Relativity, the flow of time and speed

[atymtrvlr]

Question:

According to Einstein an object traveling at relativistic speeds would not experience the passage of time (time stands still).

Speaking from the vantage point of the relativistic object:

Let's consider a photon. At 1C time stands still for the photon (T=0).

1. With the absence of time, isn’t the relative velocity of the photon actually infinite (again, from the vantage point of the photon)?

By this I mean V=D/T where V=velocity, D=distance and T=time

Speed is relative to distance traveled in a given unit of time. If T reaches 0 (zero) the calculation cannot be performed & speed cannot be determined.

In another example, if you were in a car traveling at 1C, your speedometer wouldn't function. It requires space and time to calulate speed.

Is this right? Does anyone have any thoughts on this?

I also have a follow-up question.

Thanks!
atymtrvlr

 

[Chris Hillman]

You went off the rails at the very beginning

Is this right?...
According to Einstein an object traveling at relativistic speeds would not experience the passage of time (time stands still).

No, "relativistic velocities" means "fast enough that relativistic formulas must be used". You are thinking of taking the limit v \rightarrow c=1 in the Lorentz transformation, but this fails as you can check. Physically speaking the reason is easy to understand: if you try to accelerate a particle of mass m to the speed of light you will need an infinite amount of energy, which is impossible.

Several items from the sci.physics FAQ should help: see http://www.math.ucr.edu/home/baez/physics/

 

[atymtrvlr]

Thanks

For the response.