In addition to having a large electron cloud, an unusual feature of a Rydberg atom is that its highly excited electron can exist as a coherent superposition of several different atomic orbitals. These orbitals interfere with each other, which means that the electron cloud changes shape with time. These fluctuations are much slower than the movement of electrons nearer the atomic nucleus, which is why Kirrander and Suominen argue that the fluctuations could be tracked by firing intense and coherent pulses of X-rays at the atoms.When I said not to miss looking at the trees, most people reading the article will be enamored by the proposal that we can actually view such a thing in real time, that we can see the evolution of such an atom, and the potential that we can view the dynamics of a lot more system having such short time-scale. These are the "forest".
Such pulses can be produced at accelerator-based free-electron lasers such as the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory in California or the X-ray Free Electron Laser (XFEL), which is set to come online at DESY in Hamburg, Germany in 2016. Kirrander and Suominen have also calculated that the motion of the corresponding "electron hole" in the atom – the superposition of inner orbitals that the electron has left behind – can be visualized as well. As the inner electrons are involved in chemical reactions, the new technique could therefore be a powerful tool for chemists.
The trees here, which *I* am more interested in, and what most people will have missed, is the advancement made in accelerator physics that allows the ability to make such a measurement. The instrument being used is within the realm of accelerator physics, and specifically, the study of beam physics and engineering. This field of physics is often the unsung hero that enables the advancement in many other fields of physics. Think of what the LHC and the Tevatron could do without advanced knowledge of accelerator physics.
And this brings us to a very important point here. Many areas of science can only advance in knowledge when they have the ability to perform the experiments that they want. Inevitably, this means that that they have the equipment and tools to be able to do these experiments. This ranges from high-spatial-resolution instrument to high-temporal resolution detectors. In other words, they depend on others to provide them with the instruments to advance their knowledge.
It also means that if you kill research in these grass-roots areas, you are killing more than just one area. When a lion killed the nursing mother of deer, for example, that lion took not one, but two lives with that kill. When funding for many of these areas of physics is severely reduced, the chain reaction and impact can trickle very quickly down stream. It affects the advancements in many other fields that would have gotten the benefit from it. Think of how many different usage of facilities such as a synchrotron light source or a free-electron laser.
So when you read an article such as this, don't miss paying attention to the fact that these proposed abilities to do such-and-such are benefiting from the advancement and investment in another field that you might have not realized. The interconnectedness of science is never more apparent than in an example such as this.