# What is Absolute Zero?
**URL:** https://boards.straightdope.com/t/what-is-absolute-zero/47381
**Category:** Factual Questions
**Created:** [December 27, 2000, 4:05pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381 "2000-12-27T16:05:10Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Dubland](https://boards.straightdope.com/u/Dubland)
#### Post date: [December 27, 2000, 4:05pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/1 "2000-12-27T16:05:10Z")
Hello,
This is my first post!
What is Abosolute Zero? Ive herd a few things about it but I Need to know more about it.
Also, can Absolute Zero be Achived?
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### Author:  [@Arjuna34](https://boards.straightdope.com/u/Arjuna34)
#### Post date: [December 27, 2000, 4:09pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/2 "2000-12-27T16:09:25Z")
Welcome to the SDMB!
Here’s [Cecil](http://www.straightdope.com/classics/a3_347.html) on the subject.
Arjuna34
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### Author:  [@Phobos](https://boards.straightdope.com/u/Phobos)
#### Post date: [December 27, 2000, 4:11pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/3 "2000-12-27T16:11:44Z")
Welcome to the SDMB!
Cecil had a little bit to say about it here…
[http://www.straightdope.com/classics/a3\_347.html](http://www.straightdope.com/classics/a3_347.html)
Basically, absolute zero is the coldest possible temperature. Temperature is related to the energy/motion of atoms, and if they’re completely frozen (no motion on an atomic scale) then there’s no temperature.
It does not seem possible to reach absolute zero because you cannot completely isolate something from the rest of the universe. A little bit of heat will always creep in (e.g., conduction through the walls of the test chamber or a little energy gained from the cosmic background radiation that is everywhere in the universe, etc.)
Scientists have created conditions very close to absolute zero, but you can never get that last decimal place to zero out.
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### Author:  [@starfish](https://boards.straightdope.com/u/starfish)
#### Post date: [December 27, 2000, 4:15pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/4 "2000-12-27T16:15:13Z")
Absolut Zero is a product of Sweden. It is one of the newer flavors of thier fine vodka. They also make Absolut Citron, Kurant, Peppar, amd the more popular Mandrin. Absolut Zero is served chilled colder than the other flavors.
Don’t drink warm vodka, insist on the coldest, Absolut Zero.
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### Author:  [@JeffB](https://boards.straightdope.com/u/JeffB)
#### Post date: [December 27, 2000, 4:16pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/5 "2000-12-27T16:16:39Z")
Welcome! Absolute zero is the temperature:
> [@](#):
>
> at which a thermodynamic system has the lowest
> energy. It corresponds to -273.15 on the Celsius scale and to -459.67 on the Fahrenheit scale.
(from the _Encyclopaedia Britannica_)
As to whether it can be achieved, I’m not a scientist and it’s been a long time since I’ve studied this, but I think it is possible to achieve. Don’t know how, though.
There are a couple of absolute temperature scales (ones where 0 degrees = 0 on the scale), the two main ones are Kelvin and Rankine.
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### Author:  [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)
#### Post date: [December 27, 2000, 4:17pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/6 "2000-12-27T16:17:25Z")
> [@](#):
>
> What is Abosolute Zero?
The chance that Cameron Diaz will say “Yes!” if I ask her out. . .
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### Author:  [@Phobos](https://boards.straightdope.com/u/Phobos)
#### Post date: [December 27, 2000, 4:25pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/7 "2000-12-27T16:25:56Z")
did a quick Google search and found this link…
[http://www.sun.rhbnc.ac.uk/~uhap057/LTWeb/Absolute.html](http://www.sun.rhbnc.ac.uk/~uhap057/LTWeb/Absolute.html)
I have no idea if it’s a reliable source (supposedly a college professor & expert on the subject), but it seemed good when I skimmed through it. This link also says that it’s impossible to reach absolute zero.
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### Author:  [@JeffB](https://boards.straightdope.com/u/JeffB)
#### Post date: [December 27, 2000, 4:26pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/8 "2000-12-27T16:26:16Z")
> [@](#):
>
> \*Originally posted by Phobos \*
> It does not seem possible to reach absolute zero because you cannot completely isolate something from the rest of the universe. A little bit of heat will always creep in (e.g., conduction through the walls of the test chamber or a little energy gained from the cosmic background radiation that is everywhere in the universe, etc.)
Again, I’m not a physicist, but I’m not sure about your reasoning on this. A system that is at absolute zero is one where there is no energy available, not necessarily one that retains that state. I think it would be possible for a system to reach absolute zero, but maybe not possible to maintain that state.
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### Author:  [@JeffB](https://boards.straightdope.com/u/JeffB)
#### Post date: [December 27, 2000, 4:31pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/9 "2000-12-27T16:31:07Z")
> [@](#):
>
> \*Originally posted by Phobos \*
> \*\*did a quick Google search and found this link…
> [http://www.sun.rhbnc.ac.uk/~uhap057/LTWeb/Absolute.html](http://www.sun.rhbnc.ac.uk/~uhap057/LTWeb/Absolute.html)
>
> I have no idea if it’s a reliable source (supposedly a college professor & expert on the subject), but it seemed good when I skimmed through it. This link also says that it’s impossible to reach absolute zero. \*\*
Alright, we need to quit simulposting. 🙂
The link makes sense to me, so I withdraw my suggestion that we can reach absolute zero. Now that I think about it, how could we measure absolute zero? Wouldn’t an attempt to measure it alter the system?
