First-Ever Images of an Electron In Orbit

It was only two years ago that IBM showed us an image of a complete molecule, atomic bonds and all, but today's news does that one infinitesimally-sized breakthrough better. Ladies and gents, behold the first image of an electron's path.

On August 30 2011 06:49 Nycaloth wrote:
ok.... i see there is some explaining to do here. just as a bit of a reference, i work as a PhD student for one of the people who helped obtain the results referenced in this http://gizmodo.com/5346964/ibm-takes-first-3d-image-of-atomic-bonds] article, which is also linked in the gizmodo article in the first post and work in the field of molecular microscopy.

There are some misconceptions and presented so far and id like to rectify that a bit and give a very general explanation on what we see and what it means.

The pictures we see are taken by very advanced microcopes, the techniques used are scanning tunneling mocroscopy (STM) and atomic force microscopy (AFM). though called that, they are not microscopes in the "traditional" sense and do not use light and lenses to peek into the very small. instead, both work by scanning a surface with a very narrow metal tip and recording certain surface properties at different points. these measurements can be combined into pictures of the surface, single measurements being the pixels combining the picture. Through the use of piezo crystals and sofisticated dampening of the tip-sample system as a whole, the motion of the tip can be controlled very precisely, on scales smaller the the diameter of an atom. understanding of both techniques requires a basic familiarity with quantum mechanics, but the wikipedia articles on the subject should be enough to explain how exactly they work.

Since we are doing quantum mechanics (QM), one has to be exceedingly careful when using terms such as "position", "velocity" or "path", since they cannot usually be defined in a meaningful way any more. i cant read the full article referenced in the OP at the moment since im not at the university and dont have access to it, but what we see in the pictures are molecular orbitals. what QM can only predict possibilities and other statistical quantities. orbitals are such a quantity, they represent the possibility to find an electron within a certain volume of space. this quantity can be computed numerically for complex systems such as molecules and these days can be measured by STM. due to electronic properties, namely the pauli exclusion principle, only two electrons can fit into one of these orbitals at a time. they are filled up until all the electrons in the molecule are used up. Thus, wer get the highest occupied molecular orbital, the HOMO, and the lowest unoccupied moelcular orbital, or LUMO. these two are usually involved when the molecule exchanges charge with its surroundings, eg during the formation of chemical bonds, which makes them interesting for study.

what can we learn from this? well, by studying the electronic properties of molecules, we can learn something about their behaviour! and since the STM and AFM also allow us to manipulate single atoms and molecules, we can start building things on this scale. our hope is that by understanding molecular interaction on this small scale, we will be able to build circuitry, memory or other useful things from molecular building blocks. a few advances have already been made in this area, as researchers have found molecules that can act as switches or rectifiers or have other potentially useful properties.

ill be happy to try and answer any questions on the topic!