If a hotel with an infinite number of rooms has an infinite number of guests, how could it free up space when new guests arrive? Hilbert's “Grand Hotel” paradox has fascinated mathematicians, physicists, philosophers, and theologians, as it encourages another way of thinking about the notion of infinity.

Schrodinger’s hypothetical experiment involved putting an unfortunate cat into a box with a Geiger counter and a vial of deadly poison. Until the box was opened, the cat could be said to be alive, or dead… or possibly in both of these states simultaneously.

peta2: At only 16 years old, Tia Blanco is already one of the top women surfers in the world. Learn how her vegan diet has helped Tia surf her way to the top!