michael_nielsen

Meaning that we require a deeper understanding of complex atomic and molecular dynamics in order to generate systems capable of precise electro-magnetic or bio-chemical nudging in service of complex self-assembly. Here, tools like DeepMind are useful. Are we close? Hard to say.

And it's in this sense that Smalley's use of metaphors like "falling in love" at the molecular scale are relevant, as such complex processes of self-assembly are precisely that: complex processes which are more similar to people falling in love than to building a car.

Metaphors about love and fat fingers are fun but the real problem AFAIK is Heisenberg's uncertainty principle. Atoms and molecules are not hard sand or diamond particles writ small, they are wave functions describing the probability events will happen.

After all this time Drexler & his myriad fans have still failed to convince the vast majority of chemists & physicists & more importantly failed to convince reality in the form of actually working machines, that he has figured out a way to cheat Heisenberg on such small scales.

What do you think the uncertainty of position of a carbon or even hydrogen atom is? Have you bothered calculating it? Hint: it isn't big. Just do the math if you don't believe me. And furthermore, you can IMAGE them.

Curious how you do such a calculation? Standard quantum limits (e.g. in interferometry) usually involve specifying a free variable, typically some type of frequency. Are you calculating a standard quantum limit in your calculation?

The easy place to start is from a quantum harmonic oscillator model, but you can do a back of the envelope from things like expected velocities from a semiclassical thermal model. Quantum rotation isn't usually interesting outside of the gas phase.

The harmonic oscillator needs a frequency associated to it. That's the frequency which shows up in standard quantum limit calculations; it's a free parameter in the model. I'd be curious how Eric chose it. (Of course, squeezed states evade these calculations, but still obey HUP.)