Part 1: Quantum Mechanics [This article expects the reader to have some experience with quantum field theory and path integrals] [I should also make a disclaimer here, some parts of this article use some results from conformal field theory which is beyond my knowledge. So I have to just state the results in those parts….
Quantum Mechanics(QM) is one of the greatest intellectual achievements in human history. Not only because it describes the world at the microscopic level and in turn, provides us with the technological advancement that we enjoy today, but also because it shows us how little we know about the world we’ve been living in for so…
It’s a famous result in thermodynamics that you cannot reach absolute zero no matter how hard you try. Given the definition of absolute zero, it is also meaningless to speak of “colder” temperatures beyond that point. So what are negative absolute temperatures? Below I will explain what they mean, when they can occur, and how…