“I’ve been trying unsuccessfully to understand the essence of what binds the universe together,” says Faust, the character who just over forty years ago triggered the imagination of Gerardo Herrera Corral (who was then a young teenager), who used to devour Goethe somewhere in Delicias, Chihuahua. “This first statement, when the tragedy begins, is the question asked by particle physics, which I’ve dedicated my entire life to,” says this graduate in engineering physics from the Instituto Tecnológico y Estudios Superiores de Monterrey (Monterrey Institute of Technology and Higher Education) via Zoom.
It’s the same essential question that took Herrera, who is also the author of Universo: la historia más grande jamás contada (Universe: The Greatest Story Ever Told), on a journey in search of answers through the Fermi National Accelerator Laboratory in the United States; the Brazilian Center for Physics Research; and the ARGUS experiment at the German Electron Synchrotron. However, the place where he would finally find fertile ground for his mathematical thinking was the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN), known as the biggest laboratory in the world due to its gigantic 27-kilometer underground ring crossing the border between Switzerland and France, which serves as a track for particles to collide and offer clues on the essential behavior of matter.
There, Gerardo Herrera was established as the leader of the team of Mexican scientists entrenched for more than two decades in the ALICE project, one of the LHS’s four large detectors (the other three are: ATLAS, CMS, and LHCb), for which technological and scientific contributions have been made from the design and construction of complex devices to the gathering, analysis, and interpretation of data published in more than 400 specialized publications. “This is the first time a group of Mexicans has constructed a detector, installed it, and run it for operations and data gathering. (…) We’re very proud of that. Mexico hadn’t taken part in experiments at that level before,” says Herrera Corral.
E.- Besides research, can you give me a practical example of what a particle accelerator can be used for?
G.- It has to do with the crisis that has us all in lockdown. Think about when HIV/AIDS appeared in 1984. I remember because I was about to start my life when I heard about AIDS. It affected me a lot. Back then, there was something called synchrotron light. That generation took four years to be able to describe the structure of the HIV virus, which is why it took so long to develop the antiretrovirals that are now so common for treatment of HIV.
Now, in December, we realized we had a new virus. By the middle of January, four weeks later, we already had the RNA structure of the virus. Why? Because the Chinese had an electron accelerator that emitted synchrotron light which enabled them to perform a diffraction of the crystallized virus and reconstruct its molecular structure.
E.- Would you say that having a particle accelerator is a matter of national security?
G.- Not only national security. We’d be wrong to give it time to see whether accelerators go out of fashion. Accelerators are here to stay. The new cancer treatments use accelerators. Now they’re using protons to treat cancer, not electrons, like the accelerators we have right now in Mexican hospitals. They’re building proton accelerators for hadrotherapy because protons are hadrons. (…). It’s a much more precise way of treating cancer, without damaging tissues, without invading the healthy tissue, and it allows tumors to be treated with a great deal of delicacy, like a brush painting the outline of a tumor.
Reporter.- You’ve had a long career, Gerardo. What have you learned about what binds the universe together?
Gerardo.- We now think there are four forces. Two of them are very familiar to all of us. There’s no mystery to them. One of them is gravitational force, which makes us fall down, the one that trips us up. (…) The other (which is also familiar) is electromagnetic force. It’s familiar because we’re communicating through electricity, because we know magnets, and because we know the force magnets give and the electrical force they produce.
However, in the final 40 years of the last century, we realized there were two more forces: weak force and strong force. So, we have four fundamental forces in nature that bind us together. However, like Faust, we’re not satisfied. They seem to be only four deceptive manifestations of something which is behind them. (…) We think there’s one single force that binds the universe together and we’re looking for that single force. That’s the big one, the big question.
E.- One of your most active facets has to do with your work as a communicator. How important is communication to science?
G.- It’s hugely important. It’s fundamental. (…) It’s an obligation for those of us who use public resources. We explain to people what we’re doing with their taxes. (…) Another very personal reason is trying to combat the arrogance of academia and academics who distance themselves from people. (…) But the main reason is the one given by Carl Sagan. He said that when you’re in love, you want everyone to know about it. That’s what happens to some of us with science. We’re in love and we go around telling everyone what we know.
E.- Returning to the tragedy of Faust, do you think you’ll live long enough to find the answer you started looking for in Delicias 40 years ago?
G.- (That’s) effectively the great tragedy of us physicists. We spend our whole lives asking ourselves a series of questions that unsettle us, we study and dedicate ourselves to this for a lifetime and at the end… the end comes near, we start getting old, and we realize that it’s going to be difficult to find answers to those questions. The fundamental questions such as whether there are more dimensions than the one we can perceive, whether there are only four dimensions (three spatial and one temporal), whether there’s a fifth or not, what is dark matter? Anyway, all these profound questions are still there. We’ve learned a lot from them, but the end is coming and we realize that the answers aren’t there. (…) I’m beginning to prepare myself for old age and to think about this world that String Theory suggests with a fifth dimension that establishes a fantastic duality which could sketch out at least some idea of what might be answers to those questions, those fundamental questions I’ve asked myself my entire life.
E.- If Mephistopheles were to come as he does in the tragedy of Faust and ask for your soul in exchange for that minute of happiness when he reveals to you what binds the universe together, what would your answer be?
G.- Of course I’d sign, like Faust did, but with that human juice that’s special, as Mephistopheles said, because Faust said no. He said, “Why do you want me to sign? My word is good enough.” No, no, no, no! Let’s sign with that human juice, which is blood. I’d sign in blood.