Skip to content

Stockholm Restrooms

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Section 1, session 5. Discussed together with Phone Cord Problem, in the session devoted to N-Rays and Langmuir's "Pathological Science".

The problem

Reconstructed from the syllabus: the original handout has not been found, and what follows is a modest reconstruction from the name, the session and the section theme, not Winfree's text.

The syllabus lists "discuss Stockholm restrooms" for the session on N-rays and pathological science. The item appears to have been a short observation-and-explanation exercise in the spirit of that session: an everyday oddity noticed by a traveller, to be explained by first establishing the facts and only then proposing rival explanations and ways to test them. A faithful version of the exercise runs like this.

  1. Take one of these travellers' reports about public restrooms in Stockholm. All three are things visitors have actually reported; which one, if any, Winfree used is not known.
    • (a) In Stockholm's shopping centres, cafes and even at Arlanda airport, a visitor from the United States finds that many public toilets are single rooms with no "Men" or "Women" on the door, and no urinals anywhere.
    • (b) Where there are separate rooms, the doors read "Herrar" and "Damer".
    • © At a conference reception the queue for the women's restroom is long while the men's has none.
  2. Write down exactly what was observed, and separate it from what was assumed. Is "there is no men's room" an observation, or an inference from not finding a sign you expected?
  3. Give at least three explanations, including one in which the observer is simply mistaken. For each, say what further observation would count against it.
  4. Only then decide which explanation you believe, and how strongly.

The exercise is about method, not about Swedish plumbing: notice how fast an explanation arrives before the facts are settled, and how much of the "mystery" your own assumptions manufactured.

Why it is in the course

Session 5 sits in Section 1, "Detecting Nonsense, Error Checking, False Assumptions, Cherishing Mistakes". Its readings were the N-ray story and Langmuir's "Pathological Science": honest scientists who reported effects near the threshold of detectability and then defended them against all evidence. The session before had made a related point with historical cases: "Golden Tooth: facts before explanations of facts" and "Bookworm's Journey: distinguishing things we know vs only imagine".

A small travel anecdote is a natural everyday-scale companion to those grand cases. It lets a student catch themselves supplying an explanation before the facts are in, and see how much of a puzzle can be created by an assumption imported from home. That fits Winfree's own account of the course puzzles in the syllabus: "The purpose of the puzzles (many of them silly) is to slow you down for a few minutes so you can examine the working of your own mind." But that reading is an inference. The syllabus gives the name and the session, and nothing else.

Where it comes from

No published source for a problem called "Stockholm restrooms" has been found, and the syllabus is the only Winfree document that names it. The archived copy of his course handout carries that same schedule, with the retrospective Spring 2001 dates shifted to the Fall 2001 calendar, and lists the item for session 05 with no explanation. Captures of the handout from 2002 to 2005 all carry the same text.

Nothing else he left online mentions it. The editors searched the archived pages of his University of Arizona lab site that could be retrieved: the course handout, the lab home page, the student comments, and his surviving "Adventures in Discovery" columns for the Society for Amateur Scientists (2001-2002). None contains "Stockholm", "restroom", "toilet" or "Sweden". A complete listing of the archived site could not be obtained, so the search is thorough but not exhaustive. The item was most likely a personal anecdote, handed out on paper and now lost.

The everyday facts behind the three candidate readings below are real and sourced at the end of this page, whether or not any of them was Winfree's: unisex single-occupancy toilets are the Swedish norm and surprise American visitors; the longer queue at women's restrooms is a real effect with a mundane multi-causal explanation, measured by queueing theorists at Ghent University in 2017; and hemisphere-dependent drain swirl is a misconception, the Coriolis acceleration at mid-latitudes being far too weak, as Scientific American's "Ask the Experts" panel spelled out.

Hints
  • Before explaining anything, list what was actually seen and separate it from what was inferred. "There is no men's room" may be an inference from not finding a sign you expected.
  • Ask what a visitor from Tucson assumes at a restroom door in Stockholm: how many doors there should be, what the words mean, what fixtures are inside. Test each assumption.
  • Include the possibility that the observer is mistaken among your rival explanations, and say for each what observation would rule it out.
  • Compare with the session's readings. Which of Langmuir's symptoms of pathological science (an effect near the limit of detectability, claims of great accuracy, ad hoc excuses, a ratio of supporters to critics that rises and then falls) would fit someone who refused to give up their first explanation?

Sources

  • Arthur T. Winfree, The Art of Scientific Discovery (ECOL 479/479H/579) course handout with retrospective Spring 2001 syllabus (2001), archived copy of 20 April 2002 — Wayback Machine 🔓
  • Arthur T. Winfree, A. T. Winfree lab home page, with links to the course, student comments and the "Adventures in Discovery" columns (archived 2002) — Wayback Machine 🔓
  • Irving Langmuir, transcribed by R. N. Hall, Pathological Science (colloquium of 18 December 1953; GE report 68-C-035, 1968), online edition by Theo Pavlidis and Ken Steiglitz — Princeton 🔓
  • Irving Langmuir, Pathological Science (PDF copy of the transcript with background note) — University of Virginia 🔓
  • Wikipedia, "Pathological science" (overview) — Wikipedia 🔓
  • Ghent University (Phys.org news release), "Researchers study lengths of restroom queues" (2017) — Phys.org 🔓
  • Scientific American (Ask the Experts: Brad Hanson, Fred Decker, Robert Ehrlich and Thomas Humphrey), "Does water flowing down a drain spin in different directions depending on which hemisphere you're in?" (28 January 2001) — Scientific American 🔓
  • The Local (Sweden), "Swedes confused over gender neutral toilets" (13 February 2015) — The Local 🔓
  • Accidental Travel Writer (blog), "Unisex Toilets, an Idea Whose Time Has Come?" (2016) — Accidental Travel Writer 🔓
  • Arthur T. Winfree, The Art of Scientific Discovery: original course syllabus (2001) — PDF 🔓

How sure are we that this is Winfree's problem?

Not at all: the identification is unknown. The syllabus gives the name, the session and its neighbour in the same line, the phone cord problem, which is also unidentified. The editors read the archived handout, Winfree's lab page and his surviving columns, and searched on the exact name and every plausible form of the puzzle; nothing turned up. The statement above is a reconstruction, and these three readings are inferences from the name and the session theme, all of low confidence and none tied to Winfree by any source.

  • A hidden-assumption story: an American visitor is baffled by unisex single-occupancy toilets, or misreads "Herrar" and "Damer", until a false assumption is dropped. This fits the section's theme.
  • A queue exercise: why queues form at women's restrooms and not at men's, with rival hypotheses ranked and tested. A vivid effect for which everyone has a ready explanation, few of them checked.
  • A drain-swirl exercise: the folk belief about the Coriolis effect, closest to Langmuir's first symptom, an effect at the limit of detectability, though that belief is usually framed as a comparison across the equator rather than as a Stockholm story.

If the original handout ever surfaces, from a former student's binder for instance, it should replace this reconstruction.

Back to Section 1 · All problems · The schedule

Machine-readable: this page as Markdown · raw source on GitHub · llms.txt · llms-full.txt (whole site). See For AI agents.