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You are not logged in. #1 20100819 22:18:14
Spaceship and the planetA spherical planet has only one inhabitant that can move freely on the surface of the planet with speed u. A spaceship approaches the planet. Let the maximal speed of the spaceship be 10u. Show that the spaceship can always see the inhabinant regardless of the way he moves. #2 20100824 02:11:38
Re: Spaceship and the planetAm I missing something here? As the spaceship can go lots faster, and assuming it can approach as close as it likes and manoeuver freely, what's to stop it just following inhabitant about. You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #3 20100824 07:29:30
Re: Spaceship and the planet
If the spaceship approached the present position of the object and never changed course, while the object moved, the spaceship could lose sight of the object. The object could make it to the far side of the sphere. In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #4 20100827 22:14:26
Re: Spaceship and the planetAssuming that the inhabitant doesn't want to be seen, I've found a way the spaceship can move so to always spot the inhabitant. This gives the lower limit for v/u in this case. I would like to hear your opinion on it. Here it goes... Does this look ok? #5 20100828 01:07:59
Re: Spaceship and the planetMaybe I'm missing something. Why did the vector cross the road? It wanted to be normal. #6 20100828 01:55:34
Re: Spaceship and the planetHi all; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #7 20100828 03:59:21
Re: Spaceship and the planetI also got the problem not defined well. I' assumed the ship coming form infinity heading towards the planet. In trying to find the optimal algorithm for finding the inhabitant, I assumed it stopped at the distance d and moved the way I described in post #4. 