2006-07-12 13:58:16 · 26 answers · asked by Anonymous in Science & Mathematics ➔ Physics
E=Mc2/I=N5taNtAnE10U5 as my saying goes...
Our perception of the speed of light is a constancy of the product of our understanding. To speak of a constant in the Physics/Math discipline is to understand instantaniety and to grasp the fundamentality of the term synchronous.
How a constant, in this case the speed of light, can be performed in the same relative space and time is analogous to (I make a differentiation towards actuality of the words usage and use this as the only example I can presently think of just to give you the impression of what Einstein was attempting to describe)
"HOW" you can think "YES" but speak "NO", whilst you are reading this reply...
Its an equivalence in the sense of c2 in the consistancy of its inception towards comprehending how the very definition of a constant is formed. In this case, the above example, if you think about it, has now become a part of that process.
Another example of how it is defined as a constant is the fact that if the speed of light was out of phase, so to speak, we would not understand each other at all.
Its a very finely tuned universe indeed.
2006-07-13 13:04:55 · answer #1 · answered by Paul Dalby 2 · 2⤊ 4⤋
Light is not like a car where there are so many variables that dictate speed. Particles of light, called photons, are a phenomena of physics that continually move outward at a constant speed of 186.000 miles per second. Experiment: Take a flashlight and turn it on - inside and outside. You will not be able to perceive a difference once that light source hits an object (a wall or a tree) and therein lies the proof that light is constant as it moves through space.
2006-07-12 21:09:55 · answer #2 · answered by mapman777 2 · 0⤊ 0⤋
Einstein's theory of relativity is based on the idea that the speed of light in a vacuum is constant. The theory has been very successful in predicting experimental results. This lends weight to the proposition that the speed of light is constant. But it's not absolute proof. Scientists are pushing the limits of knowledge all the time, and we may some day find out that it's not a constant.
2006-07-13 00:04:22 · answer #3 · answered by Jim H 3 · 0⤊ 0⤋
Light is a measured constant in vacuum. No matter how fast you are going or if time is being slowed because a gravitational field you will always get the same number to a carefully constructed experiment. Why this is is stilling being debated to some extent.
It is possible that the speed of light is changed but we are changed too so we do not notice the difference. After all almost all of our interactions with other matter is electromagnetic in origin and light is an electromagnetic wave.
2006-07-12 21:05:31 · answer #4 · answered by georgephysics13 3 · 0⤊ 0⤋
All the theories and all the measurements done so far say that the speed of light in a vacuum is constant. It goes a little slower when it is passing through matter, like air or glass.
2006-07-12 22:49:11 · answer #5 · answered by campbelp2002 7 · 0⤊ 0⤋
The speed of light is affected by a gravity field(space-time)hence its not really constant. However relatively speaking the speed of light as measured relative to the eath experiences miniscule neglible changes that we can basically say its quasi constant.
It has not been proven yet that the speed of light in the Universe is the same as what has been measured relative to our solar system.
2006-07-13 00:18:06 · answer #6 · answered by goring 6 · 0⤊ 0⤋
This is an exciting time in physics. Lots of things are being questioned. While it is still very controversial, some astrophysicists investigating quasars believe that the best explanation of certain evidence is that fundamental physical constants HAVE altered in the history of the universe (though not by much). There's no reason to believe that they MUST stay the same for all time. See the SPACE.COM article reported in Yahoo news below.
PS: alteration of the constants would be evidence for string theory.
2006-07-12 21:57:17 · answer #7 · answered by artful dodger 3 · 0⤊ 0⤋
No, it definitely is not. Light is like any other object, having a constant speed; about 297600 kilometres/second in a vacuum. It changes speed while changing mediums, and travels slowest in the densest materials, and fastest in lightest (air, vacuum, etc).
Light can also be changed upon the warping of space-time, whether it be a black hole, a theoretical wormhole, of an Einstein-Roslyn bridge
2006-07-12 21:11:24 · answer #8 · answered by Patrick D 1 · 0⤊ 0⤋
The speed of light in vacuum is a constant and is given by 3x10^8m/s.
Now note the meaning of constant in physics.
If the light's speed in vacuum varies with something, then we can't say that it is a constant.
There is no term in physics like " really constant and really variable"
2006-07-12 21:47:13 · answer #9 · answered by Pearlsawme 7 · 0⤊ 0⤋
the speed of light IN A VACUUM is a constant yes. Photons in lab experiements have been slowed down to less than 40mph.
Normally, all electrmagnetic radiation waves/particles move at c.
2006-07-12 21:32:27 · answer #10 · answered by quntmphys238 6 · 0⤊ 0⤋