The speed of light is only C "locally" in general relativity. The equivalence principle says that local observations of a freely-falling observer in a gravitational field will look just like local observations of an inertial observer in the flat spacetime of special relativity. "Local" means in a small region of spacetime--each observer has to only make measurements in their immediate region of space for a small period of time for the equivalence to work, and it only works precisely in the limit as the region of spacetime in which each makes their measurements becomes arbitrarily small.
So, in the context of general relativity, if you have a global coordinate system which covers a large region of curved spacetime, like Schwarzschild coordinates around a black hole, then it is perfectly possible that the coordinate speed of light will be different from C (it is also true in special relativity that if you use a non-inertial coordinate system, i.e. one in which observers at rest in that coordinate system are accelerating and experiencing G-forces as a consequence, then the coordinate speed of light can be different from C here as well). But even though light exactly at the event horizon would be at rest in Schwarzschild coordinates (and note that you have no obligation to use Schwarzschild coordinates when analyzing a black hole, you could use some other global coordinate system where the event horizon is not at rest), from the local perspective of a freefalling observer, the light will still be measured to move at C as the observer falls through the event horizon and passes next to the light beam. Also, if you imagine a series of buoys closer and closer to the event horizon, which use rockets to maintain a constant Schwarzchild distance from the BH, then an observer falling in will see each successive buoy flying past him at closer to C, with the measured speed of the buoy approaching C in the limit as the buoy's distance from the horizon approaches 0. Jesse Mazer >From: James N Rose <[EMAIL PROTECTED]> >Reply-To: [email protected] >To: [email protected] >Subject: Blackholes imply 'C' is violated/invalidated. >Date: Sat, 20 Jan 2007 07:37:08 -0800 > > >Conjecture: > >"Blackholes imply 'C' is violated/invalidated." > >Notion: If the Speed of Light is not just a >fixed constant but a fixed maxima, then, if Newton's >3 Laws of Inertia are to be maintained, especially >regarding 'equal & opposite' ... > >the current depiction of blackholes being able to >constrain photons 100% infers that any random photon >moving directly outward from the center-locus of a >singularity can only be kept from forward linear motion >by a force not just equal to, but necessarily greater >than, its vector moment - presumed to be "C". > >If only just '-C', then Probability would require >blackholes be never 'black', but accumulatively >brilliant white - unless - 'C' is out-maximummed. > >Or, the model has an error - and the dynamics of >light restriction/containment are of a wholly >different nature than currently presumed. > >Comments? > >Jamie Rose >Ceptual Institute > >> _________________________________________________________________ Get Hilary Duffs homepage with her photos, music, and more. http://celebrities.live.com --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---
