The Engineering and Physical Sciences Research Council awarded a remarkable photograph its overall prize in science photography. The subject of the photograph? A single atom visible to the naked eye. Well, perhaps not exactly the naked eye, but without a microscope. In the picture above (click here to enlarge), the atom is that pale blue dot between the two needle-like structures.
You probably learned in school that you couldn’t see a single atom, and that’s usually true. But [David Nadlinger] from the University of Oxford, trapped a positively charged strontium atom in an ion trap and then irradiated it with a blue-violet laser. The atom absorbs and reemits the light, and a camera can pick up the light, creating a one-of-a-kind photograph. The camera was a Canon 5D Mk II with a 50mm f/1.8 lens — a nice camera, but nothing too exotic.
The ion trap keeps the single atom balanced between two small needle points about 2 millimeters apart. [Nadlinger] did some math that convinced him the photograph could be possible and made it a reality on a Sunday afternoon. The pale dot isn’t especially spectacular by itself, but when you realize that it is the visual effect of a single atom, it is mind-blowing. Turns out, the lab has taken some similar photographs in the past. They don’t remember who took it, but they have a picture of 9 calcium-43 ions trapped, that you can seen below. The ions are 10 microns apart and at an effective temperature of 0.001 degrees Kelvin.
Other winning photographs included patterns on a soap bubble, an EEG headset in use, and microbubbles used to deliver drugs. There’s also an underwater robot, a machine for molecular beam epitaxy that looks like a James Bond villain’s torture device, and lattices made with selective laser melting 3D printing.
If you want to look at atoms from the comfort of your own home, maybe you should build an STM. You might even try NIST’s improved atom probe while you are at it. Just remember you can’t trust atoms. They make up everything.
Photo credit: David Nadlinger
51 thoughts on “Photograph Of Single Atom Captured With A Plain Old Camera”
Another great shot taken with the “nifty fifty” lens.
Not with a 50mm lens, I gotta call BS.
he might have the lens reversed and on a bellows. I commonly use a 3 element Nikor medium format lens for macro photography, in a reverse lens macro setup.
Which focal length would you use?
It was taken by a science student in the UK
Man, I don’t know. If that gap is 2 mm (.0787″) and that “atom” is halfway between that means it is about .039″ from each tip. If you continue to cut that distance in half again you get .028″ halfway between the “atom” and a tip. Do it again and you get .014″ and it looks like you could squeeze 3 “atoms” into that leftover space which would make that single “atom .0046” in diameter which has to be the largest “atom” I have ever heard of. I did this all by eye so I could be off maybe .002″ or so but not much more. Unless I am missing something here, or misread something (always possible) I do not think that is a single atom at all, more like a group of about 1 million atoms.
I think the light emited by the atom being excited by the laser has the optical effect of making the atom look larger. Kind of like looking at the sun through eclipse glasses versus how big it appears to be without them (don’t look at the sun, though ;-) )
Of course I am not a physicist so I could be waaaay off here.
Mike, neither am I, ha ha. I just remember being taught that you could fit a million atoms onto the point of a pin, that’s how small they are…or something like that. This just appears to be to be an order of magnitude, or more, off. Possibly what you said about the light is true but, if that is the case, then we are not really “seeing” a single atom then. I am sure they know a lot more about it than I do.
Yes. It is to do with the light emitted, and the wavelength of the light. The size is exaggerated.
The reasons for why it looks larger then it actually is is down to many reasons, like the fact that our pixels in our camera aren’t fully isolated from each other, and optical leakage will happen between them.
Secondly, our sensor isn’t likely lined up as to make sure the light will be centered on a single pixel either, meaning it can likely be off to one side of a pixel, giving even more reasons for pixel level leakage.
And even a slightly imperfect lens or lens assembly will distort the image a bit as well, and a slight bit of diffusion is not really something one can take away from an optical system, even if this is very, very tiny for any good lens.
Not to mention that if we are just slightly off focus, then what would have been a point of light will now be a field.
Or the fact that the image linked to by Hackaday is using Jpeg compression, and will therefor lose some of its sharpness for an image like this at least.
Their exposure time is also 30 seconds, and I really doubt that single atom is stationary. And the camera is not absolutely vibration free, either. I am sure they have a lot of equipment causing vibrations in that lab. Not to mention the building in general.
Shall we take it that you’ve no problem with the nine calcium atoms? The laser(s) keep the atom pretty still.
Why leads you to believe an atom cannot be stationary. Also what leads you to believe a camera cannot be stabilized despite vibrations? The bayer would resolve as well as it would a star in the sky
Don’t forget the Bayer mask. So even if it only excited a single pixel it probably showed up in something like 5-9 pixels of the image.
Has to do with the diffraction limit of the lens. A brief overview from a systems perspective: https://youtu.be/w1Z2FX8rQc0?t=44m48s
According to the linked article, it’s also inside a vacuum chamber, which means we’re looking at it through a glass enclosure so there may be some effect from passing through the glass.
Come on. Can we take pictures of single stars? Yes. And for the same reason.
This is exactly the truth! People not taking into account all the facts, and making rash decisions based on a few grossly incomplete bullet point assumptions is why we have flat earthers and moon hoaxers. People nitpicking details that they “think” are common sense, but are merely incomplete portions of a larger picture that they don’t have a complete grasp of… Ugh…
The apparent size is only related to camera resolution and the fluctuation of the photons trajectories. What the camera register is may photons reemitted by the atom. Otherway said the spot on the camera sensor is not related to the atom size, it is hugely wider. The point here is that the source of all these photons come from a single atom.
should read ‘many photons’ instead of ‘may photons’.
