The Physics of Space Elevators

Поділитися
Вставка
  • Опубліковано 23 гру 2024

КОМЕНТАРІ •

  • @mattuiop
    @mattuiop 9 років тому +4

    Excellent presentation! For someone currently studying mechanical engineering, this material could be a useful launch point for a final year project.
    However, the counterweight got me thinking. Since it's under a lot of centrifugal force. Does that mean it would experience a form of artificial gravity? If not, would it be possible to build a space station that goes beyond geostationary orbit to the point of being swung by the earth's rotation, thus making a space station that has it's own artificial gravity?
    Also. For factor of safety and strength, would it be a good idea to introduce multiple tethers that go out to the same space station?

  • @ggglew6992
    @ggglew6992 5 років тому +2

    How about inflatable hydrogen or helium sections with computerized propeller/propellant stabilizing and weight reducing propulsion systems.

  • @Azariven
    @Azariven 9 років тому +1

    I'm curious how you would respond to one of the 100 finalist, Prof. Joseph Roche's statement in the Matter's Magazine. I'm interested in how he got the number 2,761 for actual applicants compared to the advertised 200,000? And since Endemol is out of the picture, how is Mars One going to be funded?

    • @martiancolonist
      @martiancolonist  9 років тому +2

      Zhuchang Zhan Dr Roche did not write that article. It's pretty much all incorrect and I'll be explaining each point in a video on Thursday. There were not just 2,761 applicants, I don't know where that number comes from, perhaps the number of public profiles in the 1st round? In any case, there were certainly over 3,000 of those. Also, Endemol was never intended to fund the mission; as I've said before the funding comes almost solely from private investors (who get their return from broadcasting rights later on), so TV deals have nothing to do with funding the mission.

    • @Azariven
      @Azariven 9 років тому

      Martian Colonist it was an interview with him I believe. they never explained where the 2761 come from, which made themselves look quite discredited. So Endemol was not the "secret" investor that will fund mars one stage at a time?

    • @martiancolonist
      @martiancolonist  9 років тому

      Zhuchang Zhan No, Endemol is not Mars One's 'secret' investor.

  • @robertlatta2019
    @robertlatta2019 9 років тому +9

    Great presentation shame about the camera angle

    • @martiancolonist
      @martiancolonist  9 років тому +2

      Yeah, I was told the camera was angled to the area in front of the desk.

  • @csywf
    @csywf 2 роки тому

    Hi. Thanks for interesting presentation. I want to ask why Fu and Fd isn't always equal. Since I didn't major in Physics and don't know a lot about it, I couldn't understand it. Also, in my knowledge, tensile stress is valid when Fu=Fd. Isn't it??

  • @mortkebab2849
    @mortkebab2849 5 років тому +1

    Something I've wondered about: Could such extended mega-structures be detected over insterstelllar distances by some unique, spectral signature? I'm thinking by analogy with the experience of seeing a strand of spider silk next to a sunny window from the other side of a darkened room. You wouldn't normally have the visual resolution to see it but if the bright sunlight hits it just so you can detect it.

    • @martiancolonist
      @martiancolonist  5 років тому +1

      You wouldn't have much luck detecting an extra-solar space elevator, due to the low thickness of the cable. A better bet would be looking for artificial satellite constellations. There have been some papers on the detectability of this (Google: 'Clarke Exobelts').

  • @RayJin-dq1td
    @RayJin-dq1td 4 місяці тому

    This may make space travel available for an average person, and you can built a port or a mass driver too as the counter weight to get a further boost.

  • @enniopillecyn7753
    @enniopillecyn7753 9 років тому

    I have a question how are you going to Gt the asteroids orbit perfectly synchronised to the rotation of the earth without moving the platform on earth or in space couse its also going to pull up and down from time to time ?
    But great presentation by the way

    • @martiancolonist
      @martiancolonist  9 років тому

      The values I calculated are equilibrium values. When you first attach the cable to the asteroid, it will be in a different orbit because only the gravitational and centrifugal forces are acting on it. Now when you add the cable the additional force of tension alters the equation, and thrust must be applied to the asteroid to adjust it's velocity and stabilise the system to the new equilibrium value of the angular velocity of the Earth. This would use the same small rockets attached to the asteroid that were used to bring it into an Earth orbit in the first place.

