Nick Szabo  🔑

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?

As far as I'm aware, it's standard physics that both position and momentum (but ofc not both at once) variance can be reduced arbitrarily. Indeed, LIGO has begun using squeezed states (of light, not matter, but the idea is the same) to improve their strain sensitivity.

Mechanical devices have to be simultaneously precise as to both position and momentum.

That puts severe limits on how small they can be made and retain sufficient precision.

So? We're not talking about electrons here, we're talking about things with many orders of magnitude more mass. There are actual calculations in Chapter 5 of Nanosystems. Which of them do you think is incorrect?

It is not enough to say "quantum mechanics!", there are actual well understood equations that govern quantum systems, and you can do calculations using them, and the calculations say you're wrong. If you disagree, say which eq is wrong in Ch. 5 of Nanosystems.

And again, positional uncertainty is tiny at room temperature; it only becomes interesting when you're operating at tiny fractions of a degree kelvin. At room temperature, only thermal motion is important, and it's still too small to cause trouble.