David Gross wins Breakthrough Prize for strong force discovery
In 1964, a young physicist named David Gross wrote a letter to his mentor. In it, he described a puzzle that had been bothering him for months. The problem was simple to state: why do protons and neutrons stick together inside the nucleus? The answer was anything but simple. Gross was trying to understand the strong nuclear force, the invisible glue that holds the center of every atom together. At the time, no one knew how it worked.
The Mystery of the Missing Force
Think of an atom as a tiny solar system. Electrons orbit the nucleus like planets. The nucleus itself is a cluster of protons and neutrons. But here is the catch: protons are all positively charged. According to basic physics, they should repel each other. They should fly apart. Instead, they stay tightly packed. Something must be holding them together. That something is the strong nuclear force.
For decades, scientists could detect this force. They could measure its effects. But they could not explain its nature. It was like knowing that a magnet works without understanding magnetism. The puzzle grew more frustrating as experiments in the 1960s revealed that protons and neutrons are not fundamental particles. They are made of even smaller pieces called quarks. The question became: what holds the quarks together inside a proton?
The Breakthrough at Princeton
David Gross, working with Frank Wilczek at Princeton University in 1973, found the answer[1]. They discovered a property they called asymptotic freedom. The name sounds complex, but the idea is simple. When quarks are very close together, the force between them becomes weak. They move almost freely. But when you try to pull them apart, the force grows stronger. It is like trying to separate two magnets stuck together — the farther you pull, the harder it gets.
This discovery solved the mystery. It explained why quarks never appear alone. They are always locked inside protons and neutrons. Gross and Wilczek published their work in the journal Physical Review Letters. At the same time, David Politzer at Harvard University independently reached the same conclusion[2]. All three shared the Nobel Prize in Physics in 2004 for their work.
The Prize That Follows
In 2025, the Breakthrough Prize awarded its Special Prize in Fundamental Physics to David Gross[3]. The award recognized his role as a pioneer of the theory of the strong nuclear force. The prize carries a $3 million award. It is one of the largest scientific prizes in the world, founded by tech billionaires including Mark Zuckerberg, Sergey Brin, and Yuri Milner.
The Breakthrough Prize also announced its Life Sciences winners. Jean Bennett, Katherine A. High, and Albert Maguire received the award for developing gene therapy for a form of blindness called Leber congenital amaurosis. Their work restored sight to children who were born nearly blind. Stuart H. Orkin and Swee Lay Thein were honored for their discovery of the genetic mechanism behind fetal hemoglobin. This finding led to new treatments for sickle cell disease and beta-thalassemia. Rosa — the full name is Rosa Bacchetta — was recognized for her work on immune tolerance and therapies for autoimmune diseases.
The Bridges Between Discoveries
There is a thread that connects these prizes. Gross studied the smallest particles in the universe. Bennett and High studied the smallest errors in human DNA. Both groups asked the same question: what holds things together? For Gross, it was quarks inside protons. For Bennett, it was the genetic code that builds a working eye. Both answers required decades of work. Both changed how we see the world.
Other researchers are now building on these foundations. At the CERN laboratory in Switzerland, physicists use the Large Hadron Collider to test the strong nuclear force at extreme energies[4]. At the University of Pennsylvania, gene therapy teams treat inherited diseases by fixing broken DNA[5]. The tools are different. The goal is the same: understand the invisible forces that shape life and matter.
Full Circle
Today, David Gross is 83 years old. He still works at the Kavli Institute for Theoretical Physics in Santa Barbara, California[6]. He still thinks about the strong force. The letter he wrote in 1964 is now a historical document. But the question he asked is still alive. Why do things stick together? The answer he found opened a door. Through that door, scientists now see quarks, genes, and the threads that weave reality together. The letter was the beginning. The prize is a marker along the way. The journey continues.
Sources
4. CERN