Earth-Moon Fire Pole
what-if.xkcd.com
what-if.xkcd.com
Then use a pole that is strong enough to eliminate this problem.
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 geostationary to any point on the Earth.
The pole would also solve that problem ...
But given you're just making absurd "just do X" style statements I'm sure you'll reply with some remark about gluing the moon back together or wrapping it in clingfilm before you insert the pole to strengthen it's integrity.
The solution is obviously attaching rockets to the moon to accelerate it first.
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.
Probably bad ones.
I seem to have a category in my brain for cool, creative internet stuff that will last as long as it lasts, but probably won't be replaced by the modern internet.
Anyway.. these days.. xkcd would be starting on Twitter, FB or pictogram. Back then it was blogrolls and Reddit. The medium is the message and the discovery channel is the medium, I think.
I had a discussion with some 4 years old about fire extinguisher and why there were 2 at the nursery. My simple explanation was disappointing to one and I learned from his mom that it ended up looking the various type of firetruck and what number of what type of fire extinguisher they were carrying as well as the various hose option, the different type of fire and the various safety labels on product helping determining the type of fire they produce, ...
The others where also unhappy with the few details I provided, it seems "there is a big one and a smaller one" was what they were expecting.
(Sorry for saying the (possibly) obvious.)
And this is what makes it wonderful.
Anyway, sending a question to "What If?" is like sending a question to Mythbusters. You never get an easy answer, but an overthinked answer that involves some destruction and explosions.
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.
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.
For the numbers I used a safety factor of 1. The slightest nick or scratch would cause a break. Safety factor of 3 is more sensible.
Earth moon firepole staple
Actually, the person sliding the pole would be like an object changing orbit. Remember, Moon orbits Earth. Even at L1 you can't just push yourself and coast along the pole. The movement along the pole is changing orbits and as we know this requires energy. In this case if you push yourself along the pole you would suddenly find yourself drifting away from it.
That's of course if you could create a rigid pole. As every piece of the pole would be on a different orbit there would be huge forces acting on the pole.
Suppose you tether yourself to the pole with a ring, and are closer to the Earth than L1. You now are not moving fast enough to stay in the orbit implied by your current altitude, so you move in an orbit that brings you closer to the Earth.
You also try to move away from the pole, but you are tethered to it, so there is a force holding you by the pole. That force provides energy to you.
So it seems to me that it does work, and I don't understand your reasoning.
Moon orbits Earth at about 1km/s and you have to loose orbital speed as you move along the pole.
Since the pole distance is about 400000km and the orbital speed to loose is 1km/s it means you need to loose about 2.5mm/s for every km of the pole that you travel. It may not sound much, but if you propel yourself along the pole in the direction of Earth at L1 you would be surprised to find yourself travelling away from the pole at 2.5mm/s after 1km. If you push yourself hard at say 36km/h (or 10m/s) and decide to get some sleep then you would travel almost 290km but you would also find yourself moving away from the pole at almost 1m/s and at about 10km from the pole.
> Note: While you're flinging yourself along, be careful not to drift out of reach of the pole. Hopefully you brought some kind of safety line so you can recover if that happens.
Of course you have lateral forces on the pole, that's not in question. But if you're sliding down the pole then you're, you know, sliding down the pole. That means you are hanging on to it somehow, or tethered to it, or something.
The point is that if you are actually sliding down the pole then it really does actually work.
> ... you would be surprised to find yourself travelling away from the pole at 2.5mm/s after 1km.
No, I wouldn't be surprised at all, because I do know a little about orbital mechanics. Possibly not as much as you do, but I do give talks on it, so if you can explain clearly how sliding down a pole (once closer than L1) won't work, I'd be really interested to hear it, because so far what you're saying hasn't convinced me.
If all you're doing is saying "If you're not tethered to the pole then you'll drift away from it and it won't work." then we have no problem. But I'm considering the case where we are, in fact, sliding down the pole.
Of course, if you decide to actually fall to Earth from L1 that starts becoming problem. I'm too lazy to calculate exact terminal velocity you would reach when falling L1 to Earth (it won't be the 11km/s you would reach if you were falling from Moon orbit because you also have Moon tugging you). I estimate it not lower than 9km/s (Moon has 2.4km/s escape velocity).
Now, if you moved along the pole at 9km/s you would feel much more tug (noticable 2.5cm/s2) or about 1/40th of Earth surface gravity. If you were 80kg person that would mean about 2kg apparent force.
Of course, by that time you wouldn't be thinking much about it as you would have other problems in mind...
As an object falls towards earth it will surge ahead of the moon and the moon will be pulling it backwards. This makes effective apogee more in the range of 300,000 km.
A 300,000 x 300 km orbit has velocity of about 10.8 km/s at perigee.
In other words, dropping from the neighborhood of L1 will still give you speed very close to escape velocity by the time it reaches earth.
In the case of orbital tether, an elevator car would have gripping wheels in contact with the tether. If its's descending the wheels can power a generator to charge the elevator car's battery.
He already said it's a magical pole, I think that covers it. That also implies that some of the forces involved can be ignored for didactic purposes. I mean, the big problem with all of this is it's utterly impossible, but that's not the main point. "What if ... ?"