Will there be matter at the end of the universe?

[phinds]

I was watching Brian Cox on TV last night and he was talking about the heat death of the universe and made the statement that in the far future (he was talking the FFFFFAAAAARRRR future ... out there when even super-massive black holes have evaporated) there would be NO matter left and only radiation tending towards absolute zero. He did not say anything about why normal matter would disappear (or if he did, I missed it).

First, is that a correct statement and second, if it is then am I correct in assuming that this will happen because super-low-probability quantum events of particles spontaneously converting to radiation will ALWAYS, given enough time, happen ?

Thanks

 

[BillSaltLake]

If protons (that is, protons not swallowed by black holes) decay, the only stable matter that results will be positrons. These will be essentially equal in number density to the (stable) electrons. If they all meet and annihilate, only energy will be left, but it's certainly possible that some electrons and some positrons remain indefinitely.

 

[Cosmo Novice]

If protons (that is, protons not swallowed by black holes) decay, the only stable matter that results will be positrons. These will be essentially equal in number density to the (stable) electrons. If they all meet and annihilate, only energy will be left, but it's certainly possible that some electrons and some positrons remain indefinitely.

Just as an additional note to this; Increasing expansion will mean that any positrons/electrons left will exist within their own OU, with all matter "moving" due to expansion - away from everything else >c. Matter/energy interactions will eventually cease as a thermal equilibrium across the U is reached.

At lease that's how I see it and its not a terribly happy ending!

 

[phinds]

yes, I agree w/ all that both of you have said, and this DOES contradict what Cox said. He said no matter at all. It was an unambiguous statement which I found puzzling.

 

[Chronos]

Under Caldwell's big rip hypothesis [see: http://arxiv.org/abs/astro-ph/0302506] all matter will be destroyed a finite time in the future - possibly as soon as a mere 22 billion years from now. Waiting for all the supermassive black holes to radiate away would be quite boring by comparison - which would take many, many trillions of years.

 

[phinds]

Under Caldwell's big rip hypothesis [see: http://arxiv.org/abs/astro-ph/0302506] all matter will be destroyed a finite time in the future - possibly as soon as a mere 22 billion years from now. Waiting for all the supermassive black holes to radiate away would be quite boring by comparison - which would take many, many trillions of years.

Interesting, thanks. Do you have any sense of how likely/unlikely this hypothesis is to be correct?

If this is NOT the explanation, do I have it right that it would likely be essentially "quantum evaporation" overy a huge period of time?

 

[Ryan_m_b]

To be fair Cox has to present a very complex field to layman, not only that but he's restricted by being able only to give one explanation that has to be presented to a myriad of people with different backgrounds, educations, beliefs and intelligences.

 

[phinds]

To be fair Cox has to present a very complex field to layman, not only that but he's restricted by being able only to give one explanation that has to be presented to a myriad of people with different backgrounds, educations, beliefs and intelligences.

Oh, I take all that into account, which is why I didn't just take his word for it. It still seems to me that he is either right or wrong and if wrong then he should avoid such a straightforward statement of mis-information.

 

[Drakkith]

Oh, I take all that into account, which is why I didn't just take his word for it. It still seems to me that he is either right or wrong and if wrong then he should avoid such a straightforward statement of mis-information.

So you'd rather him confuse most people or present things in such a complicated way that they can't understand him?

 

[phinds]

So you'd rather him confuse most people or present things in such a complicated way that they can't understand him?

I don't believe it has to be one or the other.

 

[Drakkith]

I don't believe it has to be one or the other.

Things aren't black and white. You have to compromise between getting the overall concept across to the largest possible audience and making it accurate enough to still be "correct". If people wanted to hear a detailed explanation that truly explains the subject they can either read a bunch of books or go to college.

 

[Chronos]

Interesting, thanks. Do you have any sense of how likely/unlikely this hypothesis is to be correct?

If this is NOT the explanation, do I have it right that it would likely be essentially "quantum evaporation" overy a huge period of time?

The low timeline [22 billion years] appears unlikely, a trillion years, however, looks very realistic. The 100,000 billion years + for black hole evaporation is unrealistic, IMO.

 

[Flatland]

it will take a lot longer than a few trillion years for super massive black holes to evaporate

 

[skydivephil]

I think the largest detected super massive black hole will take 1 google years to evaporate. The idea that all matter will decay is also the heart of Penrose CCC idea. I think Cox should have emphasised that this is just one view of the far future universe, its not a matter of fact and I think it wouldn't be too confusing to present the idea with the caveat of its provisonality. Not just state it as a blunt fact ,which it isnt. Overall I think Cox does a great job of popularising science but in this show I think he overstepped what is known. We don't even know for sure that dark energy is a constant.

 

[Cosmo Novice]

I agree with Skydive Phil, to be fair to Cox he does a very good job and in honesty it was the Wonders of the Solar System series that inspired my interest in cosmology!

Would have been nice to see the other theoretical "end" of the universe scenarios in the Wonders of the Universe show, but he has limited time and the show has to entertain as well as inform.

Just so you all know the series/episode this discussion is around: Wonders of the Universe Episode 1: The arrow of time. (I am pretty sure this is still on I-player)

 

[phinds]

I'm not sure how the discussion of relatively short time durations came into play here. I did not say anything about what COX said about the time all this would takes, I use the slightly less precise term "FFFFFAAAAARRRR future"

If you want to know what he DID say, as best I can remember it he said he was talking about "a trillion, trillion, trillion, trillion, trillion, trillion years". I may be off by one in the number of trillions. but you can, perhaps, see why I'm puzzled why Chronos, for example, thought that I had said COX mentioned several different MUCH shorter times, none of which were in my post.

 

[Chronos]

You are confused, phinds, I never asserted Cox said anything of the kind. I was speaking of the Caldwell hypothesis [big rip].

 

[phinds]

Well, since your statements were directly below a quote from ME, I don't see why you would think I should have interpreted it differently. At any rate, I'm glad you cleared that up.