    • @enniopillecyn7753
      @enniopillecyn7753 9 років тому

      Martian Colonist Ah so you need to do the calculations twice ?sorry for this seccond question but if you build the elevator with a shape of a rhombus(just with a fluqsuation of max 1m in the center) as in the video what type of elevation will you youse to have no trouble with the fluquations whatsoever and if you bring a object ofnlet's say 1 ton up with the elevator won't it change its angel from ~90 to ~95 will it cause a problem cause the elevator's stress point isn't in the middle'anymore then but a little lower where the diameter is less than the requird ~1m?
      Greatings from me and thanks for replieing so fast and sorry for my lack in english

  • @you3001
    @you3001 6 років тому +1

    Would the Van Allen radiation belt cause problems for human travel on the elevator?

    • @JM-us3fr
      @JM-us3fr 6 років тому

      Yes it would! Thankfully there's a simple fix. Look at
      en.wikipedia.org/wiki/Van_Allen_radiation_belt#Proposed_removal
      for a way to fix that problem. In fact, since carbon nanotubes are conductive, you could even pass the current through the cable itself, removing the Van Allen Belt entirely.

  • @jetsetjourneysofficial
    @jetsetjourneysofficial 9 років тому

    Interesting video. Is it really hot up there?

  • @burnzey6056
    @burnzey6056 9 років тому

    If we are to think the elevator is kind of like swinging around a yo-yo, with the force of the asteroid pulling outward would this cause the earth to have an odd wobble? If so, could this affect our weather and climate as well as orbit?

  • @mortkebab2849
    @mortkebab2849 5 років тому

    Something else I've wondered about: Surely there's a way to use something like "spool knitting" (which I recall from elementary school. googling it shows what I mean), and using a tiny spool, to produce carbon nanotubes of unlimited length. The current method is a matter of blasting some raw material with heat and collecting the results, which will never produce perfect nanotubes with macroscopic lengths.

  • @brucecrawford649
    @brucecrawford649 9 років тому +1

    Your not only a person who knows what hes talking about, but you also have good skills in public speaking. I can see it in this lecture and on your television interviews. How do you do it?? lol

  • @stanislavbandur7355
    @stanislavbandur7355 9 років тому

    Hi, I am too lazy to make calculations, (maybe it is the reason why) I am wondering about moon's elevator. Rough logic tells me that gravity is 1/6 (one sixth of Earth's mass) and rotation period is 27 times longer (centrifugal acceleration is 729 times smaller /if omega is 27 times smaller and squared/). Then the ratio between gravity and omega is 121.5 which is not quite good at first sight (my first sight)
    A: distance between Earth and moon is 384,400km which is 38.4x100,000km (counterweit can hit the Earth)
    B: length of cable will be 121.5 times bigger, then its weight will be corresponded to it (without Earth it is 121.5/6 times higher tension requirements 20.25times stronger material or crossection surface in stationary point)
    Does this logic corespond to physics?

    • @stanislavbandur7355
      @stanislavbandur7355 9 років тому

      Common sense tells me that we are at Moons stationary orbit

    • @martiancolonist
      @martiancolonist  9 років тому

      Stanislav BANDUR Here's a nice little summary on the lunar space elevator concept: en.wikipedia.org/wiki/Lunar_space_elevator

    • @stanislavbandur7355
      @stanislavbandur7355 9 років тому +1

      If I understand it well it uses Earth to balance forces too. Closer to Earth is moon's gravity balanced by earth's and at far side it is balanced by centrifugal acceleration of Earth-Moon system (LAGRANGE POINTS)

  • @Jaxvidstar
    @Jaxvidstar 9 років тому

    You never discussed where to build it. Which country will have the gateway to the milky way?

    • @martiancolonist
      @martiancolonist  9 років тому +2

      Jaxvidstar It would be an ocean platform in the South-East Pacific, since that is the place with the most stable weather statistically. As of such, it would be in international waters and hence not owned by any one nation.

  • @cartercordingley6062
    @cartercordingley6062 9 років тому

    what the number to build a Space Elevator on mars

    • @martiancolonist
      @martiancolonist  9 років тому

      Jacob Cordingley Here's an excellent paper explaining the specific issues governing a Mars space elevator: www.nss.org/settlement/mars/2003-SpaceColonizationUsingSpaceElevatorsFromPhobos.pdf

  • @wadepatten8760
    @wadepatten8760 5 років тому

    I believe they will be in for a high voltage surprise that will instantly melt their contraption

  • @theatom7264
    @theatom7264 8 років тому +2

    Interesting stuff. Has SpaceX ever shown an interest in a space elevator?

    • @martiancolonist
      @martiancolonist  8 років тому +2

      Not that I'm aware of, though a Martian space elevator makes absolute sense.

