6 ms·

We're all going sideways already, since the earth spins. Climb the ladder up to about 22 thousand miles and you'll be in geostationary orbit. The catch is tha

We're all going sideways already, since the earth spins. Climb the ladder up to about 22 thousand miles and you'll be in geostationary orbit. The catch is that nobody can actually build a ladder strong enough. Space elevators from Earth require sci-fi materials.

andylynch 4y ago
Also when it fails expect the lower end to fall and wreck everything in the area underneath. Which with that length will be a lot! The insurance bill would be … astronomical (see what happened in the Foundation TV show for an example).
- Sharlin 4y ago
  Modern space elevator designs (starting from Brad Edwards’s NIAC study in the early 2000s) propose something much closer to a tether than a tower, maybe some hundreds of tons in total mass and shaped like a gossamer-thin ribbon. The worst-case failure mode of such a design would be rather anticlimactic.
taneq 4y ago
I wonder how much it would help to have jets built in to the elevator which add support using compressed gas or something being pumped through the elevator from the ground? Then it would directly support the structure and also give the option of reacting to outside disturbances.
- Sharlin 4y ago
  The ideal gas law tells you what happens when you do work on a system of gas molecules (in this case against the force of gravity).
  - taneq 4y ago
    What are you thinking of? Yeah, compressing the air at the base will increase its temperature, and then the pressure (and so temperature) will reduce as it gets higher, but it’s still going to be at a higher pressure than the air outside and so can provide support and reaction mass. You might even be able to take advantage of this by chilling the compressed air before it goes into the beanstalk, so that it absorbs heat from the surrounding air on the way up. Or have separate pipes with one carrying methane to burn as fuel. Lots of options to evaluate.
deleted 4y ago
[deleted]
knodi123 4y ago
> The catch is that nobody can actually build a ladder strong enough. Yes, we've ruled out aluminum and wood. But don't give up! Got any single-crystal graphene? That might work! https://www.azom.com/article.aspx?ArticleID=16371 https://www.azom.com/article.aspx?ArticleID=16371

andylynch 4y ago

Also when it fails expect the lower end to fall and wreck everything in the area underneath. Which with that length will be a lot! The insurance bill would be … astronomical (see what happened in the Foundation TV show for an example).

Sharlin 4y ago
Modern space elevator designs (starting from Brad Edwards’s NIAC study in the early 2000s) propose something much closer to a tether than a tower, maybe some hundreds of tons in total mass and shaped like a gossamer-thin ribbon. The worst-case failure mode of such a design would be rather anticlimactic.

taneq 4y ago

I wonder how much it would help to have jets built in to the elevator which add support using compressed gas or something being pumped through the elevator from the ground? Then it would directly support the structure and also give the option of reacting to outside disturbances.

Sharlin 4y ago
The ideal gas law tells you what happens when you do work on a system of gas molecules (in this case against the force of gravity).
- taneq 4y ago
  What are you thinking of? Yeah, compressing the air at the base will increase its temperature, and then the pressure (and so temperature) will reduce as it gets higher, but it’s still going to be at a higher pressure than the air outside and so can provide support and reaction mass. You might even be able to take advantage of this by chilling the compressed air before it goes into the beanstalk, so that it absorbs heat from the surrounding air on the way up. Or have separate pipes with one carrying methane to burn as fuel. Lots of options to evaluate.

deleted 4y ago

[deleted]

knodi123 4y ago

> The catch is that nobody can actually build a ladder strong enough. Yes, we've ruled out aluminum and wood. But don't give up! Got any single-crystal graphene? That might work! https://www.azom.com/article.aspx?ArticleID=16371 https://www.azom.com/article.aspx?ArticleID=16371