This channel is criminally under-recommended by KZread. Another fantastic discussion on the depiction of physics concepts in sci-fi.

@RyanRidden

2 жыл бұрын

Thanks! Maybe one day I'll break through the great filter that is KZread's algorithm!

@Shadow__133

2 жыл бұрын

@@RyanRidden Worked for me 🤷🏻‍♂️ 😝

@musicaldev5644

2 жыл бұрын

Do joined feature video with some scotsman living in US who also does space videos :)

@LinuxDog

2 жыл бұрын

Yeah so true, I noticed him because of some Scott Manley community post. I am glad I followed it

@lastminutepotato

2 жыл бұрын

Agree. Also, I think it is time for Ryan to open up a Patreon 🧐

the mass effect music is a subtle touch and I love it lol

@sasbrzx

2 жыл бұрын

i love it, so fitting

And I don´t remember the books ever mentioning a space elevator. the first space elevator description I ever saw in a book was Fountains of Paradise, by Arthur C Clarke. And then of course, the Mars Trilogy books.

@CyberiusT

2 жыл бұрын

Came here to say that. Glad it wasn't just my faulty memory.

The first scene of the underrated "Ad Astra" begins with an incident in an orbital elevator. And "The Fountains of Paradise by Arthur C. Clarke" is a classic about this theme.

I've read the foundation novels. The TV series is just vaguely similar. And by the way.. the god of YT (the algorithm) has noticed you. Go for it!

@PVilarnovo

2 жыл бұрын

Sad but true.

@dannybodros5180

2 жыл бұрын

I've read the books too and I think they've done a pretty good job given the circumstances. You very well know it's an impossible book to convert into a movie. It's very heavy in political discourse and there are too many paragraphs where there are just a bunch of people sitting in a room talking. That doesn't make for good cinema.

@PVilarnovo

2 жыл бұрын

@@dannybodros5180 so… why make it? Just for bucks? Isn’t a bad series. Just it’s not Foundation. They could just called it NGO….

@dannybodros5180

2 жыл бұрын

@@PVilarnovo I'll answer your question with another question: why not make it? The more people that know about the series the better, even if it's just a TV adaptation. If anything, it could be their gateway into the books. The Foundation series needs more recognition for its colossal contribution to science fiction. Ideas such as hyperdrives, laser weapons and star wars were first envisioned in the series.

@PVilarnovo

2 жыл бұрын

@@dannybodros5180 so… we will recognize the importance of Foundation with a series that has nothing to do with Foundation besides the name of the series and the name of some of the characters? Makes no sense.

The most significant damage was to my memory of the novel. Great video. Liked and subscribed.

I’m glad I stumbled across this channel, I’ve been fascinated with the idea of a space elevator since reading about one in the Mars trilogy by Kim Stanley Robinson, and I’m glad they put one in Foundation, I’m sure Asimov himself would have considered the idea too much when he was writing them originally, he admitted as much before he died too… it fits for this story.

I am glad I found your channel. Was worth it for sure. My first comment was also how underrated u are, I think Scott Manley brought me to you.

@RyanRidden

2 жыл бұрын

I'm glad you found your way here!

im very grateful to youtube algorithm to suggest me your channel..excellent content

I believe that once we have the infrastructure to build such an object, we will no longer need such an object. Also, the tether may not do much damage, but what about all the elevator pods/carts with people or cargo on them? In order to make these economical, you would need a lot of traffic going up and down at the same time and each one would probably be much denser than the cable. Also, a space elevator is not more efficient. It requires the same amount of energy to reach a particular orbit for a specific amount of mass. It just matters where you get the energy. Today a chemical solution does seem much more expensive (although a lot quicker), but don't forget that your object has to reach the top and then burn some fuel to adjust its intended orbit or escape velocity. Also, don't forget the fuel will need to be used to help with station keeping. That heavy counterweight will need some pretty nice RCS thrusters as the orbit will never truly be stable, especially when you consider all the forces acting on the cable and the dynamic amount of mass entering and leaving earth through the cable/station changes the center of mass. There are a lot of problems. These problems are/should be solvable. But just because they are solvable doesn't mean the solution will be practical. I am willing to bet that once we have confidence in building such a system, we would also no longer need to build it. But then again... who knows.

@medexamtoolsdotcom

2 жыл бұрын

Nonsense. First of all, it isn't about whether you NEED it. It's about the expense it would save. If you could DO something but it cost a thousand times as much to do it one way as another, would you not do it the cheaper way because you don't "need" it? And yes, it IS much more efficient, and you need MUCH LESS fuel, because you don't need to lift the weight of the fuel, and the extra fuel needed to lift the extra fuel, and the extra fuel needed to lift the extra fuel needed to lift the extra fuel, which is the problem you face with using rockets. The rocket equation is an exponential function for this reason. If you had a space elevator, you could have the thing POWERED by an electrical station ON THE GROUND. That is why it would be much more efficient. You really don't know what you're talking about. You know what they say, it's better to keep your mouth shut and worry about the world thinking you're a fool, than to open it and remove all doubt.

@williamozier918

2 жыл бұрын

The thing is I agree with your pointsd 100%, but keep in mind for many of these exact reasons the space elevator makes a great 'make work' project and show of empirial 'greatness'. It's kind of an Arch of St.Louis thing.

@Rekcoj

2 жыл бұрын

but having such a thing would save so much energy you would otherwise need to produce the chemical fuel aswell as saving the energy said fuel would waste in heat while being burned. you could power it electricaly, which is much more efficient then chemically, via a giant solar farm or even a nuclear power plant. once it is set up, you wouldn't need as much energy as you'd need with a rocket because you don't need to waste it anymore to fly around the earth fast to get into that orbit, you can just go straight up. having such a thing set up, could be a turning point for a young space fairing race. think about the possibilities, you could even have a little shipyard as the counter weight station and start building spacecraft in space. you could just send all the ressources and materials up with the elevator. wanna have a satelite in orbit, no need for big fucking rockets anymore, just build the satelite there and launch it without a launch vehicle. wanna send one of elons starships to mars, no need for the super heavy booster, just build the ship there and send it to mars. of course there is so much stuff to consider with these things but still, having the technology and the ressources to build this new infrastructure and not do it would be very stupid.

