I was working from the idea of a nyquist or sampling rate needed to "perfectly" reproduce a wave form. I know this works for lower frequencies but I have no ide

I was working from the idea of a nyquist or sampling rate needed to "perfectly" reproduce a wave form. I know this works for lower frequencies but I have no idea how well it translates to something like optical frequencies/light. You can find frequency from speed / wavelength: f = v/l or in our case f = c / l since we're dealing with light. I was using 635nm as the wavelength (basically a red laser). That gives you: 3 x 10^8 / 635 x 10^-7 = 4.7 x 10^14 Which should be about 470 terahertz (4.72 x 10^14) give or take a bit. To sample that "perfectly" you'd need to sample at twice the frequency or about 940 terahertz or (9.4 x 10^14). As to your second question, I know that there are single photon detectors. Past that, you've got me. I don't know if that can be classified as "seeing" or not. As to size, there's https://briankoberlein.com/2015/04/14/thats-about-the-size-of-it/ https://briankoberlein.com/2015/04/14/thats-about-the-size-o... but that might or might not make sense. That's about the limit of what I'm willing/able to say on the subject.