This is not a critique of the winning photo. Rather, it is an example of a "click bait", where the news report tries to entice you to read it because the title is so astounding. I guess it worked on me.
This news report, purportedly from Popular Mechanics, is highlighting a winning science/engineering photo of a single strontium atom being held in an ion trap. But what it says is a bit misleading:
Now, we have a photograph that shows a single atom floating in an electric field, and it's large enough to see without any kind of microscope.
This is wrong. It is not "large enough" to be seen.
They corrected this somehow later in the article, but it still does not dispel the error that this has nothing to do with size, and it requires a bit of elementary knowledge of atomic energy level to realize that the earlier description is a mistake.
The strontium atom in the photo is hit by a high-powered laser, which causes the electrons orbiting the strontium atom to become more energized. Occasionally, these energized electrons will give off light. With enough energized electrons giving off enough light, it's possible for an ordinary camera to image the atom.
In other words, the strontium atom was excited and this then causes it to emit light. This process is no different than the light that you see from neon signs or your fluorescent light bulb that has mercury vapor. The unique part about this setup is that you are seeing light from a single atom, whereas in your neon signs, you are seeing the light from many, many atoms. But the process is identical! Yet, we don't go ga-ga and proclaim that we can see an atom with our naked eye.
Just be clear, you are not seeing the atom in the normal sense. You are seeing the light from an atomic transition of this strontium atom. The fact that this is made by a captured single atom is remarkable. The fact that we can detect light from this atom with our "naked eye" does not mean that we are "seeing" the atom in the normal sense that most people understand it.
Zz.
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