2006-09-29 00:32:24 · 12 answers · asked by mick t 5 in Science & Mathematics ➔ Physics
As strange as it seems, the speed of light is always the same as seen by any observer. If you shine a light at a stationary person, that person measures the speed of your light passing him as 186,000 miles a second. You might think that if he started running toward you at 1 mile per second that he would then measure your light beam to be passing him at 186,001 miles per second, but he doesn't, he still measures it as passing him at 186,000 miles per second. This is a measured fact, not theory. Einstein's theory says that time and space must change to explain this measured fact. The result is that as you run toward that light faster and faster, distance shrinks and time slows down. If you were ever to run at the speed of light, which you can't, distance would become zero and time would stop. This just seems impossible to us because we can never run fast enough to experience it directly. But the math all works out and every measurement ever made confirms these strange predictions. Believe it or not.
2006-09-29 01:46:27 · answer #1 · answered by campbelp2002 7 · 1⤊ 0⤋
Because light is a form of radiation, not a propelled object. It moves a certain distance in a certain time (which is why you can measure distance in light minutes). Time and space are only relative to an observer, not in general terms. Light moves through the space time continuum as a wave, not as an object. It is affected by gravity, but it does not slow down unless it flows into a denser medium.
2006-09-29 00:39:05 · answer #2 · answered by stevensontj 3 · 0⤊ 0⤋
The speed of light IS always constant it's local time and distance that isn't.
2006-09-30 16:18:40 · answer #3 · answered by grating_pairs 1 · 0⤊ 0⤋
well take the earth it is always the same distance from the sum thus meaning it is always at the same time the sun also (8 Min's) so if you reduce the scale the distance the light has to travel from the monitor that you are looking at to your eyes will be constant with the reduction in time it will take making it constant
2006-09-29 00:42:49 · answer #4 · answered by silent BoB 1 · 0⤊ 0⤋
But is it a constant? Some scientist have postulated that the speed of light is slowing and about 2000 years ago it was approx 30% faster.
2006-09-29 05:04:57 · answer #5 · answered by Anonymous · 0⤊ 1⤋
You are referring to "Special Relativity", Einsteins first and second postulates say that the laws of physics (Newtionian) only apply to the the same interial reference.
I.E. for a specific observer (you) everything will be hunky dory (all Newtonian laws will hold), but an external observer will observe something completely different (different distances/times occuring).
For a fuller and more in depth explanation look at the reference...
2006-09-29 00:42:27 · answer #6 · answered by abrockhurst2000 2 · 0⤊ 0⤋
The speed of light isn't constant - it depends on the medium. The speed of light through vacuum is different to the speed of light through air, as it is different through water.
2006-09-29 00:35:19 · answer #7 · answered by k² 6 · 0⤊ 0⤋
The spped of light in vaccum is indeed constant to every viewer.
What you said is exactly the point - in order for the speed of light to be const. to everyyone, no matter even if they move in different speed tehmself' the time and space coordinates has to be different for them.
2006-09-29 00:41:06 · answer #8 · answered by Ilham Aliyev 2 · 0⤊ 0⤋
Well, you are mixing two types of physics together here: Newtonian physics and relativistic physics. They don't always give you the same answers. Newtonian physics break down when you get close to the speed of light.
2006-09-29 00:36:15 · answer #9 · answered by Anonymous · 0⤊ 0⤋
the speed of light isn't constant. light can be bent and slowed down.
2006-09-29 06:12:22 · answer #10 · answered by helenagilchrist@btinternet.com 1 · 0⤊ 0⤋