Giorgio Parisi, a renowned theoretical physicist and professor of quantum theories at Sapienza University in Rome, was born in 1948. His research interests are broad, but he is most known for his work on disordered magnetic states or "spin glasses," which has contributed to the theory of complex systems. Together with Klaus Hasselmann and Syukuro Manabe, Parisi was awarded the Nobel Prize in Physics in 2021 for this work. On July 11, Parisi's first popular science book, In a Flight of Starlings: The Wonder of Complex Systems, will be published, chronicling highlights from his career and advocating for the value of science.
Parisi's interest in physics began at a young age due to his fascination with numbers. He reportedly learned to read numbers at the age of three and would identify the numbers of trams on the street. When it came time to choose a university major, he debated between physics and mathematics but ultimately chose physics because there were more accessible books on the subject compared to the abstract nature of mathematics
What inspired you to write your book?
Initially, my goal was to explain the process of scientific research. With the rise of skepticism towards science, particularly in relation to topics like Covid, vaccinations, and climate change, it's crucial to demonstrate how scientists conduct their work.
Your field of study can be incredibly complex. How did you manage to make it accessible to a wider audience?
It was definitely a challenge. I believe that using metaphors is essential when writing about complex scientific concepts. While some popular science books use formulas to explain these ideas, I wanted to avoid alienating readers who might not be familiar with them. Therefore, I made an effort to describe sophisticated physics problems without relying on formulae.
Your book begins with your study of starling murmurations, which might seem like an unusual topic for a physicist. Why did you choose to explore this subject?
Our goal was to determine if there were specific rules governing the collective movements of starlings. This was related to attempts in physics to understand the behavior of systems composed of many interacting components. In Rome during the winter, we observed starlings flocking above the trees every evening, creating incredible patterns. One of the challenges was understanding the three-dimensional shape of the flock, which couldn't be captured from a single viewpoint. Given the vast amount of data that needed to be analyzed, we believed that physicists were best suited to tackle this problem.
Initially, my goal was to explain the process of scientific research. With the rise of skepticism towards science, particularly in relation to topics like Covid, vaccinations, and climate change, it's crucial to demonstrate how scientists conduct their work.
Your field of study can be incredibly complex. How did you manage to make it accessible to a wider audience?
It was definitely a challenge. I believe that using metaphors is essential when writing about complex scientific concepts. While some popular science books use formulas to explain these ideas, I wanted to avoid alienating readers who might not be familiar with them. Therefore, I made an effort to describe sophisticated physics problems without relying on formulae.
Your book begins with your study of starling murmurations, which might seem like an unusual topic for a physicist. Why did you choose to explore this subject?
Our goal was to determine if there were specific rules governing the collective movements of starlings. This was related to attempts in physics to understand the behavior of systems composed of many interacting components. In Rome during the winter, we observed starlings flocking above the trees every evening, creating incredible patterns. One of the challenges was understanding the three-dimensional shape of the flock, which couldn't be captured from a single viewpoint. Given the vast amount of data that needed to be analyzed, we believed that physicists were best suited to tackle this problem.
The undertaking of the experiment was immense, requiring a substantial amount of time and effort. To construct a 3D image, we positioned two cameras 25 meters apart on the rooftop of Palazzo Massimo in Rome to track each individual bird's movement among the thousands present. Reconstructing the 3D position of every bird was a daunting task, as matching the same bird in two different images proved to be a major challenge.
Our findings revealed that when a flock turns, it appears as though they move as one unit, but in reality, some birds initiate the turn, and others follow suit. We were able to determine each bird's acceleration and observe how some birds start to turn or accelerate in one direction, with others following suit. This decision propagated throughout the flock. Additionally, we discovered that flocks are flat like pancakes, not spherical, which allows them to change shape rapidly. The flatter an object, the more noticeable changes in orientation appear.
To our surprise, we also found that the flock was denser at the edges than in the center. This phenomenon is similar to what occurs on crowded buses, where passengers who have just boarded congregate near the doors, along with those who are about to disembark and those who want to continue their journey
Our findings revealed that when a flock turns, it appears as though they move as one unit, but in reality, some birds initiate the turn, and others follow suit. We were able to determine each bird's acceleration and observe how some birds start to turn or accelerate in one direction, with others following suit. This decision propagated throughout the flock. Additionally, we discovered that flocks are flat like pancakes, not spherical, which allows them to change shape rapidly. The flatter an object, the more noticeable changes in orientation appear.
