[“Quantum foundations” series] A physicist walks into a bar, and asks the bartender, “What time is it?” The bartender is about to reply but then recognizes the customer. “You’re a physicist, correct? So, it’s a trick question.” So, what’s with time? A venerable philosophical question. A foundational question in physics. We have electronic devices, extremely… Continue reading Whence the arrow of time?
I’ve thought about this question for years. A FAQ. Imagine you’re traveling at the speed of light. Well, physics says that’s impossible. Mass’ gotcha. So, what can travel at the speed of light? Photons (not just the visible ones). So, imagine … does a photon “experience” space and time? Some weeks ago I recall reading… Continue reading A photon’s frame of spacetime — no rest for the massless