How to show that light travels through space, but not time

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Light travels through space but not through time, as demonstrated by relativistic equations like the Lorentz factor (γ). The discussion highlights the challenge of understanding how to apply these equations to show that as a particle approaches the speed of light (c), time dilation occurs, leading to a scenario where time effectively stops for light. By comparing time intervals in different reference frames, it becomes evident that an observer would perceive an infinite wait for a clock carried by a particle traveling at the speed of light to tick. This raises questions about the nature of time for theoretical particles moving at light speed. The participant expresses uncertainty but intends to seek further clarification from their teacher.
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Homework Statement


Use relativistic equations and γ to demonstrate the following:
b) Light travels through space but not in time

Homework Equations


Lorentz factor γ = 1 / √(1 - [v/c]^2)

Time dilation t = γ t°

Length contraction L = γ L°

Mass relativity m = γ m°

E = m c^2

The Attempt at a Solution



To be honest, I'm not exactly sure how to approach this. I don't quite understand the concept behind what the question is really asking for. Furthermore, I don't know how I can use these equations to prove that light does not travel through time.
 
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Consider a particle traveling at a uniform velocity relative to the observer. Compare a fixed time interval t0, perhaps 1 second, in that particle's reference frame to the corresponding time interval in the observer's reference frame. Ie., pretend the particle is carrying a clock that ticks once every second.
How long does the observer have to wait to observe one tick if the particle travels at 0.9c ? At 0.95c? At 0.99c? 0.999c?
Does this behavior continue if we make the fixed unit of time for a single tick smaller? What does this imply about theoretical particles carrying these same clocks that travel at c?
With the formulas you have, you can only make a weak implication.
 
slider142 said:
Consider...
Thank you. I can't quite wrap my head around this, but I think I have a good enough idea to somehow explain this. I'll be sure to ask my teacher when I can.
 
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