Nuclear explosions are much more complex and devastating than conventional explosions. To illustrate, let’s look at the Nuke Map by historian Alex Wellerstein, an interactive map with tons of parameters that let you check the effects of nuclear weapons dropped anywhere in the world. Going the simple route, let’s arbitrarily choose to drop Little Boy — the 15-kiloton nuclear bomb dropped on Hiroshima during World War II — on the financial district of Manhattan.
Multiple damage types spread in concentric circles from the epicenter of nuclear blasts. From smallest to largest in our simulation, there’s the initial nuclear fireball, followed by heavy blast damage, moderate blast damage, initial radiation damage, thermal radiation damage, and finally light blast radiation damage that makes it west over the Hudson River and into Jersey City — if the bomb detonates on the ground, that is. Detonations in the atmosphere are more severe as blast layers propagate through air much more easily than land and all of its man-made structures. And then there’s wind, which radically alters nuclear fallout. If the wind in our example is blowing northeast, radiation could get carried in a line all the way to New Haven.
On top of all this: How big is your thumb? How long is your arm? What’s your height relative to the blast? Which damage type are you assessing? And, do you know the exact explosive yield of the nuclear device? Such questions ought to illustrate that the rule of thumb is much less effective than an even simpler rule: run and hide.
