Would Photon Clocks be possible?

In summary, the conversation discusses the possibility of a photon clock, which consists of two 100% reflective mirrors and photons bouncing between them. The question is raised about whether it is possible to construct such a device in reality. While it may be possible, there are practical limitations and challenges in building and using it. It is also mentioned that similar concepts are used in experiments with lasers and radio frequencies. The conversation highlights the complexities involved in understanding and controlling time measurement in experiments.
  • #1
tinypositrons
28
0
My question is as follows:
A photon clock (two 100% reflective mirrors exactly parallel and photons whizzing in between) actually possible. My question is made assuming we could get the mirrors exactly parallel. So really, I suppose my question is:
Are 100% reflective mirrors possible to make in reality?
Thanks all,
Joe.
 
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  • #2
For the sake of argument, let's assume it's possible to construct such a device. However, I don't see how this device would work as a clock. How do you detect any "ticking" of the clock? A photon always gets absorbed as a whole. So, when you detect the photon, the "clock" is destroyed. By the way, there already are quite accurate atomic clocks.
 
  • #3
This is done all the time at radio frequencies. You don't need 100%, just enough so that you can "top off" the wave by adding energy to it.
 
  • #4
(It might be better to call this hypothetical device a "light clock" instead of a "photon clock".)

Whether it's practical to build or one or not is almost the point. We talk about them in our thought experiments because they are drop-dead simple with no distracting mechanical details; time dilation and length contraction are the only ways of affecting their reading.

As DennisN points out, in real experiments we use physically realizable clocks. These require an enormous amount of time and money and ingenuity to understand and control all the mechanical, electrical, and environmental conditions that can affect their operation. All of this effort, although essential to experimental design, gets in the way of simple explanations of the underlying theory.
 
  • #5
tinypositrons said:
My question is as follows:
A photon clock (two 100% reflective mirrors exactly parallel and photons whizzing in between) actually possible. My question is made assuming we could get the mirrors exactly parallel. So really, I suppose my question is:
Are 100% reflective mirrors possible to make in reality?
Thanks all,
Joe.
Your description is very close to how a laser is built except that as others have pointed out, the photons will not just keep bouncing back and forth between the two mirrors on their own, you have to have some way of rejuvenating them.
 
  • #6
Perhaps some scheme wherein a cluster of photons is originally projected. Each time one of the mirrors/detectors is encountered by them, some are absorbed/ measured, while others are reflected. Thus we get an attenuating regular measurement until they are gone? And of course more can always be sent out.
 
  • #7
Vanadium 50 said:
This is done all the time at radio frequencies. You don't need 100%, just enough so that you can "top off" the wave by adding energy to it.

Surely you do need 100%, as otherwise, each time the photons were reflected some would escape, but as they go so fast, they would all escape extremely quickly? I may be wrong, but that's what I think.

Thanks,
Joe.
 

1. What is a photon clock?

A photon clock is a hypothetical device that measures time using the frequency of light waves emitted by a photon. It is based on the concept of time dilation in special relativity, where time appears to pass slower for an observer in motion compared to an observer at rest.

2. Would it be possible to create a photon clock?

Theoretically, it is possible to create a photon clock. However, it would require an incredibly precise and stable light source and a very sensitive detector. Additionally, it would have to be placed in a vacuum environment to prevent any interference from other particles.

3. How accurate would a photon clock be?

A photon clock would be incredibly accurate, potentially more precise than any other clock known to us. The accuracy would depend on the stability of the light source and the sensitivity of the detector, but it could potentially measure time with nanosecond precision.

4. What are the potential applications of a photon clock?

A photon clock could have various applications, such as in space travel and navigation, where precise time measurement is crucial. It could also be used in fundamental research to study time dilation and other concepts in special relativity.

5. Are there any challenges to creating a photon clock?

Yes, there are several challenges to creating a photon clock. As mentioned before, it would require a stable light source and a sensitive detector, which are difficult to achieve. Additionally, it would have to be placed in a vacuum environment, and any external factors, such as gravitational fields, could affect its accuracy. It is also a purely theoretical concept at this point and has not been successfully created or tested in real-life scenarios.

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