Chemical reactions are constantly happening in your body -- even at this very moment. But what catalyzes these important reactions? Vance Kite explains how enzymes assist the process, while providing a light-hearted way to remember how...

In this video Paul Andersen explains how chemical differs from physical change. In the laboratory macroscopic observations are used to infer changes at the particulate level. Evidence for chemical change include gas production, change...

If you’ve ever looked at a frog’s head, you might have noticed that they don’t have external ears. So How do they hear?

Quantum tunneling happens when a particle seemingly teleports across a barrier. But despite how instantaneous this event sounds, recent research suggests that it doesn’t happen nearly as fast as you might think.

Despite some bold claims, most supplements can’t really "boost" your metabolism, and the actual changes we can make to it are pretty limited.

Every hear of 'Sol'? Sure you have! It's our Sun! It sits at the center of our 8 planet solar system, providing us with heat and light. But how does that energy get to us? In this episode of Crash Course Kids, Sabrina chats about the...

In this video Paul Andersen explains how conservative forces can be used to store potential energy in an object or a system. The work done is equal to the amount of potential energy in the object. The following conservative forces are...

If you stick water in the freezer, it will take a few hours to freeze into ice. How is it, then, that cold packs go from room temperature to near freezing in mere seconds? John Pollard details the chemistry of the cold pack, shedding...

Snorkelers, surfers, divers. They all use them… wetsuits! So how do they work to keep you warm? It turns out layers of materials, and water itself!

Keeping a muscle clenched usually tires it out eventually, but that’s not the case for sphincters, which do things a little differently.

Organisms have evolved many clever forms of armor so that they can be ready for whatever nature throws at them. And us flimsy humans can learn to enhance our armor by taking inspiration from some of these creatures, and not necessarily...

Have you ever wondered why 75% humidity in the summer feels sticky, but 75% humidity in the winter feels super dry? Turns out, the common definition of humidity is inconvenient and confusing. But there is a better way!

GPS location apps on a smartphone can be very handy when mapping a travel route or finding nearby events. But how does your smartphone know where you are? Wilton L. Virgo explains how the answer lies 12,000 miles over your head, in an...

Eighty-five percent of the matter in our universe is dark matter. We don't know what dark matter is made of, and we've yet to directly observe it, but scientists theorize that we may actually be able to create it in the Large Hadron...

Today we are talking about the life -- and death -- of stars. Low mass stars live a long time, fusing all their hydrogen into helium over a trillion years. More massive stars like the Sun live shorter lives. They fuse hydrogen into...

So, electric current works like a river... kinda... Instead of flowing based on elevation, electric current works a little differently. But it's a good metaphor. In this episode of Crash Course Physics, Shini talks to us about electric...