@OrcephRye

2 жыл бұрын

@@Rekcoj Firstly I did have a response to earlier comments that, for some reason, got deleted or was never posted that did bring some of this up... not sure what happened to it. 1) "but having such a thing would save so much energy you would otherwise need to produce the chemical fuel": Ok sorta. The 'economy of scale' will undoubtedly reduce the price of fuel significantly. So while a space elevator would use theoretically zero how much are you saving? And what are you gaining/losing? Do not get so hung up on an advantage, for there are always disadvantages. In our history, we have invented many technically better things that never got used simply because of some other unaccounted for disadvantage. 2) "you don't need to waste it anymore to fly around the earth fast to get into that orbit, you can just go straight up.": What about objects or people who wanna leave orbit? Want a lower orbit? Not every satellite will want the same orbit. Also, the energy provided to the cargo by the time it reaches the orbiting station is not enough for the mass to achieve circular orbit. It will need its own propulsion and fuel to leave the station and circularize its orbit. The station itself will have to have station-keeping thrusters that also burn fuel. It is nowhere near the same amount as the current rocket launch, but the point is that a Space elevator doesn't completely remove the need for fuel. 3) "think about the possibilities": This is not an argument for space elevators. All space elevators do in theory is provide reliable and cheap access to space. The possibilities can come from any technology that sufficiently provides reliable and cheap access to space. This argument would only be valid if space elevators were their only option. And it simply is not. 4) "and not do it would be very stupid." Humans have done this very thing countless times in our past. Sometimes it is seen as short-sighted/stupid while others times it was clear why. My main argument is the 'chicken and the egg' situation. That once we have the technology, confidence, and infrastructure to build a space elevator, we wouldn't need one. Because a Space Elevator is a megaproject that would first require technology, confidence, and infrastructure that provides reliable and cheap access to space. ---- Also, cheap!? Really!? The unsung hero of space flight is the launch pad. Easily more expensive to build than most rockets, and it is costly to maintain as well. The prep before and after each launch isn't talked about because it's boring. It's all about the rocket. But it is easily the second most expensive part of launching a rocket. You wanna make a product that probably costs 1000X as much as a launchpad to not only build but to maintain as well, and then claim its gonna make space cheaper!? Really? Why because it doesn't burn fuel? Fuel is one of the cheapest parts of space flight. And again, as the production of a newly in-demand product increases, its price usually drops significantly. Going forward, fuel is gonna be even cheaper, and it already isn't a serious concern. Lastly, if we believe we can achieve something like a space elevator in the future, then what about all the other future tech that is possible. Single Stage to Orbit reusable craft? In-takes that liquify oxygen as it passes through the air to 'breath' so you don't have to have all the fuel on launch? Hyper-Sonic plans. All of these things are possible and have been or are being researched. And that is just what could come out in the next decade or so. What about 50 years a 100? A nation like USA would likely push for that before letting some country on the equator control 'cheap' access to space.

Great video! I remember a similar scenario in Red Mars by Kim Stanley Robinson with another space elevator built, then sabotaged above Mars. It's been years since I read it, but I vaguely remember there being equally dramatic results. Like one of the scenarios you mentioned, the book used an asteroid as the station/orbital end to provide the required mass to keep the cable taut. Due to the transit times it seems like a realistic space elevator would be more useful for cargo and bulk materials than passengers.

@RyanRidden

2 жыл бұрын

Thanks! I still need to read Red Mars, it seems like a really good book! I think you're right, space elevators would be ideal for moving non time critical stuff around. I'm not sure too many people would want to spend a month to commute into space!

@DrewLSsix

2 жыл бұрын

Transit times are on par with long distance travel in the modern world. And both are vastly faster than travel in the past. Just because a rocket will do it in a few minutes doesn't mean a few hours is unbearable.

@tonygoinggonzo

2 жыл бұрын

Due to Mars' lower mass, the cable isn't as long as what would be needed by Earth, and also due to Mars' much thinner atmosphere, the cable didn't burn up on the way down, and it was still long enough to wrap around the planet a couple times.

@GavinMorris1

2 жыл бұрын

@@tonygoinggonzo Also IIRC it was tethered to one of Mars' tiny, porous moons and the weight of the cable brought it down. If I've remembered this wrong please tell me and I'll go and write my own space opera :)

@tonygoinggonzo

2 жыл бұрын

@@GavinMorris1 it was tethered to and built using materiel from a captured asteroid. during the same war they blew up one of the moons, but I can't remember if it was Deimos or Phobos? when they rebuilt the elevator, they used another captured asteroid

I once calculated the forces on an elevator to geosynchronous orbit and found that no material could support the weight of just the string itself

@stefanr8232

2 жыл бұрын

Only applies to geosynchronous. Need to recalculate for trantosynchronous. Need the number of seconds in a day, the acceleration of gravity at the surface, and the surface escape velocity (or radius). Luna is low enough gravity the elevator could be made out of materials currently on the market. For Haumea the elevator is so easy we could almost build it as a tower under compression but not quite. Mild steel or cotton is easily strong enough for Haumea under tension. On Phobos we could do it with corrugate boxes and stretch wrap and it would support itself with both compression and tension.

@TrueFork

2 жыл бұрын

@@stefanr8232 fair enough, my calculation was for a story set on Earth

@DontScareTheFish

2 жыл бұрын

There is no currently available materials, however the tensile strength of carbon nanotubes is suppose to have a sufficient margin. The problem is a) it would need to be a continuous (perfect) nanotube, b) we cannot make the stuff in sufficient quantity or quality

@stefanr8232

2 жыл бұрын

@@DontScareTheFish Also c) you would need a large taper ratio A straight single tube would not be able to do it. It would be much wider at the top.

Imagine one month of banter in Mass Effect‘s elevator 😂 Great video and many thanks for the explanations!

@RyanRidden

2 жыл бұрын

Garrus would find a way to do calibrations for a month!

@laurensii9098

Жыл бұрын

@@RyanRidden Mass Effect reference earned you a subscriber!

