This year, the Physics Nobel Prize 2021 goes to Giorgio Parisi, the sixth Italian scientist to win one of these awards, which he shares with Syukuro Manabe and Klaus Hasselmann. The winner will receive $10 million, as half will go to Manabe, Hasselmann, and the other half to Parisi.
Last year, the prize went to American Andrea Ghez, British Roger Penrose and German Reinhard Genzel for their research on black holes.
They applied their study to:
Neuroscience, biology, and machine learning are just a few of the many applications of the study of complex physical systems. The Nobel Committee for Physics emphasized one complex system in particular in its press release accompanying the announcement: the Earth’s climate.
Thors Hans Hansson, Chair of the Committee, stated, “These discoveries demonstrate that our understanding of climate is founded on rigorous analysis of observations, and has a solid scientific foundation.”
Complex systems can be characterized by randomness and disorder, but this year’s prize rewarded new methods for describing and predicting long-term behaviour.
They laid the foundations for understanding the Earth system and how we interact with it. This has never been more important than today in addressing the challenges of our changing climate and moving toward a new green economy.
What Parisi has contributed and his background:
As for Parisi, he is an eclectic physicist from Sapienza Università di Roma and current vice-president of Accademia dei Lincei.
His research work has covered fundamental particles, condensed matter, statistical physics and disordered materials; the Nobel committee has highlighted his contributions to “the discovery of the interplay of disorder and fluctuations in physical systems from atomic to planetary scales”.Â
A pioneering study he conducted involved identifying patterns hidden within disordered complex materials, known as spin glasses. It provided a better understanding and description of various materials and phenomena that appeared random to the naked eye.
When asked about the timing of the award, Parisi responded, “We are in a situation where we can have positive feedback that may accelerate the rise in temperature.” We need to start taking action now, especially for future generations.
Meteorologist Manabe: his contributions
As CO2 levels in the atmosphere rise, temperatures on the Earth’s surface may also rise, a Princeton University meteorologist demonstrated. By harnessing early computers’ calculating power, Manabe was able to predict climates.
When he made his climate circulation model in the late 1960s, he used a computer that occupied an entire room with only half a megabyte of memory. A model of the impact of carbon dioxide on global temperatures showed that, after hundreds of hours of testing, the amount of carbon dioxide could double without affecting global temperature by more than 2°C. In the 1960s, he also developed physical models of the Earth’s climate, which laid the foundation for the current climate models.
“Haasselmann: bridging the Parisi-Manabe gap.”
Around ten years later, Professor Hasselmann at the Max Planck Institute for Meteorology in Hamburg, Germany, answered why climate models are sometimes accurate despite weather changes and chaos. Hasselmann’s model linked weather and climate together to answer this question.
Moreover, he developed methods to identify specific signals that natural phenomena and human activities leave in the climate, showing that human carbon dioxide emissions increase atmospheric temperatures.
Nobel committee chair Thors Hans Hansson said, “Even though the prize divided into two parts, there is a common theme of how disorder and fluctuations come together. We know a lot about climate because we have a rigorous analysis of observational data that underlies this year’s discoveries. All the laureates of this year’s Nobel Prize have given us more profound insights into complex physical systems.”