    • @JM-us3fr
      @JM-us3fr 6 років тому +1

      Musk has scoffed at the idea, since the materials are still far off. A company like spacex needs a proof of concept before pursuing. Someday when carbon nanotube cables are made in abundance, and are specifically used for their tensile strength, then companies will start considering it.
      The thing is, Musk misunderstands how close we are to making nanotube cables. In this video:
      ua-cam.com/video/LiE3VTc0D6w/v-deo.html
      you see Rice University creating spools of the stuff, however it's not one continuous molecule, but many smaller molecules that stick to each other because of electrostatic forces. Each molecule is perhaps 1 cm in length, so the max tension is essentially the minimum friction between the nanotubes. This might seem like a long way off from a space elevator, but it's actually surprisingly close.
      You see, as we make longer and longer nanotubes, that electrostatic friction gets stronger and stronger. Once that friction exceeds the base tension strength of the nanotube, the spool will effectively have the full tension strength.

    • @NaturalManifestation
      @NaturalManifestation 5 років тому

      @@JM-us3fr the other thing to consider is that we don't need exotic materials to make one on Mars. It would be quite smart to build one to be able to shuttle large quantities of materials in a very short period of time.

    • @mortkebab2849
      @mortkebab2849 5 років тому

      If Earth, the Moon and the other planets had any of the tethered methods of getting into orbit then we wouldn't need big rocket engines in order to go anywhere and that would put Spacex out of business.

  • @judeevans8303
    @judeevans8303 9 років тому +1

    Thats amazing!!! A system like this could be the begining of mass intersteller travel. Because the initial transfer would be free you would have plenty of fuel for manuevering and retroburns.
    Would it supply enough delta-v to send a ship to Mars with a landing pod and enough fuel to return to Earth?

    • @martiancolonist
      @martiancolonist  9 років тому +2

      It would require slightly more energy to lift the heavy payload for a return vehicle to the top of the elevator, but once you are are the right altitude you can certainly let go and just drift onwards to Mars. Or you could break up the vehicle into a number of parts, ship them up one by one, then let each one go at the right altitude to send a swarm of components to Mars.

  • @chocodaddynig1301
    @chocodaddynig1301 9 років тому +1

    I have a question. If you went to Mars how will you pay your university bills and stuff?

    • @Kelkschiz
      @Kelkschiz 9 років тому

      It would be easy for him to earn money once on Mars. His free time would be an extremely rare and thus extremely expensive commodity, if he chose to sell his services.

    • @chocodaddynig1301
      @chocodaddynig1301 9 років тому

      Kelkschiz oh alright

    • @martiancolonist
      @martiancolonist  9 років тому +1

      CanYouNot!
      Also, the wage for Astronaut Trainees is around $100,000 per annum, so as a respectable citizen of Earth I would try to pay them off before I left :-)

    • @nemvus_
      @nemvus_ 9 років тому

      Martian Colonist
      Oh whoops, terrible miscalculation on my part >.

    • @Azariven
      @Azariven 9 років тому +1

      Erifrail Sandoval 100,000*10*24 = 24 million = 0.024Billion

  • @davidfoster8187
    @davidfoster8187 8 років тому +1

    What exactly are they smoking?

  • @stardude692001
    @stardude692001 8 років тому

    Nothing worse than knowing what we will soon be capable of but also knowing almost all of us currently alive will be dead when it happens...

    • @JM-us3fr
      @JM-us3fr 6 років тому

      Not if Aubrey De Grey has anything to say about it

  • @_Teo_Dor
    @_Teo_Dor 8 років тому

    Any object lifted by the elevator needs to gain speed = increase its kinetic energy. how do you intend to add this energy to the lifted object?
    This presentation calculates just a static structure. As soon as you want to move an object along the cable ( supposedly up from earth surface) you need to add horizontal speed to the object, otherwise the whole structure exits the equilibrium state.
    In fact present day rocket launches are doing just that: add kinetic energy to the objects that we need to move to the orbit. = no need for cables! and this process in always in a dynamic equilibrium state.
    so, my question stays: how do you add kinetic energy to the lifted object?

    • @martiancolonist
      @martiancolonist  8 років тому +1

      Excellent question.
      What I've seen typically proposed for powering the lifted object is solar-cell motors driving loop lift cables every 100 km or so (with energy potentially transferred via a laser pointed upwards from the base station).
      With regards the horizontal velocity, you are correct that the payload naturally attempts to move laterally from the elevator (due to it moving to an altitude with a different rotational velocity). Since the payload is attached to the elevator though, it attains orbital velocity via a constraining side force imparted by the tether itself. In modelling the effect of this additional force, an extra very weak continual acceleration (amounting to ~5 N for a 500 kg load) is applied to the elevator.

