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Old Jun11-09, 06:06 AM       Last edited by DB Katzin; Jun11-09 at 06:13 AM.. Reason: grammer            #1
DB Katzin

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Do photons age?

In another post there is an example of a vessel moving close enough to the speed of light that the journey to the galaxy Andromeda 2.5M light years takes only 4 hrs on the vessel's clock. In its own frame of reference the vessel is moving just above 600K LY/hr. Yet a photon that left at the same instant would arrive before the vessel and always be measured as traveling at velocity c with respect to the vessel. As the velocity of the vessel S/T approaches the speed of light T (actually delta t) approaches 0, ie the 2.5 M LY trip takes, 3 hrs, 1 hr, 1 minute, 1 second, etc as v approaches c. At c, T (delta t) = 0, for all distances S, implying that time does not exist for a photon. In the photon's frame of reference its arrival and departure and the trip in between are simultaneous, its velocity is effectively infinite and since no time passes it doesn't age no matter how "old" it is--how long ago it was emitted.
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Old Jun11-09, 06:23 AM       Last edited by HallsofIvy; Jun11-09 at 03:08 PM..            #2
HallsofIvy

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Re: Do photons age?

Yes, time does not exist for an electron, it does not "age".
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Old Jun11-09, 10:40 AM                  #3
clem

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Re: Do photons age?

"In the photon's frame of reference"
This does not exist.
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Old Jun11-09, 10:47 AM                  #4
Coto

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Re: Do photons age?

Space also becomes a point.
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Old Jun11-09, 12:54 PM                  #5
Rasalhague

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Re: Do photons age?

Originally Posted by Coto View Post
Space also becomes a point.
Why doesn't space become a two dimensional surface, given that length is only contracted along the direction of movement?
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Old Jun11-09, 01:11 PM                  #6
Coto

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Re: Do photons age?

I was just ragging.

IMHO, the ideas of length and time contraction breakdown for photons. But that's just an opinion with no justifying science behind it.

Edit: Sweet, that was my 100th post.
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Old Jun11-09, 01:26 PM                  #7
DaleSpam

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Re: Do photons age?

The photon's frame of reference is non-inertial and poorly defined, but the spacetime interval between any two events on the photon's worldline is indeed 0. You cannot really say that this interval represents either proper time or proper distance since it is neither timelike nor spacelike.
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