Does Light Experience Time Differently Than We Do?

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The discussion centers on the concept of light and its relationship with time, particularly whether light experiences time differently than humans do. It is argued that light does not age and that from the perspective of a photon, emission and absorption occur simultaneously, leading to the conclusion that all light has an age of zero. The conversation highlights the relativity of time, emphasizing that while light emitted billions of years ago and light from a computer screen seem vastly different in our frame of reference, they are perceived as having the same duration from the photon's perspective. The idea that light is timeless is challenged, suggesting that time is relative and depends on the observer's frame of reference. Ultimately, the discussion illustrates the complex interplay between light, time, and perspective in physics.
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If light is timeless (photons), then doesn't that mean that everything we see is just 13.7 billion year old light?
 
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Light is not "timeless". Your mistaking a perspective dependent sense of a sequence of events as something that has absolute meaning independent of your perspective.
 
zeromodz said:
If light is timeless (photons), then doesn't that mean that everything we see is just 13.7 billion year old light?

Where did you get the idea that photons were timeless? And your conclusion indicates that's not what you believe.
 
Light doesn't age. It's proper time is always a constant, because it moves along null-geodesics.

That means from perspective of light, it's emission and absorption happen at the same time. It doesn't mean all light is the age of the universe. That right there is a strange leap of logic.
 
K^2 said:
Light doesn't age. It's proper time is always a constant, because it moves along null-geodesics.

That means from perspective of light, it's emission and absorption happen at the same time. It doesn't mean all light is the age of the universe. That right there is a strange leap of logic.
Right: it would be closer to reality to say that all light has an age of 0.
 
It depends entirely on what you regard as time.
Space is time and time is space.

From one person's point of view a parsec is a parsec. From someone else's it could be a couple of days.

You can't talk about the age of light any more than you can talk about it's length.
 
Here's an easy way to understand it: from the photon's reference frame, the time between emission and absorption is 0, but from our frame of reference, this is clearly not the case. Light emitted 13 billion years ago (cosmic background microwaves) and light emitted from your computer screen about a nanosecond ago (From memory/really rough estimation, It seems that it should take about one nanosecond for the light coming from your computer to reach your eye), from the perspective of the photon, exists for the same duration, namely zero duration. Now, from our reference frame, they take vastly different amounts of time. Now, if you moved with the photon at a speed really close to its speed, the closer both 13 billion years and one nanosecond would be to each other, and to zero. Your speed in space affects your speed in time.
 

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