It from bit

Each of us tells stories of his or her life. Different stories, depending on the point we are trying to make. Even when we do not tell the story to anybody, we are trying to make sense of our past in order to understand what has brought us to the current state and what can we learn to do better in the future.

Naturally, we select from our experience anything that helps or pleasing. We do not like to dwell on the negative; it is not productive and can even be distractive. Some events after 40 years evolve into completely different ones. I have found my old diary and was very surprised how incorrectly I remember some facts. 

We massage the facts and build a line that looks logical. “I worked hard and achieved this and that.” We conveniently forget that quite a few turns were just lucky ones. Many people work hard, but how many achieve their goals? And each of us knows people who “achieve” something by sheer luck.

Even history as a science suffers from the pressure of our subjectivity. We interpret historical facts in accordance with the view that currently dominates in the society.

All that is relatively easy to accept and agree on. But what about physics? How much the result of an experiment depends on the interpretation?

We do not have a disagreement in the areas of our immediate experience. If in doubts, we can repeat the experiment immediately. The problem arises when we try to make a statement about the phenomena we cannot touch and feel. The areas too small (quantum world) or too far away (cosmos) require interpretation – a middle man. 

One of the greatest physicists of XX century John Wheeler illustrated this statement with the following parlor game. One person steps out of the room, while the rest agree on something. Then the person enters back into the room and asks 20 yes/no questions trying to figure what they have agreed on. The expectation is that the group agrees on a certain word, an object, or a person in the room.

Well, if this expectation is not explicitly defined by the rules, the group may agree not to agree on anything. While answering the questions, they would only care about not contradicting the previous answers. For example, if one of the previous questions was “Is it a person?” and the answer was “No”, the answer to the question “Is it Bill?” should be “No.”

Now, here is the question: is it possible to narrow down the choice to one word in 20 questions? Is it possible to do in 100 questions? 1000? In principle?

That is how John Wheeler illustrated our approach to learn about the world in physics. The measuring devices (the group in the room) do not know upfront the correct answer.  They just respond to each question we ask and do not contradict previous answers.

The experiments are usually set in such a way that we get a single-choice answer in a minimal set of steps. Ideally, we set our experiment so that we can get only “yes” or “no” to our question.  

That’s why John Wheeler states that each question we ask in physics is (in its core) a binary yes/no: “Does the result matches the theory or not?” By choosing which question to ask, we already sneak in our own assumptions – the theory of what is out there. We limit the nature in its choice of possible answers. And that was what, I think, John Wheeler meant when he coined his “It from bit.” We derive the existence of something (“it”) from the binary data (“from bit”).

If you would like to see yourself what John Wheeler says on the subject, read his article INFORMATION, PHYSICS, QUANTUM: THE SEARCH FOR LINKS. It contains many very interesting (even for laypeople) statements. It seems that he was inspired by the Niels Bohr’s statement, “This quantum business is so incredibly important and difficult that everyone should busy himself with it.“

The “everyone” in Bohr’s statement is you and me.

And here is the final paragraph of John Wheelers’ article that inspires me:

“A single question animates this report: 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!”

After reading this, how one can stop thinking about the matter?