4 ms·

"Nano-architected materials are made of tiny building blocks or repeating units measuring a few hundred nanometres in size — it would take more than 100 of them

"Nano-architected materials are made of tiny building blocks or repeating units measuring a few hundred nanometres in size — it would take more than 100 of them patterned in a row to reach the thickness of a human hair." I am perpetually shocked that a structure (hair) that we can actually see is so close to nanoscale. (It's also noteworthy that our sense of touch in fact extends into the nanoscale: https://www.nature.com/articles/srep02617 https://www.nature.com/articles/srep02617)

XorNot 2y ago
You can use a light microscope to visualize things down to about 500 nm, somewhat dependent on shape (you can see down to about 100 nm, but really only that something is there - whereas nanocubes with 200nm side length had some definition when I tried it). Which is pretty shocking when you realize a nanometer will hold about 10 hydrogen atoms (give or take the fact that the electron cloud repulsion isn't well defined), meaning you're in fact only talking about 5000 hydrogen atoms at the same packing for that 500 nm linear distance. Which puts the idea of "Plenty of space at the bottom" by Feynmann in an odd contrast because it's like...well, that doesn't seem so far away when my basic eyeball and some optics can operate plausibly see down to that scale directly - photons are interacting with things and passing straight to it.
- le-mark 2y ago
  I was thinking recently how there used to be about a lot of talk about waldos and nanotechnology. I think the idea was to build a Waldo that can assemble a 1/10th scale Waldo, repeat and voila you are soon building nano scale contraptions. It’s a very intriguing idea, seemingly not practical though.
  - Jeff_Brown 2y ago
    Its operation at each scale would be very different, and it's not obvious how many different layers we'd need before we'd be at the smallest possible, but maybe.
    - XorNot 2y ago
      Technically we already can go from human scale to nano or even atomic scale in "one operation". i.e. a scanning tunneling microscope you etch a tungsten wire in acid and then can go and look at individual carbon atoms at room temperature. An atomic force microscope is even more direct - while not absolutely "atomic" - you can definitely with a sharp enough tip push things around on the nanoscale. The problem is definitely as you note: things do in fact behave very differently when you're doing that.

XorNot 2y ago

You can use a light microscope to visualize things down to about 500 nm, somewhat dependent on shape (you can see down to about 100 nm, but really only that something is there - whereas nanocubes with 200nm side length had some definition when I tried it). Which is pretty shocking when you realize a nanometer will hold about 10 hydrogen atoms (give or take the fact that the electron cloud repulsion isn't well defined), meaning you're in fact only talking about 5000 hydrogen atoms at the same packing for that 500 nm linear distance. Which puts the idea of "Plenty of space at the bottom" by Feynmann in an odd contrast because it's like...well, that doesn't seem so far away when my basic eyeball and some optics can operate plausibly see down to that scale directly - photons are interacting with things and passing straight to it.

le-mark 2y ago
I was thinking recently how there used to be about a lot of talk about waldos and nanotechnology. I think the idea was to build a Waldo that can assemble a 1/10th scale Waldo, repeat and voila you are soon building nano scale contraptions. It’s a very intriguing idea, seemingly not practical though.
- Jeff_Brown 2y ago
  Its operation at each scale would be very different, and it's not obvious how many different layers we'd need before we'd be at the smallest possible, but maybe.
  - XorNot 2y ago
    Technically we already can go from human scale to nano or even atomic scale in "one operation". i.e. a scanning tunneling microscope you etch a tungsten wire in acid and then can go and look at individual carbon atoms at room temperature. An atomic force microscope is even more direct - while not absolutely "atomic" - you can definitely with a sharp enough tip push things around on the nanoscale. The problem is definitely as you note: things do in fact behave very differently when you're doing that.