What is Nothing?

Guest: James Weatherall, PhD, Professor of Logic and Philosophy of Science, University of California, Irvine, author of “Void: The Strange Physics of Nothing” When we lament that we have “nothing to wear,” or there’s “nothing in the fridge,” we don’t mean literally nothing. But let’s say we did. A fridge with shelves completely empty – not even a cube of butter or a half-full ketchup bottle? If we took out all the shelves and the light bulb and sucked the air out of the fridge, then would it be completely empty?  This question of “what is nothing?” has bedeviled physicists for centuries – and it still does, frankly. You might wonder why they care all that much. Isn’t something more important than nothing?