Everything we perceive is in the past due to finite speed of light

I do? You must be hallucinating again.

 

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Doesn't mean that the speed of ligh is dependent on the speed of the source. You have had this bee under your bonnet for years.

 

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No, the correct statement is that once upon a time, physicists had issues to address. Then along came folks like Einstein. The motions of the source and the observer do not change the fact that both see the light propagating as a sphere. Experimental fact. They will, however, disagree on what times the light reached various points. The observer on the train will see the light touching all 4 sides of the box at 0.5s. The ground observer will see the light reaching these points at different times (except for the top and bottom which will have the same arrival time).

 

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You do?? Good news!! Share the wealth, Tach. You have a way to determine the velocity of a train in space with no reference to external objects. Let's hear it, how do you determine that velocity, just claim it to be zero and call it good??

 

Are you really that shallow to not understand what I am saying? There is a source in space. At t=0 the source emits a light sphere. Light starts traveling in all directions at the same rate. While the light sphere is increasing in size the source starts traveling away from the center of the light sphere, which is away from the point in space that it was when it emitted the light sphere. That means the source is no longer an equal distance in each direction from the expanding light sphere. How do you not understand that? Don't come back with the same old tired line that Einstein fixed the problem many years ago, because that is BS!

 

As I said, your motion relative to the source does not change the fact that a pulse of light emanating from it will still be seen by you as a sphere, no matter what. Experimental fact. Only weird if you cling to old-fashioned notions of space and time.

 

The speed of light is relative to space, not the source. When will you learn that? Light travel time defines distance in space!

 

I am not talking about MY MOTION. There is a source in space. It emits light. The light sphere increases its radius at a rate of c. While the radius is increasing in all directions the source (not me) starts traveling away from WHERE (the point in space) it emitted the light sphere at t=0. That point remains the center of the expanding light sphere, but the source (the physical object that emitted the light) starts traveling away from the point in space where it originally emitted that light sphere at t=0, which remains the center of the expanding light sphere at all times. The source is then not at the center any longer! It has nothing to do with perception, or me, or any other object! There is a point in space, a source, and an expanding light sphere. Do you still not understand?? If you say no you leave me no choice but to assume you are either retarded, or you are a liar!

 

I understand what you're saying, and that doesn't make it any less wrong. It doesn't matter if the source moves from the point where it emitted the light. It could be a pulsing lightbulb mounted on the train itself. Doesn't freaking matter, anyone standing on the train or the ground detects a spherical pulse. Experimental fact.

 

What is wrong? The light sphere is expanding, do you agree?

 

Thanks, MD. CptBork just replied to me. I will ask CptBork a question now, prompted by his response. If you disagree with his further response to my next question, please feel free to give me your answer as well.

 

I agree that observers on the train and ground see an expanding light sphere.

 

Thanks.
Can you elaborate on which 'different frames' you think are involved in the scenario he is using in his example to you? I thought there was onbly one frame, that of the on-train observer only?

 

There is no train. A source is in space at t=0 and emitted a light sphere. What is the radius of the light sphere at t=1?

 

We're mostly dealing with the old classic Einstein thought experiment, where a stationary ground observer sees lightning strike simultaneously at both ends of a train, whereas the times measured by the observer on the train will not be simultaneous. He's thrown in at least one additional scenario of his own concoction though, so it's difficult to focus on one subject and actually conclude something.

 

The radius is \(c\).

 

So you are saying the radius expands at c, which means at t=1 the radius is 299,792,458 meters, correct? You need to be more precise, c is not a radius, it is the speed of light.

 

Well you need to be more precise, because 1 is not a unit of time. Take whatever value of time you want in whatever units, and same for \(c\). The radius will be \(ct\).

 

The SI unit for time is seconds, is it not? Do you think I was referring to fortnights or something??

 

In science, we always specify the units we use, otherwise the number itself is meaningless. You could have meant 1 nanosecond, or 1 hour. I'm not going to make assumptions on your behalf.