I was a bit confused at first too, however the claim isn’t that ‘this is a representation of the atoms mass’ instead it’s a representation of the detectable light given off by the atom.
“The atom absorbs and reemits[sic] the light, and a camera can pick up the light, creating a one-of-a-kind photograph.”
It’s similar to other light sources. Imagine for a moment an LED, if we took a picture of it in a well lit room while powered off we would have a relatively accurate representation of it’s scale. However, if we placed it in a dark room and turned it on and then took a picture, we’d have a much larger representation.
In short, this picture is analogous to a lit LED with the lights off. Still, an impressive capture.
To be fair, every photo is a representation of the detectable light given off by the subject.
Get enough light out of a point source and it starts to affect adjacent spots in the film. The trick here is that he’s managed to make the atom sufficiently bright and the rest of the aparatus sufficiently dark that the atom shows up on the film as if it is larger than it really is.
Or think of this another way: You would not be able to get an estimate of the atom’s size from the photograph any more than you can measure the diameter of a star from a typical photograph of the night sky; you’d end up with a diameter of the star several orders of magnitude too large.
(Not knowing much about the physics going on here) I’d imagine that the amount of light being emitted from the atom is quite small so to capture it, a longer exposure was probably used. The atom probably wasn’t sitting perfectly still either, moving around within the electromagnetic field. This would result in the point of light appearing larger in the image.
You aren’t seeing the atom…
The atom is about 0.225 nanometers, the camera and your eye both stop detecting visible light when it drops below a wavelength of ~400nm… there is no way to light an atom for photography because the light can’t bounce off it cleanly, it can’t even hit it consistently.
In order for the atom to emit visible light it’s vibrating at a frequency consistent with visible light…
You aren’t seeing the atom, you are seeing a blur of vibrating atom shooting off photos in every direction… (though you only see the photons coming towards the camera I suppose.)
Isn’t that what “seeing” means? Picking up reflected light off off an object. Whatever light bounces of an atom can be considered “seeing” it, or at least partially, if anything else.
Light spreads out as it travels.
Of course the atom is not actually that large. Not even within a few orders of magnitude. It’s the lens flare from the photons it is emitting which we can see. But in this way it can still be though of as an image of a single atom.
My grandson is nine, and he sees the unseen.
Actually the light is from the electron shells of the atom interacting with the ones in the imaging substrate, the rest of the atom, most of its mass, is not visible. Even then the “lit up” pixels are just the boundary of where many interactions occurred and not an image of anything as there is no structural information recorded, it is just a single gaussian blob.
“it is just a single gaussian blob.”
I couldn’t sum it up better myself.
There’s nothing else I can say to convey my impression of this photo.
It should read, “0.001 Kelvin” – There are no “degrees” for the Kelvin scale.
What’s a degree Kelvin?
The term degree is used in several scales of temperature. The symbol ° is usually used, followed by the initial letter of the unit, for example “°C” for degree(s) Celsius. A degree can be defined as a set change in temperature measured against a given scale, for example, one degree Celsius is one hundredth of the temperature change between the point at which water starts to change state from solid to liquid state and the point at which it starts to change from its gaseous state to liquid.
Academic degree, an academic rank, title or award, including: Foundation degree. Associate’s degree. Bachelor’s degree. Master’s degree
is a measurement of a plane angle, defined so that a full rotation is 360 degrees.
a measure of damage to tissue caused by injury or disease — see first-degree burn, second-degree burn, third-degree burn.
AND MY NAME’S NOT KELVIN! sheesh…
I think psmay were rather trying to point out that the unit Kelvin isn’t measured in degrees.
There is some actual reason behind this, probably has to do with the fact that Kelvin is the absolute temperature.
But I personally do not know why it isn’t “degrees Kelvin”, but I know that it is formally incorrect.
It isn’t _now_ – by convention.
From Wikipedia: “In 1967/1968 Resolution 3 of the 13th CGPM renamed the unit increment of thermodynamic temperature “kelvin”, symbol K, replacing “degree Kelvin”, symbol °K”.
This means there are still many people active that may insert “degree” accidentally as that is what they learned when studying.
The one Pixel Holodeck
And nothing related to camera (esp mirror camera?) vibrations? Impressive
“about 2 millimeters apart.”
Should be “about 2 degrees millimeter apart.”
Didn’t see anyone else mention it, but there’s also an antialiasing filter over every stock canon dslr camera sensor. The AA filter (also known as a ‘Blur Filter’ is designed to spread the photons across an area roughly 4 times larger. The effect is Gausian. If such a filter where not used, the effect would either be: A: invisible; or B: only one color due to the Bayer Pattern of the sensor.
What was shown is light-painting done by a single atom.
Photograph of a blue-violet laser light reemited by a Single strontium Atom, Captured with a Plain Old Camera
Kind of ironic that the atom takes up at least 16 pixels in the image (which are displayed on an LCD screen where each pixel is made up of many many more atoms). XD
I never have trusted atoms.
They make up everything.
Gee. If only I had…
First person to replicate this in their workshop gets a cookie.
By the way, the starting pitching for Arizona had a combined 8.
There’s only a few games left until another season is wasted.
Related: Astros’ pitching prospects, David Paulino and Francis Martes play in Fall Stars GameT.
Where Portland hung around in the first, the action was all Wolfhounds in the second.
ordie Howe Hat Trick – March 27, 2018The Red Wings’ Fighting Legacy – March 26, 2018Red Wings Should Make The Most Of Their Last Games – March 24, 2018.
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