High pass filter: Lets high frequencies flow freely, while blocking or attenuati...
Low pass filters let low frequencies through: first order with a gentler (-20 dB...
Fermi gas (or free electron gas): Metals as a party - electrons move freely, cre...
Entropy: Universe's law of increasing disorder, where usable energy scatters ove...
Einstein's photoelectric effect: Light in packets (photons) ejects electrons, no...
