PHYSICS H90 Lecture Notes - Lecture 11: Transverse Wave, General Relativity, Flashlight
20 Feb 2019
School
Department
Course
Professor
Document Summary
Light can be a pulse (e. g. , a short burst of light) or a wave (e. g. , a constantly shining light source almost everything we see) Light is electromagnetic, not mechanical it can travel through the vacuum, where there"s no matter (unlike sound which requires air as a medium) It is always transverse, cannot be longitudinal. Light waves & the speed of light & relativity. We can also see the sun & planets, even though there is empty space between us & them. Even when all the air was sucked out, we could still see through the bell jar. Since every other kind of wave requires a medium to propagate, up to the 1880"s it was assumed that light requires a medium to propagate. This medium was called the ether & many people set out to detect it. Look for its influence on something you can see, namely, light.
