Quote from: Matt on July 13, 2012, 05:37:44 PM
Quote from: cyphyr on July 13, 2012, 03:48:27 PM
You may have a point there. The idea of a universal constant has always bothered me, seems too simplistic. Surly there must be variation in "c" throughout out the space-time whatsit (not going to say continuum~ too star trek. lol). It's big and we can only see a tiny part of it so I would think it entirely reasonable to see the Higgs field as vairable and so the value of c.
I don't see a problem with 'c' being constant (although I guess some day we might discover that it's not). I was asking if photons travel at something below 'c'. So if you inferred 'c' by measuring the velocity of photons, you wouldn't be measuring the real 'c'. Also, if photons travel at less than 'c', perhaps their velocity is dependent on their energy/wavelength? Could blue light travel very slightly faster than red light etc.? But this is all moot if photons really do travel at 'c'.
Ghehe, those are interesting thoughts here. It looks like most here think of light as particles, which have some kind of shape/form and thus "must" (not really) have mass.
If you consider their duality and say that it's electromagnetic radiation, which it is also, then there's no reason to think whether blue or red light is faster/slow than the other. It's the same given that it's traveling through a vacuum.
However, if light passes a dispersive material then the frequency of the light (color) determines how much slower it is than c.
The speed of light is a universal constant and has and will always be the same. This accounts for a vacuum.
For instance, in air light is traveling 0.03% slower and in anisotropic media it depends on the direction.
Quote from: Matt on July 12, 2012, 01:48:10 AM
My interpretation of the fact that mass approaches infinitity as it approaches the speed of light is that it is the *time* that's being dilated, thus affecting the rate at which forces impart a change in velocity, and that the apparent increase in mass is just a reflection of the time dilation. i.e. mass increase is the effect, not the cause. I don't know if the increased mass also causes increases gravitation effects though. If it were possible to nullify mass, would the time dilation still occur?
Mass and gravitation are not the same. In your example the increased mass is not the same as weight.
It's a common misconception where one mixes up gravity in general relativity with gravity under newtonian laws.
Increased gravitation means increased rest mass, but that's not the case here.
At relativistic speeds the objects rest mass doesn't change, only it's relativistic mass and does not affect it's weight or gravity which you would observe in another reference frame.
http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/black_fast.htmlTime dilation/contraction is an effect caused by multiple reference frames and I think has little to do with mass.
The speed of light is constant as when space curves by mass so does time to keep the speed of light constant. Curvature of spacetime by mass.
When there's no mass there's no curvature of spacetime.
I'd tend to think that because of that there are no multiple reference frames anymore and thus no time dilation.