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Gadhav
- 22
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- TL;DR Summary
- SR theory
When we say speed of light = c m/s. Who is measuring meters and second. From SR perspective, that photon is moving towards you at speed of light so there should be time dilation, correct?
Anybody, so long as their clocks and rulers are moving at the same constant velocity.Gadhav said:When we say speed of light = c m/s. Who is measuring meters and second.
Why would what the light pulse is doing affect your clocks and rulers? Also, the time dilation equations cannot be applied to things moving at the speed of light - it turns out to be self-contradictory to try to do so.Gadhav said:From SR perspective, that photon is moving towards you at speed of light so there should be time dilation, correct?
Why not. If we assume that photon is a train traveling towards you or away from you, the time from that should appear to dilate and length contract from my reference frame, right? Whether it is moving at speed of light or not can be moot. Laws of physics if give you results at 99.999999% speed of light ,that should be valid at c too. So I am still confused on who is measuring the time and distance to measure speed of photon.Ibix said:Anybody, so long as their clocks and rulers are moving at the same constant velocity.
Why would what the light pulse is doing affect your clocks and rulers? Also, the time dilation equations cannot be applied to things moving at the speed of light - it turns out to be self-contradictory to try to do so.
Gadhav said:Laws of physics if give you results at 99.999999% speed of light ,that should be valid at c too.
Gadhav said:So I am still confused on who is measuring the time and distance to measure speed of photon.
Time dilation has no effect on the speed we measure for objects moving relative to ourselves. It would effect how fast we would determine that a clock moving relative to ourselves ticks.Gadhav said:Summary:: SR theory
When we say speed of light = c m/s. Who is measuring meters and second. From SR perspective, that photon is moving towards you at speed of light so there should be time dilation, correct?
A photon is not a train. Clocks on the train would, indeed, be slowed down as measured by my clocks. But my clocks and rulers are not affected by that, and it is my clocks and rulers that I use to measure speed.Gadhav said:If we assume that photon is a train traveling towards you or away from you, the time from that should appear to dilate and length contract from my reference frame, right?
Why? You can't make a clock that travels at the speed of light, so why must we be able to describe what would happen to something impossible? And I'm not sure time dilation is really a "law of physics" anyway. It's a coordinate effect - so perhaps a decent analogy is you asking which way is north from the north pole, me saying there's no such thing, and you insisting that you can go north from everywhere else, so you must be able to go north from the north pole. That isn't remotely analogous to the physics, but pretty good for the sense of the question.Gadhav said:Whether it is moving at speed of light or not can be moot. Laws of physics if give you results at 99.999999% speed of light ,that should be valid at c too.
You are, with your clocks and rulers. Or I am. Or a guy in the train you mentioned. As long as we're all using our own clocks and rulers, anybody can do it.Gadhav said:So I am still confused on who is measuring the time and distance to measure speed of photon.
Isn't it a bit self evident that it is whoever is doing the measuring that is measuring the time and distance?Gadhav said:So I am still confused on who is measuring the time and distance to measure speed of photon.
Gadhav said:If we assume that photon is a train traveling towards you or away from you, the time from that should appear to dilate and length contract from my reference frame, right?
Gadhav said:Why not. If we assume that photon is a train traveling towards you or away from you, the time from that should appear to dilate and length contract from my reference frame, right? Whether it is moving at speed of light or not can be moot. Laws of physics if give you results at 99.999999% speed of light ,that should be valid at c too. So I am still confused on who is measuring the time and distance to measure speed of photon.
Minor quibble, but the speed of light is c. Full stop. c is a speed, not a number.Gadhav said:When we say speed of light = c m/s.
Which laws are you referring to? People routinely accelerate particles to speeds that are 99.99999% of the speed of light. They have little trouble measuring their speed or the speed of light, either. And they use the same laws of physics to do both.Gadhav said:Laws of physics if give you results at 99.999999% speed of light ,that should be valid at c too.
It equates to the difference between dividing 1 by 0.0000000...1 and dividing 1 by zero.Gadhav said:Laws of physics if give you results at 99.999999% speed of light ,that should be valid at c too.
The speed of light is a physical constant that represents the speed at which light travels in a vacuum. It is approximately 299,792,458 meters per second.
The speed of light is measured using a variety of methods, including the use of lasers, mirrors, and precise timing devices. One common method is the use of a Michelson interferometer, which measures the time it takes for light to travel a specific distance.
The speed of light is considered a constant because it has been observed to be the same in all inertial frames of reference. This means that no matter how fast an observer is moving, they will always measure the speed of light to be the same value.
The speed of light is used to define the meter and second. In 1983, the meter was officially defined as the distance traveled by light in a vacuum in 1/299,792,458 of a second. Similarly, the second is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium 133 atom.
No, the speed of light has never been broken. According to Einstein's theory of relativity, it is impossible for any object with mass to travel at the speed of light. While scientists have been able to slow down or speed up light using various methods, it has never been exceeded.