Suggestion: You wrap the cable in superconductive wire and put a few hundred amps through it. In case the cable were broken the strong magnetic field would bring the ends of the cable together again so it wouldn’t fall. OK, you’d have to go up and actually strengthen the cable again at the break point but you wouldn’t have to start from scratch again. As the magnetic flux lines are parallel to the direction that the transporter chamber would take when transporting people and freight to and from orbit, it wouldn’t apply any extra force on them, and would only be a problem with it’s interaction with the earths magnetic field which would cause the cable to tilt towards the pole. Actually that could make the cable a little shorter.

@DJAlisterCrane

2 жыл бұрын

1 2

@ItsMySpaceship

2 жыл бұрын

Would bring a lot of complexity to the system and in 99.99% of the cases whatever broke the actual cable (which is ridiculously strong) would also break the wrapping wire.

@martinstent5339

2 жыл бұрын

@@ItsMySpaceship You're right about the complexity, but on reflection, you wouldn't need to use wire, you can use a sheath, like shielded wire, and have the current just flowing inside the shielding. The shielding can also be extreamly thin, sub-micron. OK, granted you would need to use a high temperature superconductor. But there is some evidence that carbon nanotubes could be strong enough to form the backbone of the cable, and also some evidence that nanotubes are superconductive under certain circumstances. Maybe we can circulate a current through the cable itself and so produce a strong enough magnetic field to pull the broken ends together again. I know all this is speculation about things that we don't yet know how to make, but it's still fin to play at "what if...".

@TheHalcyonTwilight

2 жыл бұрын

@@martinstent5339 Why would there be a magnetic field if the superconductor is severed? Current flow would also be severed, so no field would be created.

@martinstent5339

2 жыл бұрын

@@TheHalcyonTwilight because the current is going AROUND the wire, and not along the wire. It means you need an insulating core in the centre of the supercunductive wire, but that only needs top be a few molecules thick. The current going around the wire creates a magnetic field along the wire lengthways and can't be stopped by breaking the wire, so if the wire gets broken you will immediately get a north and south pole very near each other and they will pull back together.

Great video. I had wondered about which elements of the space elevator worked and which might not. Your explanation about the forces involved, the orbital speeds, and how where the break occurred (as well as the likely mass of such a structure) impacts the aftermath were enlightening. The engineering behind how to actually create such a thing must be astounding.

They’ve got magic artificial gravity on the space ships. This technology would allow them to make the cable extra girthy.

@stefanr8232

2 жыл бұрын

If the have anti-gravity there is no point in the elevator at all. Extra gravity is not helping in this case.

@bigdopamine9343

2 жыл бұрын

@@stefanr8232 they do have anti gravity. It obviously wouldn’t be used to increase the gravity, it would be used to counteract it. Anti gravity implies advanced active suspension. You could make it so that there’s no stress on the cable. Yes obviously that tech would make the elevator pointless especially since they have the only space elevator and presumably the thousands of other planets get by just fine without them. Also they’d need to use some sort of active gravity since their ships are capable of containing Planetary mass black holes without ripping themselves apart.

@DrewLSsix

2 жыл бұрын

@@stefanr8232 I would assume anti gravity is energy consuming, theres a reason we send so much freight by slow ships rather than hovercraft, even though we have the tech its not economical to use it in all cases.

@pattheplanter

2 жыл бұрын

Magic would really help with all the engineering problems of an Earth space elevator. Magically producing a million tons of cable of supersophisticated materials. Magically getting elevators to be able to crawl up it. Magically damping vibrations. Magically healing radiation and micrometeorite damage. Magically eliminating electromagnetic effects along thousands of kilometres of cable. Most people and trades that want to travel in space would just get out of deep gravity wells and stay on nice little rocks.

@peterbonucci9661

7 ай бұрын

​@@bigdopamine9343you need antigravity to get the right force profile in the cable. You can't get it right with just tension.

They should start with a moon prototype and test orbital compensation techniques. Work on a 140km rubber ducky building, 5km long 2km under water with a hyperloop

When you describe what happens to the top of the elevator once the tether is severed, you said it would simply rise to a higher orbit. Actually, the top of the elevator would simply enter an eccentric orbit instead. Before the tether is severed, the entire elevator is orbiting the Earth its center of mass, in a circular orbit defined by the length of the tether. Once the tether is severed the two parts now each have their own center of mass. The topmost part is traveling too fast for the orbit it was previously in and would act like a spacecraft firing its engines directly downward toward the Earth, accelerating instantly outward. This would push it into an elliptical orbit were it would continue to lose velocity until it reached its aphelion, at which it would start to fall inward toward the Earth, gaining velocity until it reached its perihelion, where it would be traveling too fast to be pulled all the way back to Earth and be flung outward again. This is similar, to a Hohmann Transfer maneuver, it which a spacecraft in a lower orbit needs to rendezvous with another in a higher orbit. One thrust burn puts it into an eccentric orbit going outward. Another burn is needed to make its orbit circular again.

@2nd3rd1st

2 жыл бұрын

In the show the severed elevator station does fall back to Earth years later but is detonated into debris before it hits the atmosphere to avoid a great impact.

@Corbald

2 жыл бұрын

Didn't see your comment before I post my own, arguing the same point. One correction to your is that Aphelion only applies to solar orbits. Apoapsis is the generic term and Apogee is in Earth's SOI. As I stated in the other comment, the proper terms for Trantor's SOI are probably Apotor and Peritor.

@Corbald

2 жыл бұрын

@@2nd3rd1st The station should NOT fall back to earth (lower case E). The lowest point in it's new orbit should be the altitude it's new center of mass was at when the cable snapped.

@cheytacsnipes

2 жыл бұрын

@@Corbald But the orbit would decay slowly, and in the show considerable time passes between the elevator getting free from Trantor and Empire finally making the call to demolish the remains.

@Corbald

2 жыл бұрын

@@cheytacsnipes Yes, but not that quickly. Most of the orbital decay experienced by artificial satellites in Earth's orbit is caused by interactions with our atmosphere. While it gets very thin, our atmosphere extends nearly to the moon! Even still, objects in _geostationary_ orbit (or beyond, as the platform would have to be) experience _very little_ orbital decay. It would take _centuries_ for it to decay enough to pose a threat to the planet. An example of this is that there are still fuel tanks in orbit of the Earth from the Apollo era, and the Apollo 11 lunar module is likely still in orbit around the moon.

