The world's first nuclear clock just ticked on — and it could help detect a fifth fundamental force of physics

Physicists have built the world's first functioning nuclear clock, a major breakthrough in timekeeping. Unlike traditional atomic clocks that track electrons, this clock measures time using an atom's nucleus, making it far more stable and precise. This advancement could eventually improve timekeeping technology and open new ways to search for dark matter and possibly detect a mysterious fifth fundamental force of physics.