On: Why we picture bombs as round black balls with a b...

[kragen]

I could be wrong about this, but I think as little as 100 mm of granite between you and a modern hand grenade would probably keep you from serious injury. I'm pretty sure that with 100 mm of steel in the way, the worst you'd suffer would be ringing in your ears. So "far enough away" doesn't have to be very far.

[Doxin → kragen]

hand grenades tend to be anti-personel, so I can see them being ineffective against structures.

Still, with the amount of videos on youtube with people fumbling training grenades "far enough away" doesn't seem to be a given.

[kragen → Doxin]

Yeah, it's not. Air has some properties in which it differs substantially from granite.