Absolute Zero...doesn't exist?

[Arm0r]

If you've read into space and things of that nature I'm sure you've heard of the term absolute zero which is a temp of roughly -273°C....it is classified as a real temp but the strange part is it doesn't actually exist due to nothing actually being able reach that temp..  Below is a snippet of a site with this information (as well as some other very interesting information) that makes this claim, I can cite other sites if need be, confirmed it on a couple others:


http://listverse.com/2010/11/04/10-strange-things-about-the-universe/


"Theoretically, the lowest temperature that can be achieved is absolute zero, exactly −273.15°C, where the motion of all particles stops completely. However, you can never actually cool something to this temperature because, in quantum mechanics, every particle has a minimum energy, called “zero-point energy,” which you cannot get below Remarkably, this minimum energy doesn’t just apply to particles, but to any vacuum, whose energy is called “vacuum energy.” To show that this energy exists involves a rather simple experiment– take two metal plates in a vacuum, put them close together, and they will be attracted to each other. This is caused by the energy between the plates only being able to resonate at certain frequencies, while outside the plates the vacuum energy can resonate at pretty much any frequency. Because the energy outside the plates is greater than the energy between the plates, the plates are pushed towards each other. As the plates get closer together, the force increases, and at around a 10 nm separation this effect (called the Casimir effect) creates one atmosphere of pressure between them. Because the plates reduce the vacuum energy between them to below the normal zero-point energy, the space is said to have negative energy, which has some unusual properties"

So if quantum mechanics makes it impossible to reach this temp why is it classified as a real temp?  Is it simply to say "well, if you could reach this temp, this is when all particals would lose all motion"?  And if all particals can never reach that temp and lose motion is it safe to say after all is said and done there will still be some dynamic to the universe itself? Never growing still and never stopping it's expansion?

[quadz]

ISo if quantum mechanics makes it impossible to reach this temp why is it classified as a real temp?  Is it simply to say "well, if you could reach this temp, this is when all particals would lose all motion"?

Yes, although slightly the other way around, i.e. if all particles lost all motion there would be no heat to measure.  Using the centigrade scale makes the number associated with absolute zero seem arbitrary (−273.15°C).

But it's the jiggling atoms that are responsible for heat.  Without movement, no heat.  Which makes it a nice place to set the zero marker, which is what the Kelvin scale does. 

So even though quantum mechanics implies the complete cessation of thermal motion can never (quite) be reached, it's still where "zero" would be if we could get there.

And if all particals can never reach that temp and lose motion is it safe to say after all is said and done there will still be some dynamic to the universe itself? Never growing still and never stopping it's expansion?

Whether the universe would stop expanding would be determined by other factors.

The zero point energy still allows the future universe to become very diffuse, cold, and dark.  It is predicted that all the protons will eventually decay (although I believe we're still trying to catch a proton actually decaying in large underground tanks.)

Ultimately we expect a vast diffuse expanse of 'nothingness', no remaining particles larger than quarks, all the fields at their quantum ground states.

Just waiting however long it takes for another large quantum event to spawn a new universe, I guess.

[yahoo]

is there an absolute highest possible temp wherein particles would just simply puff out or vaporize to nothingness? whats it called?

[[BTF]Sigma]

Annihilation.

[reaper]

 

 

[Arm0r]

Thanks for the info Quadz.  I generally enjoy your comments and ideas on subjects like this because you seem vastly more educated on the topic.   I've been really into reading about space and such but I find it hard sometimes to pick a starting point and go from there.   The universe is such a huge place with so much to be learned and known and I would love to educate myself more on this.  Do you recomend any books that could possibly get me started?   I would enjoy learning as much about he cosmos as I possibly can, this stuff is just too interesting to ignore.

 

[astral]

Zero kelvin would be more scientific.....  0K

And yes it does exist.

[peewee_RotA]

I also like the comment that absolute zero changes based on pressure. At extremely high pressures, "absolute zero" can be reached only because the temperature reading matches the predefined number, not because all molecular motion has stopped.

