Your answers to other questions have told me that the space between bodies is practically empty other than electromagnetic fields . Is it possible these fields act as an aether for the propagating light ? Thanks in advance.
You're asking if the electromagnetic field could be a medium by which the electromagnetic field could propagate. Sort of like 'If a taxi wants to get across town, does it need to call a taxi?'
I was considering answers already provided by members , from which I derived my question . Specifically the video which mentions Faradays thought on light being waves of the field as opposed photons . Also was said is that the space between bodies has very little matter but does contain spatial fields . I considered the light from the sun emitting and propagating through the existing fields , the same as shining a flashlight on earth , the beam travels through the existing earths magnetic field . Am I mistaken in my thought ? Thanks in advance
Thank you for your answer and reply . How would you test that notion in a Universe that has been explained in answers , to be full of fields , that pre date our existence and science ? Thanks in advance .
For starters, if light required a medium in which to propagate, then that medium would have a preferred frame of reference. We would detect a bias in the speed of light between light sources that are moving relative to each other (such as, say Earth, at opposite ends of its orbit). We do not.
Thank you for your answer . How would or could you detect a bias if there was a hypothetical Higgs field reference frame that offered no opposing force to the propagating light because the field was also light ? In comparison mixing water with water ! Thanks in advance .
If there were a medium through which light propagated then light would have a max velocity relative to that medium. Since we are moving relative to that medium, we would detect light travelling in one direction as having a different velocity than light travelling in another direction. We don't detect a discrepancy in the speed of light, regardless of our velocity, regardless of direction - therefore, no medium.
Nope. That is purely due to your speed relative to the source. If you and the source are going the same speed, then it doesn't matter if that same speed is zero or 99.999% of the speed of light - you will see the same blue/red shift (i.e. none.)
Note, by the way that the Doppler shift doesn't show a difference in the speed of light, simply in its frequency. Because frequency is determined in the source's frame of reference.
Thank you for your reply . I always thought the Doppler shift was a result of radiation pressure at the sources frame due to velocity . Is that a correct interpretation ? The subject seems much more extensive than I first thought , I'll be old by time I fimish learning it . Thanks for the help .
Some of us are already old and still don't know everything. Please Register or Log in to view the hidden image!
I don't think I'll ever stop learning but knowing everything would take longer than a single lifetime I'm sure .
No. The Doppler shift is a wave phenomenon that applies to any kind of wave, including light waves. If a source of waves moves towards you, for example, then the wave fronts moving towards you from the source are closer together than they would be if the source wasn't moving. Therefore, the wave fronts arrive at you more frequently - i.e. they literally have a higher frequency. The reverse applies to sources moving away from you. The effect is slightly different when you move towards or away from a stationary source, but again the key is how many wave fronts you encounter per second as you move.