Why is it that when the alarm goes off or a bomb explodes, "The alarm went off" or "the bomb went off" doesn't mean "off," SHUT DOWN, NO WORKING, NO ACTIVE. Wouldn't it be correct to say that the alarm went ON if it went Sounded? Or that the bomb went ON if it exploded, "ON" means actively on? The other thing I don't understand is NEAR MISS, when two planes flew very close to each other. Wouldn't that be NEAR HIT? They almost touched, but they didn't. It was a NEAR HIT. NEAR MISS would mean they collided?
“Went off” sounds backward because we associate “off” with shutting down or stopping, but in older usage, it meant something like “departed from a state of readiness or calm.” So when an alarm goes off, it means it activated, it departed from quiet. Same with a bomb or a gun. The phrase stuck even though it clashes with how we usually use “off” now. As for “near miss,” that one actually makes sense. It means there was a miss, and it was near. They didn’t collide, but they came close. It’s not a contradiction. It’s a literal close call.