physicscentral.com

v1xWL TIL: the "legs" you see in old high speed footage of nuclear tests are a result of the explosion chasing down the wires of the support tower. The metal of the wire conducts heat faster than the surrounding air, allowing the pulses to move out ahead of the rest of the blast.
9Yd0M TIL the smoke you see when blowing out a candle isn't smoke at all, but paraffin wax vapour
N7edE TIL Night vision goggles are green because because the human eye can differentiate more shades of green than any other color.