Chapter 27 Light. Early Concepts Greek philosophers thought that light consisted of tiny particles Soctrates and Plato thought that vision resulted from streamers or filaments emitted by the eye making contact with an object Empedocles taught that light traveled in waves.
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Photon – elementary particle and basic unit of electromagnetic radiation
The observation that light can behave as both a wave and a particle is called the dual nature of light
Microwaves are unable to pass through the screen in the window of a microwave because the wavelength of the microwaves is greater than the width of the holes in the screen:
Light is emmitted by accelerating electric charges – often electrons in atoms
Light is energy carried in an electromagnetic wave that is generated by vibrating electric charges.
All materials that are springy (elastic) respond more to vibrations at some frequencies than others. Bells rings at a particular frequency, tuning forks vibrate at a particular frequency, and so do the eletrons in matter. The natural vibration frequencies of an electron depend on how strongly it is attached to a nearby nucleus. Different materials have different electric “spring strengths.”
Crepuscular rays – columns of sunlit air separated by darker cloud-shadowed regions
When wave motion is confined to one plane it is said to be polarized.