Recently, I watched a documentary on how certain species of birds can adapt to super cold temps way below zero degrees Fahrenheit, and the narrator touched on “absolute zero.” My understanding of “absolute zero” is that there would be no movement. No vibrations.
But, how could we ever test for absolute zero if an “observer” would cause some movement? Is absolute zero applicable in theory only? And does absolute zero really have anything to do with temperature, as we see it in every day life? Something can be “hot” or “lukewarm,” and we can measure temperatures but when we examine absolute zero, is it really more about lack of movement, than lack of heat?
I thought I somewhat understood absolute zero but I hadn’t ever considered that it could be anything more than guesswork if an observer is unable to truly test for it, since an observer would generate movement and in turn, heat. If it’s “untestable,” what’s the point of theorizing it?
(Jun 1, 2024 10:09 PM)Leigha Wrote: [ -> ]Is absolute zero applicable in theory only?
They already knew this, but even a
cardboard coffin in Sri Lanka could probably use another staple:
(2017)
After 100 years of debate, hitting absolute zero has been declared mathematically impossible
https://www.sciencealert.com/after-a-cen...impossible
More recent:
(2023)
Physicists discovered a quantum trick for reaching absolute zero - Not!
https://www.sciencealert.com/physicists-...olute-zero
"
An international team of researchers has now identified a new theoretical route to reach the mythical mark of zero Kelvin, or -273.15 degrees Celsius (-459.67 degrees Fahrenheit). No, it's not more likely to break any laws and remove every last shimmer of heat, but the framework could inspire new ways of exploring matter at low temperatures."
Quote:If it’s “untestable,” [or unobtainable] what’s the point of theorizing it?
Even though unreachable, the concept of such a universal or non-arbitrary "zero" is necessary for the Kelvin scale. Changes in Kelvin relate directly to kinetic energy and volume, so that temperature measurement system is the one that's valuable or suitable to the physical sciences.
- - - - - - - - - -
How they measure temperatures close to absolute zero is explained toward the bottom part of this:
How do we measure very low temperatures of atoms? One way is to simply look at the extension of the cloud...
https://www.scientificamerican.com/artic...ures-clos/
Thanks for this, CC! I was getting caught up in the ''observer effect,'' but once we (on SF) cleared that out of the way, it's all clicking now. From a theoretical perspective, it's a fun topic to me.
At SF you get general praise and positive responses. An addition to your huge collection of 'likes' and 'well done keep em coming!' ego boosters. Well I don't try and feed that kind of thing if it doesn't really deserve it.
For starters - and nobody picked you up on it over at that site - the thread title is inherently wrong headed. 'How can “absolute zero” be proven?' is a non sequitur.
Sure they mostly all knew what you probably meant (just guessing!) - 'experimentally confirming it's possible attainment'.
There should have been a not so flattering corrective to the illogical thread title, which didn't happen.
That said, all I will add is that DaveC426913 has got it wrong several times but again was not pulled up on his error by anyone there - including exchemist who surely knew better. I'm referring to the quite wrong claim beginning in #2 there where 'atoms get smeared out into a Bose-Einstein condensate', which at best is limited to a highly restricted and delicately prepared ensemble of ultra-cold gas atoms. It certainly does NOT apply to the vast majority of physical systems like crystalline materials etc. which do NOT 'smear out' into a 'cloud' when approaching absolute zero aka 0 Kelvin. It's a kind of way of thinking about Boson condensates like superconducting states or superfluids. Quite restricted in general though certainly fascinating as examples of how quantum physics can dramatically diverge from classical physics in certain instances.
Not that I think clarity on such things particularly matters to you. Butterfly powered, pixie dust filled puff-ball love bombing the world, is surely more your forte?