It's been close to a century since we established how quantum mechanics "works," and we still don't know what it really means — and that, says cosmologist Sean Carroll in the video up top, may make QM the most embarrassing subject in all of modern physics.

Quantum mechanics is real. It's spooky as hell, but it's real. Without its microscopically small probabilistic effects, we wouldn't have superconductors, lasers, and many forms of computing and cryptography. But despite our laboratory certainty, what's less clear is the role it plays in the fundamental nature of…

Here to give us the down and dirty on space excreta (because let's face it, you were always curious) is Minute Physics' Henry Reich and Smarter Every Day's Destin. It's a match made in YouTube science-explainer heaven. With poop. And spacecraft-trajectory-altering pee. In spaaaace.

This is the story of how quantum mechanics — that physical science of the very, very small — came to be. It's a fascinating tale involving Max Planck, Albert Einstein, cookies and fussy light.

An experiment conducted at the University of Toronto has thrown a fundamental aspect of the Heisenberg uncertainty principle into doubt. For decades, we've believed that you can't measure a quantum state without inducing uncertainty — but now, we're not so sure about that.

Werner Heisenberg's uncertainty principle tells us it's impossible to know simultaneously the location and the velocity of a subatomic particle. It's one of the main ideas that famously prompted Albert Einstein to declare God doesn't play dice with the universe.

Quantum mechanics says objective reality doesn't exist, that instead all we see are probabilities collapsing into one particular configuration... and all other possible realities might just exist together in a quantum multiverse. Here's the deadly experiment that could help you to test that very idea.

The Pauli exclusion principle is the quantum mechanical concept that no two identical particles in all the Universe may occupy the same quantum state simultaneously. What does that mean, exactly? Well, for starters, it means that the butterfly effect has nothing on the consequences of the Pauli exclusion principle.

If you're a fan of lucid explanations of tricky scientific concepts, it's hard to go wrong with theoretical physicist Brian Cox. But when you mix in physicist Jim Al-Khalili and Simon Pegg, you've got yourself a recipe for pedagogic gold. Also: thinly veiled sex jokes.

Quantum theory may only explain the world at subatomic scales, but the mathematics behind it may have even broader applications. How we perceive the world may be shockingly similar to some of the weirdest quantum phenomena.