Years ago I read about a topologist who was to enter the states as an immigrant and was asked a question about his profession. He indicated he was a topologist, but as this was not included on the officer's list, he wanted to check him in as a "mathematician", which was on his list.

But, the topologist refused being classified as an ordinary mathematician, and insisted on "topologist".

The argument escalated and finally they put the topologist in a psychiatric institute, out of which he was freed by a colleague mathematician who explained the situation to the police.

The question is now: what's the name of this topologist; I can't remember his name anymore.

Some years ago (must have been between september 2000 and october 2004) I read his biography, I believe in the Notices of the AMS, but it may have been another publication by AMS, MAA or EMS as well. Some details in the story might be slightly wrong due to failing memories.

Can someone please provide me his name, and maybe the reference to the biography as well? That would be very friendly!

Thanks in advance for this!

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    $\begingroup$ Interestingly, I had exactly the opposite experience in the 90-ties. When asked about my field of research I thought "what could you know about branches of mathematics", and answered "mathematics". However, the officer insisted to be more specific. I thought "as you wish" and expanded: "topology, more precisely algebraic topology, more precisely homotopy theory, more precisely homotopical localizations". The officer looked happily and was writing something... $\endgroup$ Commented Aug 8, 2014 at 13:59
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    $\begingroup$ @AdamPrzeździecki, I also struggle with what to tell immigration officers, and usually just settle on 'mathematician'. Once, I was trying to board a flight at Schiphol after a long and trying night, and was stopped by a KLM person who was not satisfied. "What kind of mathematician?" he asked, and I said "Harmonic analyst." "What kind of harmonic analysis?" he asked, and, moved by what impulse (except extreme tiredness) I don't know, I said "You wouldn't understand if I told you, so why are you asking?" Somehow I still managed to get onto the plane eventually. $\endgroup$
    – LSpice
    Commented Aug 8, 2014 at 15:00
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    $\begingroup$ I wonder how many views and votes this got as a result of being featured as a "Hot network question" on other StackExchange sites, and how many come from the misleading title. $\endgroup$ Commented Aug 8, 2014 at 21:08
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    $\begingroup$ @Adam Przeździecki That depends on the country. In Israel a lot of customs staff are Tel Aviv university students working part time. So, not only do they ask for specific field, but if I'm careless enough to say that I came to work with some faculty at TAU, they ask "Who?", "How does he look?", etc. $\endgroup$
    – fedja
    Commented Aug 8, 2014 at 23:30
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    $\begingroup$ I know of a colleague who was asked the Taylor formula, by an immigration officer in Israel. $\endgroup$ Commented Aug 9, 2014 at 5:24

1 Answer 1


It seems to me you are referring to Egbert Rudolf van Kampen (but the problem at the immigration office was quickly solved by a phone call to the university, the Johns Hopkins I believe). The story is told by Mark Kac, in his book Enigmas of Chance: An Autobiography.

rmk The point of Mark Kac's enjoyable anecdote is not that v.K. refused the label "mathematician", but that he was so immersed in his topic, and considered his activity so natural, that naively believed that even an immigration officer should have known what it was. According to Mark Kac's story, at the officer's request "what's a topologist", v.K. would have started explaining fundamental groups and exact sequences (possibly a humorous exaggeration).


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