speed of light

Energy of electromagnetic waves is proportional to their frequency. As waves slow down, their wavelength also changes, leaving the energy to what it was outside of the slowing medium. The momentum, on a macroscopic scale anyway, or rather where it goes and where it comes from when it returns, would be a more difficult question to answer. Since the total momentum is conserved, it stands to reason that the medium receives some of it and translates it into some microscopic motion which in turn "propells" the exiting photons back to their former speed, if you will. Chances are it is slightly more complicated than that but it should be something of a similar kind.

Coincidentally, just a few months ago I considered that question myself and above is the hypothesis I proposed to explain this; a simple calculation of the values at work revealed that the means currently at my disposal were insufficient to test the hypothesis, so our team had to resort to a different question in its stead.

As for stillness, motion and relativity in general, it's not like the truthiness or absoluteness of stillness is even required. The math works out irrespective of the frame of reference. If light slows down for you, so it does for everyone else and by exactly the same amount, since their respective clocks and rulers are all dependant on their motions, too. And thus, since everyone's measurements would be equivalent, we need not be concerned which of them has the "right" frame of reference, as that makes no difference either way.

but if its not self propelled wouldnt the medium that its in absorb the energy or rather dissipate/distribute it throughout its mass?

so that i essence the light would have to speed itself back up of its own volition?

lol im way out of my depth but i enjoy this very much

it just seems like this scenario indicates that light photons have some kind of internal propulsion mechanism beyond simple momentum

or maybe i dont understand the nature of the medium involved

The energy sure doesn't just disappear. So there is some kind of electromagnetic oscillation going on. Of course I was going on the assumption that the system of medium, vacuum and light is isolated and that the medium is not transfering the momentum to anything else nor keeping any of it in total. In reality of course it would. If we are to take such subtleties into account I'm no longer sure the light regains all of it's former momentum on exit and if it does, where that comes from. Chances are that the explanation is indeed more difficult than that. Since the momentum of a photon is a natural constant times its frequency, I wouldn't think that it can increase without outside influence though. And at that, why, if it did have a propelling mechanism, would it stop at light speed?

like you said, you would need to find out if light regains its full speed/momentum on exit

as far as WHY it would stop at any particular speed i dont have the background for that
but my question would be "is the speed oflight the fastest speed possible because its the fastest speed the universe allows?
or simply because light is the fastest thing we know of in the universe?"

if there is some inhibiting force on the potential speed inherent to the universe then that would be the answer i guess

lol - maybe weve got the whole thing sideways and light is the only thing in the _verse that ISNT moving