Guide to the Cosmos

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Newsletter: Spooky Action-at-a-Distance Wins Nobel Prize

Just in time for Halloween, the Nobel Prize was awarded to two physicists, David Wineland of the U.S. and Serge Haroche of France, for achieving something that would have boiled Einstein’s cauldron.

Nothing, neither fact nor fiction, is spookier than quantum mechanics (“QM”).

QM precisely describes the behavior of the natural world at microscopic scales — molecules, atoms, and the even smaller particles from which these are made — but QM predicts weird phenomena that defy our common sense.  It says a particle can be in two different places at the same time, and can simultaneously spin clockwise and counterclockwise. QM can even raise the undead. It says Schrödinger’s cat (undoubtedly a black cat for Halloween) can be both alive and dead if it’s inside a sealed box, and will remain so until someone dares peak inside.

Why is the micro-world so spooky? Fundamentally, it is just the difference between ramps and staircases.

The macro-world that we live in is like a ramp: an object can be placed at any elevation one wishes. But, the micro-world is like a staircase: only a few discrete elevations are possible. Nothing can be 2 1/2 steps high, simply because there’s no step there. In the macro-world a planet can orbit its star at any distance, while in the micro-world an electron can only exist in a limited number of orbits in an atom. For small things like electrons, the size of these steps is dramatic. For larger objects, the steps seem smaller. We’re so much bigger than electrons that the tiny individual staircase steps are unobservable and what we perceive is a ramp.

QM limits our ability to predict the future. It says we can calculate probabilities of various outcomes but never know for sure what will happen. Einstein rejected these disturbing claims of QM, famously declaring: “God does not play with dice.” His friend Niels Bohr admonished Einstein: “Don’t tell God what to do with His dice.”

QM also declares that two distant particles can be “entangled” — operating in unison, linked by an undetectable choreography that Einstein denounced as: “spooky action-at-a-distance.”

Regarding QM, Einstein was wrong. The predictions of QM have been definitely confirmed by exquisitely precise experiments. In the micro-world, nature really is spooky, as Wineland and Haroche have shown.

Wineland works at NIST, the U.S. National Institute of Standards and Technology, which makes the world’s most precise clocks. NIST clocks are driven by the oscillations of individual atoms, and are accurate to one second in 3.7 billion years. These clocks are so precise that they have confirmed Einstein’s prediction that time runs slower where gravity is stronger. When NIST scientists elevated their clock by one foot, they measured it running faster by one millionth of a second per year, because gravity is minutely weaker one foot further from Earth’s center. Time-critical functions across the world, including GPS, are synchronized to the world’s best clocks at NIST. During the past 15 years, four Nobel Prizes have been awarded to NIST scientists.

Wineland’s team is also striving to enable quantum computing. They trap individual atoms and cool them to 1/10,000th of a degree above absolute zero (–460º F). A laser beam then nudges a single electron into a higher energy state that offers two distinct orientations. As QM directs, the electron occupies both orientations simultaneously, forming a “qubit.” Numbers in normal computers are stored in arrays of “binary bits”, with each bit being either 0 or 1 (the 4-bit sequence 1001 represents 9). An 8-bit “byte” can represent any one number from 0 to 255. But, since qubits represent combinations of 0 and 1, 8 qubits can simultaneously represent every number between 0 and 255. This will allow a quantum computer to perform a calculation on all these values in a single operation, vastly expanding computing power. We’re not there yet. Wineland has can control up to 14 qubits at once; modern computer cores have millions of bits.

Haroche traps photons, individual particles of light, between superbly polished, ultra cold mirrors. The mirrors are so exquisite that a photon can bounce between them billions of times before being absorbed or scattered out the side. Haroche has arranged photons that oscillate in two opposite directions at the same time — a coherent superposition state — and measured how long the coherence lasts until the disturbing effects of the macro-world creep in. Haroche and his team have developed feedback techniques to extend coherence lifetime, which will be crucial in developing practical quantum computers.

Once quantum computing becomes possible, they will be able to rapidly crack even the most complex security codes. So all this science has immediate “real world” applications, and is heavily funded by numerous governments.

Wineland and Haroche will each receive $600,000 (tax-free).

P.S.
Haroche said he was walking home with his wife when his cell phone rang, displaying the area code of Sweden. He sat down on a nearby bench and realized what this call would mean and was overwhelmed. He planned to celebrate his Nobel Prize at home with champagne, family and friends …. and then go back to his lab.

Best Regards,
Robert

October 30, 2012

(in the Scottish Highlands after speaking

to the Edinburgh Astronomical Society)

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