What is Light clock: Definition and 64 Discussions

In physics and relativity, time dilation is the difference in the elapsed time as measured by two clocks. It is either due to a relative velocity between them (special relativistic "kinetic" time dilation) or to a difference in gravitational potential between their locations (general relativistic gravitational time dilation). When unspecified, "time dilation" usually refers to the effect due to velocity.
After compensating for varying signal delays due to the changing distance between an observer and a moving clock (i.e. Doppler effect), the observer will measure the moving clock as ticking slower than a clock that is at rest in the observer's own reference frame. In addition, a clock that is close to a massive body (and which therefore is at lower gravitational potential) will record less elapsed time than a clock situated further from the said massive body (and which is at a higher gravitational potential).
These predictions of the theory of relativity have been repeatedly confirmed by experiment, and they are of practical concern, for instance in the operation of satellite navigation systems such as GPS and Galileo. Time dilation has also been the subject of science fiction works.

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    Light Clock in a Gravity well ?

    Light Clock in a Gravity well ? Hi Thinking of the effect on a light clock taken down to regions of greater gravitational dilation . it occurred to me that the only way there could be a decreased frequency was if light itself was moving slower. That the decrease in local speed would have to...
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    Beginner's Light Clock question

    I'm having a bit of trouble with the famous light clock example, where the photon bounces between 2 mirrors and the light clock is moving laterally across my view. The description is that I see the photon's path longer (spread out) and so it should take longer to travel between ticks. The...
  3. W

    What if light clock experiment was done on top of train?

    If the light clock was on top of the train, it wouldn't be in a inertial system. If a table tennis game was played inside the train, the ball would move as if played on the platform. But it wouldn't be possible ontop of the train. Does the light react the similarly to a table-tennis ball or is a...
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    Question about light clock.

    Often to describe relativity is used example with two ships. Ship B is traveling at 0.5c speed from ship A. Ship A is standing still and shooting out beam of ligth in direction of ship B. Ship B has this light clock which is placed verticaly. I understand the time delation with vertical clock...
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    Verify special relativity by concept light clock

    Verify special relativity by concept "light clock" Hello. For verify the special theory of relativity most books use a "light-clock": Obviously, the way the light covers, when the clock is moved is bigger, than the way the light covers when the clock is not move. Because speed of light...
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    Light Clock: Exploring Questions on Light Velocity & Motion

    I am a new fish to SR and I have some questions about light clock. Hope someone to clear my concepts. Q1. As we all know, the speed (scalar) of light is "c" and is independent to the motion of the light source, but what about the velocity (vector) of light (with magnitude "c" but what...
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    Explaining Length Contraction with the Light Clock Argument

    We're just learning special relativity in class and my lecturer uses the light clock argument (two moving clocks - one parallel and one perpendicular) to explain length contraction. I didn't quite get one thing about it. My notes say the light beam reflects at different times (i.e. they have...
  8. E

    The light clock and time dilation.

    How do you argue that the equation for time dilation derived from studying a light clock can be used in general. For instance, how does it tell us that a mechanical clock would also show time dilation?
  9. T

    A question about a relativity light clock

    I'm learning about relativity and how going close to the speed of light can distort time, but I have questions/need for confirmation on a few things. After seeing a little video about I thought of some things and came to a few logical conclusions. Okay. A light clock as seen at...
  10. S

    Light Clock Experiment Flawed?

    Hi - I’m new here and I'm probably a bit of an impostor in that I’m not a physicist, scientist or even academic. I’ve been trying to increase my understanding of Relativity and often see a light clock experiment that is used to demonstrate time dilation. Given the extent that this particular...
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    Light clock and teaching of special relativity

    do you think that the light clock is a good pedagogical tool for introducing special relativity? a teacher of mine told us that there is no advantage without disadvantage! sine ira et studio
  12. D

    Exploring Light Clock Motion: An Analysis

    This question is not directly related with time dilation as much it is with the light clock that is so often used to improvise the concept of time dilation. This clock consists of two mirrors placed parallel to each other, a light blip that bounces between the mirrors. The light blip is...
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    Question about the light clock

    Question about the "light clock" I'm trying to make sense of Brian Greene's explanations of SR in The Elegant Universe. For those who don't know it, he gives the example of a "light clock" that bounces a single photon between two mirrors and produces a tick after each round-trip. Another...
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    Light Clock Thought Experiment: Parallel Moving Mirrors

    I have raised this issue in a different manner before - but never got a satisfactory analysis. In the traditional parallel moving mirrors (separated by distance d) light clock thought experiment, the photon is considered to travel back and forth over the same path in the moving train (both...
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