Of all the big ideas floating around – longtermism, degrowth, space colonization, etc. – is there one more radical than quantum physics?

For a century, physicists have known that the classical assumptions about the universe are incorrect. Electrons do not revolve around the nucleus, but they exist in waves around it. Therefore, an electron can exist in multiple places at once until you observe it. Whether Schrödinger’s cat is alive or dead can only be known by looking, which itself determines the answer. It is unclear why this is true.

This realization is “almost psychedelic,” claims Carlo Rovelli, an Italian physicist who specializes in making complex ideas look simple. Quantum physics has been used to develop semiconductors and lasers. But the first thing we must understand is that we cannot truly understand it.

Roveri tries to explain the problem in his book helgoland, and come to meditate on science and the nature of uncertainty. In an era of climate change and pandemics, his popular physics is still one of his bestsellers. “Melting glaciers are important, but to me the most powerful aspect of science is the fact that it challenges our worldview,” he said during a trip to London from his home in Canada, informally. As Roveri writes, the public is eager to understand the universe. helgoland: “Knowing my girlfriend follows Maxwell’s equations doesn’t help make her happy.”

It helps that Rovelli, citing Buddhist philosophy, put together a letter calling for global disarmament, willing to push outside the boundaries of science. For him, physics affects culture. “Good philosophers have always listened to physics. Kant wouldn’t be Kant without Newton immediately preceding him. Half of what Kant does is to understand Newton. Conversely. For example, Einstein wouldn’t be Einstein without Kant, who read Kant, and Kant’s reflections on space and time were the main ingredients for writing the equations for predicting black holes.”

Rovelli’s current hope is that popular culture absorbs the meaning of quantum physics.movies such as Spider-Man: No Way Home When All at once, anywhere So the solution to Schrödinger’s cat is that cats live and die because an infinite universe exists and covers all possible outcomes. Rovelli himself denies the theory as “crazy”.

How is it possible for physicists to have such different interpretations? “Science is not just about writing equations and making predictions. It is about reconceptualizing the world. What happened to Copernicus?” If you think about it, he understood that the earth revolves around the sun, but can you prove that the earth is not the center of the universe? The point is that changing the conceptual structure makes everything more sensible.” Likewise, black holes were predicted by Einstein’s equations before they were detected.

Rovelli asks us to accept that certainty is often out of reach. Indeed, only once in our conversation does he express certainty. It’s time to ask if we can live in a simulation, as Elon Musk puts it, “most likely.” “No. That’s for sure. We’re not simulations. It’s a silly idea. Who’s the simulator? Some guy?” You’ll be doing a lot, so you can’t be sure you’re not in the simulation.

Uncertainty does not mean that all ideas are equally valid. “You don’t learn anything about reality by making a ridiculous hypothesis and asking how you can disprove it. It’s ridiculous because everything can happen and nothing can be disproved.” “We learn more about reality by taking what we know and seeing what it means.”

Fame came late to Rovelli, who is now 66 years old. He began writing for a wide audience in his fifties.his 2014 book 7 Easy Lessons on Physics was a surprise hit. His course was an anomaly. After a failed spell of hippie activism, he applied to study physics at university, partly because the queue was shorter than other courses. “I came into science out of the disappointment of a dream of changing the world.” But in science as much as in politics, he had long felt outside the mainstream.

Good philosophers have always listened to physics. Kant wouldn’t have been Kant without Newton just before him. Half of what Kant does is understand Newton.Conversely, Einstein wouldn’t have been Einstein without Kant

His particular contribution is to the loop quantum gravity theory, which postulates that space itself is granular rather than continuous, and that particles are interwoven by loops (“The Financial Times took it seriously It is one of the first mediums”). it stays in theory. “Right or wrong, I don’t know. I’m more optimistic than he was a decade ago…Most of our competitors have problems.”

Rovelli likens the process of scientific discovery to zooming into a forest. At first you just look at the forest. And when you get closer, you see trunks, animals and insects. And get even closer. . . you gain layer upon layer upon layer of understanding… we accumulate knowledge. What Newton understood is correct. You can understand better. “

The challenge is not to derive the answer, but to figure out what is wrong with the question. “In order to take the next step, you always have to find something to throw away in your assumptions.” His own process is “very similar to that of a novelist.” Thinking back on the papers that were given, the ideas came to me while I was driving a car, walking in the woods, or doing something completely different.You need to know the subject very well.So you walks around the boundaries of knowledge and keeps saying “this doesn’t work”. And at some point, something clicks while you are thinking about something else. ”

His preferred form of quantum physics is the relational interpretation. This is the view, developed since the 1990s, that all objects influence each other and that an object’s properties are defined only at the moment it is associated with another object. This brings him closer to Buddhism. Where is the difference between physics and philosophy? “The tools of the trade are quite different, but there is a big gray area in between.” . . I understand people in whom God’s thoughts play a role, and they are great scientists.”

For Rovelli, it’s an easy jump from believing that objects are actually interactions to espousing collectivist, left-wing politics. Since his rise to fame, he feels politically responsible again. When we meet, Italy, where he still spends a lot of time, looks poised to choose a far-right coalition. “It is a low country,” he laments. “A country that has decided not to have a voice internationally. They think they are a third world country, which is not true. They think Portugal is more powerful than Italy, which is nonsense.”

Last year, Roveri organized a group of notable scientists and celebrities, including former Beatle member Paul McCartney and experimental psychologist Stephen Pinker, to support the Global Dividend for Peace Initiative banner. Below, I called for diverting military spending to climate change and other causes. A Russian invasion of Ukraine a few months later seemed inconvenient to this end. The idea is to tell the government to negotiate with the enemy and cut military spending on both sides. “

If military spending is a waste of resources, what about space travel? “It’s like asking a soccer fan if building stadiums is a good use of resources! I was 13 years old when man went to the moon, and it was clear that when I grew up, I would have my own spaceship and circle the solar system.”

Roveri’s politics can be frustrating. The day before Russia invaded Ukraine, he tweeted: Hard to say them? The next day he said in unison. Only Americans are entitled to do so on a regular basis! ‘ He defends his stance: ‘The West is making a mistake in the long run by not realizing that we must share power with the rest of the world. .

This misses a lot but reveals something about his discipline. After World War II, many nuclear physicists felt guilty about the atomic bomb their field had created. Instead, Rovelli feels a responsibility to avoid conflict. He resents British Prime Minister Liz Truss’ claims that the United Kingdom will launch nuclear weapons. “We have a new Prime Minister who has publicly stated that he is ready to push the button. It seems so, but there is only a finite amount of time we can think about without worrying about nuclear war.

Additional reporting by Dylan Neri