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That sounds like an interesting theory; is it yours, or do you have any citations / references you could share?
by chrisweekly 2y ago
That sounds like an interesting theory; is it yours, or do you have any citations / references you could share?
- ameetgaitonde 2y agoHe's just describing Einstein's Theory of Special Relativity.
- chrisweekly 2y agoHuh. I'm admittedly no astrophysicist, but I don't recall encountering this "photons have no velocity in the time dimension" before. Maybe I'm one of today's lucky 10,000[1]. 1. https://xkcd.com/1053/ https://xkcd.com/1053/
- bee_rider 2y agoBut, it is sort of common to observe the somewhat trippy fact that, unlike matter, photons don’t experience time passing, right? (Although, I will be honest, I could not ever really grok relativity like a physicist. However, I can enjoy the Lorentz factor going to infinity as v goes to c).
- da_chicken 2y agoFrom my understanding, it's more correct to say that time is undefined for massless objects. Through special relativity, our understanding of mass, gravity, and spacetime are linked. If something has no mass, then special relativity can't describe how gravity affects it's spacetime reference. Remember, however, that this explanation is based on the mathematics that explain the observations we've made or theorized. Just as the map is not the territory, the math is not the universe.
- deleted 2y ago[deleted]
- salviati 2y agoI enjoyed this video on this topic a lot. Maybe you will too: https://youtu.be/fB8eatgkOyM?si=D9s01MY8jByWREPX https://youtu.be/fB8eatgkOyM?si=D9s01MY8jByWREPX
- nh23423fefe 2y agoIt's not true. It's a mashup of a few ideas that don't belong together. 1. an object at rest has a world line which points (has tangent vectors) in the time dimension 2. light has proper time (dtau) = 0, so clocks moving at the speed of light dont tick 3. the magnitude^2 of an objects 4-velocity is c^2 (objects move through spacetime at c) 4. light has no 4-velocity (because dtau=0, you cant divide by zero) You can't say (3) means objects have 4-velocity c in spacetime and light has 3-velocity c in space and so that means the time component of 4-velocity for light is zero. Because light has no 4-velocity.
- marcellus23 2y agoIt's Einstein's :)
- wetpaws 2y ago[dead]
- xenadu02 2y agoI can't claim credit for any of this. As others have noted Einstein (and other much smarter people) are responsible.
- xeonmc 2y agoI like to put it as: Special Relativity is just the Pythagorean Theorem.
- smokel 2y agoIf you think it is implied that c stands for the first letter of the word causality, then reading the article should be enough to convince you otherwise. Einstein published his seminal works in German, and we'd be more likely to have E=mk².
- zachooz 2y agoAn introduction to general relativity spacetime and geometry by Sean Carrol
- grues-dinner 2y agoIt is, in my opinion, not extremely obvious from the usual descriptions of relativity, but basically when you move faster and faster, you trade your velocity through time for velocity through space. Rather then a funny result, that is the theory. If you're at rest, you have maximum time velocity (1 you-second per frame-second). If you're at the speed of light, it's zero you-seconds per frame-second. This is described by the Minkowski space, which is a metric that puts two events the same distance apart in spacetime regardless of reference frame. Greg Egan's series "Orthogonal" looks into what the universe would look like if time didn't have the opposite sign (so that time is another dimension just like x, y, z). The effects of that one sign change are very wierd.
- chrisweekly 2y agoI'd say it's extremely non-obvious, given "velocity" no longer means distance / time