NATS 1870 Lecture Notes - Lecture 3: Human Body Temperature, Aurora, Sun Tanning

• School: York University
• Department: Natural Science
• Course: NATS 1870
• Professor: paulin

Document Summary

Overview: electromagnetic spectrum, definition of light as a particle (photon) Light is both a wave and a particle (wave-particle duality: wave: electromagnetic radiation, wave-like behaviour (diffraction, interference, particle: photon with energy, particle-like behaviour (travels in straight lines) Lecture: 6480c35e942a28c4b50ddd92d51cd7: (cid:1875)(cid:1874)(cid:1857)(cid:1857)(cid:1859)(cid:1872) = (cid:3046)(cid:3043)(cid:3032)(cid:3032)(cid:3031) (cid:3033)(cid:3045)(cid:3032)(cid:3044)(cid:3048)(cid:3032)(cid:3030) or (cid:1858)(cid:1870)(cid:1857)(cid:1869)(cid:1873)(cid:1857)(cid:1855)= (cid:3046)(cid:3043)(cid:3032)(cid:3032)(cid:3031) (cid:3050)(cid:3049)(cid:3032)(cid:3032)(cid:3034)(cid:3047) , high frequencies = small wavelengths. Light as a particle: einstein performed experiment which lead to formulation of the photoelectric effect (1905, metals are good conductors of electricity, required: course of light (photon) and a metallic surface. Light behaves a both a wave and a particle (wave-particle duality: as a wave: Light is a wave of the em radiation: spreading of energy in form of rapidly changing electric/magnetic fields, characterized by wavelengths ( ) In a macroscopic (bigger) realm, em radiation is more usefully described as a wave: examples: blue sky, red sunsets, rainbows, as a particle, a stream of massless particles (photons): packets of energy, characterized by energy (e)