Tag Archives: quantum mechanics

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Non-Newtonian cats

I’m out of town today, so I thought I’d pre-post some stuff to keep you all diverted in my absence*. So to start with, here are some observations of quantum tunnelling behaviours in Felis catus:

In my own residence, I and several other party guests personally observed the case of Chloe, a large black Himalayan. Though the extent of the cat’s fur decreased the certainty with which one could specify the cat’s position and momentum (c.f., the Himalyan Uncertainty Principle), and our garage door is only a few inches thick, the tunneling event was no less remarkable in light of her prodigious girth (she weighed 15 pounds, frequently intimidating our German Shepherd into sharing his dinner). The cat was initially observed sleeping in the driveway. When next observed several minutes later, the cat was nowhere to be seen. We opened the garage door, at which point Chloe left the garage, obviously having tunneled through the closed door. We marveled at this phenomenon, and, as we closed the side door to the garage, discussed plans for further study.

Yeah, I know; cats and quantum uncertainty, old gag. But it made me smile, which was excuse enough to post it. Now, I wonder if quantum weirdness can also explain that infuriating way in which cats will suddenly decide to stare intently at a patch of empty air for no discernible reason whatsoever…

[ * Because Futurismic really is that essential to your daily sense of well-being… it’s okay, you can admit it. I promise not to be embarrassed. ]

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Time travel without the paradoxes?

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A new theory based on quantum mechanics promises to do away with the “Grandfather Paradox” that supposedly makes time travel impossible [via BoingBoing]:

Quantum mechanics seems to allow for such simultaneous computations of all possible outcomes theoretically, though actually making it happen is another issue altogether (such quantum computing would blow conventional computing methods out of the water). But combined with quantum teleportation – using quantum entanglement to reproduce a quantum state in space that previously existed at another point in space – MIT’s Seth Lloyd and colleagues say you can theoretically teleport a particle back in time.

This form of theoretical time travel solves two major problems associated with the feat. For one, it doesn’t require the bending of spacetime as most time travel theories do. Considering the conditions necessary to bend the fabric of spacetime might only exist in black holes, that’s a good thing. But further, due to the probabilistic laws of quantum mechanics, anything this method of time travel allows to happen already had a finite chance of happening anyhow. That means a particle can’t really go back and accidentally destroy itself.

Note that this applies to subatomic particles and not people… so we’ll not be letting time-travel stories through the Futurismic fiction selection process just yet. But as soon as we get confirmation that it’s genuinely possible we’ll send someone back to retrospectively amend the guidelines, which will have the knock-on effect of ensuring all time travel stories submitted to us that were otherwise suitable for publication were, in fact, purchased and published. Can’t say fairer than that, can you?

Bonus quantum mechanics news: a recent successful run of a “triple split” experiment has provided evidence to support the theory of quantum mechanics that was originally developed from the double-slit experiment, first performed over a century ago. If you’re hoping that’ll make quantum mechanics make more sense, however, I suspect you’re all out of luck.

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Quantum motor with just two atoms

Quantum-motorResearchers at the University of Augsburg in Germany have developed a blueprint for a kind of quantum electric motor that uses just two atoms:

Their motor consists of one neutral atom and one charged atom trapped in a ring-shaped optical lattice. The atoms jump from one site in the lattice to the next as they travel round the ring. Placing this ring in an alternating magnetic field creates the conditions necessary to keep the charged atom moving round the the ring.

As with many elements of quantum physics it is difficult to imagine precisely what you could do with such a miniscule motor, but for the time being the researchers are seeking to attach the motor to a nanonoscopic resonator, thus making the resonator vibrate.

In the meantime we are left speculating as to what peculiar corners of which unexpected futures devices such as this could find a use and a narrative.

[via Slashdot, from Technology Review][image from Technology Review]

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Light in a bottle

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microresonatorScientists have developed a technique for confining light within a bottle:

Similar to the motion of a charged particle stored in a magnetic bottle, i.e., a particular spatially varying magnetic field, the light oscillates back and forth along the fiber between two turning points. For this reason, this novel type of microresonator realized by the physicists in Mainz is referred to as a bottle resonator. Tuning the bottle resonator to a specific optical frequency can be accomplished by simply pulling both ends of the supporting glass fiber. The resulting mechanical tension changes the refractive index of the glass, so that depending on the tension, the round-trip of the light is lengthened or shortened.

This could lead to the creation of a glass fibre quantum interface between light and matter, which in turn is an important component of hypothetical quantum computers and quantum communication systems.

[from Physorg][image from Physorg]

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Quantum superposition breakthrough

theory_actualA rich seam of technological and science-fictional ideas seem ready to be mined with the development of the first light trap that can simultaneously store different numbers of photons:

“These superposition states are a fundamental concept in quantum mechanics, but this is the first time they have been controllably created with light,” Cleland said. Martinis added, “This experiment can be thought of as a quantum digital-to-analog converter.” As digital-to-analog converters are key components in classical communication devices (for example, producing the sound waveforms in cell phones), this experiment might enable more advanced communication protocols for the transmission of quantum information.

The research is funded by IARPA. Intelligence services are understandably keen to learn more about the potential for quantum computers to break conventionally encrypted communications.

[image and story from Physorg]