The enormity of the small

On a clear night, perhaps in a rural area away from city lights, a simple glance to the sky often brings people a great sense of awe at the enormity of the universe.  Hundreds, or even thousands of stars are visible to the naked eye on a clear night. Despite its complexity, the immediate beauty of the night sky is a joy that we can all experience, no matter our level of access to specialized equipment and knowledge.

It’s likely that most people would spend less time pondering the beauty of the nanoscale world. But just like the night sky, it’s incredibly beautiful and infinitely complex, and worthy of careful contemplation. This is reasonably difficult for the average person, since we can’t see individual atoms or molecules interacting with the naked eye.

Despite the theorization of the atom c. 2500 years ago, it hasn’t been until very recently that we’ve been able to see and study individual atoms or molecules. As recently as 1952, Schrodinger famously said “We never experiment with just one atom or (small) molecule. In thought-experiments we sometimes assume that we do; this invariably entails ridiculous consequences…”. Yet many of these thought experiments which were considered impossible to achieve experimentally have now been realized with the advent of powerful nanoscale techniques and technologies.

One such technique is single molecule spectroscopy, which provides detailed insight into nanoscale phenomena. In studying one molecule at a time, the highest level of sensitivity can be achieved, providing a window into the heterogeneity of complex systems. Studying an ensemble solution of molecules would instead mask this information, making it inaccessible through ensemble averaging.

Through considering only one molecule at a time, its individual behaviour can reveal information about its unique properties and environment. This technique also allows scientists to see below the diffraction limit of light, since molecules separated by as few as 10 nm can now be optically resolved. 

What was once thought impossible is now a key technique employed by scientists across many disciplines, ranging from physics to medicine. The development of this technique opened up so many possibilities for studying nanoscale processes that the Nobel Prize in Chemistry in 2014 was awarded to the pioneering minds behind its conception.   

So, I would like to suggest that the sky is not the limit – rather, the world of scientific knowledge is a beautiful fractal with an endless number of complexities to explore. Groundbreaking research is constantly pushing the horizon of what we consider possible; leading us to new techniques, new ideas, and new questions to explore. It’s rather exciting to imagine how much more we will learn about the nanoscale in years to come.