4 ms·

Radiation is measured in gray, which is 1 J absorbed by 1 kg. I can't find the conversion between flux to absorbed dose. 5 gray is fatal. If even a fraction of

• oskarkk 1y ago
  So, given that human body area viewed from the front is around 0.5 m^2, then a 70 kg human in space 1000 miles from the explosion would get 6.4 kJ * 0.5 / 70 kg = 45 gray. That would mean that even being a couple thousand miles away could be fatal. But that's assuming 100% of Tsar Bomba energy would be ionizing radiation, I don't know what % would that be in reality.
• ben_w 1y ago
  > Radiation is measured in gray, which is 1 J absorbed by 1 kg. I can't find the conversion between flux to absorbed dose. 5 gray is fatal. If even a fraction of that energy is absorbed, it would be fatal. It's measured in a lot of different ways depending on the need, and the unit "sievert" is Gy times a conversion factor that depends on the kind of radiation (for equivalent dose) and which body parts (for effective dose): https://en.wikipedia.org/wiki/Sievert#Radiation_type_weighting_factor_WR https://en.wikipedia.org/wiki/Sievert#Radiation_type_weighti... But also, beta radiation (electrons) will be stopped by a thin sheet of tinfoil, while alpha radiation (helium-4 nuclei) by paper or the outer layer of dead skin on your body and therefore only matters if you eat a source of it, and a significant fraction of any gamma radiation you're exposed to will pass right through you without getting absorbed.