6 ms·

The title is a bit misleading though. Though it would be real cool, saying we can detect molecule size pattern does not mean we could read Braille alphabet on m

The title is a bit misleading though. Though it would be real cool, saying we can detect molecule size pattern does not mean we could read Braille alphabet on molecule size dots. The eye can detect nanometer size patterns: we can make the difference between blue light ( radiation with a 400 nanometers wave length ) and red light ( radiation with a 800 nanometers wave length ). Does not mean we can see nanometer size objects. Bottom line, be careful talking about patterns ....

sp332 13y ago
Well, we can feel bumps 13 nanometers high, as long as they are 760 nanometers long :)
3rd3 13y ago
We can also see a candle in complete darkness from 50 km away so just a handful of photos are enough for a sensation. "The researchers found that the emission of only 90 photons could elicit visual experience. However, only 45 of these actually entered the retina, due to absorption by the optical media. Furthermore, 80% of these did not reach the fovea. Therefore, the human eye can detect as few as nine photons." http://en.wikipedia.org/wiki/Absolute_threshold http://en.wikipedia.org/wiki/Absolute_threshold
alister 13y ago
As another (minor) clarification to the article, where it says: If your finger was the size of the Earth, you could feel the difference between houses from cars I think it would be easier to visualize this way: If the Earth was the size of an orange, your finger could feel the difference between houses from cars
- bjornsing 13y ago
  That still requires a pretty impressive feel for the relative size of oranges and planets though. I would have preferred something like this table: 2 nm Diameter of a DNA Alpha helix 4 nm Globular Protein 6 nm microfilaments 7 nm thickness cell membranes 20 nm Ribosome 25 nm Microtubule 30 nm Small virus (Picornaviruses) 30 nm Rhinoviruses 50 nm Nuclear pore 100 nm HIV So 13 nm is on the scale of a very small virus... :)
  - lukevdp 13y ago
    Something tells me that you don't really need an analogy at all :)
  - sliverstorm 13y ago
    A virus is 30nm? Good lord. The minimum feature size of commercial transistors is half that right now.
- nostromo 13y ago
  I like your analogy better. But it still implies that you could feel one car and one house, which you couldn't. So, perhaps an even better analogy would be: If the Earth was the size of an orange, your finger could feel the difference between cities and forests. This puts more emphasis on the distinct patterns the objects form as a group, rather than the individual objects.
Florin_Andrei 13y ago
It's almost certainly all about the pattern. I make telescope mirrors. The error I'm allowed is 100 nm. I would love to just drag my fingers over the glass and tell if something is not quite right with the optical surface. In reality, I need a pretty elaborate optical setup to amplify the errors about 1/2 million times, in order to see them. I'm guessing the spatial frequency of the pattern in that experiment is on the same size scale like the vertical amplitude of it.
- taavi013 13y ago
  It is rumoured that Bernhard Schmidt had so sensitive touch, that he could physically feel polishing results by his (only) left hand. http://en.wikipedia.org/wiki/Bernhard_Schmidt#Mittweida_years http://en.wikipedia.org/wiki/Bernhard_Schmidt#Mittweida_year...
  - Florin_Andrei 13y ago
    If this is about the early stages of polishing, I believe it (and I can do it myself).

sp332 13y ago

Well, we can feel bumps 13 nanometers high, as long as they are 760 nanometers long :)

3rd3 13y ago

We can also see a candle in complete darkness from 50 km away so just a handful of photos are enough for a sensation. "The researchers found that the emission of only 90 photons could elicit visual experience. However, only 45 of these actually entered the retina, due to absorption by the optical media. Furthermore, 80% of these did not reach the fovea. Therefore, the human eye can detect as few as nine photons." http://en.wikipedia.org/wiki/Absolute_threshold http://en.wikipedia.org/wiki/Absolute_threshold

alister 13y ago

As another (minor) clarification to the article, where it says: If your finger was the size of the Earth, you could feel the difference between houses from cars I think it would be easier to visualize this way: If the Earth was the size of an orange, your finger could feel the difference between houses from cars

bjornsing 13y ago
That still requires a pretty impressive feel for the relative size of oranges and planets though. I would have preferred something like this table: 2 nm Diameter of a DNA Alpha helix 4 nm Globular Protein 6 nm microfilaments 7 nm thickness cell membranes 20 nm Ribosome 25 nm Microtubule 30 nm Small virus (Picornaviruses) 30 nm Rhinoviruses 50 nm Nuclear pore 100 nm HIV So 13 nm is on the scale of a very small virus... :)
- lukevdp 13y ago
  Something tells me that you don't really need an analogy at all :)
- sliverstorm 13y ago
  A virus is 30nm? Good lord. The minimum feature size of commercial transistors is half that right now.
nostromo 13y ago
I like your analogy better. But it still implies that you could feel one car and one house, which you couldn't. So, perhaps an even better analogy would be: If the Earth was the size of an orange, your finger could feel the difference between cities and forests. This puts more emphasis on the distinct patterns the objects form as a group, rather than the individual objects.

Florin_Andrei 13y ago

It's almost certainly all about the pattern. I make telescope mirrors. The error I'm allowed is 100 nm. I would love to just drag my fingers over the glass and tell if something is not quite right with the optical surface. In reality, I need a pretty elaborate optical setup to amplify the errors about 1/2 million times, in order to see them. I'm guessing the spatial frequency of the pattern in that experiment is on the same size scale like the vertical amplitude of it.

taavi013 13y ago
It is rumoured that Bernhard Schmidt had so sensitive touch, that he could physically feel polishing results by his (only) left hand. http://en.wikipedia.org/wiki/Bernhard_Schmidt#Mittweida_years http://en.wikipedia.org/wiki/Bernhard_Schmidt#Mittweida_year...
- Florin_Andrei 13y ago
  If this is about the early stages of polishing, I believe it (and I can do it myself).