Reacción a "Reactions: Nobel Prize in Physics to Agostini, Krausz and L'Huillier for developing light pulses to study the motion of electrons in matter"

People always think that the shortest time is the time from when the traffic lights turn green to when the car behind you beeps. Not so! This year's Nobel Prize has been awarded to three scientists who have pioneered lasers with the shortest pulses, the attoseconds. 

These pulses can now be obtained in a variety of ways, but all three pioneered them by generating harmonics. Starting from an infrared laser, they obtained multiples of its frequency (what we call harmonics). The three laureates have pioneered these techniques in order to obtain from a series of harmonics with well-controlled phases a pulse of very short duration, breaking the barrier of a few femtoseconds and going down to the next scale, the attosecond. 

The development of femtosecond lasers was key to the study of chemical reactions, which led to the Nobel Prize in Chemistry being awarded to Ahmed Zewail for the invention of femtochemistry.  

Now, these three laureates have taken it a step further. At the attosecond scale, ions have no time to move because of their mass. However, electrons, which are much lighter, move precisely on this time scale. Thinking of an atom as a planetary system (with the caveats imposed by quantum physics) the electron orbits on this time scale, hence its interest. 

In Europe, there are two major facilities dedicated to attoseconds. One is ELI-ALPS in Szeged, Hungary, based on the techniques developed by these three pioneers. The other is Eu-XFEL in Hamburg, Germany, where they have developed an alternative technique based on electrons accelerated to enormous energy. Both are ESFRI facilities. 

Attoseconds are now a reality, I would not say an everyday reality, but one that is accessible to the scientific community, and this has been made possible by the three laureates and their pioneering work.