[Correction: at 17:51 I say kinetic energy is a vector, I meant to say "scalar." Kinetic energy has a size, but doesn't point in a direction.]

The Biggest Ideas in the Universe is a series of videos where I talk informally about some of the fundamental concepts that help us understand our natural world. Exceedingly casual, not overly polished, and meant for absolutely everybody.

In this installment - the very first idea we cover! - I talk about "Conservation." The idea that a certain property, like momentum or energy or electric charge, stays the same over time. In my view, realizing that this is true - and the corollary, that the world naturally moves, rather than needing something external to keep it moving - represents the real transition between pre-modern and modern physics.

My web page: http://www.preposterousuniverse.com/

My YouTube channel:    / seancarroll  

Mindscape podcast: http://www.preposterousuniverse.com/p...

The Biggest Ideas playlist:    • The Biggest Ideas in the Universe: In...  

Blog posts for the series: http://www.preposterousuniverse.com/b...

Background image: https://www.jpl.nasa.gov/missions/voy...

#science #physics #ideas #universe #learning #cosmology #philosophy #math #conservation #momentum #energy #classicalmechanics