Nuclear security

If a nuclear bomb explodes nearby, here's why you should never, ever get in a car

The first thing you'd see if a nuclear bomb exploded nearby is a flood of light so bright, you may think the sun blew up.

Wincing from temporary blindness, you'd scan the horizon and see an orange fireball. The gurgling flames would rise and darken into purple-hued column of black smoke, which would turn in on itself. As a toadstool-like mushroom took shape, the deafening shock front of the blast would rip through the area — and possibly knock you off your feet.

Congratulations! In this hypothetical scenario, you've just survived a nuclear blast with an energy output of about 10 kilotons (20 million pounds) of TNT. That's roughly 66% of energy released by either atom bomb dropped on Japan in 1945.