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“It can be argued that in trying to see behind the formal predictions of quantum theory we are just making trouble for ourselves”*…

Context, it seems, is everthing…

… What is reality? Nope. There’s no way we are going through that philosophical minefield. Let’s focus instead on scientific realism, the idea that a world of things exists independent of the minds that might perceive it and it is the world slowly revealed by progress in science. Scientific realism is the belief that the true nature of reality is the subject of scientific investigation and while we may not completely understand it at any given moment, each experiment gets us a little bit closer. This is a popular philosophical position among scientists and science enthusiasts.

A typical scientific realist might believe, for example, that fundamental particles exist even though we cannot perceive them directly with our senses. Particles are real and their properties — whatever they may be — form part of the state of the world. A slightly more extreme view is that this state of the world can be specified with mathematical quantities and these, in turn, obey equations we call physical laws. In this view, the ultimate goal of science is to discover these laws. So what are the consequences of quantum physics on these views?

As I mentioned above, quantum physics is not a realistic model of the world — that is, it does not specify quantities for states of the world. An obvious question is then can we supplement or otherwise replace quantum physics with a deeper set of laws about real states of the world? This is the question Einstein first asked with colleagues Podolski and Rosen, making headlines in 1935. The hypothetical real states of the world came to be called hidden variables since an experiment does not reveal them — at least not yet.

In the decades that followed quantum physics rapidly turned into applied science and the textbooks which became canon demonstrated only how to use the recipes of quantum physics. In textbooks that are still used today, no mention is made of the progress in the foundational aspects of quantum physics since the mathematics was cemented almost one hundred years ago. But, in the 1960s, the most important and fundamental aspect of quantum physics was discovered and it put serious restrictions on scientific realism. Some go as far as to say the entire nature of independent reality is questionable due to it. What was discovered is now called contextuality, and its inevitability is referred to as the Bell-Kochen-Specker theorem.

John Bell is the most famous of the trio Bell, Kochen, and Specker, and is credited with proving that quantum physics contained so-called nonlocal correlations, a consequence of quantum entanglement. Feel free to read about those over here.

It was Bell’s ideas and notions that stuck and eventually led to popular quantum phenomena such as teleportation. Nonlocality itself is wildly popular these days in science magazines with reported testing of the concept in delicately engineered experiments that span continents and sometimes involve research satellites. But nonlocality is just one type of contextuality, which is the real game in town.

In the most succinct sentence possible, contextuality is the name for the fact that any real states of the world giving rise to the rules of quantum physics must depend on contexts that no experiment can distinguish. That’s a lot to unpack. Remember that there are lots of ways to prepare the same experiment — and by the same experiment, I mean many different experiments with completely indistinguishable results. Doing the exact same thing as yesterday in the lab, but having had a different breakfast, will give the same experimental results. But there are things in the lab and very close to the system under investigation that don’t seem to affect the results either. An example might be mixing laser light in two different ways.

There are different types of laser light that, once mixed together, are completely indistinguishable from one another no matter what experiments are performed on the mixtures. You could spend a trillion dollars on scientific equipment and never be able to tell the two mixtures apart. Moreover, knowing only the resultant mixture — and not the way it was mixed — is sufficient to accurately predict the outcomes of any experiment performed with the light. So, in quantum physics, the mathematical theory has a variable that refers to the mixture and not the way the mixture was made — it’s Occam’s razor in practice.

Now let’s try to invent a deeper theory of reality underpinning quantum physics. Surely, if we are going to respect Occam’s razor, the states in our model should only depend on contexts with observable consequences, right? If there is no possible experiment that can distinguish how the laser light is mixed, then the underlying state of reality should only depend on the mixture and not the context in which it was made, which, remember, might include my breakfast choices. Alas, this is just not possible in quantum physics — it’s a mathematical impossibility in the theory and has been confirmed by many experiments.

So, does this mean the universe cares about what I have for breakfast? Not necessarily. But, to believe the universe doesn’t care what I had for breakfast means you must also give up reality. You may be inclined to believe that when you observe something in the world, you are passively looking at it just the way it would have been had you not been there. But quantum contextuality rules this out. There is no way to define a reality that is independent of the way we choose to look at it…

Why is no one taught the one concept in quantum physics which denies reality?” It’s called contextuality and it is the essence of quantum physics. From Chris Ferrie (@csferrie).

* “It can be argued that in trying to see behind the formal predictions of quantum theory we are just making trouble for ourselves. Was not precisely this the lesson that had to be learned before quantum mechanics could be constructed, that it is futile to try to see behind the observed phenomena?” – John Stewart Bell

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As still we try, we might relatively hearty birthday greetings to Sir Marcus Laurence Elwin “Mark” Oliphant; he was born on this date in 1901. An Australian physicist who trained and did much of his work in England (where he studied under Sir Ernest Rutherford at the University of Cambridge’s Cavendish Laboratory), Oliphant was deeply involved in the Allied war effort during World War II. He helped develop microwave radar, and– by helping to start the Manhattan Project and then working with his friend Ernest Lawrence at the Radiation Laboratory in Berkeley, California, helped develop the atomic bomb.

After the war, Oliphant returned to Australia as the first director of the Research School of Physical Sciences and Engineering at the new Australian National University (ANU); on his retirement, he became Governor of South Australia and helped found the Australian Democrats political party.

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Yikes!…

If yesterday’s missive was about headlines that amuse, today’s is corrective:  From the BBC (Friday the 13th, natch)…

Peru battles rabid vampire bats…

(TotH to The Rumpus)

As we adjust our necklaces of garlic, we might spare a memorial thought for Hugo Gernsback, a Luxemborgian-American inventor, broadcast pioneer, writer, and publisher; he died on this date in 1967 at the age of 83.

Gernsback held 80 patents at the time of his death; he founded radio station WRNY, was involved in the first television broadcasts and is considered a pioneer in amateur radio.  But it was a writer and publisher that he probably left his most lasting mark:  In 1926, as owner/publisher of the magazine Modern Electrics, he filled a blank spot in his publication by dashing off the first chapter of a series called “Ralph 124C 41+.” The twelve installments of “Ralph” were filled with inventions unknown in 1926, including “television” (Gernsback is credited with introducing the word), fluorescent lighting, juke boxes, solar energy, television, microfilm, vending machines, and the device we now call radar.

The “Ralph” series was an astounding success with readers; and later that year Gernsback founded the first magazine devoted to science fiction, Amazing Stories.  Believing that the perfect sci-fi story is “75 percent literature interwoven with 25 percent science,” he coined the term “science fiction.”

Gernsback was a “careful” businessman, who was tight with the fees that he paid his writers– so tight that H. P. Lovecraft and Clark Ashton Smith referred to him as “Hugo the Rat.”

Still, his contributions to the genre as publisher were so significant that, along with H.G. Wells and Jules Verne, he is sometimes called “The Father of Science Fiction”; in his honor, the annual Science Fiction Achievement awards are called the “Hugos.”

(Coincidentally, today is also the birthday– in 1906– of Philo T. Farnsworth, the man who actually did invent television… and was thus the inspiration for the name “Philco.”)

Gernsback, wearing his invention, TV Glasses (source: Life)

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