SciShow
5 Types of Awesome Glass Made by Nature
When it comes to sparkly objects, the planet Earth has a lot to offer. Here are 5 especially awesome glasses made by nature! chapters OBSIDIAN 0:57 2 OPAL 4:09 3 TEKTITES 5:46 FULGURITE 6:27 GLASS SPONGES 8:07
Crash Course
Spectra Interference: Crash Course Physics
Light is everywhere … but it’s not as predictable as you might think. It’s a wave that travels in straight lines, yet it also reflects off of surfaces, refracts through various materials, and generally changes direction all the time!...