By Maria Popova
It from Bit: Pioneering Physicist John Archibald Wheeler on Information, the Nature of Reality, and Why We Live in a Participatory Universe
“Reality is what we take to be true,” pioneering physicist David Bohm asserted in 1977. “What we take to be true is what we believe… What we believe determines what we take to be true. What we take to be true is our reality.”
The question of what is true is, of course, invariably a binary one — in answering it, we must choose between true and false. Left or right, the red pill or the blue pill, the ultimate “To be, or not to be.” Information theory is built upon this binary mindset — the if this, then that logic of most programming languages is predicated on the true/false dichotomy in executing commands — and it to this elemental relationship between information and human consciousness that Bohm was speaking.
A little more than a decade later, the great theoretical physicist John Archibald Wheeler (July 9, 1911–April 13, 2008) enriched this idea in a concept he called It from Bit. More than thirty years after he popularized the term “black hole” — a term for the cosmic object which consumes most information into oblivion — Wheeler suggested that our experience of the objects, events, and phenomena that constitute reality is the result of binary decisions — true/false, yes/no, on/off — which we make in the process of observing them.
Wheeler first presented his It from Bit notion at a Santa Fe Institute conference in the spring of 1989. That fall, he formulated it in a paper published under the title “Information, Physics, Quantum: The Search for Links” in the Japanese journal Proceedings of the 3rd International Symposium on Foundations of Quantum Mechanics in the Light of New Technology. It was later discussed in the excellent 1992 essay collection The Mind’s Sky: Human Intelligence in a Cosmic Context (public library) by physicist Timothy Ferris (not to be confused with Tim Ferriss), which is how I was first led down the rabbit hole of obscure academic journals searching for Wheeler’s original text.
By the time of his death, Wheeler was last living link to Einstein and Niels Bohr, with both of whom he had collaborated directly.
In his paper, Wheeler writes:
"I, like other searchers, attempt formulation after formulation of the central issues and here present a wider overview, taking for working hypothesis the most effective one that has survived this winnowing: It from Bit. Otherwise put, every it — every particle, every field of force, even the spacetime continuum itself — derives its function, its meaning, its very existence entirely — even if in some contexts indirectly — from the apparatus-elicited answers to yes or no questions, binary choices, bits."
It from Bit symbolizes the idea that every item of the physical world has at bottom — a very deep bottom, in most instances — an immaterial source and explanation; that what we call reality arises in the last analysis from the posing of yes-no questions and the registering of equipment-evoked responses; in short, that all things physical are information-theoretic in origin and this is a participatory universe.
With an eye to the famous statement that “time and space are modes by which we think and not conditions in which we live” (which Wheeler, like many others, misattributes to Einstein, but which was in actuality thought up by Einstein’s premier biographer, Dimitri Marianoff, in his book Einstein: An Intimate Study of a Great Man), he adds:
"No account of existence can ever hope to rate as fundamental which does not translate all of continuum physics into the language of bits. We will not feed time into any deep-reaching account of existence. We must derive time — and time only in the continuum idealization — out of it. Likewise with space."
Returning to the loop upon which Bohm had puzzled a decade earlier, Wheeler writes:
"Physics gives rise to observer-participancy; observer-participancy gives rise to information; and information gives rise to physics."
His closing sentiment offers a beautiful testament to Einstein’s assertion that “every true theorist is a kind of tamed metaphysicist.” Looking back on the central inquiry animating his It from Bit concept, Wheeler concludes:
"Can we ever expect to understand existence? Clues we have, and work to do, to make headway on that issue. Surely someday, we can believe, we will grasp the central idea of it all as so simple, so beautiful, so compelling that we will all say to each other, “Oh, how — could it have been otherwise! How could we all have been so blind so long!”
Developments like the nascent Golden Age of gravitational astronomy, which owes a great deal to Wheeler’s work, are among the most thrilling such clues in the direction of headway. But before we can arrive at the moment French polymath Henri Poincaré called “sudden illumination,” when the beauty of such greater simplicity is revealed, we must wade through the thicket of greater complexity, the distillation of which is the daily and perennial task of science.