To our surprise, we also found that the flock was denser at the edges than in the center. This phenomenon is similar to what occurs on crowded buses, where passengers who have just boarded congregate near the doors, along with those who are about to disembark and those who want to continue their journey
Your expertise is primarily in the field of spin glasses. Can you explain what spin glasses are?
Spin glasses are a type of material, with the most common being an alloy of gold and a small amount of iron. In physics, "spin" refers to something magnetic, as magnetism is related to the way electrons move and act like small magnets. At high temperatures, spin glasses behave like normal magnetic systems, but when the temperature drops below a certain point, they begin to act like glass in that their magnetic changes slow down and it appears as though the system never reaches equilibrium.
What are some practical applications of your research on spin glasses?
One significant application is in artificial intelligence. The study of neural networks in the 1980s and 90s heavily relied on work done with spin glasses, and neural networks are the foundation of modern AI.
Do you have any concerns about the development of AI?
Yes, I believe regulation is necessary. For example, AI-generated images should be marked in some way so that people can distinguish between real and fake, preventing us from losing touch with reality. At a meeting of academics at the G7 in Paris in 2019, we expressed concerns about weapons systems controlled by AI. We believe that decisions regarding taking human lives should be made by humans, not machines.
Recently, you caused a bit of a stir in Italy with your claim to have discovered a more energy-efficient method for cooking pasta. Can you tell us about that?
Actually, the idea was not mine. I simply saw a post on Facebook and shared it because I found it interesting. I never actually tried it myself. It was amusing to see how much attention it received and how everyone was attributing it to me. However, it might work, although I don't anticipate a significant difference from more conventional methods. A blind experiment would need to be conducted to test its effectiveness
Spin glasses are a type of material, with the most common being an alloy of gold and a small amount of iron. In physics, "spin" refers to something magnetic, as magnetism is related to the way electrons move and act like small magnets. At high temperatures, spin glasses behave like normal magnetic systems, but when the temperature drops below a certain point, they begin to act like glass in that their magnetic changes slow down and it appears as though the system never reaches equilibrium.
What are some practical applications of your research on spin glasses?
One significant application is in artificial intelligence. The study of neural networks in the 1980s and 90s heavily relied on work done with spin glasses, and neural networks are the foundation of modern AI.
Do you have any concerns about the development of AI?
Yes, I believe regulation is necessary. For example, AI-generated images should be marked in some way so that people can distinguish between real and fake, preventing us from losing touch with reality. At a meeting of academics at the G7 in Paris in 2019, we expressed concerns about weapons systems controlled by AI. We believe that decisions regarding taking human lives should be made by humans, not machines.
Recently, you caused a bit of a stir in Italy with your claim to have discovered a more energy-efficient method for cooking pasta. Can you tell us about that?
Actually, the idea was not mine. I simply saw a post on Facebook and shared it because I found it interesting. I never actually tried it myself. It was amusing to see how much attention it received and how everyone was attributing it to me. However, it might work, although I don't anticipate a significant difference from more conventional methods. A blind experiment would need to be conducted to test its effectiveness
How did winning the Nobel prize make you feel?
I felt very happy, but I didn't have much time to dwell on it. I was busy with my work at the university and running the Accademia dei Lincei. The day after, I had to do 20 interviews over Zoom. It took some time to sink in.
Has winning the Nobel prize had any impact on your life or work?
Yes, it has. In Italy, there are only a few Nobel laureates, and all of them live outside of Italy except for me. As a result, if anyone needs a comment from a Nobel laureate, they come to me.
I felt very happy, but I didn't have much time to dwell on it. I was busy with my work at the university and running the Accademia dei Lincei. The day after, I had to do 20 interviews over Zoom. It took some time to sink in.
Has winning the Nobel prize had any impact on your life or work?
Yes, it has. In Italy, there are only a few Nobel laureates, and all of them live outside of Italy except for me. As a result, if anyone needs a comment from a Nobel laureate, they come to me.
