If Einstein said that, I'd say he was wrong at the time, because already in the 1920s it seemed probable that nuclear fusion powers the stars: https://en.wikipe

If Einstein said that, I'd say he was wrong at the time, because already in the 1920s it seemed probable that nuclear fusion powers the stars: https://en.wikipedia.org/wiki/Stellar_nucleosynthesis#History https://en.wikipedia.org/wiki/Stellar_nucleosynthesis#Histor... Of course that's a long way from practical engineering, but it is evidence that nuclear power may be obtainable.