Does Light Experience Time Differently Than We Do?

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In summary, light does not have an age as it moves along null-geodesics and its proper time is always constant. From the perspective of a photon, the time between emission and absorption is 0, but from our perspective, it can vary greatly. This means that all light cannot be considered the same age, as it depends on the frame of reference. Time and space are interconnected, and one's speed in space can affect their speed in time.
  • #1
zeromodz
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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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  • #2
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.
 
  • #3
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.
 
  • #4
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.
 
  • #5
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.
 
  • #6
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.
 
  • #7
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.
 

1. How can light be timeless?

Light travels at a constant speed of 299,792,458 meters per second, according to Einstein's theory of relativity. This means that time does not pass for light as it moves through space, making it timeless.

2. Does this mean that light has no age?

Yes, since light does not experience the passing of time, it does not age. This is also why we can see light from objects that are thousands or even millions of light years away.

3. What about the speed of light in different mediums?

While the speed of light in a vacuum is constant, it can change when traveling through different mediums such as air, water, or glass. However, this does not affect its timeless nature.

4. How does this relate to the concept of time dilation?

Time dilation is a phenomenon that occurs when an object moves at speeds close to the speed of light. As an object's speed increases, time appears to slow down for that object. This is why light, which always travels at the speed of light, experiences no time passing.

5. Can anything else be considered timeless?

In addition to light, other particles that do not experience the passing of time include photons, gluons, and gravitons. However, this concept of timelessness only applies to objects that travel at the speed of light or close to it.

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