Galileo's Pendulum

David Malki! presents a novel idea for why there always seems to be a little more toothpaste in the bottom of the tube. Click for the full comic, and make sure you read the mouseover text as well.

The interiors of large gaseous planets like Jupiter exhibit high temperatures and pressures, creating states of matter alien to our daily experience. In particular, hydrogen can become metallic, meaning that electrons are shared between the atoms in a kind of free-flowing soup. Caleb Scharf highlights new experiments showing that maybe this metallic hydrogen can actually dissolve the rocky core many astronomers believe are at the centers of Jovian planets. If this result holds up, it certainly alters the way we think about the formation and evolution of gas giants. Personally, I find the idea fascinating and will watch the development with interest. (Warning: post contains a song title, which will lodge in your brain forever.)