Physics Nobel Prize 2021

Giorgio Parisi and his jumps in several fields

Well, can I add something new or insightful about Giorgio Parisi? No at all! You will find a lot of information and anecdotes about him. So what this post is meant for? Essentially it is a printed version of the seminar I did in my company few days after Giorgio’s award for sharing my emotion for such Nobel prize having myself studied at La Sapienza university in one the research fields Giorgio founded. And my intention was also to let non-physical colleagues find out who Giorgio is.

If we want to summarize in a motto the invaluable work of Giorgio we can state “Giorgio was able to let emerging order out of disorder!”

As humans we constantly try to discover in the Nature repeating patterns, symmetries, order … and in the same way we created our Society, our Art, our Literature to reveal as much as possible a sense of order. Symmetry is a guiding principle and when it is broken, we try to recover it at a higher level. Giorgio made a further step studying complex systems where apparently there is not any kind of order, but he found the proper way to make it visible!

The Nobel prize to Giorgio is also a great recognition of an incredible italian school of physics. I tried to sketch a graph connecting all italians who were awarded with such a prize (only Marconi is missing). It is not a perfect and exaustive picture but it serves just to show how important is having great teachers and in general an incredible school. I put also some broken medals for highligthing people that should have been received the Nobel prize but for questionable reasons they did not get.

If I would find a common trait among all such people I would say that the curiosity and the joy of discovering pushed forward all of them. As Giorgio pointed in a lecture he did some days after the Nobel Prize

If you are interested in looking for further information about the research areas where Giorgio contributed the most, here it is my personal and absolutely incomplete selection:

I would report now an extract of what the Nobel Committee wrote in relationship with such Nobel prize:

Clearly this year’s Laureates have made groundbreaking contributions to our understanding of complex physical systems in their broadest sense, from the microscopic to the global. They show that without a proper accounting of disorder, noise and variability, determinism is just an illusion. Indeed, the work recognized here reflects in part the comment ascribed to Richard Feynman (Nobel Laureate 1965), that he “Believed in the primacy of doubt, not as a blemish on our ability to know, but as the essence of knowing.”. Recognizing the work of this troika reflects the importance of understanding that no single prediction of anything can be taken as inviolable truth, and that without soberly probing the origins of variability we cannot understand the behavior of any system. Therefore, only after having considered these origins do we understand that global warming is real and attributable to our own activities, that a vast array of the phenomena we observe in nature emerge from an underlying disorder, and that embracing the noise and uncertainty is an essential step on the road towards predictability.

And finally a couple of video at the time of my postdoc research in the field of animal behavior in the CoBBS group under the supervision of Andrea Cavagna, who continued the initial work of Giorgio in studying quantitatively flocks.

And the group at the time of such videos inside “Big Red”