[knodi123]

I'm fairly confident that gray goo, as described in dystopian sci fi, is impossible due to some of the consequences of entropy and its inevitable increase.

That is, the tinier a machine, the more susceptible it is to breaking down due to wear and tear. And the more energetic a machine, ditto. So incredibly tiny, incredibly energetic machines, would have a minuscule lifespan.

And that's not even touching on the issues of power supply and storage.

I think AI is a much more existential threat than gray goo.