Nice MASS EFFECT PRESIDIUM MUSIC !

I've been watching tons of Space Elevator stuff recently and Issac Arthur has a great channel where he covers all sorts of science and sci-fi stuff (shameless plug for his channel here). One idea that he mentions is that the station at the top could be attached by more than one cable. This would not only provide stability (fasten anything with three different guide ropes as an example), but the other cables would act as the buffer if one were damaged or destroyed. At a high enough orbit the station could be powered by the sun and it could even become a solar power station, sending surplus power back to Earth. As for the 'wrap around' effect from a falling cable cut high in orbit, it would take a lot of explaining to convince me that the result wouldn't be a horror show that would make 9/11 look like a fender-bender. Even if the cable weren't very heavy, it would still be traveling at terrifying speed both because of gravity pulling it down AND the rotation of the planet winding it up like a string around a yoyo.

Literally just found your channel, you're a godsent my dude. Gorgeous video and explanation! Earned a fan, you have!

Thanks a lot for this very informative video!!

I think Foundation got it right. You can't treat as a point mass because the elevator size is large compared to the size of the Earth. Any parts of the elevator out to 80% of geostationary orbit will crash into the Earth over about 4 hours. The final pieces will hit the Earth at about 10 km/sec. It won't be pretty. When it hits the Earth, it will be shorter by about 20%. Even if it's in one piece when it starts, it will tear itself apart as it falls. Things from 80% to about 150% will go into orbit around the Earth. After that it's iffy. They showed an exceptional example of how it would fall.

If you pay attention during the Halo 3 ODST Mission on at the Zoo, when they pass and one of them makes a comment about the Space Elevator snapping. You can see the Elevator cord in the middle shoot up into the sky as its support rings fall down.

Fascinating and informative. I remember reading Arthur C Clarke's novel featuring space elevators (Fountains of Paradise) and being intrigued by the whole idea so its good to see the science behind such a construction so well laid out. Thank you.

@RyanRidden

2 жыл бұрын

I've read quite a few of his novels, but I haven't read that one. I'll need to check it out!

@pcuimac

2 жыл бұрын

No. The whole video is pure nonsense.

@MarCuseus

2 жыл бұрын

@@RyanRidden It's a great book.

Bruhh there vision of the warp drive was🔥🔥🔥

One thing missing here is that space elevators were not a new concept created by the writers of this TV Series. The Foundation series was of course originally written by Isaac Asimov and published from 1942 onward. Additionally, Arthur C. Clarke's and Charles Sheffield's (both published in 1979) are generally considered to be the works that introduced space elevators to the science fiction community at large.

I gotta say, people seem to REALLY forget about the kind of voltage and current levels we are dealing with when we are talking about making an object that is going from the ground out beyond the magnetosphere. If you have ever seen the footage of NASA's tether experiment in low orbit, the crazy plasma formations produced would give you a good idea of what is going to happen to any space elevator type object. It's not just a matter of tensile strength, you're talking about trying to handle insane amounts of charge in an optimal situation much less trying to deal with large solar flares.

In episode 3 of Foundation, many years after the attack, the Empire brothers discuss what to do with counterweight that is orbiting the planet. The counterweight is orbiting, as you expected.

@Shinzon23

2 жыл бұрын

The brothers also decide to Nuke it instead of rebuilding it.... Which makes no sense whatsoever because you can use it again and another question is it's been 30 years...why hasn't it been rebuilt...?

@nicolas.p331

2 жыл бұрын

@@Shinzon23 Because the empire is broke

@Shinzon23

2 жыл бұрын

@@nicolas.p331 no indication given of any sort of economic issue.

@SmellyBones

2 жыл бұрын

@@Shinzon23 Unless you count the derelict space station.

@DontScareTheFish

2 жыл бұрын

@@Shinzon23 That's an indicator of how the empire has decayed. It's one of the main points that were predicted by psychohistory (at least in the books and yes I know they didn't have the elevator).

Thx for the video!

At first, the lower part of the cable would fall slowly, but the upper part would snap like a whip at hypersonic speed. It would send a huge continuous shock wave around the globe as it enters the atmosphere (like when the asteroid exploded over Cheliabinsk) and if it reaches the ground, you would face way more destruction...

I love how it takes less than the length of the video for commenters to come up with the solutions that the empires greatest engineers somehow failed to foresee over their lifetime of designing and building the elevator. Anyway, it does not matter how the elevator broke in the story, its used as a plot piece to show that the empire is not infallible and leads to public doubt in the empire sowing the seeds for the future.

6:29 - You're counting the total distance to the counterweight, though. The actual space station could be half way along the cable (in fact, there could be multiple stations at different altitudes).

@CharlieQuartz

2 жыл бұрын

The station in the show must be the counterweight, though, so he is doing the calculations correctly for this situation

@RFC-3514

2 жыл бұрын

@@CharlieQuartz - The one in the show does several physically impossible things; the example he was giving was an attempt to get (the main part of) the physics right. He even correctly called that mass "the counterweight" (not "the station"), but then measured the distance to it and apparently forgot that there could be a station (or several stations) at different altitudes.

Back here on Sol, rather than Trantor, space elevators for Mars are more easily achievable than for Earth. About the same rotation, but lower gravity, translates to less strength needed for the cable. Not sure whether you can keep Phobos around with a space elevator. Might need to use a sky hook with Phobos as the pivot.

thankyou for introducing me to this series :)

Thanks for mentioning coriolis force. I always wondered if it would be manageable.

Relatively simple to do. The biggest issue is what Foundation has had to deal with. Build something that big and you're painting a target on it.

The question is when you have spacecraft that have some kind of anti-gravity that lets them land and take off from planets directly, what do you need a space elevator for? 11:00 make the cable thick enough for massive traffic and even a low density material will have a high enough mass to surface area ratio to carry its momentum through the atmosphere. More feasible to build are orbital rings, tethered rings, and launch loops.

That scene reminded me of the book "Red Mars" where a similar event happened to a martian space elevator.

