Here's the problem.

P1->v-------J-------<-P2

Jerry is positioned midway between two planets that are approaching each other
at +/-v as measured by Jerry.

Jerry calculates the total energy of the system as: 1/2Mv^2 + 1/2Mv^2 = Mv^2.

A friend on P1 contacts Jerry and argues that he is wrong. P1 is
appoaching at 2v and the energy of the system is therefore: 1/2M(2v)^2 or
2Mv^2.

Who is right?

(note how easy it is to produce a factor of 2 from nowhere, just as Einstein
did with his calculation of Mercury's precession)



Henri Wilson. ASTC,BSc,DSc(T)

www.users.bigpond.com/hewn/index.htm.