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I would like "A journey to the middle of the Earth?"Or is that one taken?

Went for some fresh air?Never mind, it's not the wrapping, it's the content that matters

If you look at the bottom of the first post, it will tell you who last edited it. Right now, it says me, since I just tested changing your title and changing it back to see if my name showed up as editor. Prior to me editing, it said you last edited it. Prior to that, I don't know!It might be that your post title wasn't in the form of a question--it's forum policy to phrase titles as questions, so a mod might have changed it to try to be helpful.

why are you allowed to edit my post?

Here's how you do it:Force = -m M G r^{-2},where m is your mass, M is the mass contained within a spherical shell under your feet, at any given depth, and r is how far you are from the center.You can compute M=4/3πr^{3}ρ,where ρ is the mass density of the earth (you assume it to be uniform, but whatever... this is a back-of-the-envelope computation). ρ=M_{e}/(4/3π R^{3}),where M_{e} is the earth's mass.Plugging all this back in F=-mM_{e}GR^{-3}r.All that junk to the left of r is constant. This is identical to the force exerted by a spring, F=-kx, where k is given by all that constant stuff. The period of a spring is 2π(k/m)^{-1/2}, so the period of your oscillations through the center of the earth is(M_{e}GR^{-3})^{1/2}I get ~250 seconds transit time. I might have made a slight mistake, but your motion through the earth is just like a spring.

The results from this thread seems to confirm that that the mathematical skills of our correspondents falls short of a Hooke or a Newton, or maybe they just dont care !

Quote from: syhprum on 09/12/2010 21:25:28The results from this thread seems to confirm that that the mathematical skills of our correspondents falls short of a Hooke or a Newton, or maybe they just dont care !If I had the math skills of Newton, I'd treat you all to pizza with my Nobel prize money!

Quote from: JP on 10/12/2010 02:57:40Quote from: syhprum on 09/12/2010 21:25:28The results from this thread seems to confirm that that the mathematical skills of our correspondents falls short of a Hooke or a Newton, or maybe they just dont care !If I had the math skills of Newton, I'd treat you all to pizza with my Nobel prize money! No offense to Newton, he was beyond his own years, but his maths skills today would be somewhat lacking.