Speed of light is constant as measured relative to What point?
2006-08-29 22:08:43 · 5 answers · asked by goring 6 in Science & Mathematics ➔ Physics
The two postulates are; 1) the principle of relativity 2) the principle of constancy of the velocity of light.
The principle of relativity states that all laws of nature (and not only the laws of mechanics) are the same in all inertial systems of coordinates.
The principle states that not a single physical experiment could discover special properties for one of the inertial systems. All inertial systems are equivalent.
So far no experiment has proved that this postulate is wrong.
The second postulate pertains to the constancy of the velocity of light in vacuum for all inertial systems. The velocity of light is INDEPENDENT of the light source and measuring instruments.
The periodic rotation of double stars may be understood only on the basis of the principle of constancy of light.
Measurements of the motion of Jupiter’s satellites may be made in two cases--when the light arriving on the earth from Jupiter coincides with the direction of motion of the solar system and when it is in the opposite direction. The identicalness of the observations and the distinct periodicity of Jupiter’s annual motion demonstrate the validity of the principle of the constancy of the velocity in this case as well.
The most important development of the theory of relativity was played by the experiment performed by Michelson in 1881 with the aid of the interferometer. The validity of the principle of the constancy of the velocity was well established by this experiment.
Your next question is “Speed of light is constant as measured relative to what point?”
Speed of light is constant as measured relative to any inertial reference frame.
An accelerated system of coordinates may be viewed as an inertial system if we introduce an equivalent gravitational field. That is a change in the geometry of the system will lead to inertial system.
Therefore the speed of light is constant irrespective of any reference frame. That is it is absolute.
2006-08-29 23:38:49 · answer #1 · answered by Pearlsawme 7 · 0⤊ 0⤋
The speed of light is a constant. Period.
It is RELATIVE not to the observer, but to the universe!
The Universe of WATER is different than vaccum. But a Fish measures light as the same speed as we do.
Sound is also relative. If you were in an F-15 traveling at Mach 2 you can still TALK to the person next to you and they will hear you exactly as they do on the ground.
What Einstein is saying, is that if you were in the Star Ship Enterprise traveling AT the exact speed of light and you turned on a flash light, it would still work.
The light coming out of the flashlight is NOT travelling at 2 times the speed of light, but AT the speed of light.
If you walk to Sulu, you are NOT travelling 2 MPH faster than the speed of light, because the ship is traveling at the speed of light and you are moving forward at 2 MPH!
That is relativity.
You are in a car travelling at 65 MPH and hit a brick wall 3 feet tall. The car STOPS you don't, because your body is not a part of the car it is in a seat. YOU are still trying to move forward at 65 MPH. The only thing that stops you are seat belts and an air bag. Without these you'd go through the windshield at 65 MPH.
You are in a bus and you walk to the front door at 2 MPH while the bus is moving 35 MPH. You are moving at what? 37 MPH! Wow, that is FANTASTIC. Become an Olympic runner, because that speed will DEFINATELY get you a GOLD METAL!
2006-08-29 23:59:03 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Relative to the observer!
-Follow-up to other answers below:
Excuse me, I should have said Relative to all observers. Because it is a universal constant. No matter what motion the observer has, the speed of light, C, will measure the same in a vacuum.
I wish these guys with degrees in physics would consider taking a course in English too someday, and perhaps anger management.
2006-08-29 22:14:31 · answer #3 · answered by KALEL 4 · 0⤊ 0⤋
Jose is actual, yet (d) is the most the ideal decision answer of the options. Einstein did assume (d) and extra to it the idea that the speed of light is an similar of all observers. In a fashion, although, the fidelity of the speed of light must be considered a organic extension of postulate (d) in case you comprise Maxwell's equations in "guidelines of physics". Maxwell's equations say that the speed of light is consistent. So in the adventure that they follow both nicely to any inertial observer (and in no way in some particular body of reference--the ether--as changed into theory), then the speed of light must be consistent to any observer. All this confirms that any instructor who provides assorted decision (and semi-ambiguous) assorted decision questions is both lazy or stupid.
2016-11-23 14:08:46 · answer #4 · answered by ? 4 · 0⤊ 0⤋
speed = distance
time
the speed of light is a constant measured in time between a starting and ending point. the easiest way we figure this out is the time it takes a solar flare to leave the sun and its effects felt on the earth. (which is appr. 8.5 minutes)
2006-08-29 22:15:13 · answer #5 · answered by Littlemman 2 · 0⤊ 0⤋