Haverly wants a bigger blast, a device with a yield of 81 gigatons, over 1600 times that of Tsar Bomba. Such a bomb, he writes solemnly, "is not to be taken lightly". Quite how we are supposed to ...

And all this came from a 1.4 megaton bomb. Tsar Bomba, which was the largest nuclear bomb that has ever been detonated, was 50 megatons. So what would happen if we detonated that above the United ...