Is there a symbol for absolute zero the way pi has one?
Yes. It is
|0|
Absolute zero rules 0K. 
Ouch.
This from a layperson: Couldn’t absolute zero be a condition in which the HUP does not apply? From the tiny bit I can understand from the conversation here, much of the reasoning sounds like this: It can’t happen because the law of XYZ says it can’t. But that sounds a little like the pre-Einstein thinking that assumed that time is a constant. The most reasonable (to an ignoramus such as I) answer stated so far is that the heat from something has to go somewhere that it’s colder in order for something to cool off. Don’t laws (e.g. the HUP) DESCRIBE our observations? They don’t determine them, do they? I see this is pretty jumbled, but I guess I am put off by answers that invoke law rather than reason. Is quantum physics so counterintuitive that reason, as we know it, doesn’t apply? Heeeeelllllllppppp!!!
Not reason, but “common sense”. Our sense of what’s “right” is derived from our experience with the macroscopic world (and with velocities much slower than light, and distance scales much smaller than galactic, etc.) When something seems “wrong” we fall back on our experience with the way things behave in our realm of experience. Outside of our realm of experience – the really small, really big, really fast, etc. is outside our experience, and “common sense” isn’t a very good guide. Down on the quantum level things get weird. This is one of the weird things.
The Uncertainty Principle isn’t the result of describing our observations – it follows from logical and mathematical rules based upon a plethora of other observations. As long as you buy that matter is describable by de Broglie waves, you’re going to get an uncertainty principle limiting the state of knowledge of pairs of properties like position and momentum. And there’s too much evidence from other observations (and consistency of theories) that indicates that matter is composed of such waves.
Just don’t get on his nerves or you’ll find out.
The Heisenberg Uncertainty Principle is not actually something we have as a law to describe our observations but rather something that is mathematically derived from the quantum conditions. In fact there is not just one uncertainty product, but many. For instance, energy and time also have an uncertainty; how to derive these is something that is a little to in-depth for a posting here.
But try to picture it this way. Imagine you have a camera and are trying to take a picture of a person riding a bike. If you have an instantaneous shutter speed, the resulting picture will be from an exact instant in time. Except at that instant, you can get no information as to how fast the rider is moving. You know her precise position, but her speed could be anything from 0 to infinity (at least theoretically). But say your camera shutter now moves a little bit slower. The picture will appear fuzzy and smeared out. Now you have some information about her speed, but unfortunately, the fuzziness of your picture prevents you from knowing where precisely she is. Now imagine this continuing with progressively slower cameras. The riders looks fuzzier and fuzzier, but you can start to get a better and better picture of how fast she is moving. That is uncertainty.
Yet, you might ask why not use two cameras, one fast and one slow. Well at this point the thought excercise breaks down. A quantum unmeasured particle will simultaneously be moving to the right and to the left; what we call a superposition of states. Similarly, it will also be smeared out within the boundaries in no fixed location. A fixed position or momentum will not occur until it is measured. Thus, when momentum is measured, the particle will have no fixed position, it will be smeared out. When position is measured, it will have no measureable momentum. You can’t have two cameras operating at the same time.