I never understood why you can't go faster than light - until now! - floatheadphysics - 16m

I always though it's kinda depressing how even if we could travel close to speed of light, the time it would take to get to the nearest galaxies would still be hundreds if not thousands of years. However I recently learned that it's not quite so because when traveling at that speed you're also traveling in time, so from your perspective it wouldn't take long at all. It's just that you can't really ever come back because everyone else would be dead by then.

Unless you have a energy source that weighs next to nothing, or you somehow can decrease your mass down to next to nothing you will never go as fast or faster than light. (E=m*c² and all that jazz)

Eh.

Physics does some weird shit based on frame of reference. Until something goes faster than the speed of light, that's the limit. If it goes back to nothing moving faster than light, it's a limit again. But that time I'm between... Maybe?

Like, we're talking about something that has a coinflips chance of being a wave or particle each time we look at it. And if no one's watching, it's somehow both. Similarly the speed of light might just be the equivalent of draw distance. And just like Rick glitched out that weird alien simulation, maybe we can glitch the actual universe so that by somethings frame of reference, it's moving faster than light. Maybe light will just speed up and the current speed of light is really because of some random thing trucking along at that speed and maybe someday it changes?

Maybe because light is both a wave and a particle, it's just setting its own standard for the wave speed by the particle speed.

It's stupid to assume there's more weird shit we haven't noticed yet.

And that's not even getting into the grey areas around FTL where you get between two points faster than light could, but you didn't travel the same distance between points.

Like, once physics gets complicated, if you think you understand it, it just means you dont.

The smartest physicist currently alive almost constantly tells people about how much he doesn't know, and that guy has pretty much all of human knowledge regarding math (not just physics) in his head.

He freaking came up with the ideas for MC Escher's most famous drawing (the stairs and hand drawing hand) when he was a bored teenager.

If Roger Penrose says he doesn't understand it none of us do.

The stuff in the video makes sense, but what I can never understand is how we choose reference. Like if the space ship is the reference, wouldn’t everything else be moving at the speed of light and therefore slow down instead? Is it safe to assume some universal fixed point that’s everything else is moving around?

Here’s what I don’t understand. It all seems like a limitation based on the assumption that the observing ship is not moving at all. You can’t travel the speed of light relative to me because it would look like you’ve stopped accelerating.

What if the observing ship is moving half the speed of light, and the other ship is moving in the opposite direction at half the speed of light? Relative to each other, they are both traveling the speed of light now. I am definitely missing something here.

flying sausage?

The simplest way I can explain it is that everything is always moving at the exact same speed, divided up between the three spacial dimensions and the time dimension. Light does not move through the time dimension at all, and therefore is always moving at full speed through the three spacial dimensions: ie. speed of light.