Good piece

Posted Nov 29, 2012 23:21 UTC (Thu) by davidescott (guest, #58580)
In reply to: Good piece by Cyberax
Parent article: LCE: Don't play dice with random numbers

> Newtonian mechanics has no problems with infinitely fast objects, as long as you don't collide them with something else.

WHAT?

If you think that is the case solve the following single particle 1-dimensional, force-less system:
t=0: the particle is "at" x=0 and has dx/dt=\infty and d^2x/dt^2=0.
Solve for t=1 to get x_1,v_1,a_1

Now solve the following systems for t=1 and t=-1:
t=0: x=x_1, dx/dt=-v_1, d^2x/dt^2=a_1
t=0: x=2*x_1, dx/dt=-v_1, d^2x/dt^2=a_1
t=0: x=x_1, dx/dt=-2*v_1, d^2x/dt^2=a_1
t=0: x=2*x_1, dx/dt=-2*v_1, d^2x/dt^2=a_1

Either you cannot do this, or something will be contradictory.

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Good piece

Posted Nov 30, 2012 0:33 UTC (Fri) by Cyberax (✭ supporter ✭, #52523) [Link] (1 responses)

That's just an artifact of a chosen coordinate system. If you really want to solve it - write down Lagrangian of a system and see what happens.

Good piece

Posted Nov 30, 2012 2:18 UTC (Fri) by davidescott (guest, #58580) [Link]

I'm telling you I can't solve that. I don't know how. If you think it is so easily solved I would love to see your solution.