Open Thread May 2019

What does philosophical sophistication matter? Are the quoted facts false? Is “A blue-violet laser blasts the atom, which then absorbs and re-emits enough light particles to be photographed with conventional equipment” a lie?

The sentence you quote is true. And "The sun blasts the cover of the book, which then absorbs and re-emits photons to be photographed with conventional equipment" is an equally valid description of taking a picture of a book. I'm honestly confused as to what you're expecting me to find inconsistent here. Are you implying that since you can describe scattering of light using scientific talk like "photons" and "re-emission," you can't describe it using unscientific talk like "the atom was purple?"

Ah, or maybe you're expecting me to know that you mean something like "What if the atom is only purple because it's being 'blasted' with purple photons, making this photo useless in terms of understanding its color?" That's a reasonable thing to think if you've never had reason to study atomic spectra, but it turns out the direction of causation is just the opposite - scientists chose a purple laser because that's one of the few colors the atom would absorb and re-emit.

I think what this shows is that my perception of what's "everyday" has definitely been skewed by a physics degree, and things that just seem like the way everything works to me might seem like unusual and rare sciencey phenomena to everyone else.

Like, you ask me to refute this fact or that fact, but I already quoted precisely the statements I thought deserved highlighting from the articles, and none of them were facts about how light or atoms work. That should tell you that I have zero intention of overthrowing our basic understanding of optics. But since we might have different understandings of the same sentences, I will go through the specific ones you highlight and try to read your mind.

the purple speck at the center of this photo is not the true size of the strontium atom itself

This is due to the limitations of the camera - even if the light came from a single point, the camera wouldn't be able to focus it back down to a single pixel on the detector. This is due to a combination of imperfections in the lenses plus physics reasons that make all pictures a little blurry. The same thing happens in the human eye - even if we were looking at a point source of purple light, it would look to our eye like a little round dot of purple light.

Mind reading: Maybe you are implying that if the camera can't resolve the true size of the atom, it's not "really" a picture of the atom. This is sort of true - if the atom was blue on the left and red on the right (let's ignore for a moment the physical impossibility), it would still look purple in this photo despite never emitting purple photons. Of course, we do know that it emits purple photons. But I think the thing that is actually mistaken about worrying about whether this is "really" the atom is that it's forgetting the simplicity of just looking at things to tell what color they are.

Even when I argue that things invisible to the planet eye, like the planet Neptune, can have color, it's not necessarily because of complicated sciencey reasoning, but more some heuristic arguments about process that preserve color. You can look at Neptune through a telescope and it has color then - so since telescopes preserve color, Neptune is blue. Or if I took a red teapot and shot it into space somewhere between the orbit of Mars and Jupiter and we never saw it again, it would still be red, because in color-logic, moving something somewhere else is a process that preserves color.

In short, I didn't bother to actually do the math on whether you could see an atom with the naked eye until today because I think of time lapse photography or using lenses to look at something as process that preserve "intuitive color."

When bathed in a specific wavelength of blue light, strontium creates a glow hundreds of times wider than the radius of the atom itself (which is about a quarter of a nanometer, or 2.5x10 to the −7 meters, Nadlinger said).

I'm not sure what the reporter is getting at here. I think they are comparing the wavelength of the light to the electron radius of the atom, and the wavelength of the light is what they mean by "creates a glow." It's definitely inaccurate. But I'm not sure I could do better to explain what's going on to an audience that doesn't know quantum mechanics. Maybe a water analogy? The atom emitting a photon is like a tiny stone tossed into a pond. The size of the ripples emitted by the tiny stone is a lot bigger than the size of the stone itself.

Mind reading: Maybe you read this as something like "We're not actually seeing the atom, we're just seeing 'a glow created by the atom' that's a lot bigger than the atom, therefore this isn't a picture of the atom." That's false. This goes back to why I was making fun of the reporter who said "We're not seeing the atom, we're just seeing the light emitted by the atom." Seeing the light emitted by something is what seeing is. You could just as well say "I'm not actually seeing my hand, I'm just seeing the light emitted by my hand," and you'd be just as wrong. Learning about photons should not destroy your ability to see things, and if it does you're doing philosophy very wrong.

This glow would be barely perceptible with the naked eye but becomes apparent with a little camera manipulation.

Yup, this is that "long exposure to the atom + short flash of the surroundings" technique I talked about in the previous comment. Maybe you see the word "manipulation" and assume that everything is meaningless and this "doesn't count"? I think this question stops being useful when you understand what was actually done to get the photo.

“The apparent size you see in the picture is what we’d call optical aberration,” Nadlinger said.

See above about the limitations of cameras.

(it's not his credentials or address, it's the credentials of the person who originally made the claim in a book that sparked this thread)