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Japan starts space elevator experiments

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Re: Japan starts space elevator experiments

#71

Post by onion2k »

sandworm101 wrote: post #2

Carbon nanotubes are cool, but i will believe space elevators possible once someone shows me a carbon nanotube rope i can climb with. I'd settle for a bike or motorcycle chain. A nanotube-based shoelace would be worth a noble prize or two.

On a practical note, if you drop something on your foot you need to be able to take your shoe off quickly - cutting the laces is often the best approach. Shoe laces as strong as steel would likely lead to you losing your foot.

Same goes for titanium wedding rings...

Re: Japan starts space elevator experiments

#72

Post by mipmap04 »

DoreenMichele wrote: post #60
tomovo wrote: post #56

Earlier quoted context omitted.

Stairway to Heaven is about 8 minutes long, so they better work hard on speeding the elevator up to match that.

Only if they want this to be a fancy burial service where we slingshot your corpse into space for kicks.

I don't doubt there's a market for that service.

Re: Japan starts space elevator experiments

#75

Post by perl4ever »

a1369209993 wrote: post #65
tomovo wrote: post #56

Earlier quoted context omitted.

Stairway to Heaven is about 8 minutes long, so they better work hard on speeding the elevator up to match that.

You'd need to accelerate at 68 G's[0] (foreward for the first four minutes, backward for the last four). Not neccesarily unsurvivable, but your passengers (and most cargo) are likely to be unpleasantly pastelike. We should probably treat it more like commercial air travel than compressive-structure elevator rides. 0: 200kph*8day/8min/2min => 67.981081 gravity

TIL forwards acceleration is called "eyeballs in" and backwards is called "eyeballs out".

It looks like 6 Gs is about as much as is feasible for an extended period of time.

Re: Japan starts space elevator experiments

#76

Post by DavidSJ »

Someone wrote: post #70
Barrin92 wrote: post #36

Earlier quoted context omitted.

six oval shaped cars with those measurements each is about 780 square meters in total. The average Tokyo condo is about 65 square meters (for a family of three). Somewhat unpleasant for 30 people but not really that small. Like 3 people in one Tokyo apartment density wise.

”Obayashi envisages a space elevator using six oval-shaped cars, each measuring 18m x 7.2m holding 30 people, connected by a cable” I can’t see how one would read that other than as each car holding 30 people. You would need an extra comma to make it six cars holding 30 people in total: ”Obayashi envisages a space elevator using six oval-shaped cars, each measuring 18m x 7.2m, holding 30 people, connected by a cable”

But the original sentence is ungrammatical either way. Under your interpretation there’s still a missing “and”: “each measuring 18m x 7.2m and holding 30 people”.

Re: Japan starts space elevator experiments

#77

Post by Keyframe »

p1mrx wrote: post #54
Keyframe wrote: post #38

Earlier quoted context omitted.

And how exactly do you plan to 'knock out' people safely for eight days, or even just a few? Heck, even for just a few hours without medical equipment and personnel?

The medical technology for human stasis doesn't seem particularly unattainable, when compared against building a carbon nanotube tether into orbit. Some mammals are able to hibernate for months.

So far, for humans, that lives within same realm that warp drives occupy in science fiction.

Re: Japan starts space elevator experiments

#79

Post by ckemere »

sandworm101 wrote: post #2

Carbon nanotubes are cool, but i will believe space elevators possible once someone shows me a carbon nanotube rope i can climb with. I'd settle for a bike or motorcycle chain. A nanotube-based shoelace would be worth a noble prize or two.

We can already make CNT based fibers at scale fairly cheaply. Would happily sell you a shoelace for much less than the $1M that a Nobel prize comes with...

http://news.rice.edu/2017/10/16/long-nanotubes-make-strong-f...

(Though note that this is not one long nanotube, but a macroscale fiber made by extruding micron-scale CNTs in a special way so that they align.)

Re: Japan starts space elevator experiments

#80

Post by Atheros »

zadler wrote: post #64
ethbro wrote: post #9

Earlier quoted context omitted.

Physics would tend towards "No." Assuming a catastrophic break near the upper end of the cable (before the counterweight), there's not much you can do to keep it from coming down.

Perhaps unless you decide to detach the cable at the earth end? You might be able to react to a break faster than the cable can fall.

Even if you could react and cut the cable in 1 ms, if the counterweight is disconnected, the rest of the cable is coming down to Earth.
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