Excitation of thorium-229 brings closer the creation of working nuclear clocks

For the first time in history, researchers used laser light to push the nucleus of a thorium atom to a higher energy level. This scientific success paves the way for a new generation of watches of unsurpassed precision, capable of helping us understand the most fundamental forces in the Universe. How do atomic clocks work? Atomic clocks, which are the most accurate in existence today, are based on an amazing principle of quantum physics. They use atoms to measure time with extreme precision. Think of the atom as a miniature solar system, with a nucleus at the center and electrons orbiting around it. These electrons can occupy different energy levels, like the floors of a building. When an electron receives a certain amount of energy, it can “jump” from one floor to another. This is what we call the energy transition.