[ddebernardy]

> I blame this on pictures of Hiroshima from after the bombing there, where nearly everything is just wiped clean. People don't realize that this is because most of the buildings in the city were practically built out of paper.

But then, you do realize that today's nukes are orders of magnitude stronger, right?

[icegreentea]

Well, so Hiroshima/Nagasaki were 15-20kT weapons. While there was a while were the US and Russia were routinely plopping 5MT+ weapons on strategic platforms, these days its more down to 100-400kT range, so we're already sitting at ~one order of magnitude for most common nuclear device that'll go off near you. Granted, there will be a lot of them, but still.

Ok, so outside of the immediate fireball, the majority of immediate damage is going to be caused by overpressure, which will obey square distance law. So you're 20x weapon will only cause ~4.5x the overpressure at some distance.

So now its civil engineering of modern buildings vs whatever they had at Nagasaki/Hiroshima. I honestly cannot answer this, but I suspect that they could probably sustain twice the overpressure at least. So you're actual lethality (from building collapse) at set distance is only about ~2x despite the ~10x increase in weapon power.

Now, it's all kinda moot cause there's not going to be 'just one nuke'.

For your enjoyment and horror, http://www.nuclearsecrecy.com/nukemap/ you can watch how dead you'll be.

[ddebernardy]

Thank you for the sane and argumented response.

[mikeash]

Bigger nukes increase the area of total destruction but they also increase the area of partial destruction. Furthermore, the area of total destruction is still not going to be big enough to cover an entire metropolitan area unless you're talking about something along the lines of Tsar Bomba. The point remains that civil defense procedures like "duck and cover" would save many lives.

[ddebernardy]

As would "run for underground shelters", admittedly.

But then you're assuming reasonable and conscious plebes. Personally, I'd readily picture rednecks going "Meh, they won't finance these shelters on my dime lest it turn into yet another .gov fiasco, and I wouldn't budge anyway because .gov is just scaremongering us into living in rabit holes! I'm ME and I'm invincible. [Roar!]"

Plus, your story doesn't say if whoever goes for a subterranean shelter or ducks eventually digs her way back out. (I'd hope we never know if it does.)

[mikeash]

I'm not sure I understand your point here. It doesn't take a whole lot of reasonableness to take cover when you know you're about to be hit by a massive blast wave. As for digging out, many of the survivors will just be able to climb out from the rubble. Escaping death by fallout then becomes interesting for many, but that won't affect many others.