@stefanr8232

2 жыл бұрын

Kim Stanley Robinson is a brilliant writer. Profound incite into human behavior. Unparalleled ability at describing scenes. He is not a physicist though. He actually makes fun of a few errors in later books. I recommend reading both the Mars trilogy and later publications. I would not use them as orbital physics reference.

@lanebowles8170

2 жыл бұрын

@@stefanr8232 I have only read Red Mars of all of his books so far. Got sidetracked from the rest of the series by other books from other authors a while ago and the profuse profanity and sexuality makes me hesitate to return even though I very much enjoyed the story. Call me a prude, but I wasn't raised that way and so such elements didn't add to the story, only distracted me. I have the same problem with Tom Clancy.

So I had an idea on how to possibly get space elevators ''soon''. Stage 1: Copy the movie Geostorm and create a net around the world in which there are satellites to control weather phenomena to prevent natural disasters. Stage 2: Start the construction of a frame on the net around the world creating part/s of the basic frame of a ring world. Stage 3: Build space elevators up to the frame. With this we can transport materials directly into space without rockets much earlier, meaning less wasted resources. The distance will be nowhere near as far as a traditional space elevator meaning less transport time while if made of the right materials the frame will be able to support it? Not only can we create multiple space elevators for the cost that just 1 traditional would have cost but we can build shipyards on the frame and so many other things. Not only that but stage 1 is also essentially a prototype terraforming system, meaning we could learn all kinds of things for when we start to colonize other planets. I am by no means an expert, this is just an idea I got out of nowhere.

Excellent use of Mass Effect music 😍

@RyanRidden

2 жыл бұрын

Mass Effect has an incredible sound track!

To prevent an Earth cable catastrophe, how about this for an answer: -We send millions of robots to mine for materials at the asteroid belt. -Build Mars colony with Base, Observatory, Mining Factory, Space Elevator Factory, Space Ship Factory, Asteroid Robot Mining factory, and a terraforming Mars company. -Send asteroid belt materials to Mars. That way if any tragedy were to occur, it wouldn't happen on Earth, there's less gravity on Mars, so a space elevator probably wouldn't have to be as long.

Robert Forward has done some interesting speculation (with an eye to the physics!) about the space elevator and several variants not requiring any geostationary orbiting. [ interesting point, some of his designs are chain-drive! ]

Sometimes it's better to tell the truth. Carbon nanotubes, even boron nitride, don't come within an order of magnitude of the tensile strength needed for a surface-orbit structure on Earth. On Mars or the Moon, it _might_ be possible due lower gravity effects and shorter distances. And the idea that the collapse of such a structure would do minimal or no damage is.. optimistic. The amount of PE embodied in such a structure is immense, far greater than the sum of all nuclear weapons yet made, so there would be significant backlash.

Examining the Coriolis effect would be interesting. If you can, please cover it. Also, all information gets stored. Storage is cheap.

Another great video. What do you think about Orbital Rings? To me they seem more achievable because they can be built with known materials. Mass production of grapheme and carbon nanotubes always seems to be 20 years away.

Very fine.

Would definitely recommend 'The Space Elevator' by Dr Bradley C. Edwards. Great read, spends a lot of time on the physics, logistics and economics of elevators. All we need is a CNT ribbon that can self support about 30 000 tons and is about 50,000 miles long ...he didn't say it would be easy :)

@tonycourtenay1933

2 жыл бұрын

Try 'The Fountains of Paradise' by Arhtur C Clarke

Any ideas of the electrical static charges that would build up? Use that to power the elevators..? And what of the atmospheric jet streams and windstorms... This will turn out to be a flexible system with an undoubted resonance of some sort,

RIP string :( Thanks for making me aware of another cool show.

@RyanRidden

2 жыл бұрын

Sometimes science requires sacrifices

@zaphenath6756

2 жыл бұрын

@@RyanRidden It's just Foundation, not 'The' Foundation

I mean maybe they discovered stronger materials in the future, which could enable such big and heavy cables. The station is pretty huge.

The math is down cold, all that remains is the materials science.

Great video on the general concept of space elevators, really enjoyed it. The other day, I've read about a concept of putting the counterweight/ "top floor" of the elevator another 38.000km away, making the center of gravity the midpoint of the whole structure - giving any outgoing spaceships one hell of a slingshot into deep space (minus the energy required to counter the corriolis effect, of course). Also, wouldn't a failing space elevator, busted near the top floor as shown in "Foundation", wrap severa times around Earth/ Trantor? God knows it'd be long enough? If I'd be building the damn thing, I'd orient my design on Arthur C. Clarke's design in "The Fountains of Paradise", using little more than cables (also doing dry runs on mars to get the engineering right might be a great idea, too). And when using carbon based nanotubes, I'd include some self- destruct charges along the cable to cut it into bits small enough so they'd definitely burn up upon re- entry. Which carbon is prone to do.

The issues I have with Space elevators are: 1. Everyone talks about when it is operating, but no one explains how you would build such a space elevator… perhaps you can explain how such an elevator can be constructed… do you pay out the cable from space to ground, or take the cable from ground to space… as an engineer… I am not interested in ‘well it just get made..”… I am interested in practical solutions… perhaps you should do a video on that would show your mettle… 2. You need to take into account the atmospheric drag the cable would have, because such a wide cable going through the atmosphere will have a considerable wind loading pressure and force applied to it 3. Electrical potential voltage across the cable.. especially in space. This is because of the experience from the application of space tethers on the space shuttle that were cut because the high voltage difference and high current through it burned out the space tether. This voltage can be induced by cutting the lines of earth’s magnetic field, and the charge particles coming from the sun, and at 40 000 km in length will this space elevator be in the Van Allen belt?

@atomic_wait

2 жыл бұрын

Seems like Red Mars had a relatively realistic approach. Kick one of Mars' moons to areostationary orbit, use automated machines to convert its material into the tether material and use the remaining mass as the 'anchor' and space station. Seems like the real trick is inventing a tether material that's strong enough to resist all the forces you've mentioned as well as micrometeorite and debris strikes and other dangers, while still be light enough to not just collapse under its own weight within the higher gravity regions closer to the surface. Correction: I think they used a captured comet injected into mars orbit, since the higher carbon content of the comet made it useful for manufacturing massive amounts of carbon fiber.

