“My suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose.” - JBS Haldane
“We will first recognize how simple the universe is when we recognize how strange it is.” - John Archibald Wheeler
“If you haven’t found something strange during the day,” John Archibald Wheeler once remarked, “It hasn’t been much of a day.” And throughout his academic life, the soft-spoken particle physicist and cosmologist certainly came across some head-scratchers.
“There is no hope of comprehending the “big picture” unless one takes account of both relativity and quantum mechanics,” he observed in his 1998 autobiography, Geons, Black Holes and Quantum Foam: A Life in Physics. In his attempt to fuse the cosmos and microcosmos into some comprehensible framework, Wheeler hit on one particularly bizarre thought experiment that was later confirmed in laboratory experiments. We’ll get to that in a moment.
Wheeler was born on July 9, 1911, in Jacksonville, Florida. The son of two librarians, he found his interests ran toward the sciences. His studies took him from Baltimore City College and then on to John Hopkins University. He received a PhD from the latter in 1933 at the ripe age of 21. He married the following year and served a brief apprenticeship in Copenhagen with Neils Bohr, the grand old man of quantum mechanics. In 1938, he joined the faculty of Princeton University, where he taught and studied for much of his career.
In a 1939 visit to the US, Bohr collaborated with Wheeler to write a paper on the theoretical underpinnings of the recently discovered phenomenon of nuclear fission. “Like most physicists, I was interested in nuclear fission for what it revealed about basic science, not for what it might have to do with reactors or bombs,” Wheeler later recalled.
In his theoretical work Wheeler worked with a graduate student, Richard Feynman, on a revised theory of electrodynamics, which was based on the adventurous notion that an interaction between charged particles might allow for their propagation both forwards and backwards in time. The fruit of the two’s collaboration, the so-called theory of “Wheeler-Feynman electrodynamics” was published in 1945 and soon became a staple of advanced physics texts.
It wasn’t until the late 1950s that the scientist returned to one of his favourite objects of study, general relativity. A science of extreme scales, masses and time, Einstein’s theory involved the conception of gravity as resulting from the warping of spacetime geometry by mass-energy. As Wheeler put it concisely if somewhat circularly: “spacetime tells matter how to move; matter tells spacetime how to curve.”
Black holes and things that go bump in the lab
At the blackboard Wheeler discovered the cosmic code of general relativity held within it an unwelcome easter egg. A dying star could collapse into a shrunken state of such density that even light would be unable to escape. The object contained at its centre a “singularity,” a mathematical horror where the curvature of spacetime goes to infinity.
Throughout the fifties, Wheeler studied articles by his peers on the physics of collapsed stars - a perfect theoretical laboratory for understanding the play between gravity and electrodynamics. The result of his efforts to fuse the two domains was his 1962 textbook, Geometrodynamics.
The notion of a singularity continued to trouble the scientist. But he presumed this paradoxical state of affairs was unavoidable for massive collapsing stars, and in 1967 he coined the term “black hole” for such objects.
Wheeler’s mathematical spelunking into the singularity problem resulted in his ‘no-hair’ theorem, which states that black holes are ‘bald’: meaning that the only physical properties remaining for the objects are their mass, charge and angular momentum. This did not particularly impress his more conservative colleagues in the physics community, who preferred a more stately cosmos populated by astronomically discreet objects.
While general relativity had been confirmed by observations of occluded stars and satellite clocks, physicists largely believed it to be largely irrelevant to their domains of inquiry. It was mostly Wheeler who changed his colleagues’ tune, and in the process making Princeton University a world centre for research into relativity and cosmology.
It took a decade for the term coined by Wheeler, ‘black hole,’ to reach the mainstream scientific press and the popular imagination. The term exploded into the media in 1978, when astronomers announced the discovery of a powerful galactic x-ray source, Cygnus X-1.
The only possible explanation for such powerful signal from a relatively small source was a disc of gaseous material radiating x-rays as it funnelled past the black hole’s ‘event horizon,’ into a singularity. Since the discovery of Cygnus X-1, astronomers believe they have detected black holes throughout the cosmos, including a supermassive black hole at the centre of our own galaxy, the Milky Way.
The black hole “teaches us that space can be crumpled like a piece of paper into an infinitesimal dot, that time can be extinguished like a blown-out flame, and that the laws of physics that we regard as ‘immutable’ are anything but,” the scientist wrote in his autobiography.
In other words, Wheeler had an intellectual fascination with extreme states where physics breaks down. As professor of physics at the University of Austin, Texas (where he remained until retirement), he returned to the paradoxes of quantum mechanics. He understood that the Uncertainty Principle pertains not just to the detection of subatomic particles, but to space-time itself. Below the level of “Planck length” - 10-39 metres in scale - space-time dissolves into a “quantum foam”: a bubbling nowhere-land of disconnected points and wormholes, where chaos reigns supreme. Gravity, a force that is overwhelmed by the other three forces at the human scale, becomes monstrous at the Planck scale, with supermassive particles quickly popping into and out of the vacuum (following a mathematical twist of the Uncertainty Principle which involves time and energy rather than position and momentum).
The participatory universe
On to that thought experiment I mentioned earlier. In 1978, the professor proposed a “delayed choice experiment’, an update of the famous double slit experiment
This rather ingenious but complicated experiment using semi-silvered mirrors was an attempt to trick light into displaying its true nature - by changing the settings while the photon was still in flight. Could light somehow “sense” the change in the double-slit experiment and adjust its behaviour accordingly, and assume the appropriate determinate state? Or would it remain in an indeterminate state, neither wave nor particle, until measured?
Wheeler insisted that the choice to measure a photon while in flight - and determine if it behaves as a particle or wave - would condition its behaviour in the past. Meaning a decision in the present alters the past itself.
