How Speeding Particles Froze Into Darkness: A Cosmic Plot Twist Explains Dark Matter

What if dark matter—the invisible force sculpting our universe—was once pure light? A bold new theory suggests that massless, high-energy particles in the early universe collided, cooled, and abruptly transformed into the heavy, slow particles we call dark matter. Not only does the model explain this unlikely metamorphosis, but it also makes predictions testable via [...]