The Nature of Light (by Albert Einstein)

Albert Einstein's work on the nature of light revealed that light behaves both as a wave and as a particle, called photons. This duality means light can spread out like waves or travel in tiny packets of energy. Einstein's insights explained phenomena like the photoelectric effect, where light kicks electrons loose from materials. His discoveries reshaped our understanding of physics, showing that light's energy depends on its frequency, not just its brightness. This understanding is fundamental to modern technologies like solar cells, lasers, and quantum mechanics.