If we are light, what would we see?

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Discussion Overview

The discussion explores the hypothetical scenario of perceiving the universe from the perspective of light, focusing on the implications of traveling at the speed of light. It touches on theoretical considerations, relativistic effects, and the nature of time and space as understood in physics.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants suggest that if one were to travel at the speed of light, they might perceive the entire universe instantaneously, while others argue this leads to the conclusion of seeing "nothing" or a still frame of existence.
  • There is a proposition that as one approaches the speed of light, time would slow down significantly, leading to a perception of the universe as if fast-forwarding through time.
  • One participant questions whether light would see a beautiful scene or if existence would appear as non-existent, suggesting a limitation in human understanding of such scenarios.
  • Another viewpoint emphasizes that if objects with mass could travel at light speed, it would contradict the special theory of relativity, necessitating a new theoretical framework.
  • Some argue that achieving light speed would require infinite energy, making it impossible for objects with mass to reach that speed.
  • There is a claim that at light speed, the universe would appear two-dimensional due to Lorentz transformations, with all lengths in the direction of travel collapsing to zero.
  • Participants discuss the implications of light speed on perception, including the idea that stationary objects would be subject to extreme Lorentz distance contraction.

Areas of Agreement / Disagreement

Participants express a range of views, with no consensus on what light would perceive or the implications of traveling at light speed. Disagreements exist regarding the nature of time, perception, and the feasibility of reaching light speed.

Contextual Notes

The discussion includes assumptions about the nature of light, time, and space that may not be universally accepted. Theoretical limitations and the implications of special relativity are central to the conversation, but these remain unresolved.

touqra
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If we are light, what would we see?
 
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Light doesn't have eyes! Perhaps you could rephrase your question?
 
The whole universe in 0 time, i.e. nothing at all
 
Something like that, but we can only approach the speed (from a pseudo-theoretical quasi-practical point of view.). Our time would slow down to the point of vanishing with respect to the time of the rest of the universe, and, we would basically see the whole thing zoom to the end like a really fast fast-forward to the end of a movie. Then, who knows.
 
turin said:
Something like that, but we can only approach the speed (from a pseudo-theoretical quasi-practical point of view.). Our time would slow down to the point of vanishing with respect to the time of the rest of the universe, and, we would basically see the whole thing zoom to the end like a really fast fast-forward to the end of a movie. Then, who knows.

To see things zooming like a real fast-foward movie is still moving but it's just that it's fast. So light still experiences time.

But techwonder said, "The whole universe in 0 time, i.e. nothing at all".

If it's 0 time, does it mean that light sees a beautiful piece of art scenery but's it's still life. Nothing moves?
 
touqra said:
If it's 0 time, does it mean that light sees a beautiful piece of art scenery but's it's still life. Nothing moves?
That's one of those things that I don't believe we humans are privelaged to know (at least, not for a long time). I would assume that there would be no picture at all; nothing. As if existence itself didn't even exist. But that is just based on a narrow-minded model that assumes there is nothing beyond. I am pretty sure that there would be no still-frame picture to look at. Quite the opposite. That was my reason for the limiting consideration. Just imagine the fast forward being cranked up to infinity. How long would it take to watch the movie? Would the picture look still? Would you even know you had watched a movie? What happens after the movie is over?
 
If we (or any other objects with mass) were ever able to travel at the speed of light, it would mean that the special theory of relativity was wrong, and a new theory would have to be found to explain why light speed for objects with mass IS possible. That theory might very well say what it would be like to go that fast.

But SR says we can't go that fast, and when a theory in physics says something is impossible, that theory has zero to say about what the thing would be like if it WERE possible!
 
We have mass therefore it would require infinite energy to go c...
 
Perhaps if you were to say you could see at c... although it really wouldn't be possible as i mentioned before the second you reach c the universe freezes, from Einsteins discription of speed you have taken all of your "velocity" out of the time dimension and are using it in the other 3 dimensions. Therefore the second you reach c you would have a snapshot of the universe, however if you were to ever decrease ur speed it would start to move again. however this is unrealistic that you could go c to being with (again see previous post), in the same aspect you could ask if were WERE able to go faster than c would we see the universe in reverse ie travel through time.
 
  • #10
Of course you would be able to see when traveling at light speed! There are no textbook answers because such a situation is impossible since we would require infinite energy to be accelerated to such speeds. But since objects emit/reflect photons constantly, we would observe lorentz distance contraction in the extreme from stationary objects. Of course, if something was moving into our path, we wouldn't see it and would hence collide with it before it could be seen, such is the nature of light speed.
 
  • #11
Hypothetically, if you could see anything while traveling at c, the Universe would spatially appear 2-dimensional. All lengths parallel to the direction of your velocity would be reduced to 0, hence only the dimension perpendicular to the directional vector your velocity would exist. This is also how light can get away with us observing time to stand still for it. We say it travels from point A to point B and doesn't "age" while traveling between them (stretch your mind a little, I suppose a hypothetical [and impossible] object traveling at c would illustrate this better) while from the light's perspective, it doesn't age simply because it doesn't have to go anywhere- there is no distance at all between points A and B. That's the best answer I can give: according to the Lorentz transformations, from light's perspective the universe is 2-D.
 

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