Originally posted by RJHindsThat's a deal.
Okay, I'll make a deal with you. If you will stop trolling my threads I will stay out of the Science Forum.
Whenever I see you, in any thread in Science, I will troll you so hard in every of your threads that you wish you never came up with this idea.
I'm brand new here and just stumbled across this thread and I haven't read all of the posts.
I've always wondered if Dark Energy is actually a result of a "near by" universe in the multiverse proposals. Perhaps two Universes bumped together creating our Big Bang and our Universe.
Using Universe in the plural is strange ..... !
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Originally posted by Great King RatThe matter/energy density of the universe is decreasing as a function of time.
Sorry for butting into this thread, but if the universe is expanding, does this mean that over time the universe is getting less dense?
As the rate of expansion is currently believed to be increasing, the rate of reduction
in density is also increasing.
If this continues, each particle will eventually end up residing inside it's own event horizon,
the sole particle in it's visible universe.
Originally posted by Great King RatDon't apologise, it's a reasonable question. The matter density is certainly decreasing. The energy density is dominated by dark energy, so the question is more subtle. It depends on the properties of dark energy. If dark energy behaves like a negative pressure gas then the amount of dark energy increases as the universe expands. With one possible end point being a big rip, where the universe expands so rapidly that even atoms are torn to pieces and every elementary particle becomes causally isolated from every other one.
Sorry for butting into this thread, but if the universe is expanding, does this mean that over time the universe is getting less dense?
Originally posted by googlefudgeYeah, I have this awesome book at home simply called "Bang!" Which states that if the universal expansion continues like it does now then in 10^66 years the average distance between two electrons is estimated to be 100000 times the width of the current universe.
The matter/energy density of the universe is decreasing as a function of time.
As the rate of expansion is currently believed to be increasing, the rate of reduction
in density is also increasing.
If this continues, each particle will eventually end up residing inside it's own event horizon,
the sole particle in it's visible universe.
Mindboggling.
Originally posted by DeepThoughtThe big problem I (and many others) have with this idea of space expanding is that I don't understand what space actually is. Might have to crack open a book again.
Don't apologise, it's a reasonable question. The matter density is certainly decreasing. The energy density is dominated by dark energy, so the question is more subtle. It depends on the properties of dark energy. [b]If dark energy behaves like a negative pressure gas then the amount of dark energy increases as the universe expands. With ...[text shortened]... are torn to pieces and every elementary particle becomes causally isolated from every other one.[/b]
Originally posted by Great King RatThe thing is: space isn't. Its what is in the space that counts. Space is about relationships. At first glance, it appears that space is about distances between things, but if you introduce relativity, it becomes apparent that even that doesn't hold up - then you have to start talking about distances in 'space time'.
.... I don't understand what space actually is.
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Originally posted by twhiteheadUnless M-Theory is correct, in which case 'space' is the 'membrane' we are on.
The thing is: space isn't. Its what is in the space that counts. Space is about relationships. At first glance, it appears that space is about distances between things, but if you introduce relativity, it becomes apparent that even that doesn't hold up - then you have to start talking about distances in 'space time'.
Originally posted by twhiteheadAlright, but then what is expanding? If the distance between a proton and a neutron in an atomic nucleus is expanding, what is expanding? The vaccuum? Is dark energy making the vaccuum bigger? If the whole universe is expanding, does this mean that matter - being a part of said universe - is also expanding? Are protons getting bigger ever so slightly? Or is it only the vaccuum that is expanding?
The thing is: space isn't. Its what is in the space that counts. Space is about relationships. At first glance, it appears that space is about distances between things, but if you introduce relativity, it becomes apparent that even that doesn't hold up - then you have to start talking about distances in 'space time'.