Horizon - How Big Is the Universe
Discussion
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
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
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.
BTW: I didn't see the actual Horizon prog. so can't comment spciifically on it.
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 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.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
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
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.
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.
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.
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?It is like religion. They can't all be right. However, they could all be wrong.
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)
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)
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.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)
Solid matter is mostly empty space.
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."
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."
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.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)
Solid matter is mostly empty space.
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