So you’re into sci fi? But what about sci fact? Sometimes fact is stranger than fiction…
Each month our very own Voyager Science Queen* will bring you interesting, quirky and downright bizarre tasty morsels from the world of science. And its all completely, totally, 100% true!
As excited as I was by the discovery of the Higgs Boson Particle, I have discovered that this historic event did the scientific community in Queensland no favours. The day before the announcement, there was another science news story causing waves in the world of Physics. Scientists at Griffith University in Queensland had taken a photo of the shadow of an atom. I was lucky and got to meet with two of them: Professor Dave Kielpinski & Ben Norton, a PhD student.
Now, you might think that this doesn’t sound like the most exciting achievement – after all, we’ve all seen those amazing pictures taken by electron microscopes. But electron microscopes are old hat and old technology (heck, I was taking photos of the nematocysts of peanut worms using one back in the 1980s). Taking the photo of a shadow of an atom is a whole new quantum level of technical difficulty – and I’m using the word ‘quantum’ in its correct sense here. Atoms are so tiny and it is hard to manage to isolate just one, let alone managing to photograph it.
Firstly, you have to pick the right atom: Ytterbium (atomic weight 70), because the atom has to be opaque to the frequency of the beam of laser light. The atom has to be big, so it will cast a large enough shadow to register. You have to use a special lens to trap miniscule levels of light – the scientists in Griffith University’s Centre for Quantum Dynamics designed the lens and it was fabricated at the Fraunhofer Institute in Berlin. The atom has to be manageable, in the sense that you can arrange to have a single atom in the beam and not fifty or none. There has to be no vibration, so the atom has to be in a nearly-perfect vacuum so it can’t get ‘knocked’ out of place by other atoms or molecules. You have to slow the atom down with the cold of absolute zero. There are a lot of factors that have to line up perfectly for the photo to happen.
Now, I was lucky enough to see the equipment on the Griffith University Open Day and to meet with some of the team who managed this supremely difficult feat. (And, at this point, I want to mention that one of them, Ben Norton, admitted he had actually READ the Science Page and had heard of me – which thrilled me to no end.) The equipment was as complex, but not dramatically so. There was a screen above it that actually showed the photo of the atom’s shadow.
Now – some of you may ask ‘Why wasn’t this photo of an actual atom?’ Well, for a start, an atom isn’t a ‘solid’ object as we understand solid. It is more like a vibration, or a cloud, or a spinning particle, and the reality is a combination of all these and so much more. And – as I mentioned – they are tiny beyond our ability to imagine. We tend to think science controls atoms, thanks to CERN and the magic the collider seems to control; this is incorrect. Part of the reason the photo of an atom is such an amazing achievement is because atoms are so hard to control. And our scientists at Griffith University did it without a machine the size of a city and a budget of billions.
Ordinarily, an achievement of this magnitude would have created a buzz that would have lasted for weeks. Only news that they had discovered the Higgs Boson was big enough to push it out of the headlines. As a footnote … I also saw a plasma dot on the same day and in the same laboratory. All-in-all, I had a wonderful day. )