Parable of the vanilla ice cream curse (and how it would prevent a car from starting!)
Story from https://www.cs.cmu.edu/~wkw/humour/carproblems.txt (my thoughts follow):
For those of us who understand that the obvious is not
always the solution, and that the facts, no matter how implausible,
are still the facts …A complaint was received by the Pontiac Division of General Motors:
“This is the second time I have written you, and I don’t blame you
for not answering me, because I kind of sounded crazy, but it is a
fact that we have a tradition in our family of ice cream for dessert
after dinner each night. But the kind of ice cream varies so, every
night, after we’ve eaten, the whole family votes on which kind of ice
cream we should have and I drive down to the store to get it. It’s
also a fact that I recently purchased a new Pontiac and since then my
trips to the store have created a problem. You see, every time I buy
vanilla ice cream, when I start back from the store my car won’t
start. If I get any other kind of ice cream, the car starts just
fine. I want you to know I’m serious about this question, no matter
how silly it sounds: ‘What is there about a Pontiac that makes it not
start when I get vanilla ice cream, and easy to start whenever I get
any other kind?’”The Pontiac President was understandably skeptical about the letter,
but sent an engineer to check it out anyway. The latter was surprised
to be greeted by a successful, obviously well-educated man in a fine
neighborhood. He had arranged to meet the man just after dinner time,
so the two hopped into the car and drove to the ice cream store. It
was vanilla ice cream that night and, sure enough, after they came
back to the car, it wouldn’t start.The engineer returned for three more nights. The first night, the
man got chocolate. The car started. The second night, he got
strawberry. The car started. The third night he ordered vanilla.
The car failed to start.Now the engineer, being a logical man, refused to believe that this
man’s car was allergic to vanilla ice cream. He arranged, therefore,
to continue his visits for as long as it took to solve the
problem. And toward this end he began to take notes: he jotted down
all sorts of data, time of day, type of gas used, time to drive back
and forth, etc.In a short time, he had a clue: the man took less time to buy
vanilla than any other flavor. Why? The answer was in the layout of
the store.Vanilla, being the most popular flavor, was in a separate case at
the front of the store for quick pickup. All the other flavors were
kept in the back of the store at a different counter where it took
considerably longer to find the flavor and get checked out.Now the question for the engineer was why the car wouldn’t start
when it took less time. Once time became the problem—not the
vanilla ice cream—the engineer quickly came up with the answer:
vapor lock. It was happening every night, but the extra time taken to
get the other flavors allowed the engine to cool down sufficiently to
start. When the man got vanilla, the engine was still too hot for the
vapor lock to dissipate.Moral of the story: even insane-looking problems are sometimes real.
There are times when people tell me that (metaphorically) their car won’t start because of the vanilla ice cream spell.
I usually assign rather low probability to their claims that (metaphorically) “vanilla ice cream causes their car to not start”.
But I also would still assign very low probability to the “vanilla ice cream spell” explanation of the causation even if I believed a lot of scientifically sound data was collected to support the causal link between “buying ice cream” and “car won’t start”.
I’m not “refusing the evidence” by not believing in the vanilla ice cream spell hypothesis. The data just says there’s a causal link—it doesn’t say why. Jumping to the spell hypothesis disregards everything else we know about physics—it’s more likely that there’s a more reasonable explanation we didn’t think of. By reasonable, I mean an explanation that would add up to normality—that wouldn’t require us to update our would model nearly as much.
See also: The case of the 500-mile email
This claims that connect calls were aborted after 3 milliseconds and could successfully connect to servers within 3 light milliseconds, but that doesn’t make sense because connecting to a server 500 miles away should result in it sending a handshake signal back to you, which would be received 6 milliseconds after the call had been made and 3 milliseconds after it had been aborted.
This story appears to be made up.
See the FAQ.
His defense on the handshake is to acknowledge that he lied about the 3 millisecond timeout but the story is still true anyway. This is the opposite of convincing! What do you expect a liar to say, “Dang, you got me”? Elsewhere, to fix another plot hole he needs to hypothesize that Sun was shipping a version of Sendmail V5 which had been modified for backwards compatibility with V8 config files.
There is some number of suspicious details at which it becomes appropriate to assume the story is made up, and if you don’t think this story meets that bar then I have a bridge to sell you.
For what it’s worth, I sent this story to a friend the other day, who’s probably ~50 now and was very active on the Internet in the 90s—thinking he’d find it amusing if he hadn’t come across it before
Not only did he remember this story contemporaneously, but he said he was the recipient of the test-email for a particular city mentioned in the article!
