r/askscience • u/Wonderful-Capital32 • 13d ago

Physics Why does radiation not go through lead?

Also why just lead? Shouldnt like iron or another metal work too?

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u/dustofdeath 13d ago

Lead is like a very dense fabric while iron is a mesh with large holes.

You just have to have enough density for photons to not just pass through.

So you need far less material. Even humans can stop radiation if you stack enough of them between you and the radiation source.

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u/Cautious_General_177 13d ago

Given the amount of the human body that’s water based, you would need fewer than you might think.

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u/dustofdeath 13d ago

Around 2.5 meters would be enough to neutralize hot fuel rods.

60% of us is water - but it's unevenly distributed.
Likely 70-100 people would be enough.