'The plutonium in an atomic bomb needs to have this "mass" to go kaboom!'
critical mass
UH-OH: The plutonium in an atomic bomb needs to have this mass to go kaboom!
The plutonium in an atomic bomb needs to have this "mass" to go kaboom!
The plutonium in an atomic bomb needs to have this "mass" to go kaboom!
UH-OH
critical mass
UH-OH