Matterclock

Matterclock: "Quantum mechanically, mass can be used to measure time and vice versa." Image Source: University of California at Berkeley.

A newly-developed atomic clock-scale links time to an atom's mass. Science News:

It’s part clock, part scale: A newly developed atomic clock measures time based on the mass of a single atom. The research, published online January 10 [2013] in Science, is controversial but could provide scientists with more precise methods of measuring both time and mass.

“This is the first clock based on a single particle,” says Holger Müller, a physicist at the University of California, Berkeley. “Its ticking rate is determined only by the particle’s mass.”

The idea for the clock stemmed from the quantum principle that particles also behave as waves, and vice versa. In particular, Müller and his colleagues wanted to determine how frequently the wave form of a single atom oscillates, a quantity that in quantum mechanics is inherently linked to the atom’s mass. Then the researchers could use those oscillations like swings of a pendulum to create a clock.

See more on this at Physics and Physicists and from Berkeley. Müller commented in the Berkeley press release:

“When I was very young and reading science books, I always wondered why there was so little explanation of what time is,” said Müller, who is also a guest scientist at Lawrence Berkeley National Laboratory. “Since then, I’ve often asked myself, ‘What is the simplest thing that can measure time, the simplest system that feels the passage of time?’ Now we have an upper limit: one single massive particle is enough.” ...

The idea that matter can be viewed as a wave was the subject of the 1924 Ph.D. thesis by Louis de Broglie, who took Albert Einstein’s idea that mass and energy are equivalent (E=mc²) and combined it with Ernst Planck’s idea that every energy is associated with a frequency. De Broglie’s idea that matter can act as a wave was honored with the Nobel Prize in Physics in 1929.

Using matter as a clock, however, seemed far-fetched because the frequency of the wave, called the Compton, or de Broglie, frequency, might be unobservable. And even if it could be seen, the oscillations would be too fast to measure.

Citations

S.-Y. Lan et al. A Clock Directly Linking Time to a Particle’s Mass. Science. Published online January 10, 2013. DOI: 10.1126/science.1230767. Abstract available: [Go to]

---

Suggested Reading

C. Petit. The Ultimate Clock. Science News. Vol. 180, October 22, 2011, p. 22. Available online: [Go to]
M. Cevallos. Holy moley. Science News. Vol. 178, November 20, 2010, p. 12. Available online: [Go to]
A. Witze. 2012 physics Nobel recognizes experiments probing quantum world. Science News. Vol. 182, November 3, 2012, p. 13. Available online: [Go to]