The finest burritos in the world are made in San Francisco's Mission District. But how can you get a hot & fresh one in New York City in time for lunch? Physics, that's how. For this very serious and scientific video, we dug a classic documentary out of the vault that tells the story of the transcontinental burrito tunnel, and its successor, the transcontinental burrito hypertunnel.

A human with the metabolism of a hummingbird would need to eat about 80,000 calories a day to survive. That's because staying warm by making your own heat takes a ton of energy; creating your own body heat is incredibly expensive. So, why aren't cold-blooded… like crocodiles? Here's the science.