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Comment by novacole | Hacker News Reader

It’s not an atom, it’s a picture of the light emitted from an atom. So it’s a picture of light.

All pictures are actually pictures of the light either emitted by or reflected from things.

Ceci n'est pas une pipe.

What does this atom look like? Do you see an atom or do you see light? Of course, all pictures are pictures of light. But there’s a difference between taking a picture of the light coming from a light bulb and a picture of a light bulb, as I am sure you’re aware.

There isn't, no.

It is the same exact thing.

> But there’s a difference between taking a picture of the light coming from a light bulb and a picture of a light bulb, as I am sure you’re aware.

OK, explain it.

In the first one you can see details.

Look at a light bulb when the filament is heated and is emitting light. Then look at it when it is not. The only people who can’t see the difference are blind, literally.

When the filament is cold, you can see it because of light that comes from it after having been reflected off of it, rather than having been emitted from it originally; or, if it's dark on a light background, because of light that comes from other parts of the lightbulb after being transmitted through it from behind. In all of these cases, what you see in the photo is light that came from the lightbulb, and all of them are equally legitimately "pictures of the lightbulb", although they might display more or less detail.

You're looking for the word "glow". People are (somewhat rightfully) piling up on you because all pictures indeed are pictures of light, whether that light is reflected by an inactive lightbulb or is from its powered, glowing filament.

Despite the haters, this is pretty much on the money. This is the light scattered from a single atom that came through the lens and hit exactly just one pixel on the sensor. That dot is (guessing) millions of times larger than an actual single atom.

This is no different in principle than a photo of a starry night sky, where the size of the pixel is far greater than the actual angular size of the object from our vantage point.

Take a zoom at the original picture. It's 4 pixels.

This is the most pedantic thing I've ever seen posted on HN.

If an object is illuminated by the sun or by a flashlight, you see the light. When you illuminate a single strontium atom with a laser while it's suspended in an ion trap, you see the light.

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