Huh?
Wheeler’s setup was a thought experiment, so it didn’t really make ‘waves’ at the time. But three decades later researchers succeeded in constructed an apparatus based on Wheeler’s whimsy, and confirmed what he had suspected about quantum weirdness. The scientist, cheered by laboratory evidence that the physicist/observer can act in the present to alter the past of a photon, introduced his notion of an “observer-participatory universe.”
“The experimental verdict is in: the weirdness of the quantum world is real, whether we like it or not. . . . The very building blocks of the universe are these acts of observer-participancy. You wouldn’t have the stuff out of which to build the universe otherwise. The participatory principle takes for its foundation the absolutely central point of the quantum: No elementary phenomenon is a phenomenon until it is an observed (or registered) phenomenon.”
“The strangeness of the quantum world, from which Einstein incessantly sought escape and from which Bohr saw no escape, is real,” Wheeler added in his 1998 autobiography.
Again, we find light implicated in extraordinarily strange phenomenon. But the extreme thinker took it one more step: now that it had been confirmed in a real-world laboratory setting, he extended his thought experiment to giant scales. Wheeler imagined light from a distant quasar en-route to Earth distorted by the gravitational lens of a galaxy in between. The light gets bent around both sides of the the galaxy to the observer’s eyes, in manner similar to his first thought experiment.
“We must conclude that our very act of measurement not only revealed the nature of the photon’s history on its way to us, but in some sense determined that history. The past history of the universe has no more validity than is assigned by the measurements we make— now!”
This sounds like human consciousness has some role in determining the history of the cosmos as a whole, no? Not exactly, said Wheeler, but kind of.
From his autobiography:
“Reasoning like this has made me ask whether the universe is a “self-excited circuit” —a system whose existence and whose history’ are determined by measurements. By “measurement” I do not mean an observation carried out by a human or a human-designed instrument— or by any extraterrestrial intelligence, or even by an ant or an amoeba. Life is not a necessary part of this equation. A measurement, in this context, Is an irreversible act in which uncertainty collapses to certainty. It is the link between the quantum and classical worlds, the point where what might happen—multiple paths, interference patterns, spreading clouds of probability —is replaced by what does happen: some event in the classical world, whether the click of a counter the activation of an optic nerve in someone's eye, or just the coalescence of a glob of matter triggered by a quantum event.”
He gives an example of a piece of mica that, at some point in the past, has preserved the path of a subatomic particle that struck it. The mica has “registered” that particle’s existence. No consciousness is required have brought that particle out of the spectral world of superposition: it came into being at the time it carved a path into the mica.
Wheeler raised the spectre of clouds of probability floating about the universe, “that have not yet triggered some registered macroscopic event.” In his final years, he sketched out a drawing to illustrate his participatory universe, a big “U” representing the Universe, with an eye on the top of the left vertical looking to the right. Atop the right vertical is a point representing the birth of the universe, which over time evolves into the left vertical. “By looking back, by observing what happened in the earliest days of the universe, we give reality to those days,” Wheeler writes of the backward-looking eye on his diagram.
A cosmic figment of the imagination?
This doesn’t sound like Wheeler is hedging between nonhuman registration versus conscious conjuring of the world into existence. He’s saying the latter. But regardless, quantum physics is Tricksterish. How much so has only been found out in recent laboratory updates to the split screen experiment. The patterns produced aren’t quite the multiple interference bands expected from interfering waves or the less numerous solid areas produced by particles. This is even stranger than straight wave-particle duality, which hinges on the light demonstrating either one or the other property. In this case, it displays both simultaneously.
In discussing these astounding results, Markus Arndt of the University of Vienna seems to be somewhere between a pragmatist and mystic. “Wave and particle are then just constructs of our mind to facilitate everyday talking,” he told New Scientist.
Not that the situation results in a complete demolition of common sense. Examine nature to its depths and all you find are patterns, and patterns within patterns, said the prescient Zen philosopher Alan Watts:
So is the ultimate nature of light, subatomic particles, and everything that partakes of wave/particle duality, ultimately unknowable? This argument hearkens back to the 18th century philosopher Immanuel Kant’s notion that the “thing in itself” is beyond discovery. All we know of anything are its properties reported to our senses. It’s essence eludes us.
The German philosopher Johann Goethe expressed the same idea in more familiar terms, anticipating Alan Watts:
“In reality, any attempt to express the inner nature of a thing is fruitless. What we perceive are effects, a completed record of these effects ought to encompass this inner nature. We labour in vain to describe a person’s character, but when we craw together his actions, his deeds, a picture of his character will emerge.”
( A half hour before he died, Goethe asked that the window shutters be opened to allow more light into the room where he lay. He had spent much of his life in intellectual battle with Isaac Newton over optics and other phenomenon. How appropriate that Goethe’s last words are said to have been, “More light!”)
“I do take 100 percent seriously the idea that the world is a figment of the imagination,” Wheeler told physicist/science writer Jeremy Bernstein in 1985. Another science writer, John Horgan, assessed his bold claim this way:
Wheeler must know that this view defies common sense: Where was mind when the universe was born? And what sustained the universe for the billions of years before we came to be? He nonetheless bravely offers us a lovely, chilling paradox: At the heart of everything is a question, not an answer. When you peer down into the deepest recesses of matter or at the farthest edge of the universe, you see, finally, your own puzzled face looking back at you.
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I think that the only person who has an answer for these paradoxes thrown up by Wheeler's research and theories is Thomas Aquinas; there has to be a hierarchy of Angels observing the universe into being throughout all eternity. At least, this is the kind of place these speculations lead me towards.