Absolute zero and time

1. Mar 14, 2004

neokill3r

I was thinking time is just change in matter. So theoretically if something was cooled to absolute zero would time stop for it?

2. Mar 14, 2004

Clausius2

I can't give you an answer. In this zone of the planet the weather is not so cool as zero kelvin. I think I will have to wait till next winter.

Well, time dilation and thermodynamics are linked in black holes, isn't it?.
But, remembering my lectures of one of Hawkins book, I think temperature of black holes is not zero kelvins. They emit radiation. Its temperature corresponds to the formula:

T=hc^3/(8*pi*k*G*M)
h=Planck constant
k=Boltzmann constant
G=Universal gravity constant
M=black hole mass
c=light velocity.

The temperature of a black hole of some solar masses is 0.000001 K.
It is said that inside a black hole there is no time rate.
Althoug I'd better think that an astrophysic could answer straightforward you than I can.

3. Mar 14, 2004

HallsofIvy

"So theoretically if something was cooled to absolute zero would time stop for it?"

What do you mean by "something"? If you cool a living creature to absolute zero, for sure time (and everything else) will stop for it!

If you are not talking about living things how would you know if "time stopped for it"? I suppose you could look at the "life spans" of elementary particles but when you are at that level, how do you stop it long enough to find out?

4. Mar 15, 2004

Phrozin

History channel lol

Actually I was just watching the history channel two or three days ago and saw a show on this very subject.

They have had different things at close to absolute zero (+/-0.01 deg I think was the temp range of absolute zero) and stuff started acting really weird, liquids were rolling up the walls and some solid don't remember now what it was turned to liquid. it was really interesting, might want to look up the history channel line up for the past 2 or 3 days and try to figure out the name of the show and watch it.

5. Mar 15, 2004

StephenSwires

I posted a year ago proposing that time is the same as the transfer of energy by points of matter.

See my current post in Quantum physics on particles and spacetime. The point is that spacetime is an EFFECT of elementary particles exchanging energy. They do not exist in spacetime but give rise to it.

It is my conclusion that yes, if something is frozen to absolute zero time would stop and it would not interact with other matter. It would not only act weird, it would probably disappear. As to the question of what the object might be, it would not matter. If something is frozen to only near absolute zero, time continues and there is some interaction and deterioration, but at absolute zero there would be no change at all.

However, I believe it is impossible to freeze anything to absolute zero.

Last edited: Mar 15, 2004
6. Mar 16, 2004

Gara

i doubt very much that black holes are near Absolute Zero.

all that gravity, on such a dence object, would make one hell of a friction reactor.

i'd say a black hole is one of the hottest things in the universe.

7. Mar 17, 2004

Clausius2

Yes, you're right. You are the only person that would say that. And you would have a further disagreement with Stephen Hawkings too.

8. Mar 17, 2004

Gara

well pardon me for using logic.

if something is being squeesed, it will heat up. that is why suns are hot.

black holes having gravity so strong not even light can get out, would surely there for have the same effect.

9. Mar 17, 2004

Integral

Staff Emeritus
You are missing a lot. If what you are saying were correct Black holes would be visible. Since this is not the case we must assume that your logic is flawed. Perhaps you need to do a bit of research into the life cycle of stars, "gravitational collapse" is a nice key word.

10. Mar 17, 2004

Staff: Mentor

Last edited: Mar 17, 2004
11. Mar 17, 2004

jcsd

It should be noted that molecules still vibrate at absolute zero with what is known as zero-point energy, it is impossible to completely 'freeze' something (as indeed by thermodynamics it is impossible to reach absolute zero).

Black hols do have a property called 'temperrature' and it's simply a measure of the amont of blackbody (i.e. Hawking) radiation they emit. Gara's not too far off the mark, the accretion disk of a black hole can and often does get very, very hot (see active galactic nuclei, for the most extreme examples), due to friction, though the Hawking temperature of a black hole is dependent on it's size menaing tyat all black holes formed by stellar collapse (i.. all observed black holes)have Hawking temps below that of the CMBR (i.e. very nera absolute zero), though a primordial black hole could be very 'hot' indeed.

12. Mar 18, 2004

Clausius2

I think talking about temperature inside a black hole has no sense at all. You are forgetting the statiscal meaning of the temperature. Surely the particles inside black holes don`t have the behavior of classical kinetic theory than have outside it. The heat transfer inside a black hole is in particular very difficult to imagine for me. Then we cannot state of an unique temperature inside, or you think that particles inside have kinetic energy?. I'm not sure at all.

13. Mar 18, 2004

Clausius2

The sense of temperature here is the one shown by the radiation spectrum of the hole, non the internal temperature. Both are not the same thing. The sun shows a 5500 K spectrum of radiation, but it doesn't go with its internal temperature, that likely will be different.

14. Mar 18, 2004

jcsd

As it happens string thery offers a statistical interpretation of a black holes temp. The term 'internal temp.' is non-sensical when applied to a black hole, a black holes temp. is simply a measure of the Hawking radiation it produces (just like the temp. of any perfect balckbody is a measure of it's radiation spectrum).

15. Mar 19, 2004

Gara

a blackhole cant have friction because of its density, nothing has room to move.

or am i wrong on that too?

16. Mar 19, 2004

jcsd

Well what do you mean? you have to be more specific than black hole, as I siad before the accretion disc of a balck hole has plenty of friction, but this lies outside the event horizon.

17. Mar 20, 2004

Gara

i mean what the singularity (sp?). if everything is broken down and made into one giant (pea sized, i hear) atom/molecule, 1 atom/molecule cant rub against its self. so that means no friction.

18. Mar 20, 2004

Time does not exist, so it cannot stop.

19. Mar 20, 2004

Mr. Robin Parsons

If you could measure the temp. inside the BH's event horizon you would probably find -1 K as "temp"...a distinct absence of EMR...as evidenced by the absence of emissions (from inside the BH's EH)

As for atoms, as I have heard, the Nucleus remains active, thermally even as low, in K, as they can get them...

20. Mar 20, 2004

jcsd

The singularity is a point (i.e. it has zero volume) that cannot be well-described.

Mr. Robin Parsons, rember that there is nothing special about the event horizon orthe region inside the event horizon locally, an observer falling into a black hole would (as always) measure a temp. above 0K.