If distance and time can change then how can c be constant?

In summary, the conversation discusses the concept of the speed of light being constant even though distance and time can change. The speaker asks how one can prove that the speed of light is indeed constant without relying on it in a solution. Another speaker explains that the Lorentz transformations cancel and that the relativity of simultaneity must also be taken into account. The conversation ends with a thank you.
  • #1
ChristianKing
2
0
If distance and time can change then how can c be constant? I guess what I'm asking is how can someone prove that c=c' without relying on c in a solution such as setting the Lorentz space contraction over the Lorentz time dilation?
 
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  • #2


The Lorentz transformations cancel.
 
  • #3


ChristianKing said:
If distance and time can change then how can c be constant? I guess what I'm asking is how can someone prove that c=c' without relying on c in a solution such as setting the Lorentz space contraction over the Lorentz time dilation?
If you're talking about the speed of light in a single direction (as opposed to measuring the two-way speed by sending a light beam away from a clock, having it bounce off a mirror and return to the clock, and using that time interval to divide the distance from the clock to the mirror and back), you can't derive it from length contraction and time dilation alone, you also have to take into account the relativity of simultaneity. I gave a numerical example of how it all works out in post #7 of this thread.
 
  • #4


thank you
 

1. How can the speed of light be constant if time and distance can change?

The speed of light, represented by the letter c, is a fundamental constant in physics. This means that it does not change, regardless of the reference frame or conditions. This has been confirmed through various experiments and is a cornerstone of Einstein's theory of relativity.

2. Can the speed of light ever change?

No, the speed of light is considered to be an absolute constant in the universe. It cannot be altered or changed by any known means. This is due to the fact that it is not a property of any material object, but rather a fundamental property of space and time themselves.

3. How does the concept of time dilation affect the constant speed of light?

Time dilation is a phenomenon observed in Einstein's theory of relativity, where time appears to pass slower for objects moving at high speeds. However, this does not affect the constant speed of light. Instead, it is the relative perception of time that changes for objects in motion, but the actual speed of light remains constant.

4. How does the constant speed of light relate to the theory of relativity?

The theory of relativity, proposed by Albert Einstein, is based on the idea that the laws of physics are the same for all observers, regardless of their relative motion. The constant speed of light is a crucial aspect of this theory, as it is the only speed that remains constant for all observers. This concept helped explain the relationship between space and time, and has been confirmed by numerous experiments.

5. Are there any exceptions to the constant speed of light?

No, the speed of light is considered to be a universal constant that applies to all objects and situations. It is a fundamental property of the universe and has been confirmed by numerous experiments and observations. While there may be theories that suggest otherwise, the constant speed of light remains a cornerstone of modern physics.

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