However...
If you were to travel in a spaceship approaching the speed of light, time would appear to slow down to almost "zero" to another stationary observer.
To you, on the spaceship, time would just pass by normally.
(
Mex3 =mememe, Fri 9 Oct 2020, 22:46,
Reply)
However...
A photon is massless, so time does exist for it, but it's just zero. Re. the however; that's why we talk about frames. So for you it takes monkeys' years, but for the poor photon it's observing your grans' undies as soon as she gets them out of the washing.
Except, if a young photon doesn't want to see your grans' undies it can rely on gravity to swerve seeing the unmentionables. Especially if your grans' pants are extremely massive and effect spacetime giving the photon a dodge.
I know photons can have mass but not in thought experiments that involving them sniffing your grans' knickers.
(, Sat 10 Oct 2020, 0:00, Reply)
I heard someone call the speed of light the "speed of causality" recently
- so it's the speed at which events propagate through space-time, which is why it's also the speed at which massless things propagate.
Dunno whether that's supported by the clever people. I'm just a guy in a blue pointed hat.
(
Invisible Wizard - 13th Level Scrote, Sat 10 Oct 2020, 17:13,
Reply)
I think it's sort of mostly true except when it isn't...
e.g. we infer from observation the expansion of spacetime at speeds greater than the speed of light/causality, and time gets strange when you have interactions/observations between multiple bodies at relativistic speeds, and things also get strange with various wormholes and singularities swapping space for time and time for space.
(
brb man-child cuck corporate supplicant fuck, Sat 10 Oct 2020, 20:20,
Reply)
if spacetime is expanding - then does that mean the earth and everything on it is getting bigger
(, Sun 11 Oct 2020, 12:08, Reply)
I don't think so.
The expansion evidently only takes effect in the absence of one or more of the fundamental forces - which are observed to be constant everywhere (even within the galaxies observed to to be receding faster than others). The expansion only affects the sparse space between dense regions of spacetime.
In order for us not to notice our own physical expansion all the laws of physics would need to scale up at the same rate, otherwise we'd notice the density of matter decreasing. Physics, chemistry and biology would all start to go wrong. Gas giants would start swallowing their moons. Your cells would stop working. It would be no fun at all.
(
brb man-child cuck corporate supplicant fuck, Sun 11 Oct 2020, 16:34,
Reply)