Some of the stuff I see in the tv series I recognise in books by...Arthur C. Clarke. He too posited that it would be more practical to build on on Mars. The trick would be to tune the bean stalk so it would bow allowing Phobos and Deimos to pass safely. In terms of energy consumption, as with conventional elevators you have a counter-balancing compartment at the other end of the cable. As one ascends the other descends. The challenges of a beanstalk on Earth are described in his novel Fountains of Paradise.

There are also untethered rotating elevator Skyhawks. Conservation of momentum.

This video has made me think: Can space elevator be a game changer for delivering supplies from the surface of the Earth, when it is not that important the time it takes?

Tbh, I don't think a space elevator should be the endgame but relatively early in a space faring civilization. That way our ships, depending on their purpose, don't have to consider taking off from the planet but can be built in orbit.

@Wustenfuchs109

2 жыл бұрын

You can build the in orbit right now if you so wanted - you just need to get resources from space (other objects with low gravity well - asteroids, moons...) instead from Earth. You will always have a problem of going to orbit from a planet. But there are two approaches. One is to build an entire ship on surface, then launch. That is a huge waste. The other is to have large ships in orbit and some system to just facilitate surface-orbit transfer. And, in fact, that is what Space Shuttle was originally designed to be. It was supposed to be a truck that would transfer people and what not to orbit, and then other craft up there, nuclear powered, would take over. It was supposed to be a two stage system. So the thing you've said - it was actually planned. Just not with an elevator but multi-use rockets instead. And the end game for a civilization is a ship like Millennium Falcon - one that does not care where it goes, it is the same to it. Is such a thing even possible - who knows. But that is the end game concept for space travel :) Elevators are simply not that practical. A lot of resources spend, and one damn huge target. Not to mention that is one accident away from global disaster. Earth is showered by meteorites all the time... and you'd have a gigantic piece of infrastructure that has to endure everything that humanity and space can throw at it... for several centuries... in order to pay itself off? I am not holding my breath.

Everything that I've ever really known, and disseminated about space elevators was gleaned from many readings of 'The Fountains of Paradise'. I'm glad that nothing you've explained contradicts any of what Mr. Clarke wrote. One small point; in episode 1 of Foundation is seems as though the "cable" is cut just below the docking station. It's not clear whether this is the synchronous orbit point, or the counter-weight. No other object is shown that could act as a counter-weight, but at the same time, the synchronous station would be the easiest place to dock, since it's the one point along the structure where you can match orbits.

@tannji5971

9 ай бұрын

In theory, if the geostationary point is approximately 22000 miles above the surface, you could manufacture the cable in the station, feeding it at first down towards the earths surface, and then as the weight of the cable begins to pull the station out of position, simply move the stations position on the cable to keep the system/orbit in balance. This would create an immediately obvious obstacle, with an almost as obvious solution, concerning how the cable is extruded in such a way as to allow the station to move in either direction along its length. You might really enjoy Kim Stanley Robinsons Mars series especially the second book which goes in depth on the construction, technical issues, and destruction of the (first) space elevator. Tolkien, Asimov, Clarke, and probably Heinlein were my early gods of literature, and due to not being sent to school until late 9th grade, I do mean gods, to my parents chagrin. (I grew up in a religious cult)

I never understood why geostationary orbit works before this. Thanks

In Kim Stanley Robinson's trilogy about the terraforming of Mars, one of the books -- I think it's late in the first book, "Red Mars," a space elevator is sabotaged and there's quite a good description of what happens on the ground as a massive cable long enough to reach high orbit comes crashing down & wrapping itself around the planet. (If it's not in Red Mars, then it's in one of the sequels: Green Mars, or Blue Mars -- I recommend them all for anyone interested in "hard" SF.)

i think this scene is taken from Kim Stanley Robinsons Mars Trilogy, where a falling Sppace elevator cable wraps itself around the martian Equator (with much less atmosphere than on a habitable word).

The car can go really fast while out of the atmosphere and slow down a lot when entering it and vice versa

Mass Effect!!!!

Talking about space elevator rides, and the time they might take, Star Trek: Voyager did an episode that took place mostly during one such ride. It might be interesting to look that up, and see if the travel time there was realistic or not.

Loved the video! Do you think going with an Orbital Ring as opposed to a Space Elevator would be easier? The ring can be made only a couple hundred KMs up, so the tethers only have to support that much weight as opposed to trying to stretch it up to geosync. The only downside is that once you reach the ring, you have no orbital velocity, so you have to expend energy to get up to speed. But at least there's no atmosphere anymore.

Two things I noticed is that the counterweight station in foundation provides thrust while rotating, as if the plan was to weaken the cable and then twist snap it off. Also, the videogames halo 2 & 3, and Halo odst features a space elevator cable snap near the base and some of the aftermath. It's been 20 years so I don't recall what the exact scale of damage was in the game lore. And I think Halo also snapped another space elevator cable in a tie in movie. 😕

Very fascinating. How long would the space elevator take to ascend if it takes 14 hours to descend? I am just imagining "The Girl From Ipanema" instrumental looped for 210 times while the space elevator takes 14 hours to descend.

Nice KSP music for elevator. LOL

Perhaps severing the elevator near the ground (actually as high as possible for the base to be self supporting) would be a good counter to catastrophe further up - hmm, what would happen if both ends were severed? (impact of atmospheric drag etc.)

@jeremygoodall7799

2 жыл бұрын

Depends on where and what delay there is between the two severing events. But in general, a second severing would only cause more uncertainty about where and how the debris would fall. Either the first cut occurs low enough that the bulk of the system is flung away, or it is cut near the top in which case the bulk is gonna come crashing down regardless of how many pieces it is broken into.

In the novels, the Encyclopedia was a ruse to get people to go to Terminus.

For the case where the cable break was low, would tidal effects tend to keep the cable pointed toward earth? Or would the cable stretch out in front of the main body of the counterweight, since most of it once was going faster than the counterweight?

@RyanRidden

2 жыл бұрын

Not too sure to be honest, though I suspect you could be right. After the initial bouncing from tension being released settles, then gravity will probably take over and keep it pointed towards the planet. I've been thinking about trying to model the system to see what really happens!

