While the purpose of the picture was to show how many atoms it would take to produce a shadow, the team was also able to hold the atom long enough in one place to take the picture and capture its shadow using a specific frequency of light as well as a super high-resolution microscope.
Dave Kielpinski, who led the research project at Griffith University's Centre for Quantum Dynamics in Brisbane, Australia, said that they trapped a ytterbium atom in a chamber and held it with electrical forces. Then they exposed it to light and aimed its shadow onto a detector. Key to the picture was the light frequency.
"If we change the frequency of the light we shine on the atom by just one part in a billion, the image can no longer be seen," Kielpinski said. "Because we are able to predict how dark a single atom should be, as in how much light it should absorb in forming a shadow, we can measure if the microscope is achieving the maximum contrast allowed by physics."
As a result of the research, scientists say it is now possible to predict "how much light is needed to observe processes within cells, under optimum microscopy conditions, without crossing the threshold and destroying them." Microbiologists in particular may benefit from the findings as they will be able to take a much closer look at tiny structures, such as DNA strands, without exposing them to light that could harm them.
It was quite cool looking.
I say that this time they've done an awesome job, not just science for the sake of it.