Computronium

Is there a limit for Moore's Law ? Sure, an exponential growth is not sustainable and soon the limit will be reached. Soon ?
Science fiction writer Charles Stross, made the calculations and it stands that at one atom per bit all data we have recorded so far can be stored in few milligrams of diamond.
May be it is even possible to store data and make computations at proton level, or even at a lower scale. After all, today's hard disks use spins to convey bits. We do not know for sure how far we can go and research in physics will not stop to progress just now.
wikipedia:

computronium refers to a hypothetical material engineered to maximize its use as a computing substrate.

OK, we got a limit: when all the matter on earth will be transformed in computronium, Moore's law will end. Or should we say, all the matter in the solar system ? all the matter in the universe ?
Physical limits for Moore's Law are far and the exponential growth will not be exhausted by lack of substrate. Not in this century.