I was reading Introduction to Quantum Mechanics by David Griffiths and I am in Chapter 2, page 45. I know that since the solutions from Schrödinger equation cannot be normalized for a free particle. This must imply that the wavefunction of free particle must be non separable i.e., $$\Psi(x,t)\neq...

I've often heard that Infrared rays are called "heat rays". However, I feel like this term is a misnomer. Don't all the wavelengths of electromagnetic radiation carry energy? Judging by how Gamma rays are highly penetrating and are dangerous when absorbed by tissues, radiations of lower wavelengt...