AST101H1 Lecture : Chapter 5

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Clifford Orwin

Document Summary

energy that light carries is called radiative energy. in astronomy we are concerned more with the rate of energy transfer not the amount of energy transfer. rate of energy flow is called power and is measured in units called watts. (1 watt = 1 joule/s) The energy of the light comes from electrical potential energy supplied to the light bulb. Absorption: when you place your hand near a light bulb, your hand absorbs some of the light, and this absorbed energy warms your hand. Transmission: some forms of matter, such as glass or air, transmit light, which means allowing it to pass through. Reflection/scattering: light is able to bounce off of matter, leading to what we call reflection (bouncing all in the same general direction) or scattering (when the bouncing is more random) materials that transmit light are transparent, and opaque if they absorb light. many materials are never perfectly transparent or opaque.