Science Questions

What would a substance at absolute zero look like?

Sun, 29th Nov 2009

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Question

Davy Stump asked:

What would a substance at absolute zero look like?

Answer

Dave -   I see no particular reason why it would look any different to how it would appear at any other temperature (below melting point).  If its staying at absolute zero, especially if you can look at it and you’re shining light on it, then it’s not absorbing very much energy, because as soon as you shine some light on it, and if any of the light was absorbed, then its going to get hotter than absolute zero. But I’ve seen very, very cold substances down to sort of minus 270-odd and they look pretty much like other substances.

Chris -   Wouldn’t the pure act of looking at them, visualizing them, wouldn’t that put some energy and so it couldn’t be at absolute zero anyway?

Dave -   Yes.  Essentially, if you’re shining light on them, you’re going to give them energy and you’re going to heat them up.  And that said, it could be transparent, so the only one thing you could look at and keep at absolute zero will be transparent but it’s not to say that all things at absolute zero are transparent.  Not that you can ever get there!

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Davy Stump asked the Naked Scientists: While watching a show on space, I had a question. What would an object taken to Absolute Zero (0° K) look like? Would it be black, shiny, white, or what?   Thank you, David Stump What do you think? Davy Stump , Thu, 27th Aug 2009

it depends on if light gives things it hits energy. i think it must. but that means it's no longer at absolute zero. so we couldn't actually observe things at absolute zero. i am not sure about this, though.

what if dark matter is mass that can't be heated? is that a possibility? wouldn't that fit the criteria of being unable to be interacted with? glovesforfoxes, Thu, 27th Aug 2009

I don't think you can talk in terms of 0K but, at a very low temperature, there doesn't seem any reason why the surface charges couldn't be moved. That would produce reflection, if the energy gap was appropriate.. lyner, Thu, 27th Aug 2009



It's impossible to tell. We cannot even observe a zero-temperature. It seems to not even exist. Mr. Scientist, Tue, 1st Dec 2009

At a zero temperature all emanations will stop. As we only can define subatomic particles by probability and those are what makes what we call matter we better look at a subatomic particle first.

And as that is a matter :) of probability only, unable to be defined as anything else? Well, I think it wouldn't be 'there' any more. yor_on, Wed, 2nd Dec 2009

You can't get to 0K but you can get arbitrarilly close.
There's no reason why something shpould look different near 0K than at some higher temperature. Obviously, for example, if it's water it will look like ice rather than water, but that transition happens at about 273K. It won't seem to change much as you cool it further. Bored chemist, Wed, 2nd Dec 2009

It is a interesting question BC.

Let us assume that you are right and that we take a particle to 0K and that it still is there. Well, to my eyes we then seem to have split times arrow from matter :) We would have us a chunk of primordial 'time'

That as I think that matter just might be what creates time(s arrow) , and if we take it to 0K there will be no uncertainties any longer to it (HUP) which then should contradict all physics we have today.

Crazy? yor_on, Wed, 2nd Dec 2009

Which part of "You can't get to 0K" didn't you understand?
Bored chemist, Thu, 3rd Dec 2009



Shouldn't that be: "We can't observe 0K" ? Nizzle, Thu, 3rd Dec 2009

You cannot observe it because it cannot exist, and if it did the light needed to see it's colour would give it energy so it wouldn't be 0K anymore.

But if it came up in a Star Trek episode my bet is it would be black. ...lets split up..., Thu, 3rd Dec 2009



Shouldn't that be: "We can't observe 0K" ?

No.
It's true that we cant observe it but since it doesn't exist that doesn't tell you a lot.
It's like asking you for a description of my sister.
I don't have a sister so it isn't just that you have not observed her, but that she doesn't exist. Bored chemist, Thu, 3rd Dec 2009



Shouldn't that be: "We can't observe 0K" ?

No.
It's true that we cant observe it but since it doesn't exist that doesn't tell you a lot.
It's like asking you for a description of my sister.
I don't have a sister so it isn't just that you have not observed her, but that she doesn't exist.


I tend to agree with you Bored - it's pretty straight forward.

Since no one has ever been able to observe or attain to such a temperature,is surely a proof alone that the temperature itself does not exist. There is always going to be half that heat of single quantum oscillator, where there is no absence of temperature in any square box of spacetime. Mr. Scientist, Thu, 3rd Dec 2009

I'm betting 0K would turn the universe to scrambled eggs, which might explain why the closer we get to absolute zero the harder it is to get there. ...lets split up..., Fri, 4th Dec 2009



There is no state for the universe at OKelvin, because it doesn't exist. There would be no scramblin of eggs, because it doesn't exist. Mr. Scientist, Fri, 4th Dec 2009

I prefer my scrambled eggs hot anyway !! neilep, Fri, 4th Dec 2009

Sorry BC
got the impression you wanted to discuss it?

thanks. yor_on, Fri, 4th Dec 2009

What is there to discuss?
One of the laws of thermodynmics says you can't get to absolute zero. Bored chemist, Sat, 5th Dec 2009



Without observational evidence however, the arguement of what it may or could look like is redundant, especially in a vacuum were OK ceases to even have an existence. Mr. Scientist, Sat, 5th Dec 2009



Quite right BC, why even bother to say something?
It would have been sufficient in that case to say.. It can't.
Voila. the rest is just verbal subterfuge :)

Don't know why I react at your answer, probably the tone of it?
Uncivil? yor_on, Sat, 12th Dec 2009

if your talking about getting to "absolute zero" then, no, its not possible. we have attained -273 Celsius or -459.4 Fahrenheit. which is pretty close to -273.15 Celsius/-459.67 Fahrenheit (the supposed number of absolute zero). but it is impossible to remove all the heat from an object. something colder must exist to transfer the heat to, but since absolute zero is as cold as it gets it is unattainable. ..., Wed, 10th Feb 2010

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