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Black Dwarf

PostPosted: Mon Mar 18, 2013 4:17 am
by Panrock
Here's a severely off-topic post for the off-topic section. Hope it will be considered within bounds... :D

harry dalek's signature says:

"Our sun has perhaps another 5 billion years before it becomes a red giant Some red dwarf stars will live trillions of years before they run out of fuel.
If the very first star in the universe was a red dwarf its still some where ."

As Harry says, red dwarf stars cool down very slowly. But what about after hundreds of billions of years or so, when they have cooled down to room temperature? Then, they would be to all intents and purposes 'black' but they would no longer be too hot to touch. So take a torch along if you want to 'walk on a star'. Only, because of the gravity, you may then get squashed into a thin layer of slime.

I've asked various astronomical authorities but no one seems prepared to answer what the surface of such a dead star would actually be like or even care - it's all too far in the future. They use terms like 'a cinder' or similarly unhelpful words.

It seems the atomic fusion process that drives stars generally ends with carbon. So would this cold surface be crystallised carbon say, effectively diamond dust, or perhaps there would be a diamond shell going miles down? Would such a shell be cracked or crazed? How high could any surface features be? Although the gravity would be crushingly strong, diamond is a pretty hard and unpersuadable material. But then maybe it would be super-smooth, like a billiard ball, the size of a small planet. Because of the strong gravity, it would probably be a pretty perfect sphere too.

Or would there be a diamond core surrounded by shells of lighter elements?

Active stars don't have solid surfaces but this would be different. I just am curious what the landscape of a spent star would look like.

Steve O

PostPosted: Mon Mar 18, 2013 4:26 pm
by Harry Dalek
When i found out about red Dwarfs i found it every interesting ,if you have a planet like ours at the right distance for a star of that size you pretty much have a home for life for who knows how long ? perhaps the universe will out live that type of star but for life you have won lotto if thats your star for us we pretty much lucked out 5 billion more if we are lucky in any case we need to move what ever we become in time .

I have read of brown dwarfs failed stars black dwarfs due to the age of the universe their may not be any yet those red dwarfs are all still burning away very slowly ...but every dies in time .

Steve I like the diamond end idea bet there would be a dirty carbon black pretty flat land scape with perhaps a diamond core there would be no gold thats only made in supernovas or iron which is the killer for large stars that cause them to explode.

Perhaps living things could never walked on some thing like that gravity and radiation bit of a problem but probes rovers

:wink:

PostPosted: Mon Mar 18, 2013 7:17 pm
by Viewmaster
harry dalek wrote:Steve I like the diamond end idea :


"Diamonds are forever."
.........Well, Shirley Bassey thought so. :lol:

PostPosted: Mon Mar 18, 2013 9:55 pm
by Dave Moll
I'll see whether anyone at my local astronomical society (which meets next week) has any thoughts on the subject.

PostPosted: Tue Mar 19, 2013 2:24 am
by Panrock
Thanks Dave. I'm primarily interested in the landscape one would see on a normal star, such as our Sun, once it had finally winked out - rather than supernovae, neutron stars and the like, which are well covered in the literature.

Thanks too to Harry for your ideas. And not forgetting Albert for his wit...

Steve.

PostPosted: Tue Mar 19, 2013 4:53 pm
by Harry Dalek
Panrock wrote:Thanks Dave. I'm primarily interested in the landscape one would see on a normal star, such as our Sun, once it had finally winked out - rather than supernovae, neutron stars and the like, which are well covered in the literature.

Thanks too to Harry for your ideas. And not forgetting Albert for his wit...

Steve.



It will be interesting to hear back from Dave and he's astronomical friends As this thing cools there must be gases an atmosphere like a bigger version of Jupiter so perhaps it would look like a planet ?

PostPosted: Tue Mar 19, 2013 6:11 pm
by Viewmaster
What interests me is how humanity will survive as our sun wipes this planet out.
We will have to go light years to reach other suitable planets and in due course every thing burns out and we find ourselves (or other alien life) in a cold, expanded universe with all the stars burnt out.

Just imagine how the very last survivours will die, unless technology beyond our dreams can reinvigorate the system.

Has any sci fi book been writen about the very last creature in the Universe and it's cold ending?

