The conceptual step that took humans from their pre-conceived “classical” notions of the world to the “quantum” notion was the realization that measurements don’t commute. This means, as an example, that if you measure the position of a particle exactly, you cannot simultaneously ascribe to it an infinitely precise momentum. This is not simply a … Read More “A story of commutators” »
Category: Quantum Mechanics
This article concerns a new paper I just submitted. It concerns a peculiar feature of quantum mechanics (and also of classical mechanics). The feature is this. The Laws of Physics appear indifferent to the direction of time. If you play a video of two balls colliding elastically with each other, you could play the video … Read More “Schrodinger’s Cat Lives again!” »
This article was inspired by a very nice article in Quanta magazine (by Natalie Wolchover) about the connection between error-correction codes and space-time. I thought the quantum mechanics concepts were glossed over, so decided to expand on it a little. Electrical engineers and digital-signal-processing engineers study error correction for a simple reason – the same … Read More “Error Correcting Codes and the Quantum version” »
I have been enjoying reading Richard Muller’s “Now: The Physics of Time” – Muller is an extremely imaginative experimental physicist and his writings on the “arrow of time” are quite a nice compendium of the various proposed solutions. Even though none of those solutions is to my liking, they are certainly worth a read. Meanwhile, … Read More “Schrodinger’s Zoo” »
Imagine you were walking around in Manhattan and you chanced upon an interesting game going on at the side of the road. By the way, when you see these games going on, a safe strategy is to walk on, since they usually reduce to methods of separating a lot of money from you in various … Read More “Master Traders and Bayes’ theorem” »
The Special Theory of Relativity, which is the name for the set of ideas that Einstein proposed in 1905 in a paper titled “On the Electrodynamics of moving bodies”, starts with the premise that the Laws of Physics are the same for all observers that are traveling at uniform speeds relative to each other. One … Read More “Special Relativity; Or how I learned to relax and love the Anti-Particle” »
I have always been fascinated by the weirdness of the Universe. One aspect of the weirdness is the quantum nature of things – others relate to the mysteries of Lorentz invariance, Special Relativity, the General Theory of Relativity, the extreme size and age of the Universe, the vast amount of stuff we don't seem to … Read More “Can a quantum particle come to a fork in the road and take it?” »
Quantum Mechanics was the result of analysis of experiments that explored the emission and absorption spectra of various atoms and molecules. Once the electron and proton were discovered, very soon after the discovery of radioactivity, it was theorized that the atom was an electrically neutral combination of protons and electrons. Since it isn’t possible for … Read More “Here’s an alternative history of how quantum mechanics came about…” »