Thread: pulsating universe

This is one of the most interesting theories i have read for the creation of the universe.

http://www.mail-archive.com/eristocr.../msg00037.html

Basically says that the universe pulsates kinda like a heart. After the Big Bang it expands as far as it can (what its doing now), and then gravity begins to pull it in until all the matter is once again on top of each other...then, BOOM! ...another Big bang.

so if the sheer size of the universe didnt make you feel lonely enough. It is possible that we are just one spec of life in one pulse that has happend millions of times before.

Still an infant theory that doesnt have a lot of science to support it yet, buts its very interesting i thought.

I thought of that a while ago. Lemaitre was a priest before a scientist. Expansion of the universe implies it was once smaller. Big Bang implies a creation. The public is comfortable with that thought. It is familiar, enabling them to swallow the idea of the expansion of the universe more readily.

Of course, I also think that each "pulse" of the universe is "simultaneous" (the universe is outide of time). I've toyed with the idea that the only reason the pulses restart is because the system is imbalanced--it requires sufficient "awareness" to continue.

Well, what the website described, as far as I can see, is nonsense. Even if there was some reason for the universe to repeatedly stop growing for a while, it would not be infinitely old. The whole reason we believe there was a Big Bang is that we observe that all galaxies are flying away from us; then we just extrapolate backwards in time.

What you described is actually an extremely well known cosmological theory. If there is a high amount of mass in the universe, this would be true. However, by current estimates, there is not enough, by a factor of around 100; the universe will continue expanding forever, and fizzle out.

Personally I believe that there are many universes though.

I've never understood how the cyclical universe hypothesis dealt with entropy. Either the laws of thermodynamics break down at the big bang, or there's an external area outside our universe, giving us more energy. Neither option is very satisfying.

That's an interesting point... a singularity is a singularity, I don't see how the singularity at the end of time could have any less entropy than that at the start, violating the second law of thermodynamics...

Then again I haven't studied entropy.

Originally Posted by drewmandan

I've never understood how the cyclical universe hypothesis dealt with entropy. Either the laws of thermodynamics break down at the big bang, or there's an external area outside our universe, giving us more energy. Neither option is very satisfying.

Energy is never lost. It is lost as thermal energy, and dissipates through the universe. It doesn't leave the universe--the universe is a closed system (for this argument. Just as you said, it doesn't make sense for energy to come in from an outside source, it also doesn't make sense for it to leave to an outside place.). The universe has the same amount of stuff (energy and matter) as it had in the first place.

Everything in the universe is cyclic, so why not the universe itself too? As above, so below..

Originally Posted by Abra

Energy is never lost. It is lost as thermal energy, and dissipates through the universe. It doesn't leave the universe--the universe is a closed system (for this argument. Just as you said, it doesn't make sense for energy to come in from an outside source, it also doesn't make sense for it to leave to an outside place.). The universe has the same amount of stuff (energy and matter) as it had in the first place.

That's a violation of the 2nd law of thermodynamics. Here are two versions, both of which don't allow what you just described:

"Heat generally cannot spontaneously flow from a material at lower temperature to a material at higher temperature."

"It is impossible to convert heat completely into work in a cyclic process."

The background radiation is almost completely unusable, at least according to thermodynamics.

well, id think that the idea that the universe is "pulsating" would explain where all the matter came from (Kinda)

Not really.

but all the matter in the universe had to have been on top of each other at some point (as described by the big bang).

No

i dont know, im a man of ignorance with a willingness to learn

Well, you're dealing with advance ideas that needs advance understanding of mathematics.

Saying that I think the most popular view is something called inflationary cosmology, which is kind of like the universe was kind of like alot of bubbles, were one of the bubbles that was inflated and grew into our universe.

I would say no.
About 5 billion years ago, the universe sort of had a 'break' in expansion. Since then it's been expanding ever more rapidly.
Thanks to this is the effect of Gravity and Dark Energy (the energy of the vacuum): gravity has a limited reach (go read Newton), while Dark Energy has an infinite reach. Dark energy is gravity's counter force: it makes object get away from eachother.
First, the DE pulls the objects away, but struggles against gravity. As the objects get further and further apart, the gravity lessens, thus accelerating the objects. That's what's been happening to the universe lately

Originally Posted by ThreeLetterSyndrom

I would say no.
About 5 billion years ago, the universe sort of had a 'break' in expansion. Since then it's been expanding ever more rapidly.
Thanks to this is the effect of Gravity and Dark Energy (the energy of the vacuum): gravity has a limited reach (go read Newton), while Dark Energy has an infinite reach. Dark energy is gravity's counter force: it makes object get away from eachother.
First, the DE pulls the objects away, but struggles against gravity. As the objects get further and further apart, the gravity lessens, thus accelerating the objects. That's what's been happening to the universe lately

It doesn't sound like you know what you're talking about.

Actually I have read about this information in the Scientific American many different times with different articles with new developments.

The science community has been very close to this idea for a little over a year now.

But this article has a tone of flaws and makes ridiculous questions for the big-bang theory which he himself does not own up to in his theory.

Either way, his theory is still using the idea of the big-bang theory.

but all the matter in the universe had to have been on top of each other at some point (as described by the big bang). So how did it all get there? Because it was all pulled in by gravity.

where else could it have come from?

i dont know, im a man of ignorance with a willingness to learn

It was just there. You're saying that mass was created separated by space, then it came together under gravity to form a singularity, then it exploded to make the universe; the first step is completely unnecessary. We might as well just say the singularity exploded to form the universe.

Actually I have read about this information in the Scientific American many different times with different articles with new developments.

Have you read any uni books on cosmology? and not just dumbed down crap they put in Scientific American.

gravity has a limited reach (go read Newton),

I'm pretty sure there have been some recent developement in the theory of gravity.

We might as well just say the singularity exploded to form the universe.

Entropy has to be really low at the time of the big bang, so no explosion.

Originally Posted by wendylove

Entropy has to be really low at the time of the big bang, so no explosion.

Agree..

It amazes me however, considering the Universe itself has a well-defined thermodynamic arrow of time. But this doesn't address the question of why the initial state of the universe was that of low entropy? If cosmic expansion were to halt and reverse due to gravity, the temperature of the Universe would once again increase, but its entropy would continue to increase due to the continued growth of perturbations and eventually blackhole formation. Kind of makes you wonder.