Though everyone in the UN agrees the most dangerous threat to America right now is eating refined sugars and refusing to walk up airport escalators even when you don't have a bag, the second most dangerous threat is unquestionably texting while driving. But somewhere, a lot farther down that line, good old Cold War Era nuclear annihilation is probably lingering on there too. So prepare for the thing that so freaked out your parents with Nukemap.
Both weirdly addictive and worrying, Nukemap is a Gmap that'll display damage zones for the bomb targets of your choosing, created by a Harvard PhD'd science historian at the American Institute of Physics, who hopefully doesn't kick off blind dates by saying, "You want to see something that'll blow your mind, plus a several-mile radius around your mind, depending on tonnage?". Simply drag your target anywhere in the world (watch yo' back, Orange County), or pick from a list of major cities (we're thankfully not on there), then enter a yield size in kilotons, or choose from terrifyingly specific options, like the six-kiloton "Largest North Korean Weapon Tested", or the 10.4-megaton first H-bomb nicknamed "Ivy Mike", presumably so named because its payload makes safety schools look pointless. If you're messed up like that, press "detonate" and the map will fill with concentric circles showcasing your weapon's air blast, radiation, thermal radiation, and fireball, as well as "convenient rules of thumb for estimating short-term fatalities from all causes due to nuclear attack"... so, have fun, kids!
Seriously though, the map's designer does not want you to explode Orange County just for kicks, but instead intends that the map be used as a teaching tool, and has future plans to add a graphic representation of fallout, which is apparently not as bad as the looming spectre of death that is ill-fitting rollercoaster safety bars.