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Comment by sudhirj | Hacker News Reader

Didn’t see if this was mentioned in the article, but it was interesting to find out somewhere that for a photon time doesn’t pass even as it travels across the universe. Basically the time component is 0 so the space speed is 100%.

That’s why I find it easier to stop thinking of the speed of light, and thinking of it as percentage of speed of information transfer in the space-time medium. Light (or rather electromagnetic waves) travels at 100% the speed of space, but it has no special treatment in the medium, and does so by travelling at 0% the speed of time.

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I'm not sure if it's exactly the same thing, but I've heard the phrase, "From the perspective of light, everything happens at once".

It's a bit unclear to me how light or a photon could have a perspective, but I guess it's not really relevant? This kind of thing is part of why I haven't taken a deeper dive into physics. The metaphors and allegories always break down if you look at them too hard, you really need to wade into the underlying math to get a real understanding I think.

Yeah, that's really everything with all caps EVERYTHING, isn't it? From the beginning to the end of the universe, it would all happen in an instant.

This perspective you mention is exactly why I made a video on the subject: https://youtu.be/A-2XQQDD6QQ

It seems so simple to me now!

The last time someone brought this up I was surprised that I reacted to it. Knowing a thing and hearing it explained can be a different experience.

The presenter I’m thinking of offers us a self aware photon that is born in a star and then is immediately absorbed by a planet in the next galaxy. Or put another way, from the photon’s perspective it isn’t a vector so much as a line segment between two points.

For photon time passes only for itself (because relative to itself it is not moving). Any interaction with photon (i.e. what we call "observing"), happens with t=0 from perspective of something that collided with photon, and normal time from the perspective of photon (which happens to be spatial distance from perspective of something that collided with photon).

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