Horizon - How Big Is the Universe

[skeeterm5]

I watched this the other night, quite a good program but it got me thinking and wondered if any other PHers had any insight;

1) Excepted theory is that the universe started at the Big Bang, a singularity which was a tiny (really tiny) point in space.

2) The Horizon program showed that current measurements "prove" the universe to be infinite in size

So I then started wondering when did the universe change from finite in size (singularity) and become infinite in size? Doing my head in trying to reason it....

S

[JBM78]

I've wondered this too.... anyone?

[Simpo Two]

Is 'the universe' the name for the collective cloud of gas and lumpy bits that's expanding, or the void into which it's expanding?

[Twobad]

It may always have been infinite in the same way as the Equator is. No matter how long you walk along it you'll never get to the end. The universe may be the same but in more dimensions. Anyway it's moot because the extremities of the universe are beyond reach unless someone finds a way to breach the speed of light barrier.

BTW: I didn't see the actual Horizon prog. so can't comment spciifically on it.

[br d]

Simpo Two said:

Is 'the universe' the name for the collective cloud of gas and lumpy bits that's expanding, or the void into which it's expanding?

I didn't see this program but my understanding was that there isn't a void into which the universe is expanding, the whole thing is the universe. I once read it described like a giant fruit cake expanding, the currants are the galaxies etc and the dough is the 'space', it's all coming up together.

[RealSquirrels]

Simpo Two said:

Is 'the universe' the name for the collective cloud of gas and lumpy bits that's expanding, or the void into which it's expanding?

it's not expanding into anything, it's just expanding.

[Simpo Two]

That's the first one then, ta

So the bit it is expanding into must be extra-universal...?

[Derek Smith]

RealSquirrels said:

Simpo Two said:

Is 'the universe' the name for the collective cloud of gas and lumpy bits that's expanding, or the void into which it's expanding?

it's not expanding into anything, it's just expanding.

Matter creates space. Without things there can't be space. So there is no such thing as a void if by that you mean a place that is empty. Or at least that's what 'they' say.

[jmorgan]

For some reason I understood it to come into existence pretty much on a big scale. Not expanding from anything. On second nothing, next second young universe that is expanding.

[RSoovy4]

http://en.wikipedia.org/wiki/Flying_Spaghetti_Mons...

[kowalski655]

You can't have a 'how big is the universe discussion without:

Space is big. Really big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.

Doesn't really help much though...,sorry

[GokTweed]

I remember watching a programme where they thought the universe had a finite size and was football shaped, when you reached the edge of the universe you appeared on the opposite side (like an old gameboy game or something) they were also looking for proof of parallel universes pressing up against these sides. Blew my mind. Morgan Freeman was presenting it and the reasons did appear to make sense even though the research is in its infancy.

[Derek Smith]

The problem is that the universe can only be described by math. Models, such as rubber stretched like a drum, are very limiting. We are told there are membranes and then that everything is made of string.

It doesn't help when the majority of the universe is given the name of dark matter, or dark energy, but no one knows what it is.

The universe is not eternal. It has changed a number of times in my lifetime. Yet each time the scientists who have proposed a new idea have come in, all shiny faced, with enthusiasm and real belief. It is touching to watch. Yet everyone knows, perhaps even then, that all it is is a guess.

[Dogwatch]

Derek Smith said:

The universe is not eternal. It has changed a number of times in my lifetime.

Hmmmmmmm

[Derek Smith]

PW said:

Derek Smith said:

Yet everyone knows, perhaps even then, that all it is is a guess.

Is that quaint theory based on superior scientific knowledge, or complete ignorance of the subject?

Statistical evidence, old son. If every explanation is proved wrong then one must accept that the likelihood is that those who put forward the ideas as proven fact are a bit off beam.

It is like religion. They can't all be right. However, they could all be wrong.

[scdan4]

Never mind the universe, just the solar system is almost beyond comprehension.

This is really, really good to do, and demonstrates the point so well

http://www.noao.edu/education/peppercorn/pcmain.ht...

(and that's a really, really crowded bit o' space)

[Jandywa]

There is the observable universe, then there is the 'rest' which we cannot see. I suppose the universe being referred to as infinite is more to do with its continual expansion, as something continually expanding doesnt have a finite size.

[Halmyre]

scdan4 said:

Never mind the universe, just the solar system is almost beyond comprehension.

This is really, really good to do, and demonstrates the point so well

http://www.noao.edu/education/peppercorn/pcmain.ht...

(and that's a really, really crowded bit o' space)

If you want 'empty space', the hydrogen atom beats that. If the nucleus of a hydrogen atom was the size of the sun, the electron would be TEN TIMES further out than the orbit of Neptune.

Solid matter is mostly empty space.

[Caruso]

An interesting article on the BBC today:

http://www.bbc.co.uk/news/science-environment-2149...

A concept known as vacuum instability could result, billions of years from now, in a new universe opening up in the present one and replacing it.

"It turns out there's a calculation you can do in our Standard Model of particle physics, once you know the mass of the Higgs boson," explained Dr Joseph Lykken.
"If you use all the physics we know now, and you do this straightforward calculation - it's bad news. What happens is you get just a quantum fluctuation that makes a tiny bubble of the vacuum the Universe really wants to be in. And because it's a lower-energy state, this bubble will then expand, basically at the speed of light, and sweep everything before it."

[omgus]

Halmyre said:

scdan4 said:

Never mind the universe, just the solar system is almost beyond comprehension.

This is really, really good to do, and demonstrates the point so well

http://www.noao.edu/education/peppercorn/pcmain.ht...

(and that's a really, really crowded bit o' space)

If you want 'empty space', the hydrogen atom beats that. If the nucleus of a hydrogen atom was the size of the sun, the electron would be TEN TIMES further out than the orbit of Neptune.

Solid matter is mostly empty space.

My head hurts now!