Is it because at absolute zero you would know with certainty the momentum and the position of the particle? Or is there another reason? Would we ever be able to overcome the Heisenberg uncertainty principle?
In: Physics
Physics as we understand it doesn’t give a way, but there are many things we can’t really explain in Physics. Is the Universe full of dark matter, or is our understanding of gravity incomplete? Maybe new physics in some area could lead to a means to remove Heisenberg Uncertainty from quantum mechanics, but today that’s science fiction like Star Trek’s Heisenberg Compensators.
Essentially yes, but that just pushes the question back to why the HUP exists, so it’s not really an answer. But at incredibly tiny scales (the “quantum level”), things don’t have a definite position. Nothing at that level is in one place the way we think of “place” at the everyday level. Absolute zero is defined as the complete cessation of motion – no vibration, no jitters, no movement at all. That is simply not possible at the tiniest scales.
Not an expert but… cooling doesn’t require observation so Heisenberg’s Uncertainty Principle does not apply. I think the problem is likely that as you approach the boundary, it becomes exponentially harder to make gains. There are many functions in nature that are exponential. Air resistance, for example. As you go faster the force of air resistance grows exponentially. If you want to make a passenger car go 10 mph faster, it’s not a big deal. Air resistance is barely a factor. But if you want to make a fighter jet go 10 mph faster, it is a much bigger engineering problem. In this case, when cooling to absolute zero, you have to remove every last bit of energy from the system. I expect that is an exponentially more challenging problem the closer you get.
I’m not a phycist, but I think your question makes no sense. First, absolut zero does not mean subatomic particles cease to move. And second, Heissenberg principle is more a mathematical construct than an explanation of how particles behave.
The uncertainty principle does add a pretty decent reason behind why we cannot reach absolute zero, leading to zero-point energy.
However, we can use thermodynamic arguments with entropy and the third-law to show that any closed system cannot reach zero by any procedure in a finite number of finite operations. This is kind of a macro-level explanation really as opposed to the QM level explanation, but they’re essentially equivalent.
There’s probably some level of explanation towards this in QFT too, ie quantum foam.
If the HUP was a limit then you could try to reach absolute zero by arranging a system where you can’t know anything about the position of a particle, so then the HUP would not prevent you from reaching zero velocity.
The main problem with reaching absolute zero is in how you would get there. You could wait for thermal radiation to lose all the energy, but as you get colder the radiation power drops significantly, and the rate of loss is proportional to the current temperature, so it would basically take infinite time to reach absolute zero.
The other normal way to cool something is to expand a gas or evaporate a liquid into a gas. In order to reach absolute zero you would need to expand the gas to infinite volume, so that won’t work. If you cook a liquid too far it won’t evaporate, so you can’t get low enough that the evaporation temperature change can get you to absolute zero.
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