Saturday, June 6, 2026

"Feynman solved ‘restaurant dilemma’ 50 years ago — now a study confirms his mathematics"

From the journal Nature, June 1:

An experiment with 2,520 participants backs Richard Feynman’s answer to every diner’s dilemma: do I want to try something new?  

In a scene that could have easily featured in an episode of the US television sitcom The Big Bang Theory, the late US physicist Richard Feynman once turned a visit to a Thai restaurant he often dined at into a mathematical riddle: how adventurous should we be in trying new dishes? Feynman promptly solved this on a sheet of paper.
Now, behavioural scientists have revisited Feynman’s solution — some of which had been obscured by his inscrutable handwriting — and found that his was indeed the optimal strategy.
Feynman’s dilemma is one that will be familiar to any restaurant-goer. Do we keep ordering the best dish we’ve had so far, or do we explore the menu in the hope of finding something better? A study published in the Proceedings of the National Academy of Sciences on 1 June probes this question, and includes experimental findings that participants adopt meal-choosing strategies that closely approximate Feynman’s mathematical solution1.
Behavioural scientist Shoham Choshen-Hillel at the Hebrew University of Jerusalem says that the authors wrote a “super creative article”. “The restaurant example stands in for decisions in many settings,” she adds. Real-life examples include choosing a home to buy, deciding whom to partner up with and selecting a parking spot.

Are you ready to order?

The story begins with a regular visit by Feynman, a Nobel prizewinning physicist at the California Institute of Technology in Pasadena, and his friend Ralph Leighton, to a Thai restaurant in nearby Glendale in the late 1970s. (Leighton helped Feynman to write his popular 1985 memoir Surely You’re Joking, Mr. Feynman! and was the son of the late physicist Robert Leighton, the co-author of the influential 1964 The Feynman Lectures on Physics, together with Feynman and Matthew Sands.) Leighton wondered whether he should order ginger chicken — his favourite dish — or explore the rest of the menu. Feynman began scribbling and promptly claimed he had found a mathematical solution: in his simplified model of the situation, he calculated a threshold — a number of visits beyond which Leighton’s rational decision would be to always settle on his favourite dish

What Feynman had done was turn the restaurant dilemma into a question in decision theory — a field at the intersection of economics and psychology that analyses strategies in one-person games. In particular, it was an original contribution to a larger family of problems in decision theory called stopping problems. These include real-life problems in which someone has to decide whether the possibility they have in front of them is good enough, or whether to keep searching....

....MUCH MORE 

Also at Nature:

Revisiting Feynman on physical law  

In retrospect: The Feynman Lectures on Physics 

And at Climateer Investing, the outro from "COLD CASE — Who smeared Richard Feynman? [FBI FILES]": 

....And later Feynman hangin' at Esalen, Big Sur, CA:

During the Middle Ages there were all kinds of crazy ideas, such as that a piece of rhinoceros horn would increase potency. Then a method was discovered for separating the ideas -- which was to try one to see if it worked, and if it didn't work, to eliminate it. This method became organized, of course, into science. And it developed very well, so that we are now in the scientific age. It is such a scientific age, in fact, that we have difficulty in understanding how witch doctors could ever have existed, when nothing that they proposed ever really worked -- or very little of it did.

But even today I meet lots of people who sooner or later get me into a conversation about UFO's, or astrology, or some form of mysticism, expanded consciousness, new types of awareness, ESP, and so forth. And I've concluded that it's not a scientific world.

Most people believe so many wonderful things that I decided to investigate why they did. And what has been referred to as my curiosity for investigation has landed me in a difficulty where I found so much junk that I'm overwhelmed. First I started out by investigating various ideas of mysticism and mystic experiences. I went into isolation tanks and got many hours of hallucinations, so I know something about that. Then I went to Esalen, which is a hotbed of this kind of thought (it's a wonderful place; you should go visit there). Then I became overwhelmed. I didn't realize how MUCH there was.

At Esalen there are some large baths fed by hot springs situated on a ledge about thirty feet above the ocean. One of my most pleasurable experiences has been to sit in one of those baths and watch the waves crashing onto the rocky slope below, to gaze into the clear blue sky above, and to study a beautiful nude as she quietly appears and settles into the bath with me.

One time I sat down in a bath where there was a beatiful girl sitting with a guy who didn't seem to know her. Right away I began thinking, "Gee! How am I gonna get started talking to this beautiful nude woman?"

I'm trying to figure out what to say, when the guy says to her, "I'm, uh, studying massage. Could I practice on you?"

"Sure", she says. They get out of the bath and she lies down on a massage table nearby.

I think to myself, "What a nifty line! I can never think of anything like that!" He starts to rub her big toe. "I think I feel it", he says. "I feel a kind of dent -- is that the pituitary?"

I blurt out, "You're a helluva long way from the pituitary, man!"

They looked at me, horrified -- I had blown my cover -- and said, "It's reflexology!"

I quickly closed my eyes and appeared to be meditating.....
That, of course is the introduction to Feynman's famous 1974 CalTech commencment speech, "Cargo Cult Science"
More here.

And dozens and dozens more