This video from Vsauce discusses cardinal numbers, the cardinality of the natural numbers (aleph null), ordinal numbers, and all sorts of infinities.

# Misconceptions About the Universe

This video from Veritasium discusses the expansion of the Universe, the Hubble sphere, and the possibility of an infinite Universe.

# Tattoos on Math

What’s the point of learning secant, cosecant, and cotangent, if they’re just the inverses of cosine, sine, and tangent? Do they have any purpose other than confusing students?

# European Astronomy Picture of the Day (EAPoD)

# Heisenberg’s Uncertainty Principle Explained

This quick video by Veritasium conceptually explains Heisenberg’s uncertainty principle and how it relates to the single-slit experiment.

# Why is glass transparent?

Also, why can’t you get a suntan through a window?

# Journey to the Center of the Earth

“Journey to the Center of the Earth” is a curated collection of articles published by the Smithsonian magazine. As you scroll down the page, you move deeper into the Earth — a thermometer and a depth gauge keep track of how far down the page you’ve scrolled. At each division (surface, crust, mantle, outer core, inner core), you’re given a selection of pieces about that layer as well as quick facts about the materials and physics which can be found at that depth.

It’s a lot to take in, but it’s very interesting!