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Q & A: What does a photon see?

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Most recent answer: 02/09/2013
Q:
If I were a photon wouldn't I be hanging out at the end of time with all the other photons? As a photon, I was once seen by many but how could I have ever experienced being seen or even moving at all because for me all time passed the moment I was created? Thanks.
- Richard Broderick Jr. (age 54)
Lincoln, Maine, USA
A:

Hi Richard,

That's an interesting age-old question; in fact, it helped motivate Einstein to create his special theory of relativity. Unfortunately, even given our knowledge of relativity, we can't understand how a photon sees the world. Special relativity simply does not apply to reference frames traveling at the speed of light.

If you tried to apply special relativity to a photon, you would find that its proper time integral (which measures how much time passes in the photon's frame) is 0. So, I'd say your poetic summation is as good a guess as any. However, trying to apply relativity in a frame moving at the speed of light yields unphysical results, so we don't yet know what a photon sees.

Hopefully someday a more comprehensive theory will help us understand the world from a photon's point of view!

David Schmid


(published on 02/09/2013)

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