We are told that the speed of light is constant. Constant relative to what? Is there an underlying framework of reference in the universe?
Michael Johnson, Neston
- The question is meaningless. Constancy is the quality of not changing. If something stays the same, it stays the same regardless of the relation of other things to it. If I always move at 5mph my speed is constant regardless of whether a car goes faster or slower relative to me.
Charlie Hartill, London
- The same conundrum is apparent with the movement of any object through space. What is it moving relative to? The best theory comes from quantum physics, which suggests that every atom in the universe is "connected" to every other atom by a form of instantaneous action at distance, that stems from the moments afetr the big bang, when all matter was literally connected.
Steve , Bristol, UK
- Unlike sound, the speed of whch differs depending on the air density (which is why people qualify the speed as being at sea-level and at zero degrees Celsius), the speed of light is not subject to atmospheric conditions, and thus never varies. As far as there being an underlying framework of reference, there is - it is the speed of light, which is why we talk about "light years" rather than "sound years".
David Allard, Portland, Oregon, USA
- There is no universal frame of reference. The speed of light is constant relative to any observer, no matter what speed he may be travelling relative to any other observer. All clear?
Geoff, Toronto, Canada
- The speed of light is constant insofar as it does not obey the "common sense law" of adding velocities. If I run at 20 mph and throw a ball forwards at 50 mph relative to me, then the ball will appear to travel at 70 mph to a stationary observer. However, the speed of light given off by a stationary source or a moving source is identical to all observers, although it does slow down in different media.
Mark Lewney, Cardiff
- Basically, if you are travelling -1MPH the speed of light, and someone standing still turns on light, light will pass you at the speed of light. Light is the same speed no matter who observes it, no matter where the source is. It is unexplainable but "proven" correct (basically by not being able to be proven incorrect). Light is why we no longer know how gravity works, light is why we believe the universe to be expanding. But we know very little about light, and we could be totally wrong. Redshifts could be caused by particles in space rather than the shifting of space. Light could be the 5D. It does not obey laws everything else follows.
Chris, Texas USA