PostPosted: Tue Mar 19, 2013 7:30 pm
by gary
Oh Albert! Haven't you read Isaac Asimov's "The Last Question" ?


Edit:
http://www.youtube.com/watch?v=ojEq-tTjcc0

PostPosted: Tue Mar 19, 2013 9:48 pm
by Panrock
I also haven't read 'The Last Question' (yet) but it seems to me that Homo Sapiens is such a recent short-term arrival on the cosmic timescale that 'humanity' will almost certainly have been replaced by something else when the time comes, whether it's more advanced or less, whether it's by then distributed over the universe, or perhaps extinct.

As seen by a more advanced intelligence, the very 'reality' in which the material universe seems to exist may by then be understood as less absolute. Just 'flip realities' and you escape the Universe's death. A bit like waking up in another dream.

Our present standpoint is as humans sitting on a rather beautiful pinprick going round a middle-aged star in the suburbs of a very average galaxy. Maybe this middle period is the peak, the heyday of our Solar System. This might be as good as it gets and it's downhill from now on..

All pure and almost meaningless speculation. But we have brains which can imagine and it's fun to let them run free.

Steve O

PostPosted: Tue Mar 19, 2013 10:06 pm
by Viewmaster
gary wrote:Oh Albert! Haven't you read Isaac Asimov's "The Last Question" ?


Edit:
http://www.youtube.com/watch?v=ojEq-tTjcc0


No I hadn't, but just listened to your link. Thanks.

Glad to hear that man will still have pockets and a desk for many years to come!
But the aliens should be part of a better ending, for man may well have destroyed himself earlier on.
I did deliberately mention 'creature' and not 'man' for that reason.

PostPosted: Tue Mar 19, 2013 10:26 pm
by gary
Hmmm, I admit that I am an adherent to the Carter Prophecy - the logic of it is very hard to refute - and nothing that has happened in the last 2 decades has done anything to change my mind.

However, in reference to a "cold universe" it is important to realise that the average temperature of the universe will always be the same (if it is indeed expanding unendingly - if it isn't there are other implications) - if it wasn't then the law of conservation of energy would be violated. The problem is that everything will be at the same temperature (or energy level) and therefore no "work" is possible and therefore no life. Entropy is the ultimate undefeatable enemy.

Before that happens though it seems that what we regard as matter will degenerate to pure energy which seems to imply other problems for the survival of life as we know it (sorry about that overused and misused phrase).

PostPosted: Tue Mar 19, 2013 10:43 pm
by gary
Viewmaster wrote:Glad to hear that man will still have pockets and a desk for many years to come!


Well once the kids these days get over the fad of iPhones and such and take full responsibility for their telecommunication bills we may indeed get back to more sensible things.

Viewmaster wrote:But the aliens should be part of a better ending, for man may well have destroyed himself earlier on.


Well I think we need to verify the existence of (extraterrestrial) aliens first before cheering them on.

Whilst I have already "outed" myself in my preceding post as having grave concerns for the immediate future of our species I am not as convinced that it will be self destruction - I think it will be a more "natural" exit...

PostPosted: Wed Mar 20, 2013 1:13 am
by Viewmaster
gary wrote:Well I think we need to verify the existence of (extraterrestrial) aliens first before cheering them on.


Yes true.
At one time I started building a small rig and antenna to search at the 'water hole' frequency on 1,420 MHz for outer space signals.
But after considering that rigs much more powerfull than mine have never found diddly squat in over 60 years of searching,
I chucked it all in even before I began.

But verification will come one day methinks. If we reveal our location, let's hope they are a friendly bunch of 'lads and lassies'. :)

PostPosted: Wed Mar 20, 2013 8:53 am
by gary
Yes let's hope so. We can console ourselves with the history here on earth that, when a civilisation comes into contact with a significantly more advanced civilisation, it generally turns out well for them.... :shock:


Some say our "natural" successors will be our machines, but I fear that our progress in that area has been too slow to catch up with the impending tragedy...

PostPosted: Wed Mar 20, 2013 5:01 pm
by Harry Dalek
Viewmaster wrote:But verification will come one day methinks. If we reveal our location, let's hope they are a friendly bunch of 'lads and lassies'. :)


Or Hermaphrodites ! that don't look like this Zanti misfit i think we would not get a long with an intelligent insect .