What is the velocity of a photon through the four dimensions?

In summary,The velocity of a photon through the four dimensions is undefined. Physicists disagree on whether x4 is a physical dimension. If it is, then the physical photon is doing something relative to the physical dimension x4.
  • #1
Epic Mythology
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What is the velocity of a photon through the four dimensions?

What is the velocity of a photon through the three spatial dimensions x1, x2, x3?

What is the velocity of a photon through the fourth dimension x4?
 
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  • #2
Epic Mythology said:
What is the velocity of a photon through the three spatial dimensions x1, x2, x3?
Either ##c## or more or less anything you want depending on exactly how you define this.
Epic Mythology said:
What is the velocity of a photon through the fourth dimension x4?
I don't think this has a sensible definition.
 
  • #3
Ibix said:
I don't think this has a sensible definition.
I agree, it is undefined since proper time is not defined for a pulse of light.
 
  • #4
Interesting. Do physicists agree that a photon is a physical object? Do physicists agree that x4 is a physical dimension?

If so, what is the physical photon doing relative to the physical dimension x4? How is the physical photon moving relative to the physical dimension x4?
 
  • #5
Epic Mythology said:
Interesting. Do physicists agree that a photon is a physical object? Do physicists agree that x4 is a physical dimension?

If so, what is the physical photon doing relative to the physical dimension x4? How is the physical photon moving relative to the physical dimension x4?
If you are talking about four dimensions, nothing moves in four dimensions. "Motion" is looking at different three dimensional slices of 4d objects and noting that those different slices aren't the same.
 
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Just because a series of words can be strung together gramaatically and terminated with a question mark does not make it a valid question. Do colorless green sheep sleep furiously?
 
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  • #7
Ibix said:
If you are talking about four dimensions, nothing moves in four dimensions. "Motion" is looking at different three dimensional slices of 4d objects and noting that those different slices aren't the same.
Do gravity waves propagate through four dimensions, or only three dimensions? Do objects move through spacetime or only space? Do objects move only through space, but never through time? Are you saying all objects are stationary in time?
 
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  • #8
Epic Mythology said:
Do gravity waves
Gravitational waves. Gravity waves are a kind of deep water wave, the naming and study of which predate relativity by centuries.
Epic Mythology said:
Do gravity waves propagate through four dimensions, or only three dimensions?
In a relativistic model everything is a 4d structure. Whether you use the word "propagating" to describe them and how you interpret that is really up to you, but generally if you are thinking of anything as changing over time then you are thinking in three dimensional terms. Which is fine, but will severely hamper your understanding of answers about four dimensions.
Epic Mythology said:
Do objects move through spacetime or only space?
If you are thinking of spacetime then you are (or should be) thinking of 4d structures whose "change over time" is encoded in their structure. To have a notion of motion you need to split spacetime up into space and time, and then you can talk about rate of change of place in space, which is motion.
Epic Mythology said:
Are you saying all objects are stationary in time?
What would you mean by "moving in time"?
 
  • #9
Ibix said:
Gravitational waves. Gravity waves are a kind of deep water wave, the naming and study of which predate relativity by centuries.

In a relativistic model everything is a 4d structure. Whether you use the word "propagating" to describe them and how you interpret that is really up to you, but generally if you are thinking of anything as changing over time then you are thinking in three dimensional terms. Which is fine, but will severely hamper your understanding of answers about four dimensions.

If you are thinking of spacetime then you are (or should be) thinking of 4d structures whose "change over time" is encoded in their structure. To have a notion of motion you need to split spacetime up into space and time, and then you can talk about rate of change of place in space, which is motion.
What would you mean by "moving in time"?

Do you agree that mass curves both space and time? As a mass moves through spacetime, do you agree that the mass curves both space and time? Do you agree that as the mass passes a point, the space and time will curve in the vicinity of the point, and then, as the mass leaves the area, the space and time will return to being flat or uncurved?
 
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  • #10
Epic Mythology said:
What is the velocity of a photon through the four dimensions?

What is the velocity of a photon through the three spatial dimensions x1, x2, x3?

What is the velocity of a photon through the fourth dimension x4?
3 questions

Epic Mythology said:
Interesting. Do physicists agree that a photon is a physical object? Do physicists agree that x4 is a physical dimension?

If so, what is the physical photon doing relative to the physical dimension x4? How is the physical photon moving relative to the physical dimension x4?
4 questions.

Epic Mythology said:
Do gravity waves propagate through four dimensions, or only three dimensions? Do objects move through spacetime or only space? Do objects move only through space, but never through time? Are you saying all objects are stationary in time?
4 questions

Epic Mythology said:
Do you agree that mass curves both space and time? As a mass moves through spacetime, do you agree that the mass curves both space and time? Do you agree that as the mass passes a point, the space and time will curve in the vicinity of the point, and then, as the mass leaves the area, the space and time will return to being flat or uncurved?
3 questions

Ok, so that is 14 questions. This is starting to feel less like a conversation and more like an interrogation. Particularly when you don’t respond to questions that others asked you. Let’s dial it back a lot!

We are not suspects in a criminal investigation

This thread is closed. Please feel free to open a new thread where we can have a conversation about one or two key questions. When you do so, please keep it centered on those questions and be responsive to other people. Conversations should go two ways
 
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