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Varsect t1_j680hi6 wrote

By the laws of physics nothing can approach (reach) 0 Kelvin because by that point,all thermal exchanges stop AKA atoms stop moving entirely (that's not the most accurate way to say it but for simplicity's sake) Our current understanding of Dynamics and Statistical Physics cannot allow for such things to exist in our universe. Nevermind anything below that.That is why it is absolute in temperature, so really, there is no necessary single fixed mechanism except for thermal exchange that can stop 0 Kelvin from being reached. Also, the uncertainty principle would be screwed.

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Yaver_Mbizi t1_j68ilyz wrote

> Nevermind anything below that.

Well, it actually is possible to get below 0 K. It's pretty different to how one might imagine it, though - it's hotter than the hottest temperature, rather than colder than the coldest temperature for starters.

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AssCakesMcGee t1_j68rpdq wrote

That's not a conventional definition of temperature. A particle gaining energy but losing entropy is strange, but it's not what people think when you say 'negative temperature' since these particles are indeed, quite hot.

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Awhodothey t1_j693ug3 wrote

Yeah, because defining temperature is, in fact, not as straightforward as you might imagine.

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QuantumCakeIsALie t1_j69wxbt wrote

It's a very conventional way to define temperature in thermodynamics/physics.

Fun fact, you could create infinite energy if you could create a Carnot thermodynamical cycle that crosses + and - temperatures. That was a big issue with the concept of negative temperatures, until someone proved that it's impossible to create such a cycle to begin with.

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Putrid-Repeat t1_j6ae0nv wrote

Well it's not the layman definition of temperature but, it is the actual definition 😉

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sebzim4500 t1_j6ck159 wrote

What definition of temperature are you thinking of? The only definition I know is based on how the entropy changes with energy, which clearly makes negative temperature objects extremely hot.

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Varsect t1_j68j8hk wrote

Nature doesn't really factor in such stuff where entropy decreases (unless you're freezing stuff like crazy) and energy levels go crazy but uh, sure?

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Lyress t1_j6hjakx wrote

What do you mean nature doesn't factor that in? In what sense?

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XtremeGoose t1_j6b37o7 wrote

That's because temperature as it's classically defined has a coordinate asymptote (at 0K). The fix used in quantum thermodynamics is to talk about thermodynamic beta which is the inverse of temperature, where heat flows from a low thermodynamic beta to a higher. That fixes the coordinate issue and you can cross easily from the classically to the quantum.

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buff-equations t1_j68u129 wrote

Sounds like how a lot of computer counters work. -1? Nah that’s just 2 billion

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Chemomechanics t1_j69zwi7 wrote

As a side point, it's not. Such counters click down from 0 to the maximum count since they can't represent a negative. Temperature is different—arguably, the more fundamental parameter is the reciprocal 1/T, which is positive in most familiar systems but can in some circumstances swing below zero. This implies (very weirdly) that the temperature shoots up to ∞ and then to -∞. Again, it takes special effort to construct such a system; it won't occur around the house.

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DeathByFarts t1_j696d9k wrote

>By the laws of physics nothing can approach 0 Kelvin

Yeah , you are using the wrong words .. You can never REACH 0k , but you can sure approach it.

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[deleted] t1_j69azqu wrote

[deleted]

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big_sugi t1_j69uyfb wrote

When someone corrects your error, you could graciously accept it, or you can get defensive and pretend it wasn’t really an error.

The first way is much better, and it increases your credibility instead of diminishing it.

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