Thought I heard Mass Effect music 👌🏻

You need to also consider electrical implications. The elevator would carry an enormous current down to Earth, emptying the ionosphere-Earth capacitor. How would that affect life on Earth?

Oh, here's another problem... We don't know the size of Trantor compared to Earth, but given the sheer MASS of the space elevator in Foundation, I would believe not only that the center of mass of Trantor would be well OFF axis, but would even threaten to PULL the planet into an exotic orbit of its sun. Perhaps the rotation of Trantor would be somewhat erratic as the elevator daily pulled harder as it swung away from and then swung in the direction of planetary travel.

If the journey to the orbiting station does take the better part of a month or even a week, you might quickly run into the problem of a significant part of the elevator car's mass being taken up by food and especially water for the human passengers. And you'd probably want to put a toilet, a shower, and some bunks in there too, further limiting passenger capacity. I would imagine with the travel times discussed in the video, space elevators would primarily be used for cargo, transporting raw materials and finished goods for space industry.

A method to mitigate the damage that a severed falling cable would cause would be to detect the point where the break had occurred and at that moment sever the rest of the cable up into much smaller links where each link would settle into a slightly lower orbit. They could eventually be rejoined from the top down as long as the links had been designed with contingency thrusters to maneuver them back into place. There are still other ways to space now possible without requiring rockets or super long singular space cables. Think tethered concentric orbital rings. That’s where all the plastics/co2/carbon fossil fuels should be going to - raw carbon based construction material - we will need a crazy amount to pull it off.

Would the tether really burn up in the atmosphere though, its relative velocity to the atmosphere would not generate enough braking force for that to happen as I see it?

Great video! What about a Orbital ring?

I wrote a novel, ATROPOS, that also has a scene where a space elevator cable snaps (Chapter 7). I wrote this scene several years ago. I'd be curious to hear your thoughts on how accurate my portrayal is as compared to what we saw on Foundation.

Non-physicist / writer here, rate my idea: Build /half/ a space elevator with a huge staging area at the top, and then launch stuff via mass drivers and/or lighter than air balloons. Higher altitude means less air density, and a bit of decrease in gravity would make it much easier to get into orbit, correct? The structure could pull double duty as a powerplant, too, since it's of course going to have extremely high security anyway and built like a fortress at its base. To me this seems like a better idea than a traditional (read: vulnerable) space elevator, at least until the civilization has gotten around to building full orbital rings.

@Mark_Bridges

2 жыл бұрын

What you're describing is simply a tall building, not a space elevator. The difference is a tall building holds itself up off the ground with the structure in compression, while a proper space elevator is anchored down to the ground with the structure (cable) in tension.

@ClassicMagicMan

2 жыл бұрын

Your right, I feel silly for the faulty nomenclature, but otherwise how would this idea stack up against the traditional space elevator design? I still envision it as much more robust of a deliver system to space.

@NullHand

2 жыл бұрын

Your idea would work if we stand it on its head! Build a space elevator, but start from the only place such a thing can start from... geostationary orbit. Once you have reached the tensile limit of your materials, you just let it dangle there, still thousands of kilometers above Earth surface. There is really no need to connect it all the way to Earth, indeed you would not want to, because its lower reaches would be imbeded in swarm of LEO satelites doing 24,000km/hr relative to it. To reach the bottom of the cable several thousand kilometers up I would suggest a series of skyhooks. These are like smaller versions of the geostationary orbiting cable you built, but as they orbit closer to the Earth they are going progressively faster around the planet. Instead of hanging vertically, these cables will be cartwheeling end over end. A spaceplane with electromagnetic grapple could climb these much like a flying trapeze acrobat. Grabbing on at the lowest point of its cartwheel and realeasing at the highest, to catch the next higher skyhook, and so on up and around the Earth orbits untill reaching the base of your hanging geostationary cable station.

The welcome KZread algorithms strike again. Dr Ryan, you are my kind of nerd.

How about an elevator from the surface of the moon to some space station somewhere directly between earth and the moon? Could we not use the L1 lagrange point to aid in counteracting some of the stresses that the cable experiences, or reducing its length?

While ordinary metals melt between ~420 and ~1500°C, 60 nm carbon nanotubes melt around 3100°C. During atmospheric re-entry, the rise in temperature only appears when crossing the dense layers of the atmosphere at an altitude of 100 km and disappears at an altitude of 30 km. Even when falling from GEO orbit, the temperature of the carbon cable will remain well below 500°C (compared to 1650°C for the space shuttle) and it will not burn out. On the other hand, it risks disassembling either in the sections fitted out during its construction or in places where there are structural weaknesses and defects such as impacts. Even if part of the cable will fall out of the Earth, given that we will not know the position of the cable and therefore its trajectory with precision (< 1 km), fragments of several hundred kilometers long weighing tens of kilograms or more will fall on planes and even in inhabited places in the middle of traffic...

Would the cable (in case it snaps) create the "Mould effect" when falling? That would be really cool to see it happening in the sky (space) ... but I'd doubt we'd been able to see it from Earth.

Like the Mass Effect music

Thanks for informing me there is a Foundation TV series. I didn't know! I have read EVERY one of the Robot. Empire and Foundation books. Including all the "connecting" like

@DontScareTheFish

2 жыл бұрын

I'm very sad to say if you enjoyed the foundation books then you probably won't like the Foundation TV series. The apple TV series should have a "Adapted for TV from the Foundation Series by Isaac Asimov" disclaimer.

@theblitz9

2 жыл бұрын

@@DontScareTheFish yeah. Watched them so far. Good sci-fi but not really like the books.

Given the time for transit, a space elevator would be used for transporting cargo to orbit. The life support requirements for carrying people for a week would be problematic.

@TheInsaneupsdriver

2 жыл бұрын

it doesnt need to go all the way to the the station, but it would be beneficial as it would be close to the moon and reduce the fuel use needed to get there and come back. but they can build a "pod" that can handle that duration with current technology.

@davidwright7193

2 жыл бұрын

@@TheInsaneupsdriver The transfer to a spaceship has to occur at geostationary hight. At any other point the differential between the speed of the elevator and the orbital speed is too high to get a safe dock/undock.

