Gravity is so weak that flies can walk on the ceiling.

We're used to the idea that some numbers never change: the strength of gravity, the speed of light, or the electric charge carried by an electron — this is why these numbers are called constants. But are they really unchanging? In this podcast John D. Barrow tells us how it all depends on which constants you choose, and how changes in the constants that define our Universe might have implications for extra dimensions, gravity, and climbing flies.

You can also read the article accompanying this podcast.

Return to the Plus Advent Calendar