What Does A Nuclear Weapon Do?

The destructive power of the nuclear bomb dropped on Hiroshima was equal to 12,500 tons of TNT. In the 53 years since it was dropped, nuclear bomb manufacturers have made bombs which go into the megaton range -- that is, a million tons of TNT -- a hundred times as powerful as the Hiroshima bomb. These powerful bombs are hydrogen bombs or fusion devices, which achieve much higher instantaneous temperatures and hence burn their targets more thoroughly. The bomb-makers have also made smaller bombs in the subkiloton range -- that is, with destructive power under 10,000 tons. It is these smaller bombs that are mounted on to missiles, and can be delivered at various ranges from a few kilometers to 5,000 kilometers. The advantage of a missile is that it does not have to be manned, and is therefore immune to the accidents that might befall a pilot before he reaches the target.

 

It can, of course, be shot down just like a bomber. Technologies to shoot down intruding flying devices have improved considerably since World War II. Then the belligerent powers largely relied on manned anti-aircraft guns. Two men sat by these guns, and turned them around rapidly to aim at incoming planes. Their accuracy was low, especially at night; countries tried to compensate by having a lot of them. They also used fighters to intercept incoming bombers before the bombers reached sensitive targets. The so-called Battle of Britain was a battle between German Stukas trying to get to targets in Britain and British Spitfires trying to shoot them down before they penetrated British airspace. The Spitfires -- astonishing little planes -- did manage seriously to maim the air attack. But once the Germans developed V1 and V2 rockets, many more of them got through. The German government, however, was run on Indian lines; sycophancy prevailed over competence. Hence the success of the rockets was never followed through.

Later in the war, the Allies won such overwhelming air superiority that hundreds of planes bombed Germany every night with little obstruction from anti-aircraft guns. By the time war ended, there were many German cities in which most buildings were bombed out. I went to Germany 15 years after the end of the War; even then there were entire derelict areas in Hamburg and Kiel. The people whom the bombs killed had been removed. But their absence was obvious. There were many more women than men -- the Germans, though they were Aryans, did not have our custom of wives burning themselves on the pyres of their men. The last of the bombed ruins can be seen being removed right now in Berlin: the Berlin Wall is gone, and the no-man's land, which had been left undeveloped, has become Europe's largest building site in preparation for the move of the German capital to Berlin in 2000. But bullet marks can be seen to this day on old buildings slightly further east from Reichstag.

Today, manual anti-aircraft guns have been replaced by guns with automatic radars which search out incoming planes or missiles and shoot multiple warheads at them. They are, of course, much more effective. But they are also much more expensive; hence air defence in a future war would be costly -- so costly that India is unlikely even to bother to protect its civilian population.

It is theoretically possible to load a bomb on to a satellite which revolves around the earth; it could then be directed at any target over which the satellite passes. But such a satellite-borne bomb could be attacked by other powers and even perhaps hijacked; and powers would work on technologies to detect such bombs and to deflect them.So by agreement amongst nuclear powers, none of them has sent bombs into the stratosphere.

What would happen if a nuclear bomb was dropped on Delhi? Instead of using imagination which might be mistaken for sensationalism, let me simply describe what happened in Hiroshima. August 6, 1945 was a beautiful day: temperature 30 degrees centigrade, humidity 80 per cent -- like Calcutta on an early winter morning. "Shimmering leaves, reflecting sunlight from a cloudless sky, made a pleasant contrast with shadows in my garden," wrote Michihiko Hachiya in his diary. Eight thousand schoolgirls were helping to clear the ruins of bombed buildings. Four warnings were sounded of US B-29s, but no one bothered to take cover.

At 8:15, a girls' teacher looked up and said: "Oh! There is a B!" Just then there was a flash of lightning. It lasted less than a tenth of a second. But in that instant, tiles a kilometre away melted. Everything flammable burst into flames within 4 kilometres -- including human beings. People within half a kilometre were burnt to a temperature where their internal organs boiled away; they became small black bundles, stuck to pavements, walls and bridges. The outline of a handcart puller was etched in the asphalt surface of a street which he prevented from melting.

But only a few were so lucky. Anyone who looked up at the plane had his retina burnt away. The skins of those people who were singed peeled and hung down like rags. Their bare bodies were covered with blood. Their muscles, unsupported by skin, hung out; their organs came out, their faces swelled, their hair vanished. A boy was blown out as the house fell apart, was hurled through a couple of windows, and fell outside on the street, his body stuck full of glass.

They were the survivors; but that was not the end of the story. For the bomb started a firestorm. In a firestorm, the epicentre of the target begins to burn; the air in it catches fire and rises, sucking in air from the surrounding area. An intense fire is ignited, which spreads in a widening circle. This is not peculiar to nuclear bombs; intense conventional bombing also leads to firestorms. Dresden, one of Germany's most beautiful cities, experienced one, and was burnt to the ground. Hiroshima also had a firestorm, and those who survived, whatever their condition, ran to get away from it. Only those who could run survived; amongst the survivors, only 4.5 per cent had fractures. Anyone who suffered bone injury in the first second was unlikely to get away even if he lived.

This is gory enough; anyone who wants to know how it was should read Richard Rhodes's The Making of the Atomic Bomb.

Instead of Hiroshima, think of Delhi; what happened there is perfectly possible here. On the night before Pakistan's blasts, its rulers were convinced that Indian planes were coming to bomb its nuclear facilities; if they had been ready with one, they could have sent a nuclear bomb in supposed retaliation. Both India and Pakistan have the bomb, but neither has the checks required to ensure that they do not slide inadvertently into a war. They may do precisely that if they go on with the present hostilities on the line of actual control in Kashmir. Destructive power has come too easily to both, but responsible government is still remote in either. That is what worries the rest of the world.