Space elevator

Check out this article:

I have read other articles on this but they never give any theory as to how it will work so… How will that work? Doesn’t it have to orbit? Will it not come down if something were to pull on it?

An SDMB search on “space AND elevator” will turn up all the answers to your questions, plus about 18 more pages of questions you don’t have.

Thanks… I have 56k… didn’t want to uspet the system. More importantly, didn’t want to spend my time doing it.

Short answers:

  1. Geosynchronous orbit.
  2. When you send something down, you also send something up (counterweight).

The mathematics and physics have been worked out for decades already; there’s nothing unknown about this, except when it will actually get done.

But you’re perfectly happy having other people spend their time delivering all of that on a silver platter for you?

If you’re really interested, find a copy of Robert L. Forward’s book url=]Indistinguishable from Magic. There’s a long chapter on space elevators, skyhooks, space fountains, rotovators, and other variations on the same idea.


OTOH, there’s a lot of people with practical engineering knowledge who consider it a joke. Will definitely never happen.

I believe the same was said about crossing the ocean, flying, and landing on the moon.

You are right. But that does not reflect on the plausibility or not of this scheme. Mistaken (or correct, for that matter) judgements on unrelated matters are irrelevant to this one.

Why not? The only technology required which we don’t currently have is long nanofibers, and I’ve never seen anything to suggest a maximum length for nanofibers. Even if we weren’t trying to build a space elevator, a material like that is well worth developing, and will be developed eventually.

If Motorola has their way, it’ll be sooner rather than later. And judging from the comments in one of the articles linked to in the thread, it looks like the hard part will be in preventing the nanofibers from becoming long tubes!

Crap. And ftg, I’d like to see a site for that comment of yours. (Not that it proves anything, IIRC there were engineers who said in July 1969 that Apollo would never succeed.)

Another problem is having the tapes (of,say, carbon nanofibres) avoiding lower orbit satelites.

Likelihood of a point object (satelite) hitting another point is very slim, but once you have a line the chances are much greater.

I have no cite for this, but I’ve heard that some speculate the elevator could be attached on Earth to an ocean-based platform that could be moved around.

I question the physics of this particular idea, but I have no scientific knowledge to back up my doubts.

What if something goes wrong and the elevator freefalls? If I “jump” before it hits the bottom, will I be O.K.? :smiley:

If the elevator is in free fall, it’s working correctly, Crafter_Man.

One question I’ve never gotten a satisfactory answer to in discussions of a space elevator (and I searched on the SDMB for this) is how you’d deal with the fact that your payload has a steady angular momentum which means that as the height of the elevator changes, so too must the angular velocity. In other words, as a massive payload travels outward on the elevator, the angular momentum of the payload is going to make the entire structure want to lean backwards relative to the rotation of the earth.

Presumably the same reason why a heavy rope whirled above your head doesn’t collapse to your hand (unless you stop spinning it and let it wrap around your arm) – momentum of the rope and continuous acceleration towards the center creates permanent tension in the rope. The rope’s momentum wants it to continue in a straight line at any given point, and you’re ‘pulling it back in’. Put a knot at the free end, or a bucket, or something, if that helps the experiment. While not necessary, this will help keep the rope taut.

Or, if you want a little bit better of an example, holding the rope at waist level, and spinning yourself in a circle. Difficulty: Spinning fast enough. Downside: you may be in no condition, due to dizziness, to make judgments, so bring a friend. In any case, as long as you and the rope (and bucket/knot) keep spinning, the rope should remain taut.

Admittedly not a rigorous experiment, but if you can get the elevator to hold itself up by way of balancing momentum, centripedal acceleration, and gravity (doable, of course, and well known for years) then it will remain taut. (Drastic oversimplification, as the elevator will likely have to be ‘manipulated’ to account for other environmental variations)

Every time the subject of the space elevator comes up, you claim this. I have yet to see you offer any substational engineering evidence of any sort why this is so. I have seen multiple engineering studies showing the feasability of the space elevator concept, includiong step-by-step on how it would be built and erected.

I suspect your engineering freinds don’t have a clue as to what they’re talking about in this case.

It might take a hundred years for carbon nanofibres to be produced long enough for this purpose; you don’t want something which is close to the engineering limit, you want something safe

it will then take two hundred years of politicking to get the thing built.
But this is not a long time in the scheme of things…

I am optimistic that mankind will last a lot longer than that, and once it is built, you are halway to anywhere

SF worldbuilding at