A train travels relative to the earth and thats how its velocity is calculated. The earth travels relative to the sun and the sun travels relative to something else. But what does speed of light travel relative to because it has to travel relative to something!
2006-08-16 23:16:54 · 20 answers · asked by Clarsair 2 in Science & Mathematics ➔ Physics
Is it superman
2006-08-16 23:23:04 · answer #1 · answered by halloweenpumpkinuk 4 · 0⤊ 1⤋
The speed of light has always been measured relative to any stationary object... speeds are always measure relative to an object which is, or appears to be stationary to the observer, in fact usually the observer himself however, as is correctly stated, the constant c (the speed of light) is always the same whether measured relative to a moving object or not . The length of a metre is actually defined as the distance light travels in a specific amount of time and so it give us a very exact and fixed speed for light as measured in a vacuum... In this sense the speed of light is not actually measure, more defined... that is why the speed of light is never stated with an approximation of error... it is EXACT
2006-08-16 23:27:29 · answer #2 · answered by hadley_banks78 2 · 1⤊ 0⤋
The speed of light doesn't travel any more than 35MPH does. It's a measure of speed, I.E. 30% the speed of light or impractically 4 times the speed of light. Things travelling at the speed of light travel releative to their own trajectory often as not as there are few other things that opperate at that speed and distance that we're aware of. So we use an imaginary line from Origin to destination to calcuate distance over time.
2006-08-16 23:25:18 · answer #3 · answered by W0LF 5 · 0⤊ 0⤋
Those that responded that the speed of light is a constant, no matter the speed you are travelling are correct.
But- your question is a good one, and the answer is:
***Time***
which would explain the frequency shift we see in light when the observer and sender are moving relative to each other in space.
2006-08-17 03:43:38 · answer #4 · answered by Morey000 7 · 0⤊ 0⤋
When we measure the speed of a train we fix two stations on earth and we measure the time for the train to travel that distance.
When we measure the speed of light we fix two stations on earth and we measure the time for the light to travel that distance. Thus the speed of light is with reference to the earth.
Michelson measured the speed of light using interferometer.
He measured the speed of light when a light beam is parallel to the motion of the globe and its speed when the beam is perpendicular to the motion of the globe.
That is he measured the speed with reference to a stationary observer as well as with reference to a moving observer.
In all cases it was found to be a constant.
Hence it is concluded light’s speed is absolute. It is not relative to any inertial frame of reference. In all inertial frame of reference, its speed is invariant.
The mass, length, time and speeds of all are changing in such a way that the speed of light is measured as a constant.
2006-08-17 01:14:56 · answer #5 · answered by Pearlsawme 7 · 2⤊ 0⤋
Thats the magic about the speed of light. Whatever you take as the base it is always the same.
If you and I were travelling in different directions at high speed and we both measured the same light coming from the same source we would both get the same answer.
2006-08-16 23:24:39 · answer #6 · answered by Bob-bob 3 · 1⤊ 0⤋
Relative to a stationary object.
The link below takes you to an article that explains how speed of light has been measured experimentally.
2006-08-20 23:09:33 · answer #7 · answered by philturner66 3 · 0⤊ 0⤋
Whether the train is on the moon, on earth, or traveling in space, it's speed is measured from one point to another, usually in miles per hour. The earth's speed is measured from one point to another too. The universe is expanding from one central point outward. Light is measured the same way, and it travels at approximately 186,282.4 miles per second from one point to another. Interestingly enough, if you were traveling from on point to another, and began to approach the speed of light, time would slow down for you, your mass would increase, and your length would decrease.
2006-08-16 23:30:05 · answer #8 · answered by Anonymous · 0⤊ 0⤋
You are wrong about the train. speed = distancextime
speed of light is relative to the matter it is traveling to
light moves slower in water/glass
2006-08-16 23:23:15 · answer #9 · answered by yeah well 5 · 0⤊ 0⤋
It travels relative to the observer as the observer is always thought to be stationary, and of course, it is the observer that is observing it.
But, according to Einstein's second postulate, the speed of light is constant irrespective of the speed of the observer of the speed of the source. This is known as the 'constancy of the speed of light'. This is essential as it leads to time dilation, length contraction and eventually to the famous equation, E=mc².
2006-08-16 23:24:46 · answer #10 · answered by Veefessional 2 · 5⤊ 0⤋
the speed of light is calculated to sun and earth
2006-08-17 00:50:07 · answer #11 · answered by jalaj 2 · 0⤊ 0⤋