Very good watch. I posted a link to that on another thread somewhere. Lawrence Krauss is one of my favs. To think that 90% of the mass in the atoms comes from the empty space between quarks in the nucleus is mind blowing. 90% of the mass of your body comes from the empty space in the atoms. A Universe of quantum fluctuations. Virtual particles popping in and out of existence on time scales we can't directly observe. Makes muh brain hurt.