Kevin Brown http://www.mathpages.com/rr/s6-04/6-04.htm gives the acceleration of particle in the Schwarzschild metric as measured in terms of the proper time of the particle as:(adsbygoogle = window.adsbygoogle || []).push({});

[tex] \frac{d^2 r}{d\tau^2} = -\frac{m}{r^2}[/tex]

Does this not cause a problem for those that assert Schwarzschild coordinates are invalid below the event horizon because it impossible for a particle to remain stationary below the event horizon? This is the acceleration in terms of proper time which is often taken to be the final abitrator of truth in determing what is really happening in GR. This equation is independant of the velocity of the particle and is clearly not infinite for values of 0<r<=2m and K. Brown derives the equation assuming the velocity is zero. Further more the coordinate acceleration for a stationary particle is not infinite at or below the event horizon either, except for the case r=0. Where does the noton that a particle can not remain stationary (spatially) below the event horizon come from?

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# Stationary below the event horizon?

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