Can we see a nanowire, whose dia is say 1 nm but length is 10mm, with naked eye? To see an object does at least two out of three dimensions must be greater than the minimum size one's eye can see?


2 Answers 2


no, a nanometer is much smaller than the wavelength of light, so you can not even see it with an optical microscope.

May be worth a note the "nano-" prefix is often abused in the literature. Things described as "nano" are often "really" micron sized. Additionally such small stuff often exists as agglomerates/mat/powder , etc. which then of course you can see if there is enough of it


No. Absolutely not.

Think about it. Visible light has wavelengths roughly from 400 to 700 nm. You are talking about feature sizes many times smaller than the wavelength of anything your eyes can see.

In addition to that, you certainly can't see things that small with a naked, as you asked about. Again, actually think about it. If you could see things even remotely that small with a naked eye, there would be no need for optical microscopes. Of course anything using visible light, which includes optical microscopes, are limited by the wavelength of light they use. Even the best optical microscope can't resolve 10 nm features, not even close.

  • $\begingroup$ Hmmm this article makes the case that it has to do with the amount of light emitted or reflected off the object, not necessarily the size. sciencefocus.com/qa/how-small-can-naked-eye-see $\endgroup$
    – Drew_J
    May 30, 2017 at 12:15
  • $\begingroup$ @Drew: 400 nm photons don't get reflected by 10 nm objects. $\endgroup$ May 30, 2017 at 12:20
  • $\begingroup$ Under normal conditions it will not but the object can still emit that light through other processes. $\endgroup$
    – joojaa
    May 30, 2017 at 12:39
  • $\begingroup$ @joo: If the 10 nm wire emits 400 nm photons due to black body radiation, then you still can't resolve the details of the wire. The emission will look like coming from a 400 nm fuzz ball, not a 10 nm x 1 nm object. $\endgroup$ May 30, 2017 at 12:58
  • $\begingroup$ @Drew_J While some long-wave photons may get scattered, you still won't get anything like a resolvable image. $\endgroup$ May 30, 2017 at 14:55

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