In school we’re taught that atoms look like this:
But the diagram is about as different to an actual atom as a kid’s drawing of a bus is to an actual bus.
It gets the point across but it’s point has never been to be accurate.
The most colourful description of the world of the atoms that I’ve ever read comes from Stephen King:
“The pencil point is not solid; it is composed of atoms which whirl and revolve like a trillion demon planets. What seems solid to us is actually only a loose net held together by gravitation. Shrunk to the correct size, the distances between these atoms might become leagues, gulfs, aeons.” Stephen King, The Dark Tower
For a long time, almost a century, diagrams and imagination was as close as we could get to seeing this universe of ‘demon planets’. It was thought that no microscope would ever be able to see an atom directly, as the resolution it would need was beyond the limit of what light could reflect.
That was, until scientists Gerd Binnig and Heinrich Rohrer made a breakthrough. They invented a new type of telescope using electrons instead of light, allowing people to see individual atoms for the first time. For their ‘scanning tunnelling microscope’ they won the Nobel Prize. Below is the surface of a thin sheet of gold from one of their microscopes, and every tiny hexagon is an individual atom.
Wikipedia, Atomic resolution AU100
In the 30 years since, we’ve managed to capture surface atoms on video. This is a real-time look at a thin layer of graphene, showing individual atoms dancing around a puncture hole.
In 2013, scientists at UC Berkley took the idea even further. They used the same electron tunneling technique to watch a molecule undergo a chemical change.
In this picture, each corner of the hexagons is an atom, and the lines between them are the chemical bonds holding the molecule together.
But as we get closer and closer to seeing individual atoms, a strange thing starts to happen. Rather than coming more into focus, the honeycomb structure starts to blur. The shape of the atom becomes less defined, and the strange rules of Quantum Mechanics begin to take over.
The atom below is a hydrogen atom, with the red area being its nucleus, and the light blue area is its electron cloud.
At this level, strange patterns in the electron cloud become prominent – and they are shaped not like individual particles like in the diagram, but as a series of buzzing clouds shaped into strange mathematical designs called ‘orbital shapes’. Below is a hydrogen atom showing off a bunch of different orbital shapes.
Wikipedia, Hydrogen Density Plots
For our microscopes this is the end of the line, for now.