Why is it not possible to see an atom using visible light?

Answer 1

Hi Aleshkia -

The answer to your question is contained in the properties of the light and the properties of matter. In order to resolve the shape of an object, the wavelength of the light must be shorter than the size of the object by a significant degree. Otherwise, the light cannot form a coherent picture of the object. This is why, for example, a radar (which uses radiation with a relatively long wavelength and low frequency) can see aircraft only as fuzzy spots, not as winged shapes with engines, etc.

Light with wavelengths in the range of the visible spectrum is good for looking at people, stars, houses, cars, -- even very small things like bugs -- but it cannot resolve things as small as molecules, much less atoms.

Electron microscopes use radiation with a very high frequency and a very short wavelength. They can see things in the world of the very small. Insects look like dinosaurs, and some big molecules become sort of visible. However, when they try to see atoms, the best they can do is fuzzy shadow images. Also, at this point, quantum mechanics begins to have an effect, and things like the Uncertainty Principal make it even more difficult to resolve how things really look at that level. This is hard to describe in this limited space, but it basically states that there is a physical limit to the information that we can obtain at the subatomic level because of the nature of the matter in the universe. Things are fuzzy at that size because they really are fuzzy. Atoms, electrons, etc are basically indeterminate and are ruled not by cause and effect but by statistics and probability. This is probably profoundly unsatisfying to someone with an active curiosity like yours, but it forms the basis for the operation of most of our modern electronic equipment. - So I encourage you to pursue it further - maybe you'll help me understand it better.