A Rock is a Clock: Physicist Uses Matter to Tell Time

What is stranger than time itself? Have you thought about what time is? Wondering about that since he was a kid growing up in Germany lead Holger Müller to come up with a fundamentally new way to measure time as assistant professor of physics at the University of California, Berkeley. To accomplish this, he used the fact that matter, like light, has a frequency.

Taking advantage of the fact that, in nature, matter can be both a particle and a wave, he has discovered a way to tell time by counting the oscillations of a matter wave. A matter wave’s frequency is 10 billion times higher than that of visible light.

“A rock is a clock, so to speak,” Müller said. …

While Müller’s Compton clock is still 100 million times less precise than today’s best atomic clocks, which employ aluminum ions, improvements in the technique could boost its precision to that of atomic clocks, including the cesium clocks now used to define the second, he said. …

Müller can also turn the technique around to use time to measure mass. …

“When you make a grandfather clock, there is a pendulum and a clockwork that counts the pendulum oscillations. So you need something that swings and a clockwork to make a clock. There was no way to make a clockwork for matter waves, because their oscillation frequency is 10 billion times higher than even the oscillations of visible light.” …

One morning…, however, he realized that he might be able to combine two well-known techniques to create such a clockwork and explicitly demonstrate that the Compton frequency of a single particle is, in fact, useful as a reference for a clock. In relativity, time slows down for moving objects, so … a cesium atom that moves away and then returns is younger than one that stands still. As a result, the moving cesium matter wave will have oscillated fewer times. The difference frequency, which would be around 100,000 fewer oscillations per second out of 10 million billion billion oscillations (3 x 1025 for a cesium atom), might be measurable. …

“This is a beautiful experiment and cleverly designed, but it is going to be controversial and hotly debated,” said John Close, a quantum physicist at The Australian National University in Canberra. “The question is, ‘Is the Compton frequency of atoms a clock or not a clock?’ Holger’s point is now made. It is a clock. I’ve made one, it works.”

via SciDaily

I find it interesting that matter has a frequency 10 billion times greater that of light. I can’t visualize that at all. In New Age circles, light is described as a being “higher vibration” than matter, but it isn’t. Light is a 10 billion times lower vibration than matter… but light can, of course, do amazing things that matter cannot…. like travel at the speed of light. Matter can’t.

Also, to be clear, matter waves are not electromagnetic waves sped up 10 billion times. Matter waves cannot be radiated in empty space unlike electromagnetic waves. They are associated with the particle, not emitted by it. Their group velocity is smaller than ‘c’ (the speed of light) and phase velocity is larger than ‘c’, 10 billion times larger. Phase velocity is visualized below as the red square.

Imagine this animation below, the whole thing, is a zoomed in view of some matter. This shows the difference between group vs phase velocity.  Got it?

Frequency dispersion in groups of gravity waves on the surface of deep water. The red square moves with the phase velocity, and the green circles propagate with the group velocity. In this deep-water case, the phase velocity is twice the group velocity. The red square overtakes two green circles when moving from the left to the right of the figure.

It is still a very strange concept that matter has a wave property.

Matter waves are a central part of the theory of quantum mechanics, being an example of wave–particle duality. All matter can exhibit wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wave. …

Matter waves were first experimentally confirmed to occur in George Paget Thomson‘s cathode ray diffraction experiment and the Davisson-Germer experiment for electrons, and the de Broglie hypothesis has been confirmed for other elementary particles. Furthermore, neutral atoms and even molecules have been shown to be wave-like.

via Wikipedia

What can we do with this knowledge? I don’t know, but when I go to the ocean, it waves at me.


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