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> First is that the energy required for generating a human-sized body is huge, several hundreds times greater than that of a nuclear bomb I thought this was a

> First is that the energy required for generating a human-sized body is huge, several hundreds times greater than that of a nuclear bomb I thought this was a bit short, I'm pretty sure it's closer to: 1 gram = 90000000000000 joules 1 average us man = ~89000 grams Google tells me 1 Hiroshima bomb = 63000000000000 joules So the average us man should be ~127,142 Hiroshima bombs, or ~110,000 Hiroshima bombs for the average us woman.

adrian_b 5y ago
I have said that a factor of hundreds applies for the same weight of active material. Most nuclear bombs have just a few kilograms of active material, much less than a human. Also the number that I have given was for ideal conversion and for a fusion bomb, which is more efficient per weight. The fission bombs, like that from Hiroshima, are limited by the excess energy of uranium or plutonium, which is only about 0.13% of mass compared to iron. Because we cannot actually split plutonium into iron but into nuclei with higher energy, the available energy from fission is slightly less than 0.1% of mass. Taken into account that only a fraction of the active material is consumed, let's say 10% and that the active material of a bomb is ten times lighter than a human, then an annihilated human mass would be equivalent to 100 thousand fission bombs, so your numbers match this. For a fusion bomb, the efficiency is much higher, about 0.5% of mass becomes energy and also the mass of active material can be much higher, so an equivalence with less than one thousand nuclear bombs is possible. In any case I have given just the most optimistic limit, i.e. a few hundreds nuclear bombs of maximum energy, with smaller bombs, of course you need more.
goohle 5y ago
This amount of energy is required to CREATE mass from scratch. IMHO, it's much easier to use transmutation of atoms to print an object layer by layer instead.

adrian_b 5y ago

I have said that a factor of hundreds applies for the same weight of active material. Most nuclear bombs have just a few kilograms of active material, much less than a human. Also the number that I have given was for ideal conversion and for a fusion bomb, which is more efficient per weight. The fission bombs, like that from Hiroshima, are limited by the excess energy of uranium or plutonium, which is only about 0.13% of mass compared to iron. Because we cannot actually split plutonium into iron but into nuclei with higher energy, the available energy from fission is slightly less than 0.1% of mass. Taken into account that only a fraction of the active material is consumed, let's say 10% and that the active material of a bomb is ten times lighter than a human, then an annihilated human mass would be equivalent to 100 thousand fission bombs, so your numbers match this. For a fusion bomb, the efficiency is much higher, about 0.5% of mass becomes energy and also the mass of active material can be much higher, so an equivalence with less than one thousand nuclear bombs is possible. In any case I have given just the most optimistic limit, i.e. a few hundreds nuclear bombs of maximum energy, with smaller bombs, of course you need more.

goohle 5y ago

This amount of energy is required to CREATE mass from scratch. IMHO, it's much easier to use transmutation of atoms to print an object layer by layer instead.