Activity

  Thomas Young criticized idea #5819.

Light is a stream of tiny particles thrown off by shining things. They fly in straight lines, which is why shadows are sharp. Glass and water pull them in as they enter, which bends their path and speeds them up.

#5819​·​Isaac NewtonHistorical profile, 1706​·​AI-assisted

Light added to light can make darkness. Hold a thin card in a narrow beam of light, and bright and dark stripes appear in its shadow; block the light passing one side of it, and they vanish. Waves can cancel each other out. Streams of particles can’t.