According to The Big Bang Theory, from which I derive most of my scientific understanding, light is the speed limit of the universe. Nothing can go faster than light. This point is also made in the seminal physics documentary IQ (starring Walter Matthau as Albert Einstein).
However, in this video, it says that:
So…how does that work? How can light be the fastest thing in the universe if, in the first moments of the Big Bang, the universe expanded faster than light?
The speed of light is the fastest anything can travel through space. But space itself can expand even faster than that!
Where are the “edges of the universe”? I thought no matter where you are in the universe, you’re always at the center. Does that mean that we’re expanding faster than the speed of light (since we’re at the “edge of the universe” from the perspective of those at our edge)?
Yes, it does, just as there are parts of the universe receding from us faster than light so that they can never be seen in the future.
AFAIK it’s more correct to say that c is held to be the speed limit of the universe, and light (actually all electromagnetic radiation) is the only thing known to be able to travel at that speed.
Jolly weird, but this is the correct answer. In the “expansionary phase” of the Big Bang, the cosmos itself expanded much faster than the speed of light, carrying matter (and light) along with it.
This version of the BBT has, at this point, strong evidence supporting it, and it also has remarkable explanatory power. It answers several riddles about cosmology – for instance, why space is so very close to perfectly “flat” in the observed universe.
There is a great deal to understand in science that’s not part of the BBT.
I assumed the OP meant the tv series, not the actual theory.
Good assumption, since he also referenced not Einstein but Walter Matthau as Einstein.
Of course, reliable knowledge comes from Troy McClure.
We also think (with a small amount of doubt) neutrinos travel at c, and believe that gravity does as well. Any massless particle must travel at c. (Hence the question about neutrinos - could they have a very very tiny mass and travel very very close to c? It would have to be very very tiny as current measurements of their speed are not allowing much wiggle room. But the question is important.)
I thought the issue of whether neutrinos have mass - they do and it’s very tiny - was settled more than a decade ago. Here’s an article from Berkeley that references a 2002 paper.
It is known that at least two of the three varieties of neutrinos have nonzero mass, and there is circumstantial evidence that all three of them do. That nonzero mass is known to be very small, at most a few electron volts (for comparison, electrons, the lightest particle for which the mass is actually known, are about a half a million eV). Given typical neutrino energies, this still puts them at very close to c.