Actually that's me regurgitating interesting things I read in my science book in highschool. May not be accurate. Oh well. 

[VaeVictis]

I also like the comment that absolute zero changes based on pressure. At extremely high pressures, "absolute zero" can be reached only because the temperature reading matches the predefined number, not because all molecular motion has stopped.

Actually that's me regurgitating interesting things I read in my science book in highschool. May not be accurate. Oh well. 

i believe its still not possible to reach 0k with extreme pressure...

its REALLY cool when they discovered the next state of matter though by trying to reach absolute zero it slows down light beams  that pass through it to about the speed of a bicycle if i remember correctly... i think it also defies some laws of physics like gravity... i forgot what the state of matter was called but it happens down at a fraction of 1k i think... its REALLY cool and worth checking out if you are interested

anyway, absolute zero is a theoretical base for which we can have a standard measurement for temperature... if you think about C and F they are fairly random :/ kelvin was a scientific solution to have 0 be the lowest temperature even imaginable because it would literally be 0, nothing, due to a lack of any molecular movement... just because its not obtainable doesnt mean its not real because its simply just a base for measurement... i guess you can think bout it like other numerical values that never reach zero, a vacuum is never a TRUE vacuum because it never really has 0 particles inside of it, although they can get REALLY damn close, they can never get to 0, but they know what 0 is even if its not obtainable so if they felt like counting the particles they have a base to start from of 0, nothing... i guess thats not a best example im not much of a science teacher...

[astral]

The closet they have come to absolute zero, was in 2003 MIT came to 450 pico-kelvin or -273.15 degrees Celsius.

Ironically enough the hottest temperature every created by man was 4 trillion degrees Celsius.  This was created at Brookhaven Laboratory Particle Collider.

So man has made absolute zero before.

[reaper]

That doesn't sound right, there's even scientists proposing it's impossible to reach absolute zero:

"
An even stronger assertion is that It is impossible by any procedure to reduce the temperature of a system to zero in a finite number of operations.
"

The maximum is the opposite of zero and has not been reached.  They've come close to absolute zero but not to it, and there are unknowns as well, such as what particles even exist, and how they work..

[QwazyWabbit]

Lord Kelvin, (praised be the Lord Kelvin) predicted absolute zero based on the slope of the temperature scales. He determined there would exist an "absolute" scale where absolute zero would be the absence of all heat. The scale was named after him in his honor.

Absolute zero is an asymptote, a limit that can be approached but not exactly equaled. Besides the zero point energy problem, in order to remove heat from something you must be in contact with it and the system that is in contact with it must have a quantity of heat in it, you basically can't get ALL the heat out of a system. The Heisenberg uncertainty principle limits how much you can know about the state of a particle and therefore the state of the chilled system. (You can't measure something without affecting the measurement.)

[astral]

OK for those of you, who don't think humans have created absolute zero before.....

450 pico-kelvin is only half-a-billionth of a degree above absolute zero!!!!!!!!!!!!!

OR 0.00000000045 degrees above absolute zero.

CAMBRIDGE, Mass. -- MIT scientists have cooled a sodium gas to the lowest temperature ever recorded -- only half-a-billionth of a degree above absolute zero. The work, to be reported in the Sept. 12 issue of Science, bests the previous record by a factor of six, and is the first time that a gas was cooled below 1 nanokelvin (one-billionth of a degree).

Source

So I'd figure that is prettty darn close...

 

[astral]

is there an absolute highest possible temp wherein particles would just simply puff out or vaporize to nothingness? whats it called?

You cannot create, nor destroy matter. So matter cannot be vaporized to nothingness. There are 4 know states of matter:

• Solid
• Liquid
• Gas
• Plasma

Hope that helps yahoo...

[Whirlingdervish]

well technically, you can turn what we see as solid matter into energy, which can't be destroyed.

everything is composed of energy in some form

say you burn a piece of wood, the solid thing that we see would appear to vaporize, but all told it's just been converted into a form of radiation (heat) that most would just define as "energy"