US Particle Collider Closes After 25 Years of Discoveries

For a quarter century, scientists on Long Island created conditions that existed just microseconds after the universe began. Now they're building something even more powerful to continue the journey.

The Relativistic Heavy Ion Collider at Brookhaven National Laboratory officially shut down this month after 25 years of revolutionary discoveries. The massive machine smashed atomic nuclei together at nearly the speed of light, recreating the fiery soup of particles that filled the universe 13.8 billion years ago.

The collider's achievements read like a greatest hits album of particle physics. It created the heaviest antimatter ever seen and brought scientists closer than ever to understanding the Big Bang. Most impressively, it helped solve a decades-long mystery about where protons get their spin, a quantum property that stumped physicists since 1987.

"I wish I could go sit in a corner and cry, to be honest," says Angelika Drees, an accelerator physicist who worked on the project for 27 years. "It was such a beautiful experiment."

The Bright Side

The tears are bittersweet because something extraordinary is coming next. Scientists are building a far more powerful electron-ion collider using parts from the retiring machine, including one of its two giant underground storage rings.

The new collider will dig even deeper into the mysteries of the strong force, the most counterintuitive of nature's four fundamental forces. While gravity and magnetism weaken as objects move apart, the strong force does the opposite. It gets stronger when you try to pull quarks apart, which is why these fundamental particles always stick together inside protons and neutrons.

This quirky behavior explains a mind-bending fact: quarks make up only 1 percent of a proton's mass. The rest comes from massless particles called gluons that act like glue between quarks. Understanding how massless particles create mass helps explain how the entire universe got its substance.

The shutdown ceremony captured the moment perfectly. When Under Secretary Darío Gil pressed the red button ending operations, the control room filled with applause. "It'll be good to sleep well for a while," says Travis Shrey, who coordinated the final run.

America's investment in particle physics continues, ensuring the lab remains a center of discovery for decades to come.