The Quantum Microphone

[Mal12345]

http://www.scientificamerican.com/article.cfm?id=quantum-microphone

Before someone here bashes Scientific American for being only slightly above Omni magazine, versions of this article have appeared in highly reputable sources.

'Physicists have long known that, following the laws of quantum mechanics, objects at the scale of atoms or smaller can exist in multiple simultaneous states. For example, a single electron can move along multiple different paths or an atom can be placed in two different places, simultaneously. This so-called superposition of states should in principle apply to larger objects, as well, as in the proverbial thought experiment in which a cat is simultaneously dead and alive. And in recent years various teams have shown that the weird phenomenon does occur among objects as big as molecules, and also in truly macroscopic systems such as electrical currents in superconductors.

In the new experiment Aaron O'Connell, a graduate student at the University of California, Santa Barbara, and his co-workers have shown for the first time that larger objects can also be in two places at once. "It tells us that quantum mechanics works for macroscopic objects in space," says O'Connell, who presented the results here at a meeting of the American Physical Society. The results were also published online Wednesday in Nature.'

 

[Mal12345]

A commenter of the above article has a question to be addressed: 'I must say I don't understand what the following really means: "in the superposition of states the resonator is never really in two totally distinct places. But still, the experiment showed that a large object (the resonator is made of about 10 trillion atoms) can display just as much quantum weirdness as single atoms do.

Was the resonator in two distinct places or not?"

The article states that "the resonator was in a superposition of vibrating and not vibrating." And by "vibrating" is meant "to expand and contract." It is not like a tuning fork which oscillates sideways.

The confusion occurs where the article states, at the top, that the resonator "acts as if it exists in two places at once." Later on, the article more accurately states that the resonator is in a state of superposition. "Superposition" is not just about spatial coordinates, or places. It simply means the object is in two states at once, a situation not allowed for by common-sense logic, which tells us that a tuning fork cannot be both resonating and not resonating at the same time.

Toward the end of the article, we read "As to how the day-to-day reality of objects that we observe, such as furniture and fruit, emerges from such a different and exotic quantum world, that remains a mystery." That's really not a mystery, perhaps it is to the author of the article. Note the fact that the quantum resonator must be cooled down to within 20 thousandths of a degree above absolute zero. Kinetic energy, which is responsible for generating heat, creates the macro world around us, and in order to return it to a quantum state, it is simply necessary to remove nearly all of its kinetic energy.

There is a video of a TED lecture on this subject somewhere online...

 

[Mal12345]

[video]http://www.ted.com/talks/aaron_o_connell_making_sense_of_a_visible_quantum_ object.html[/video]