As someone who struggles to take usable photographs of his cats, it’s hard not to be dispirited when someone manages to take a flawless picture of a single atom. The cat, after all, is made up of around 150,000,000,000,000,000,000,000,000 of them, so isolating a single one is no mean feat.
And yet that’s exactly what physicist David Nadlinger from the University of Oxford achieved with the above image. It’s the tiny blue dot held between those two metal needles – which, to put things in perspective, are about two millimetres apart. Still can’t see it? Zoom and enhance!
You may not be an expert in atom spotting, so I’ll go ahead and tell you this particular fellow is a positively charged strontium atom, illuminated by a blue-violet laser. The laser energy causes the atom to emit photons, which is why Nadlinger was able to capture it on a long-exposure snap, which was taken through the window of an ultra-high vacuum chamber, cooled to keep the atom still and ready for its close up.
“A back-of-the-envelope calculation showed the numbers to be on my side, and when I set off to the lab with camera and tripods one quiet Sunday afternoon, I was rewarded with this particular picture of a small, pale blue dot.”