Beams or Rays of Light

[geordief]

Here is an example

 

http://users.sussex.ac.uk/~waa22/relativity/Complete_Derivation_files/derivation.pdf

 

My question is whether these diagrams are misleading. They show these beams as unbroken lines .

 

Is this wrong?

 

Is it a better picture of what actually happens to draw an expanding (non physical) sphere to represent the points where a photon can be created when it meets an object?

 

Is the line that is drawn actually just a geometric line joining up the points where interactions do take place. So this line which is drawn is actually just a mathematical or geometrical extrapolation?

 

I mean ,in the clock mirror in my above link can we say the the light is only to be found at the actual mirror surfaces provided there is a vacuum between them and that ,even if there was no vacuum we would be talking about a "dotted line" -not a continuous line? (the dots occurring where the expanding sphere encountered "obstacles)

 

As an analogy I remember reading (incorrectly as it happens I think ) that the human eye is unable to actually see a small electricity wire (the kind that birds might be sitting on) but infers it and presents to the mind a seeming picture of the said wire.

[StringJunky]

Here is an example

 

http://users.sussex.ac.uk/~waa22/relativity/Complete_Derivation_files/derivation.pdf

 

My question is whether these diagrams are misleading. They show these beams as unbroken lines .

 

Is this wrong?

 

Is it a better picture of what actually happens to draw an expanding (non physical) sphere to represent the points where a photon can be created when it meets an object?

 

Is the line that is drawn actually just a geometric line joining up the points where interactions do take place. So this line which is drawn is actually just a mathematical or geometrical extrapolation?

 

I mean ,in the clock mirror in my above link can we say the the light is only to be found at the actual mirror surfaces provided there is a vacuum between them and that ,even if there was no vacuum we would be talking about a "dotted line" -not a continuous line? (the dots occurring where the expanding sphere encountered "obstacles)

 

As an analogy I remember reading (incorrectly as it happens I think ) that the human eye is unable to actually see a small electricity wire (the kind that birds might be sitting on) but infers it and presents to the mind a seeming picture of the said wire.

The line represents the path of a photon; nothing else. That's the only information, i think, you should take from. it,

Edited November 8, 2016 by StringJunky

[geordief]

The line represents the path of a photon; nothing else. That's the only information, i think, you should take from. it,

Is the path** "empty" apart from the points along it where an interaction takes place ?

 

Is the "expanding sphere" model any way superior to the "line" model ?

 

**is "trajectory" the correct term?

[Strange]

SR is a classical (non quantum) theory so it doesn't help to think in terms of photons. Any classical path can be represented in terms of photon behaviour, but it just complicates things.

[geordief]

SR is a classical (non quantum) theory so it doesn't help to think in terms of photons. Any classical path can be represented in terms of photon behaviour, but it just complicates things.

If I find the expanding sphere more satisfactory/appealing ,is it OK for me to try and work out those time dilation diagrams using that model ?

 

Does it give a more intellectually satisfying result?

[Strange]

If I find the expanding sphere more satisfactory/appealing ,is it OK for me to try and work out those time dilation diagrams using that model ?

 

 

Certainly. You will need to work out where the expanding circle (sphere) intersects with the mirror. Then draw a straight line from there to the source. Hopefully, that will be the same as the ray!

[geordief]

 

 

Certainly. You will need to work out where the expanding circle (sphere) intersects with the mirror. Then draw a straight line from there to the source. Hopefully, that will be the same as the ray!

thanks