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### Author:  [@mongrel\_8](https://boards.straightdope.com/u/mongrel_8)
#### Post date: [December 27, 2000, 5:27pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/10 "2000-12-27T17:27:22Z")
Sorry for the minor hijack here, but if for absolute zero to exist there is no energy then wouldn’t inside a black hole be absolute zero? Or am I completely confused?
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### Author:  [@Nen](https://boards.straightdope.com/u/Nen)
#### Post date: [December 27, 2000, 5:39pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/11 "2000-12-27T17:39:40Z")
> [@](#):
>
> \*Originally posted by mongrel\_8 \*
> Sorry for the minor hijack here, but if for absolute zero to exist there is no energy then wouldn’t inside a black hole be absolute zero? Or am I completely confused?
The is lots of energy inside a black hole. Energy and mass are equivalent. Black holes are massive, ergo, black holes have energy. Thus, reaching a temperature of absolute zero would not necessitate the formation of a black hole.
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### Author:  [@Phobos](https://boards.straightdope.com/u/Phobos)
#### Post date: [December 27, 2000, 6:23pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/12 "2000-12-27T18:23:11Z")
> [@](#):
>
> \*Originally posted by Nen \*
>
> > [@](#):
> >
> > \*Originally posted by mongrel\_8 \*
> > Sorry for the minor hijack here, but if for absolute zero to exist there is no energy then wouldn’t inside a black hole be absolute zero? Or am I completely confused?
>
> The is lots of energy inside a black hole. Energy and mass are equivalent. Black holes are massive, ergo, black holes have energy. Thus, reaching a temperature of absolute zero would not necessitate the formation of a black hole.
Not sure about this one. Although mass and energy are equivolent, energy and temperature are not.
As far as black holes go, the question would be whether the singularity has any temperature. There are certainly huge temperatures just outside an active black hole (the accretion disk), but modern physics cannot describe the singularity itself inside the black hole’s event horizon. So it’s an interesting possibility, but probably unanswerable at this point (no pun intended).
> [@](#):
>
> \*Originally posted by JeffB \*
> Wouldn’t an attempt to measure it alter the system?
A good point. Hitting the system with light (or whatever means of detection) would increase the system’s temperature.
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### Author:  [@Perderabo](https://boards.straightdope.com/u/Perderabo)
#### Post date: [December 27, 2000, 10:11pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/13 "2000-12-27T22:11:48Z")
Could one of you nice physicists comment about temperatures _below_ Absolute Zero? [Here](http://math.ucr.edu/home/baez/physics/neg_temperature.html) is what the sci.physics FAQ says on the subject. I read it, but instead of understanding the subject, I just shorted out. 😕
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### Author:  [@Rysdad](https://boards.straightdope.com/u/Rysdad)
#### Post date: [December 27, 2000, 10:45pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/14 "2000-12-27T22:45:27Z")
> [@](#):
>
> \*Originally posted by Dubland \*
> \*\*What is Abosolute Zero? \*\*
As paraphrased in another thread, absolute zero would be the ambient temperature in Hell when the Vikings win the Super Bowl.
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### Author:  [@cornflakes](https://boards.straightdope.com/u/cornflakes)
#### Post date: [December 27, 2000, 11:03pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/15 "2000-12-27T23:03:08Z")
And now another tangent…
I understand that someone in a physics lab recently brought some matter down either to absolute zero or into the single digits Kelvin by stopping all subatomic motion in the matter. Would most physicists consider the matter to actually be at the claimed temperature, or is this considered some sort of a “parlor trick”, like the “faster than C light” packets that were announced a few years ago?
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### Author:  [@Mr.Cynical](https://boards.straightdope.com/u/Mr.Cynical)
#### Post date: [December 27, 2000, 11:24pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/16 "2000-12-27T23:24:01Z")
> [@](#):
>
> _Originally posted by Nen Energy and mass are equivalent. Black holes are massive, ergo, black holes have energy._
If this is true, then why can’t I seem to get off my fat arse and go to the gym once in a while? Is the inverse true for slobs?
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### Author:  [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)
#### Post date: [December 27, 2000, 11:31pm UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/17 "2000-12-27T23:31:15Z")
One could cop out and just say it is the point at where the entropy of a perfect crystal is zero (Third Law of Thermo, paraphrased?)
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### Author:  [@tomndebb](https://boards.straightdope.com/u/tomndebb)
#### Post date: [December 28, 2000, 12:27am UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/18 "2000-12-28T00:27:24Z")
Sorry, wrong thread. I thought this was the **peace** credibility thread.
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### Author:  [@jb\_farley](https://boards.straightdope.com/u/jb_farley)
#### Post date: [December 28, 2000, 12:57am UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/19 "2000-12-28T00:57:13Z")
took me a while to get it, **tom**.
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### Author:  [@manhattan](https://boards.straightdope.com/u/manhattan)
#### Post date: [December 28, 2000, 1:08am UTC](https://boards.straightdope.com/t/what-is-absolute-zero/47381/20 "2000-12-28T01:08:07Z")
Aw, jeez.
Could we _please_ keep the digs at fellow members in the Pit? Or at least on target?
Thanks.
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