it has been plausibly argued to me that all the roads to nuclear weapons, including plutonium production from U-238, may have bottlenecked through the presence of significant amounts of Earthly U235 (apparently even the giant heap of unrefined uranium bricks in Chicago Pile 1 was, functionally, empty space with a scattering of U235 dust).
All is such a strong word unless supplemented with qualifiers. I question the plausibility the arguments at supporting that absolute. The route “wait for an extra century or two of particle physics research and spend a few trillion producing the initial seed stock” would still be available.
All is such a strong word unless supplemented with qualifiers. I question the plausibility the arguments at supporting that absolute. The route “wait for an extra century or two of particle physics research and spend a few trillion producing the initial seed stock” would still be available.
In context, Fermi was considering something rather more short-term: WW2.
That said, he may not have scoped his statement to such a small scale.
One of many suitable and sufficient qualifiers that could make the arguments plausible.