B Question about the relative motion of an eye relative to light source

[Chenkel]

Hello everyone,

I've been thinking about 2nd postulate of relativity, it seems that and the Michaelson-Morley experiment seems to imply that there is no ether, but I was thinking about a special situation that doesn't seem to go against that postulate.

I think my question is basic so hopefully it makes sense and I don't make any major blunders.

Suppose there is an initial light source at distance D away from an eye and the light turns on at the start of the problem, and the eye moves with a relative velocity of v towards the light source, how long does it take light to reach the eye?

I was thinking about it and the gap seems to be closing at a rate of $c + v$ So I would expect the light to reach the eye at the time $\frac {D} {c + v}$

If the eye is moving away from the light source at the start of the problem when it turns on at a distance D I would imagine the gap to be closing at a rate of ${c - v}$ so the time to cover the distance D should be $\frac {D} {c - v}$

Hopefully I'm not making any major mistakes in my analysis, let me know what you think.

Thanks.

 

[Orodruin]

In the rest frame of the light source where the eye is moving, yes, these are the expressions. It is unclear why you think this affects the results predicted by relativity.

 

[Chenkel]

In the rest frame of the light source where the eye is moving, yes, these are the expressions. It is unclear why you think this affects the results predicted by relativity.

I don't think it affects the results predicted by relativity, I'm just trying to make sure I'm not making any mistakes regarding the postulates of relativity and the framework of it.

 

[Ibix]

I don't think it affects the results predicted by relativity, I'm just trying to make sure I'm not making any mistakes regarding the postulates of relativity and the framework of it.

You have specified everything in one frame here, so the same intercept calculations you do in Newtonian physics apply. It's only when you want to do more complex physics (conservation laws or frame changes, for example) that you will find differences.