look as though it was curling. as you go farther up the great you would have to move sideways to stay right above. how far can they go, you would have to pose that to NASA or Spacex (i would assume once you hit escape velocity you could go on as far as you would like)
If the Rock is in space, it is a Meteroid not Meteroite
Yay, I'm from SL too!
Now yes but like I said time and resources are the two main problems. To prevent an economic crash when it is finished the structure would be built over 400 years to a millennium. With the population rising the way it is a similar structures; even if it's city's in artificial caverns will be necessary if we don't start moving people to other planets and space stations. This way we get an orbital elevator and delay the time in which it is needed
You'd think someone would come up with a good solution to two issues at once. Figure out a way to collect all that space debris and use IT as the counter-weight.
An easier and much cheaper way of sending things to space would be using nuclear bombs . You only need to put such a bomb at the bottom of a very long vertical underground tunnel filled with water , place the stuff you want to send to space on top of the water , then detonate the bomb . The powerful explosion will create shockwaves that will travel through the water and push the objects on top with such strength that they will be able to escape Earth's gravity .
They said the "PROJECT" starts in 2020, they didn't predict it would happen 2020, by project meaning that they'll start designing, making parts, looking at it politically etc.
The correct answer is yes, but it is unlikely anyone born before 1990 will see it. I imagine something like a maglev would be the most feasible. The only hard part would be assembly, but once we see the rise of automated building systems it would be possible.
This was fun!
The guys at the Liftport Group are working on a Lunar Space Elevator that can be built with current technology before this decade is out.
perhaps not by a significant margin. Again, we still need something sent up to collect the debris, and then we need to move it in place. Satellites have been proposed that will fish for debris, but their goal is to send debris into a deteriorating orbit, rather than a giant counterweight. Still, it doesn't seem like a bad approach...
No, he would actually enter orbit if the rope was going relative to the earth, at 1000 mph. which a space elevator would do.
Having the rope anchored in space would make it so that the middle is spinning at earth's rotational velocity, and so stepping off would just make you be in orbit.
If you're talking about the guy on the Jenga blocks, at that height, he would indeed be in orbit.
If someone was to lower a rope from orbitable space, and the rope being (optimistically) 20 cm in diameter, the amount of space volume needed for it to reach the earth and space would already be well over 1 million cubic meters. The weight of it depends on the material it is made of.
Centrifugal is the normal force to a *centripetal force - it exists in so much as it's a name for a force.
James May is my favourite of the three. There I said it.
Just rise the rockets with giant balloons to 40 km high, there is already very thin air and the sending the stuff to space is much cheaper.
With balloons that big, we can probably keep heating them with microwaves from the ground and actually mostly hit what we're aiming for.
The biggest hurdle to space elevator construction is that we don't have a material strong and light enough to build something that's several hundred or thousand kilometres tall. Carbon nanotubes or some modified grafite material could work well. Though we've yet to make something more than a meter long with carbon nanotubes and similar materials.
The only force acting on the mass would be the centripetal force going down towards the center of the earth. If you're going past earth's gravitational field, correct me if I'm wrong, the centripetal force would simply be the tension force in the rope.
it would produce tension, yes. My issue with this concept though is that the Earth is rotating on its axis, as well as revolving around the Sun. It's not as easy as James puts it.
I don’t know why, but I laughed out loud at the idea of dropping a rope from space. That would either be a disaster if it fell into a populated area. Or the craziest amusement park ride if it worked.
Only Jeremy can build a space elevator
Just wondering. If we had a counterweight at one end of the rope and tie the other end to the Earth. Would this have any effect on slowing down the Earth's rotation?
I bet it'd be minuscule but still...
So. The highest mountains have 8 km. We can surely add the 2km tall building to form 10km high structure. Maybe in the next century, we can get at least to the ISS.
Yesterday I watched the episode of James mays big ideas which covers the space elevator.
When was this discussion?
For a long time the materials problem was seemingly insurmountable, as no material known to us had anywhere near the strength required.
This has changed in recent years, with the advent of extremely strong artificial materials, such as the various new types of carbon.