The Constitution of the Interior of Earth, as Revealed by Earthquakes

How to tell if the loaf of bread in your oven is cooked? You can see the outside is nicely browned, but you can’t see the middle – is it doughy still? Give it a tap and listen. If it sounds hollow then it’s ready. The sound of the tap passes through cooked bread differently than through… Continue reading The Constitution of the Interior of Earth, as Revealed by Earthquakes