    • @JM-us3fr
      @JM-us3fr 6 років тому

      It's a straight forward idea. The lift climbs the outside of the cable. The lift gets energy from a laser at sea level beaming it up to a receiver mounted on the climber. As the lift climbs the cable, it will naturally add vibrations into the structure that will need to be dampened. Dampeners could be placed every 10 kilometers or so. This will be helpful for the added instabilities that the Moon's gravity might cause, or slight variations in tensile strength. The best design uses multiple flat sheet cables, partly for redundancy and partly to make reparations possible. The "taper ratio" design is probably not gonna happen, because making a cable with inconsistent width is not practical from a manufacturing perspective.
      Anyway, altogether, the cable should have roughly twice the mass of the minimum functioning width. This more than accounts for the weight of the lift

  • @OwnageApe
    @OwnageApe 9 років тому

    awesome

  • @luvbotany
    @luvbotany 8 років тому

    its not long before we can mass produce CNT cables. 2090 seems too far out for the elevator, im guessing before 2050. Because there is nothing else on the drawing board that offers this much advancement into space, i see this as our future.

  • @theirishreptilian
    @theirishreptilian 9 років тому +1

    That moment when you see a Halo style space elevator in the middle of your city...

  • @zalphero618
    @zalphero618 9 років тому +2

    You're very smart

  • @sandeepsrikonda7352
    @sandeepsrikonda7352 8 років тому

    such interesting results from basic maths.....awesome concept.I thought space elevators are impractical.

  • @chateytung
    @chateytung 9 років тому

    1st - I will Choose Mount Everest as the base, Not an Island, it save 10000 meters of cables weight. 2nd - I get a helium big balloon as a second base, it save 15 km of cables weight...............than follow by a space station or big meteor as a third base

  • @IsaacOrson
    @IsaacOrson 9 років тому

    What is your opinion on this controversy: medium.com/matter/mars-one-insider-quits-dangerously-flawed-project-2dfef95217d3

    • @martiancolonist
      @martiancolonist  9 років тому +1

      IsaacOrson The short answer is that it is factually incorrect. For the detailed answer, I'm working on a video now which should be out on Thursday.

    • @IsaacOrson
      @IsaacOrson 9 років тому

      Martian Colonist Ahhh, okay cool, looking forward to it ;)

  • @ax23w4
    @ax23w4 9 років тому

    This is a bit off the subject, but I just wonder if you have any thoughts on technological singularity. There's this great article full of facts and quotes by famous people that says it will most definitely happen in 10-30 years from now:
    waitbutwhy.com/2015/01/artificial-intelligence-revolution-1.html
    Just curious about your opinion on this.

    • @martiancolonist
      @martiancolonist  9 років тому +1

      Ah yes, a fantastic article, saw it a few weeks back after Elon Musk recommended it.
      I think a technological singularity is an inevitabiltiy. We only need to look at how difficult it is to reliably predict what will happen even 10 years from now, since things are changing so fast. I encountered this problem when writing my own science fiction novel (set in the 2080s, where the world is on the verge of a singularity) where I almost certainly will have made predications that either won't come true or will come true decades before I predicted.
      I'm unsure about whether we'll see an AI revolution the likes of which Ray Kurzweil predicts in the 2045 time frame, but I'm about 30% sure that I will witness radical life extension during my lifetime (unless I'm on Mars of course!)

  • @craigglewis
    @craigglewis 5 років тому

    Have Access to 100 Millin Ton Graphite deposit, for making Graphene and Carbon Nanotubes. I think we can build the tether now :) Looking for Investors to start. :)

  • @ianbloom4934
    @ianbloom4934 8 років тому

    Tilt. The. Camera. Down. :)

  • @calvinsylveste8474
    @calvinsylveste8474 5 років тому

    You pronounced Jerome as if it was Jeremy, maybe it's a British thing.

  • @Blue.star1
    @Blue.star1 7 років тому

    only this is possible , not space elevator , link v=e5s26VzZe0U

  • @googleskype3490
    @googleskype3490 6 років тому

    Slow down!!!

  • @TyWooly42
    @TyWooly42 4 роки тому

    spend some money on a good sound engineer

  • @nPcDrone
    @nPcDrone 5 років тому

    Loooooooser
    The concept of a tower reaching geosynchronous orbit was first published in 1895 by Konstantin Tsiolkovsky.
    What he wants to talk about is NOT a novel brand new way to potentially approach space access. 10 seconds to thumbs down.

    • @martiancolonist
      @martiancolonist  5 років тому +1

      If you had watched to 1:17, you would have seen a discussion of Konstantin Tsiolkovsky's idea.