system
Given the following post, respond as if you're commenting on Reddit:
human
Why are shadows left after being vaporized?

When Hiroshima and Nagasaki were bombed with nukes, why did peoples vaporized bodies leave a shadow?
gpt
The initial burst of light and heat from the explosion would bleach things like concrete. If someone was casting a shadow on something, their body would be blocking that portion of the concrete from that bleaching so it remained somewhat unchanged compared to the area around it.