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Space Elevator

neal.fun

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Re: Space Elevator

#201

Post by hermitcrab »

joenot443 wrote: post #173
enraged_camel wrote: post #162

Earlier quoted context omitted.

A version of this also happens in the first season of Foundation, the Apple TV series based on Asimov's novels.

Would you recommend that show to the HN crowd? The books are super well liked around here, for good reason. Apple's put out a staggering amount of content the last few years, I wasn't even aware this one debuted!

It's about 45 years since I read the books, but the whole idea of being able to predict the future of human societies accurately with maths seems rather silly. Especially since chaos theory became mainstream.

Re: Space Elevator

#202

Post by kingkawn »

joenot443 wrote: post #173
enraged_camel wrote: post #162

Earlier quoted context omitted.

A version of this also happens in the first season of Foundation, the Apple TV series based on Asimov's novels.

Would you recommend that show to the HN crowd? The books are super well liked around here, for good reason. Apple's put out a staggering amount of content the last few years, I wasn't even aware this one debuted!

If you go into it looking for interesting sci-fi, especially the story of the Cleons, you’ll enjoy it. If you go into it looking for Asimov’s Foundation you’ll be disappointed

Re: Space Elevator

#203

Post by kingkawn »

gizmo686 wrote: post #180
isgb wrote: post #133

> Space elevators are actually a possible idea being considered by scientists. > The hard part is making a strong enough cable. And finding enough elevator music... Most engineers would bring up a lot more issues than just finding a strong cable. Also, most attempts with e.g. carbon nanotubes have been abandoned ages ago https://www.newscientist.com/article/2093356-carbon-nanotube... . - We don't have a good ascent m…

Isn't the entire point of the space elevator to be the ascent/descent mechanism? Once you have the cable up, you can grab onto it and pull yourself up.

Doesn’t the weight of the cable itself let alone any payload preclude this from becoming real based on all plausible material science

Re: Space Elevator

#205

Post by reaperducer »

isgb wrote: post #133

> Space elevators are actually a possible idea being considered by scientists. > The hard part is making a strong enough cable. And finding enough elevator music... Most engineers would bring up a lot more issues than just finding a strong cable. Also, most attempts with e.g. carbon nanotubes have been abandoned ages ago https://www.newscientist.com/article/2093356-carbon-nanotube... . - We don't have a good ascent m…

Most engineers would bring up a lot more issues than just finding a strong cable.

He did. The elevator music!

Re: Space Elevator

#206

Post by gizmo686 »

kingkawn wrote: post #203
gizmo686 wrote: post #180

Earlier quoted context omitted.

Isn't the entire point of the space elevator to be the ascent/descent mechanism? Once you have the cable up, you can grab onto it and pull yourself up.

Doesn’t the weight of the cable itself let alone any payload preclude this from becoming real based on all plausible material science

It's more of the strength-to-weight ratio than just weight. But yes, there is no known material that would work as a cable for a space elevator.

Re: Space Elevator

#207

Post by Symmetry »

isgb wrote: post #133

> Space elevators are actually a possible idea being considered by scientists. > The hard part is making a strong enough cable. And finding enough elevator music... Most engineers would bring up a lot more issues than just finding a strong cable. Also, most attempts with e.g. carbon nanotubes have been abandoned ages ago https://www.newscientist.com/article/2093356-carbon-nanotube... . - We don't have a good ascent m…

Impractical on Earth given existing technology, but there are a lot of bodies in the solar system which have enough gravity to make them worth while but where they're small enough that the materials needed are ones we have right now. The Moon in particular.

Re: Space Elevator

#209

Post by bisby »

gizmo686 wrote: post #180
isgb wrote: post #133

> Space elevators are actually a possible idea being considered by scientists. > The hard part is making a strong enough cable. And finding enough elevator music... Most engineers would bring up a lot more issues than just finding a strong cable. Also, most attempts with e.g. carbon nanotubes have been abandoned ages ago https://www.newscientist.com/article/2093356-carbon-nanotube... . - We don't have a good ascent m…

Isn't the entire point of the space elevator to be the ascent/descent mechanism? Once you have the cable up, you can grab onto it and pull yourself up.

A space elevator doesnt just take you to the karman line (like in the OP website), to get to orbit, you'd need to get up to geostationary height. That's 22,000 miles.

What's the best way to pull yourself directly vertical along a cable for 22,000 miles?

What's the best way to descend 22,000 miles quickly, but also with a braking mechanism that isn't going to require a heat shield?

Some sort of slow cable car going at 10mph even is going to take 2200 hours... 1000mph is going to take 22 hours still. That's a full day to orbit even going REALLY fast. And getting up to 1000mph vertically, for a sustained 22 hours... that's not an easy feat.

And if the goal is just to get up past the karman line and use the elevator as a stage 1 for a rocket launch and detaching from the elevator while suborbital is fine, then it's a one way trip, and still need to re-enter the old fashion way.

The scale of space makes all of the problems far more complicated (edit: not just the cable strength issue, but traversing the cable)

Re: Space Elevator

#210

Post by hermitcrab »

bombcar wrote: post #147
isgb wrote: post #133

> Space elevators are actually a possible idea being considered by scientists. > The hard part is making a strong enough cable. And finding enough elevator music... Most engineers would bring up a lot more issues than just finding a strong cable. Also, most attempts with e.g. carbon nanotubes have been abandoned ages ago https://www.newscientist.com/article/2093356-carbon-nanotube... . - We don't have a good ascent m…

All we have to do is make the global religion require bringing a rock to a specific location; after long enough we’ll have a mountain so high it extends out of the atmosphere!

To get to the Kármán line (100k) a mountain with a 60 degree slope would require a base of 115km. A cone with 115km diameter base has a volume of 3.5×10^5 km^3. Which is 3.5x10^14 m^3, which is about 10^15 kg of rock. So it is going to take you a while!
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