Fun fact: the orbit of the Moon around the Sun is concave in every point.
Convex.
Earth-Moon Fire Pole
31–40 of 72 posts
Re: Earth-Moon Fire Pole
#32Re: Earth-Moon Fire Pole
#33Wouldn'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.
If you fix it to a point on the earth, how will it get to the moon?
The (fire) pole wouldn't meet the (geographic) pole vertically. In fact, I suspect it would have to travel through the Earth, which might be a little bit disruptive as the moon orbits...
Re: Earth-Moon Fire Pole
#34Unfortunately it is inaccurate. 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 co…
> 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.
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.
Re: Earth-Moon Fire Pole
#35So he doesn't actually answer the question - how long would it take? He goes off on a tangent about disembarking from the pole
He does, indirectly. He just can't give a precise estimate. A few years to climb to L1, a matter of weeks afterwards.
Re: Earth-Moon Fire Pole
#36Earlier quoted context omitted.
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…
> such as the moons surface not being geostationary to any point on the Earth. The pole would also solve that problem ...
...not without tearing the moon apart in the process. At which point you have much bigger issues (as well as no need for a pole in the first place).
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.
Re: Earth-Moon Fire Pole
#37Unfortunately it is inaccurate. 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 co…
> That's of course if you could create a rigid pole
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 ... ?"
Re: Earth-Moon Fire Pole
#38Reading 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.
Re: Earth-Moon Fire Pole
#39Wouldn'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.
If you fix it to a point on the earth, how will it get to the moon?
the pole doesn't need to be straight. It could be hook shaped.
Re: Earth-Moon Fire Pole
#40Unfortunately it is inaccurate. 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 co…
> 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. Suppose you tether yourself to the pole with a ring, and…
The mentioned loop around the pole attached to your waist would do but since none of the extremely detailed drawings contained the loop we must assume that the person travaled the pole without the loop.
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.