According to Mr Einstein’s theory nothing can travel faster than the speed of light,yet according to the big bang theory in the first milisecond the universe had expanded to a diameter of 600 billion miles.How come?
RORY
Because relativity wasn’t invented until the beginning of the 20th C, so no one explained its limitations to that which banged before it banged.
Or Timothy the mouse gave it a magic feather. Maybe.
(but frankly, I’d like a good exposition on this myself. Someone has some splainin’ to do.)
The speed of light has only significance within the universe, within spacetime. The universe is expanding, meaning spacetime itself is expanding. It is not a flat Euclidean space, but highly curved. The constancy of the speed of light holds only good in a flat space (Einstein’s special theory of relativity).
In other words: the universe is not expanding in a flat, non-curved space. But space itself is expanding. Therefore the laws of special relativity have no bearing on this expansion, be it now or at the early big bang stage.
Because it was not the energy/matter of the universe that was moving. It was the universe itself, spacetime itself, that was moving. There may be a constraint on the speed of light within spacetime, but that’s not a contraint on the “movement” of the geometry of spacetime itself.
Here’s a related thought experiment. Step outside at night and point your finger at the North Star - Polaris, located 430 light years away. Imagine the end point of the line formed by your fingertip and the star, the end point resting on the star.
Now quickly move your finger to point to the Andromeda Galaxy. That should take a second. Now the end point of your line is sitting somewhere on Andromeda, located 2.5 million light years away. In a second, your end point has travelled ~2.5 million light years through space! Even if it took you an entire year to move your finger, the end point would still travel 2.5 million times the speed of light. How is that possible?
Because a point is not a thing - matter or energy. It’s just a point, only geometry. And geometry can move as fast as it likes.
[ I crossed posts with Hans. 
]
So does this mean that the enery/matter diamater of the universe is alot smaller in diameter than the spacetime diameter of the universe?
RORY
Something tells me you’d never be able to tell.
I guess the model would say that the two were (and are) coterminous - i.e., the same. But density decreases as the energy and matter fills a “larger” universe. And the changing density (and decreasing temperature) accounts for some of the effects during the first second.
Think of a balloon covered in tiny dots. As you blow up the balloon, the dots have no choice but to follow along. But they’re not really moving around on the balloon. It’s the space on which they sit that’s changing. And becoming less dense. Even if you draw measuring lines on the balloon as it grows, it’s no use for judging distances. Because the measuring lines grow along with the balloon itself.
I don’t remember what the model says about the speed of light. But I wouldn’t think it was necessarily the same then as now. Not until the separation of the four forces and the differentiation of matter from energy.
my brain hurts
This is the part in high school physics class where I’d catch a sunbeam on the edge of my eyeglasses. I had really thick eyeglasses and I could get the sunbeam to refract into a rainbow to travel up and down the edge of my eyeglasses just by moving my head ever so slightly. No one ever knew what I was doing. And then Pink Floyd came out with the Dark Side of the Moon Album with the prism and the rainbow and I knew someone heard my cry for help.
Quick, ask a relevent question to make it seem like I was paying attention. Just out of curiousity, why did you ask your question?
I read all about it–and seemingly understood–a few years ago, in my quantum physics jag, but afterwards (like the Japanese I’m currently studying will do soon) it all ran together into a strangely cluttered dreamlike piece of abstract art from which I can only extract a thing or two. Such as the thing about how, in one of the dimensions numbered above 10, things are all involuted such that size there becomes a reciprocal of size here, or something. I bet Pink Floyd could draw it better than I can reconstruct it, actually.
I left that phase with a deep belief in quantum entanglement, but little to zero ability to describe anything.
Weird. Right when I was reading this thread,
I was watching the Daily Show which was
showing a clip of Morgan Freeman describing
the Inflation Theory of the universe’s expansion.
I was waiting for him to answer your question,
but they stopped the clip too early.
So, if you have the Science Channel, maybe
you should tune in Wed. night. You may not
get your answer, but you will be soothed.
Newton, Einstein, they were wrong more than once.
Just in case anyone is not following emm & I, here are graphics and audio/visual aids
PF’s DSOTHM with the Wizard of Oz
This is the first three songs and some kind of space time warp parallel universe overlay continuum thingy.
but does it work in Kansas?
As time and space came into being with the BB, there was no time before the BB.
So there was no stage of the universe, however brief, where matter was packed into a small
volume, about to explode. That would have been before the BB.
So the matter in the universe came into being
exploding outward from a point, that is, travelling at terrific velocity. It never ‘stood still.’
Now according to General Relativity, there are indeed entities (tachyons) that travel faster
than light. Nothing can ACCELERATE THROUGH the speed of light, but that in no way precludes
entities moving faster than light.
So if the matter in the universe came into being moving faster than light,
it didn’t violate relativity theory, as it didn’t accelerate through the speed of light.
There. Doubtless this is horribly wrong, but it’s a thought…
Tachyon drive. That’s what I need.
those aren’t legal in the city are they?
Pfft. Let 'em try and catch me.
Come and get me copper! I’m moving backwards in time!