Not Your Father's Objective Reality: 100 Years of Quantum Weirdness

 

by Adam Frank

It's more than a century since physicists stumbled upon the disconcerting fact that Nature acts very differently on the scale of "fundamental" particles then it does on the scales of billiard balls and people.

'What do you do when your best theory of reality offers no guidance about what reality looks like?'

Beginning in the late 19th century, new experiments took us down to regimes measured in the billionths of a meter and physicists were suddenly able to probe a staggering array of new phenomena: the nature of atoms: the interaction between matter and light: the physics of solids at ultra-low temperatures.
The experiments unveiled bewildering new behaviors that proved exceedingly difficult to understand. Attempts to make sense of the experiments using the physics of the day, what we now call "classical physics," failed entirely.
In desperation, and a phenomenal display of human creativity, scientists created an entirely new branch of physics we now call quantum mechanics. The difference between classical and quantum physics is the difference between "common sense" and something else entirely. Our common sense classical physics derives from stuff that is "about our size" (for a physicists this can mean anything from millimeters to mountain-sized objects). As kids we play with rubber balls, ride our bikes and scream our heads off on roller coasters. All of these experiences condition us to expect certain kinds of behavior from the world of "things". But as Niels Bohr once said "Atoms are not things."
I will eschew describing the various examples of quantum weirdness here. Wave-particle duality, the Heisenberg Uncertainty principle, the Problem of Measurement, Entanglement - the list is long and I cannot do any justice to it in a single blog post. What I do want to note here, however, is an important point for our discussions of Cosmos and Culture.
What do you do when your best theory of reality offers no guidance about what reality looks like?
  100 years or so ago we were forced to abandon the classical physics, "billiard ball" picture of reality. What replaced it was not, however, a new set of pictures. The language of quantum mechanics that emerged was rooted in an abstract mathematical formalism, which didn't allow one to imagine an electron the way you imaged an ordinary object like, for example, a chair or a rock. While the mathematics borrowed broad ideas like the conservation of energy from classical physics, it did not provide a way to "picture" what was happening the way classical physics did. You could not imagine, or draw a sketch on paper, the "things" quantum physics described. This is the origin of many of the paradoxes in Quantum Mechanics - like Schrodinger's Cat - that point us to a world radically unlike our everyday experience.
Early on I asked a professor how I was supposed to think about quantum objects like, say, an electron. I have never forgotten his answer, "In quantum mechanics an electron is simply that to which we ascribe the properties of an electron". Wow. That was really helpful. This kind of thing is not what I was thinking when I imagined being a physicist.
Make no mistake; Quantum physics is a triumph of human creativity and the power science. The magnitude of this triumph is evident in the culture transforming technologies quantum physics engendered from the laser to the microchip. Nonetheless, the reality it reveals is very, very weird and that leads me to my second point.
Reality, a'la quantum physics, has been very, very weird for more than 100 years.
For all the enthusiastic efforts of generations of smart scientists, the weirdness of quantum physics has not gone away. New, ever more powerful experiments have only deepened the conclusion that whatever sense reality makes at a fundamental level, it is not common.
So how does culture absorb this fact?
The first wave of reaction appears to have been the New Age movement of the 1960s and 1970s. New Age enthusiasms embraced quantum physics as proof that consciousness was more important than matter and that the world was imbued with spiritual realities of great and grand potential. It seemed very exciting. Unfortunately it was wrong, missing the essential point that quantum mechanics doesn't really "say" anything. It raises questions. It does not answer them. The New Age movement with movies like the infuriating "What the Bleep Do We Know" just inserted its own pictures into a theory that does not allow them.
Hopefully this first wave has passed and we are ready for a deeper discussion about how culture absorbs the quantum. Its weirdness is persistent and an idea like that is too powerful to simply rest at the edges of human activity.