@DontScareTheFish

2 жыл бұрын

"The life support requirements for carrying people for a week would be problematic" That hasn't been a problem for the international Space Station. The elevator wouldn't be the same size elevator car you currently take up and down within a building now days. We're talking anything up to the size of a cruseliner

@brownro214

2 жыл бұрын

@@DontScareTheFish The larger your elevator car, the larger and stronger your cable needs to be. Using Ryan's estimate of elevator speed of 300 km/sec and allowing for sufficient time for acceleration and deceleration, the transit time is about 6 days. You need to have capacity for life support for whatever number of passengers you carry plus the general cargo. The ISS is not an apples to apples comparison as the number of crew members on the station is small. If you only carry 3-4 people on each 6 day one way trip, might not be a huge problem. If you are carrying tons of cargo and 50-100 people as they did on the TV show, you need a really big elevator car.

hmmm, you forgot something, the elevator would short circuit the ground to the solar wind. there would be a massive flow of energy from the van-alan belts to the ground, normally we see this as Aurora and red and blue sprites above dense cloud formations. such a structure could create a pretty spectacular light show and cause, some interesting ground voltage, EMF/RFi effects at the point of ground contact.

@medexamtoolsdotcom

2 жыл бұрын

An interesting point. You could potentially use the space elevator as a power generator then, of a type never before seen.

The counter weight is going faster than orbital speed for that altitude. Make the counterweight a large space station, rotating to achieve 1G. "Launching" a space ship from that space station requires just letting it go at the right point in rotation. This energy is recovered by returning ships. Put a space elevator and space station on Mars. A space ship slung from earth can be captured by the Mars station. Earth to Mars transportation of crew and supplies requires substantially less fuel.

You would probably need some emergency disconnect on the planet side along with some backup propulsion systems built into the cable to yeet it into space if there ever is a failure

If you would snap the caple at the bottom, with most of its weight in low to zero gravity _ would it start rising until its all out in space ?

If you actually made a space elevator, you would want two space stations. One being the counter weight as described here, and one being a station at geostationary orbit would allow you to launch spaceships to go to other locations - other orbits or other planets. Anywhere else and after you detach you would be at the wrong speed thus creating a very rapid acceleration. Although, I guess if you could build a space elevator, you could figure out how to detach at any point along it... Another interesting point not discussed, but I assume to be the case, if you are not at geostationary orbit I assume you would feel a force that would create a sensation of gravity.

I've always wondered the possibilities of building one of these science fiction marvels

@RyanRidden

2 жыл бұрын

They would certainly be hard to build, but they would look pretty amazing!

@pcuimac

2 жыл бұрын

They are not possible. The forces are higher than ANY chemical or physical bond between atoms.

@stefanr8232

2 жыл бұрын

@@pcuimac Depends on a planet's rotation rate, mass, and density. If it is small enough and rotating fast you could build a space elevator using rubber bands or braided grass.

they should use active lift to hold up sections of it to reduce the strain on the materials, eliminating the need for things like carbon nanotubes, and to use common materials like plastic and aluminum. things like hot air balloons (made more structural to not fail at higher altitudes) or fans or electric based propulsion.

@DontScareTheFish

2 жыл бұрын

The lifting sections you're talking about are in the first 100km of a cable that is 36000-72000km long (some designs have the cable go an equal length past geo sync which is about 36K km up

Just out of curiosity, what happens to the Cable at the base if a hurricane or other significant weather system hits it? To be sturdy enough to withstand a hurricane seems to argue against the necessary lightness of the Cable.

I'm not an expert, but the weight of the object at the top of the cable should make a significant difference on how it behaves when it starts to orbit freely. Also, after it is free to orbit, any internal friction that is created is being borrowed from the orbital potential energy, causing it to lose some of its orbital energy and altitude. Its endpoints will probably be busy whipping around and breaking off with enough energy to leave orbit and return to the ground. Your comment at 7:25 said "to minimize strain on the cable" seems wrong, because the strain on the cable is already enormous, and the extra strain caused by a moving vehicle along the cable is relatively zilch compared to the strain that's already there. Besides, there's probably no physical contact between the cable and the vehicle, since it's probably using electro-magnetism to keep them apart. Eg, MAGLEV. In any case, good clip. But I want more math.

The station shouldn't be on the top of the tether, but rather at the geostationary orbit height (with the counterweight above), so incoming ships could just be at orbital speed and dock without much fuss. So, if the cable gets severed right above the station, the counterweight moves on to a higher orbit and the station gets pulled down by the weight of the cable. In the series it was a terrorist act, so they would want to cause maximum destruction. A very large space station falling down on the surface would be quite a statement. It remains to be seen if the station would break up in large or small chunks as it entered the atmosphere.

Given the scale the elevator presented is not a tethered cable is a tethered skyscraper, spacescrapper or space tower if you will (if there was any cable it was probably used only for construction). But how would a building of that size never colapse under it's own weight? Not if you depend on passive material strength to maintain it standing, but if you create a loop of cables or pipes and pump massive amount of energy or matter into a loop instead of building like passive support columns. The energy necessary to pump this energy/matter upward create active support and keeps the structure standing. The benefit of this type of active structure is that you are not limited by material strength to how big and massive you can build. You are limited only by how much energy you can constantly produce to maintain the structure standing. Today something like that is not viable, a building like that would require a dedicated power plant to itself and backups, because if power runs out the structure will collapse. But a galactic empire in the future with space ships that create black holes probably has the resources to build like 2-3 fusion power plants and pump whatever power they need constantly in they capital planet with trillions of inhabitants. We here in the 21 century will have to content with tethered cables, after you build one, you use it to build the others. After you have like 10, 100 or 1000 cables travel time is a non issue. Also a real elevator probably will not do most of it's trips to the tethered counter weight it being a station or not. A space elevator is to put thing into low-earth orbit not to leave earths orbit. Getting to or beyond geosynchronous orbit is useless for most applications. And those that need to go beyond can either continue to that the trip in a different set of elevator after the low earth orbit station or a rocket/spaceship built and refueled in space to get there. So travel time of real ones will not be that long.

What if there were multiple elevators all with their own bases but also connected to each other? Would on losing its connection to the base cause the whole system to fail?