In Vikram Seth’s poem ‘A doctor’s journal entry for August 6,1945’ the following phrase indicates the occurrence of two flashes one after the other :
‘A strong flash, then another’
Why were there two flashes?
The first flash was obviously from the original explosion of the atomic bomb that was dropped on the city of Hiroshima. And I think the second flash was caused by the lighting up of other dry and inflammable objects nearby. It might even be the lighting up of the old stone lantern that the narrator mentions just the next line. But I’m not quite sure on that.
I read about atomic bombs and found out that they work on the basis of fission.
In this method there are two explosions which take place:
1. The initiation explosion to start the chain reaction
2. The final explosion which causes the main destruction.
Actually the nuclear material in these bombs is separated and kept apart from each other. The initiation explosion is required to bring both the different parts of nuclear material together which results in the bigger explosion
So this could be the reason for two flashes.