This is someone of high-integrity whom I trust, and makes me more confident this happened, even if some details are smoothed over as described
This is addressed in the FAQ linked at the top of the page. TL;DR: The author insists that the gist of the story is true, but acknowledges that he glossed over a lot of intermediate debugging steps, including accounting for the return time.
wow, nice, thanks for sharing 😅
When I started making double batches of pancake batter, they came out fluffier.
I checked and re-checked all the math on the doubling so many times to make sure I wasn’t adding too much or too little of something, but the ratios were all right.
Eventually I realized I was going through baking powder faster and so the baking powder was fresher.
This story isn’t true. It is an urban legend and intrinsically hard to confirm, but we can be quite confident this version of the story is false because almost every detail has been changed from the original telling (as documented in Curses! Broiled Again!, a collection of urban legends available on Libgen) where it was a woman calling the car dealership which sent a mechanic, and the vapor lock formed because vanilla ice cream was slower to buy because it had to be hand-packaged.
When someone says something incredibly implausible is happening, the more reasonable explanation is not that it somehow makes sense, it’s that they’re making shit up.
True or not, wouldn’t you say the idea it illustrates is sound? No matter how small a percentage of the time, a nonzero number of people claiming ridiculous things are telling the truth (just framing it in a ridiculous way with wrong correlations).
If as a society we investigated these cases more often instead of dismissing them, would it lead to a net positive for humanity? For example, if everyone heard “drinking mud soup in this specific part of the world consistently cures X affliction”, and dismissed it- wouldn’t most pharmaceutical companies not have found their star compounds used in bestselling drugs?
To be clear, I agree that majority of these wild tales lead nowhere, but I wonder if it’s worth investigating even for the minority of cases which lead somewhere unexpected.
If investigating things was was free, sure. But the reason we don’t investigate things is that doing so takes time, and the expected value of finding something novel is often lower than the expected cost of an investigation. To make it concrete, the story as presented is an insane way to run a company and would result in spending an enormous number of engineer hours on wild goose chases. If I as the CEO found out a middle manager was sending out engineers on four day assignments to everyone who writes us a crazy-sounding letter, I would tell him to immediately stop wasting company resources.
I have no strong opinion on whether society investigates too many or too few of these claims, but I keep observing that many people’s models seem to lack the “maybe he’s lying” theory, which would give them an inflated estimate of the expected value for investigating things.
I am hopeful that cheaper expert intelligence via AI will lower investigation costs, and maybe help clear up some stubborn mysteries. Particularly ones related to complex contexts, like medicine and biology.
Yes to both! The lying model is great to have especially on the internet where everyone trolls for fun. But to Nathan’s point especially as cost of intellectual labor goes to zero, the net benefits of investigating these cases would keep increasing. Seems worth a try to find some obscure low hanging fruit!
This definitely happens too, but have you ever had to deal with customer service departments unwilling to think anything is something other than the most obvious? Or dealt with a hard to diagnose medical condition and had doctor after doctor keep insisting on going through the same useless-to-you diagnostic flow chart until you finally find one willing to actually think with you?
In some contexts, there’s also the opposite problem of people seeing a hard to understand problem and insisting they need to investigate when that’s not necessary for finding a solution. In analogy to the (yes, very possibly false) vanilla ice cream story, the man could have tried switching brands of vanilla, or walking to the aisle instead of buying from the endcap, or buying multiple pints of ice cream during normal grocery shopping to last the week instead of making a special trip, without ever bothering to investigate. Or, if you have symptoms that your doctor thinks come from an inoperable congenital defect, but the solution for the symptoms is the same medication whether you have the defect or not, then there’s no value in finding the etiology, and no real reason for them to insist on expensive tests, but they often will anyway before treating, and pointing out this fact doesn’t always help.
Link?
Link. But you know you can just go onto Ligben and type in the name yourself, right? You don’t need to ask for a link.
I didn’t, actually; I’ve never used libgen before and assumed there’d be more to it. Thanks for taking the time to show me otherwise.
Love this example!
Reminds me of the “haunted apartment” case in Korea, where dogs kept going insane near a certain spot by the entrance of the apartment complex, and eventually investigators realized there was a malfunction that caused an electric current on the entrance floor, which the dogs’ paws could feel but humans with shoes couldn’t detect.
I wonder what other phenomena we’re too quick to dismiss because they’re framed in a way that sounds absurd.
Working as the programmer on a game, I would get bug reports from artists playing through themselves, often including their own hypothesis as to what was causing the issue. These issues were all obviously real and required immediate diagnosis, but over time (for issues with non-obvious causes) I learned to take the artists’ “helpful” speculations as indicators of where not to start looking.