Barnard’s Loop [left], in the constellation Orion, is the apparent remnant of an ancient supernova. The physics of celestial explosions is surprisingly similar to that of the tin-plasma bursts [right] used to illuminate chips in lithography machines, despite drastically different scales: tens of light years for the supernovas versus tens of millimeters for the tin plasma. We are all made of star stuff, as astronomer Carl Sagan was fond of reminding us. Supernova explosions, the catastrophic self...