PCS 181 Midterm: Astronomy_Test1_Notes.docx

• School: Ryerson University
• Department: Physics
• Course: PCS 181
• Professor: Margaret Buckby

Document Summary

Astronomical information is transmitted by electromagnetic waves or starlight. Astronomy is the only field you cannot take into the laboratory. You can only observe and extract all possible information. Starlight: tells us temperature, chemical composition, motion, pressure, magnetic fields. Light: mutually perpendicular oscillating electric and magnetic fields. Light moves in a wavelike pattern at a speed of c = 3 x 10 m/s (c=speed of light) Theory of relativity says nothing with mass can go as fast as the speed of light. Wavelength : distance between peaks of waves (important because it determines colour) Default of lambda is wavelength of light. There is a debate whether light is a little photon (a burst of energy) or a wave. When testing whether light behaves like a wave or a particle, it behaves according to the test you set out for it, i. e. testing if it behaves like wave it behaves like a wave and vice- versa.