Ricard Solé: "There is no machine or AI capable of time travel like humans do."

With an insatiable curiosity, Ricard Solé (Barcelona, ​​1962) devoured every secondhand book that arrived at the family library. Those readings further spurred his imagination, and questions piled up in his mind. Perhaps that's why the questions he now tries to answer move between disciplines, between science and the humanities, between physics and neuroscience, chemistry and philosophy, and science fiction.

A physicist and biologist, and also a professor at the unique and legendary Santa Fe Institute in New Mexico (USA), this ICREA researcher From Pompeu Fabra University in Barcelona, ​​he also currently heads the Laboratory of Complex Systems within the Institute of Evolutionary Biology (IBE UPF-CSIC). In his work, he seeks to understand the origins and evolution of complexity, and of natural and artificial systems, including possible cognitions and what he calls 'liquid brains'.

He is currently preparing a book about fantastic beings that could have existed, which he draws and attempts to scientifically argue why, ultimately, they do not. Author of numerous books, he has curated several exhibitions. The latest: "The Invention of Time", which can be visited at the Martorell Exhibition Centre, linked to the Natural Science Museum of Barcelona.

Where did the idea of ​​dedicating an exhibition to time come from?

— For years I had been preparing a book about prediction, about how humans try to figure out how to make predictions about the world, and I was reading the book The invention of the futurewhich talks about mental time travel. And it fascinated me. Then, in Carlos Lalueza-Fox The director of the Museum of Natural Sciences proposed that I curate an exhibition on human diversity. And I replied with another proposal: the invention of time. "Wow, do you want to be the curator of this exhibition?" he asked me immediately. And here we are.

Time is a complex subject.

— My entire scientific career revolves around complexity. I try to understand its origins and evolution, and one of the aspects I'm currently immersed in is cognitive spaces: how cognition emerges in evolution, how it diversifies, and how different kinds of cognition arise. Because systems must necessarily have the concept of time incorporated.

As?

— With memory. The ability to recall the past and the ability to understand the future. Understanding it sheds light on evolution. For example, something curious is that memory doesn't work perfectly, and we can have false memories. Obviously, it's incredibly powerful, but it's not entirely reliable. And this is due to natural selection. For our survival, what's essential is creating futures, not so much whether we can accurately remember the past.

Biology incorporates time.

— The first cells to appear on the planet do this. And it makes perfect sense. A bacterium that needs to replicate rapidly must be efficient. And the only trick is to anticipate what will happen through an internal clock, the circadian rhythm, which tells it whether the sun is rising or if it's nighttime. With the Cambrian explosion of life forms, between 540 and 530 million years ago, the first predators with eyes appear: they must navigate an uncertain environment and are equipped with sensory organs. And all of this must be integrated, synchronized. How? With a brain. A brutal revolution begins: memory, learning, anticipation, and planning emerge. It's the start of a change in the biosphere.

And when does the awareness of time begin?

— Although we are probably the only ones in the animal kingdom who know we have a finite existence, inferring its beginning is not easy. However, even though there are no fossils of language or the mind, we do have cave paintings, for example. Whoever painted the scenes at Altamira didn't do so to communicate with people who were there; rather, those drawings are a message for the future.

Weren't they tools for telling each other stories?

— Yes, stories are useful for connecting with those around you, but these paintings transcend that. They are permanent. Humans are a unique species, and within that uniqueness, we find elements that can be found in small doses in other species, such as complex language and the ability to identify the emotions of others. In a cooperative group like ours, knowing how to put yourself in someone else's shoes and mind is a very powerful factor. Furthermore, we are capable of mentally traveling through time, something no machine can do. Not even AI.

What does it mean?

— We don't just remember the past; our memory systems are incredibly complex, and we can even imagine futures. We can project ourselves ten years into the future and project others onto it, not just into a single scenario, but into infinite possibilities. When you invite friends over for dinner and think about what to cook, whether someone will like it, or if someone else will make a joke, you're making assumptions about things that haven't happened yet, things that belong to the future. This ability to imagine multiple scenarios is truly extraordinary—a super time machine that actually exists!

Is the ability to mentally understand the past and the future an innate or learned skill?

— Children eventually begin to understand that there is a past and a future. It's a process of development. And, in fact, in some neurodegenerative diseases like Alzheimer's, time is lost at a certain point, and patients become unable to plan because they don't understand that a future exists. Interestingly, studies using functional magnetic resonance imaging show that when we voluntarily think about something we did two days ago, three specific areas of the brain light up—the same areas that light up when we try to think about what we will do tomorrow or the day after. Memory is the culture that allows us to build the future.

It is surprising how humans have an internal clock that, in a fairly universal way, allows us to know if 20, 5 or 30 minutes have passed.

— We are beginning to discover that some neurons are capable of maintaining an internal time counter. Diseases and injuries provide clues. For example, videos of Parkinson's patients taken by the American neuroscientist Oliver Sacks showed how some moved extremely slowly, but when the images were played back at increased speed, the patients moved normally, albeit on a different timescale.

When did humans begin to want to measure and control time?

— With agriculture, we rediscover something nature invented: that a seed is a plant of the future. Science communicator Ann Druyan says that from that moment on, humans began to experience the future. Agriculture is an incredible revolution that also means that, from that moment on, being efficient and productive in our tasks is linked to the cycles of day and night, to the seasons. We must understand them well in order to anticipate them. And this led to the emergence of the first astronomical calendars.

It's curious how some cultures understand time in a linear way, and others, on the contrary, in a circular way, like the aliens in the movie Arrival, by Denis Villeneuve (2016).

— There are also those who don't have time, like culture. Pirahã In the Amazon, as the American linguist Daniel Everett discovered, this tribe lacks a language for numbers or time. In fact, they don't need one, because they live in an environment of unlimited resources. They go fishing, knowing they will catch fish because the river has fish, and if they catch a lot, they eat them all; they never store any. They don't need to anticipate a future where they might not have one.

When did science begin to study time?

— Saint Augustine is always cited, but the truth is that philosophers long before him were already pondering the concept of time, whether it exists or is our own invention. Scientifically, in physics right now there's a debate about whether time is real, whether it exists, whether it has multiple dimensions. We are in a moment of transition.

Einstein turned everything we thought we knew about time upside down with the theories of relativity.

— Time and space. Even Einstein thought that time was linear and that a clock on Earth and another in Andromeda would be synchronized and show the same time. Through thought experiments he began as a teenager, Einstein himself eventually realized—and this is very counterintuitive—that if you have a moving object, the passage of time is different for that object. And this idea overturns the previously established principle of simultaneity. Now time depends on the observer, and this has incredible consequences, such as how matter and energy warp spacetime.