system
Given the following post, respond as if you're commenting on Reddit:
human
Why are nuclear bombs detonated while they’re still thousand of feet in the air?
gpt
To get a bigger area of effect.

If you detonate the bomb at ground level, only the part of the explosion around the horizontal circumference that will do major damage to buildings and the surroundings. You lose a lot of the force of the explosion upwards into the sky, and down into the ground directly under the explosion (which will do massively damage, but to a small area).

If you detonate the bomb in the air, the force of the explosion that is directed upwards still does no damage, but all the force that would have gone directly into the ground on a surface detonation now spreads out over a much larger area.