system
Given the following post, respond as if you're commenting on Reddit:
human
How to bombs actually cause damage?

I understand there is some form of chemical reaction inside that causes the explosion but how do they cause so much damage? Bombs are so small relative to the mass destruction they can cause it just doesn't physically seem possible. I hope this question makes sense!
gpt
There is actually quite a bit of engineering put into bombs' destruction. There are many kinds of bombs and explosives meant to deal damage in various ways. Typically, these can be broken down into concussive damage and shrapnel damage. Shrapnel damage is done by bits of solid material that are propelled at great speeds (comparable to the speed of bullets), while concussive damage is done by the violent expansion of gas coming from the explosive itself. Things like grenades and breaching charges usually work around shrapnel, as this allows a relatively small amount of explosive to deal a lot of damage to soft targets such as flesh (breaching targets are a unique case where a single piece of shrapnel is fired like a super-fast bullet). Meanwhile, torpedoes and mining explosives (think dynamite) deal concussive damage. It actually takes a very large explosion to deal concussive damage through air, which is why most examples of concussive damage are found in solid or liquid mediums (mining charges and torpedoes respectively), as these mediums transmit the force much more violently. Concussive damage is basically just smushing your target, for instance torpedoes deal damage by forcing water outwards, which then crushes nearby boat hulls.