uziq wrote:'c' is the speed of light in vacuum. which has not necessarily been the same everywhere and throughout the entire history of the universe (even einstein wrote about this).
this is counter to my understanding then. I was under the impression that massless particles move at C in a vacuum, regardless of what time in the universe. You can slow it down, make it travel through air or water etc, but a vacuum is a vacuum whether just after the big bang or just before the heat death, no?
uziq wrote:there are other constants, like planck's constant. what he's getting at is the misbegotten idea that the universe started out with 'laws' and is just unfolding according to those 'rules'.
This reminds me of something I saw explaining that the laws we deal with, are the way they are because they're at the bottom of a hill. They may have come down another hill to rest, but to change them would require extra energy. Something like this:
So therefore before what we call the universe existed, the laws may have been at the higher state, and rolled down to rest where they are now. Is this what you're referring to?
uziq wrote:but no scientist seriously thinks this; even a biologist or a chemistry working in a lab on very particular problems now realizes that everything occurs within a 'reference frame', relative to being on Earth, etc. and especially an astrophysicist like freeman dyson who spent his entire career thinking about the long-view of the universe's history, i.e. its very beginnings and its eventual late end.
Feels like you're kicking the can down the road? I know about reference frames, but it feels a bit pedantic to say "yes, light moves at 300km/s, unless you're moving away from it at 300km/s". From the observer in that scenario, the speed of light would be 0, but from our reference, they would both be moving at C..
I'm aware you're not an expert on the topic but I have a kinda passive hobby like interest in physics and watch quite a bit of content on it, and this is so counter to my understanding. Maybe it's a definition thing, or a timescale thing.