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Earth-Moon Fire Pole

what-if.xkcd.com

51–60 of 72 posts

Re: Earth-Moon Fire Pole

#51
post #6

> There's one more problem: The Moon doesn't always stay the same distance from Earth. Its orbit takes it closer and farther away. Then use a pole that is strong enough to eliminate this problem.

At these scales the rock that makes up the Earth and Moon is just a low-viscosity liquid. A strong pole would just go through the Earth without a ripple.

Re: Earth-Moon Fire Pole

#52

Earlier quoted context omitted.

Let me guess - your favorite map projection is Goode Homolosine. You like easy solutions. You think we wouldn't have so many problems if we'd just elect normal people to Congress instead of Politicians. You think airlines should just buy food from the restaurants near the gates and serve that on board. You change your car's oil, but secretly wonder if you really need to.

For reference: https://www.xkcd.com/977/

For mobile: https://m.xkcd.com/977/

Re: Earth-Moon Fire Pole

#53
Hey Randall! If you put a microwave in a sub-zero walk-in fridge, and after the device had reached equilibrium with ambient conditions, you connected the microwave to mains power, then put a chunk of ice in the microwave and turned it on at full power, would the ice ever melt?

Re: Earth-Moon Fire Pole

#54
post #53

Hey Randall! If you put a microwave in a sub-zero walk-in fridge, and after the device had reached equilibrium with ambient conditions, you connected the microwave to mains power, then put a chunk of ice in the microwave and turned it on at full power, would the ice ever melt?

I guess the answer would be similar to the toaster-in-fridge question[1] from a previous what-if, namely: yes, it would melt.

[1] https://what-if.xkcd.com/155/

Re: Earth-Moon Fire Pole

#55
post #53

Hey Randall! If you put a microwave in a sub-zero walk-in fridge, and after the device had reached equilibrium with ambient conditions, you connected the microwave to mains power, then put a chunk of ice in the microwave and turned it on at full power, would the ice ever melt?

I guess the answer would be similar to the toaster-in-fridge question[1] from a previous what-if, namely: yes, it would melt. [1] https://what-if.xkcd.com/155/

but what if microwaves don't heat solid ice at all, they heat the water that forms on the ice because the microwave is at room temperature? google "how to melt glass in a microwave".

Re: Earth-Moon Fire Pole

#56

Wouldn't attaching the pole at a pole (heh) be a better strategy to avoid uncomfortable relative velocities? It would also have the advantage of providing a fixed place on the earth to find a stash of warm clothes and an energy drink.

You're going to have yet more fun with the fact that as your position on the (metal) pole approaches the (planetary) pole, gravity is going to start tilting until at the very end you are traveling horizontally, or at least close to it.

Evaluating how much this effects the problem is difficult, as for the (metal) pole meeting Earth on the equator the answer is "laughably impossible", and for the (metal) pole meeting at (Earth's) pole the answer is "laughably impossible", and which one is "harder" will depend entirely on your assumptions about how the impossibilities relate. Relative to having actually climbed up to L1 and relative to surviving descent into Earth, being on a horizontal pole rather than a vertical one may not be seen as a very big deal.

Re: Earth-Moon Fire Pole

#57
wait but he didn't answer how long it would take! i was reading for a big payoff at the end when he takes an integral to all those stages!

Re: Earth-Moon Fire Pole

#58

Reading these makes me very happy, I'm so grateful Mr Munroe is still working on them.

Do you know of any similar websites? I have a couple of questions that I would like to see answered. I emailed mr Munroe in the past but he never replied, I'm sure he has thousands of questions from readers to choose from.

https://waitbutwhy.com/ is pretty good, you need to set aside a decent chunk of time for each article typically.

Re: Earth-Moon Fire Pole

#59
post #12
post #6

> There's one more problem: The Moon doesn't always stay the same distance from Earth. Its orbit takes it closer and farther away. Then use a pole that is strong enough to eliminate this problem.

What material would you suggest is strong enough to handle the orbit of two massive bodies (relative to girth of a poll one could realistically hold onto)? And what do you suppose the consequences of altering the moons orbit would be? Something with elasticity would be a better option than something that is strong but even that wouldn't resolve some of the other issues presented; such as the moons surface not being g…

"What material would you suggest is strong enough to handle the orbit of two massive bodies (relative to girth of a poll one could realistically hold onto)?"

I'm not sure that question is well-defined; to the best of our knowledge we're firmly in the realm of magic here regardless of the details. Nothing even like a metal pole could traverse that distance. The materials that just might barely work to build a space elevator from Earth to Earth geostationary orbit are strong against tension, but this "pole" would be experiencing not only a lot more of that, but also some shear forces, and given how close to the theoretical maxes the space elevator already is, I don't think I have to work any math to know that it's just out of the question.

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