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Comment by gus_massa | Hacker News Reader

The title is misleading. They don't get an X-ray image of the atom , like the X-ray of a person where you can see the bones and look if one of them is broken. So you can' get a "photo" of the atom with this method.

I think they don't even collect the X-rays after they hit the atom.

IIUC they use x-rays of different energies to light an atom, and use a tunnel microscope probe to collect electricity. Each different energy of the x-ays produce a different amount of electricity in the tunnel microscope. They get an spectrum, like the one near the bottom of the article, that can be used to identify the atom, but not to take a "photo".

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Isn't that the point of X-ray spectroscopy? As a layperson I don't know of any point in trying to "photograph" a single atom, but surely being able to do spectroscopy on a single atom is really useful.

They "forgot" the word "spectroscopy" which changes the meaning of the sentence.

Isn’t an X-Ray better than a photo in this context because it delivers way more information?

The problem is that when people read "x-ray" or "photo", they expect a 2D image/array of values, where each pixel represent a part of the space (or a projection of it).

As a sibling comment says, this is an spectroscopy. You regulate some level of frequency/energy with the input (x-ray) and you get only one value (current in the tunnel tip). So you get a 1D array of values that is easy to see like a function. But each point does not correspond to a part of the space, it's some abstract value connected to the whole atom.

Oversimplifying, look at the image at the bottom. When people read "x-ray" they expect something like the left panel, but their result was the right panel.

Note that spectroscopy is very useful. There are like 5 or 10 methods and each one is related to a different property of the atom/molecule. So a new one is always welcome, but it may take a while to understand all the advantages and disadvantages of his one. The problem is the whole story about x-rays. They are using x-rays, but the method and result is very different from the x-ray images people know.

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