Childhood Color-Glasses,
and the Fights Between Labs

When I was in high school, my friend Mehdi Lessani — the same Mehdi I name at the very beginning of my book, because he is one of the reasons I ever turned my head toward physics — said something to me one ordinary afternoon that has never left me.

He pointed at something red and asked: What if the red I see, right now, is the color you would call green? What if, ever since we were children, we both simply learned to pin the same word — red — onto two completely different experiences happening privately inside each of us? You would never find out. I would never find out. We would agree on the word forever and never once suspect we were living in different-colored worlds.

I had no answer. I still remember the small vertigo of it — not fear exactly, but the strange weightlessness of realizing that the most basic thing two people can supposedly share, the color of a thing sitting right in front of them, might be locked inside each of us, with only a borrowed word stretched thin across the gap. It bothered me that night. If I am honest, it has bothered me ever since.

The same question, turned around

But somewhere in the same restless thinking, a second idea arrived — the same philosophy, turned to face the other way.

Forget, for a moment, what is sealed inside our heads. Imagine instead something simple and outside of us: a plain white sheet of paper on the table. Now imagine I am wearing green-tinted glasses, and Mehdi is wearing red-tinted glasses. I look at the paper and insist it looks greenish. He looks at the very same paper and insists it looks reddish. We argue.

And here is the important part: neither of us is lying. We are each honestly reporting what actually reaches our eyes. The paper has not changed. The only thing that differs is the glass each of us is looking through.

If the disagreement comes from the glasses, then maybe the glasses are something we can study.

Maybe we can measure the tint. Maybe — and this is the thought I have chased for much of my life — maybe we could design a glass that tells us whether two people’s red really match, or whether they only seem to.

A real fight in physics

It took me decades to understand that I had stumbled onto the exact shape of one of the hardest arguments in modern physics. And the argument is happening right now.

Deep in the vacuum — in what looks like empty space — there is a faint hidden vacuum pattern that nudges how a tiny particle called the muon wobbles inside a magnetic field. Physicists badly want to read this pattern precisely, because if our reading disagrees with our best theory, that little gap could be a doorway into new laws of nature. To read it, laboratories around the world smash electrons together, watch what sprays out, and from that each computes a single number.

Here is the trouble. The laboratories do not agree. One experiment, CMD-3 in Russia, reports a high number. Another, BESIII in China, reports a noticeably lower one. The gap between them is wide — wide enough that it cannot comfortably be blamed on luck. And every one of these labs is honest. Every one is painstakingly careful. They are all looking at the same vacuum, the same underlying pattern — the same white paper — and reporting different colors.

Do you see it now? Each experiment is wearing its own glasses. Not glasses made of glass, but glasses made of machinery, calibration, binning, covariance, radiative corrections, and the thousand tiny choices that any real measurement must carry. The pattern in the vacuum did not change between Beijing and Novosibirsk. What changed is the tint each instrument quietly adds without meaning to.

The glass I once wished for

This is where the idea I had been carrying since high school finally turned into a tool.

The usual instinct, when labs disagree about a number, is to argue about the number — to fight over the color of the paper head-on. But that fight has no floor, because every attempt to measure the true color is itself made through some tint. So in my framework, Quantum Traction Theory, I tried to do the two things that childhood puzzle had secretly been teaching me.

First: write down what the paper should look like, ahead of time, and freeze it. Before peeking at any experiment’s answer, I commit in public, in writing, to the pattern the vacuum’s paper is allowed to have, worked out from the structure of the theory, and sealed so it cannot be quietly repainted later to match anyone. That frozen prediction is the white paper, finally laid on the table for everyone to point at.

Second: remove each lab’s private tint and compare only the markings underneath. In plain words, instead of comparing only the overall color, which depends on each instrument’s tint, the method separates source, access, and row height. It asks a cleaner question: once the glass is accounted for, does the pattern that remains match the frozen source grammar, and does it match between the labs?

And here is the quietly beautiful result. The labs that disagree about the color can still be read as laboratories looking at the same underlying paper once the access grammar is kept honest. It is as if I finally built the glass I had wanted as a boy, held it up to Mehdi’s red-tinted paper and my green-tinted paper, accounted honestly for both tints, and found the same faint markings hiding beneath each. The disagreement about the color lived partly in the glasses. The pattern underneath became a testable object.

What I will not pretend

I will not tell you the story is finished, because my father taught me to always ask why, and never to dress a half-answer up as a whole one.

Matching the pattern is not yet the same as declaring the paper’s true color. The final step — saying, from the theory alone, what the real absolute number is, and therefore whose glass is the faithful one — is exactly where the live work now sits. It is harder. It may yet prove me wrong. A frozen prediction is brave for exactly that reason: it is allowed to fail, in public, with no place to hide.

But for the first time, the question stands on a floor instead of falling through it: a fixed reference, a declared glass, and a rule that does not let the laboratory row repaint the source after the fact.

For Mehdi

I think about Mehdi often. He could not have known that an idle afternoon question — what if your red is my green? — would become the design principle of a grown man’s physics. The despairing version of his question, the one locked inside our skulls, may never be answered. But its mirror image — the white paper and the colored glasses — turned out to be the most practical question in the world:

How do you tell whether two honest observers, each looking through their own lens, are really seeing the same thing?

You build a better glass. You agree on the paper first. And you keep the courage to be told you were wrong.

That, in the end, is what the muon experiments are teaching us. And for me, it began in a high-school classroom, with a friend, a red object, and a question I could not answer.

— Ali