Thorium Nuclear Clock Ticks with a Whisper of Light ⚡ экспресс
Физики впервые возбудили ядерный переход в тории-229 непрерывным лазерным лучом мощностью менее нановатта. Это похоже на запуск точнейшего маятника, но внутри атомного ядра. Такой метод ускоряет считывание сигнала, приближая создание сверхстабильных ядерных часов. Представьте часы, которые не собьются за время жизни Вселенной — возможно, они откроют новую физику.
A laser beam as faint as a whisper of light has stirred a thorium-229 nucleus into a higher energy state. Most nuclei demand a blast of energy, but thorium-229 has such a tiny energy gap that even this gentle nudge works. Instead of waiting for the nucleus to emit light, scientists used absorption spectroscopy—measuring the fraction of the whisper absorbed, giving a fast, clean signal. They placed the thorium in a calcium fluoride crystal, in a spot so quiet that the crystal's hum was almost inaudible.
A clock based on this could be so steady it would miss less than a second over the age of the universe. It might reveal whether the standard model, the rulebook of fundamental forces, ever drifts. And the laser's power? A firefly's brief glow outshines it by far.
🎯 Thorium-229 is the only nucleus that responds to such a faint whisper of light: its excitation energy is a mere 8 electronvolts, compared to the millions required by other nuclei. That’s the difference between a soft sigh and a thunderclap.