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Space Elevator

neal.fun

161–170 of 414 posts

Re: Space Elevator

#161
post #132
post #86

Earlier quoted context omitted.

I don't like to input Cc details into random sites whose main business is processing said transactions.

I'm not understanding this sentiment at all. You'd rather input your CC details into a site whose main business isn't dealing safely with credit cards - rather than inputting it into Stripe (which is what his site uses), whose entire raison d'etre is doing so?

Sorry, I got the expression wrong. You must inverse the logic :)

Re: Space Elevator

#162
post #150
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…

Kim Stanley Robinson's description of a Martian space elevator falling and wrapping twice around the entire planet convinced me that they aren't a good idea. https://www.kimstanleyrobinson.info/content/clarke

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

Re: Space Elevator

#163
post #138
post #90

Earlier quoted context omitted.

A space elevator on Earth would be over 35,000 kilometres long. Depending where it broke it could wrap halfway around the Earth.

At first I was confused by this because the Kármán line is less than a percent of Earth's circumference up, but then I realised we're probably talking a geostationary anchor or something, which is very nearly a circumference up.

Yes, you need a geostationary orbit for the tether, otherwise it would either fall down or spiral away with time.

Re: Space Elevator

#164
post #84

Earlier quoted context omitted.

Only if the material is way over provisioned. In general, the higher the intrinsic structural load is on a material, the easier it will be to destroy. So, to defend from these attacks, you not only need a cable that can support its own weight, plus the weight of the desired payload, plus some small-is extra tolerance. Instead, you probably need a cable that can support, say, twice its own weight plus four-five times…

You only need to defend the easy to reach parts. So the base and the cargo pod. To hit the upper parts you need advanced rockets and targeting systems.

Why advanced? It's a stationary target that's 35,000 km long. I don't think it would be that hard to hit.

Not to mention, securing the cargo would be an extremely difficult task in itself, especially when one of the main thinga you'd like to raise through the space elevators is rocket fuel.

Re: Space Elevator

#165

This was incredible! Couldn't stop scrolling and reading. For a kid of a certain age and curiosity it'll blow their mind! I'm so grateful the creator made this, shame that his "buy me a coffee" isn't a simple PayPal or Apple Pay but you have to put in credit card or bank details!!

How do you pay with PayPal if not putting in your credit card or bank details? link is a pretty well-known online wallet and much simpler to use than PayPal.

Re: Space Elevator

#166
post #158

Very cool. One thing I wish was better shown: space is close, it's just hard to go up. Our liveable breathable atmosphere is razor thin compared to the size of earth. In most cases, 100km is less than the distance between sizeable metropolitan areas. It's a day long bike ride. Air runs out less than a bus ride across town. A 15k jog/hike would put you in the stratosphere. Those jet aircraft that seem so high are clos…

> it's just hard to go up Going up is the comparatively easy part, it's not exactly rocket science. Going fast enough sideways so you stay up there is the tricky bit.

> Going fast enough sideways so you stay up there is the tricky bit.

nah, thats the simple part. getting up there efficiently is the difficulty. once we're up, its just a matter of force over time to create a nice orbit.

The faster you go, the more friction you face, and the more heat and vibration your equipment must endure.

Going slower reduce friction and stress but use more energy just negating gravity. Slow rocket is inefficient rocket.

So we wanna leave the atmosphere as soon as possible, but not so fast that the rocket melts or engines collapse. Prefferably just below the sound barrier.

once we're up, its pretty chill... until you wanna go down again. Slow rocket is alive rocket.

Re: Space Elevator

#167

Earlier quoted context omitted.

Darwin started with survival of the "fit". It changed to "fittest" in later editions.

People focus on the wrong issue so most quotes about evolution are highly misleading: the keyword should be about reproducing. Survival is almost irrelevant. Darwin awards in particular should never be given to anyone with kids (unless they kill their kids too). "Most grandkids" is good but not catchy. Or Idiocracy "evolution began to favor those who reproduced the most".

I agree to some extent but I don't think you can really separate the two. You have to survive long enough to reproduce enough. For almost all species, reproduction implies a non trivial amount of survival.

Edit: actually, "almost all species" is not right. Maybe "almost all interesting species"... which is admittedly too subjective a take.

Re: Space Elevator

#170
post #8

TIL it's estimated that over 48 tons of meteors hit the atmosphere every day. Regarding actual space elevators though, while they're not sci-fi to the extent of something like FTL travel - ie. they're technically not physically impossible - they're still pretty firmly in the realm of sci-fi. We don't have anything close to a cable that could sustain its own weight, let alone that of whatever is being elevated. Plus,…

There are designs for untethered structures in orbit that could function with current technology, e.g. https://en.wikipedia.org/wiki/Skyhook_(structure)
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