[OS X TeX] hebrew?

Peter Dyballa Peter_Dyballa at Web.DE
Fri Jun 11 14:20:03 CEST 2010


Am 11.06.2010 um 12:37 schrieb David Derbes:

> Imagine an astronomical object so massive and so compact that even  
> \emph{light} is too slow to leave the object's surface; for this  
> object, $v_{\text{esc}} \ge c$. Presumably it would be  
> \emph{invisible}.

Is this really correct? Most artificial objects that left our Earth  
started with zero velocity (relative to the surface where they stood  
before ignition of the rocket engines). Isn't the curvature of space  
and time responsible for the effect that a black hole's supposed  
surface would look kind of dark? (Actually no-one would see it,  
because light from back or the sides is redirected into the beholder's  
eyes. And at the event horizon there's the effect of spontaneous pair  
production of particles which could involve some delusive gleam of  
light.)

--
Greetings

   Pete

A blizzard is when it snows sideways.




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