MOLECULES UNDER A MICROSCOPE. What do we see if we look at a molecule through an optical microscope?

What will we see if we look at a molecule or atom through an optical microscope?
All people, and especially schoolchildren, are familiar with pictures like the one shown above. However, will we see something like this if we look at a molecule or atom even through the coolest optical microscope?
We know that optical devices such as microscopes exist. These devices allow you to view very small objects. In them, you can see the cells of living organisms and even their internal structure, as well as many other things that are not visible to the ordinary eye. But is it possible to step further and see the molecules that make up cells?
Strictly speaking, all microscopes have a certain limit to which they can enlarge the image, or in other words, how small an object in them can be viewed. And we must honestly admit right away that there is no such optical microscope in which one could examine an object as small as a single molecule or atom. This is prevented by some fundamental laws of optics.
However, let's assume that we managed to get a microscope with such a gorgeous resolution that it would be ready to show us an object as small as a single molecule or atom. And so we pointed this microscope at a single atom or molecule, what will we see?
The answer is very simple: virtually nothing. The fact is that light consists of photons. And in order to see an object through a microscope or even just with the eye, and to examine its structure, we need many photons to be reflected simultaneously from different parts of this object and then fall in abundance into the eyepiece of an optical device or into our eye. Of course, it is also possible that the object itself glows, i.e. emits photons. The meaning remains the same, many photons from different parts of the object must simultaneously enter the optical device.
But molecules or atoms interact with photons in a different way. They don't reflect them.
Molecules and atoms can only absorb or emit photons. And most often, photons generally fly past molecules and atoms without interacting. At the same time, an atom or molecule usually emits only one photon, which then flies in an unpredictable direction. In addition, in order for a molecule or atom to emit a photon, it (or he) must first absorb another photon.
Thus, our experiment of observing a molecule through a microscope would look like this: we illuminate an atom or molecule with light, but most photons fly past the atom or molecule under study. Then, at some point, one of the photons is still absorbed, and after a while an atom or molecule emits a similar photon in an unpredictable direction (often, by the way, it flies in the same direction from where the previously absorbed photon came from).
Thus, we can hardly distinguish this single photon emitted by a molecule or atom from the illumination that we shine on the object under study, i.e. billions of other similar photons flying nearby. And if the molecule is not illuminated, then the photon emitted by it may have to wait a very long time.
But even if we can separate the photon that flew out of the molecule from the illumination photons, nevertheless, the best we can expect from a molecule or atom that we look at in an optical microscope is that at some unpredictable moment, it (or he) will still radiate away The eyepiece of the microscope has one photon. A single photon is not enough for the human eye to see at least something. But the microscope can probably be made so that it can detect and amplify the signal received when a single photon hits.
In any case, the best thing we get when observing a molecule or atom in the coolest optical microscope is vanishingly small and rare flashes of light that last for a fleeting moment, occurring at unpredictable moments. At the same time, these flashes will not visually reflect the structure of a molecule or atom in any way (although their spectrum will contain some information about it), and we will never see a picture like the one shown above. Generally speaking, the picture above is just a poor visualization of the internal structure of the atom, which has been studied using other methods, but not with an optical microscope.
#molecule, #atom, #microscope
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