In the fifth installment of the series in which Fellows of the EATCS
provide their advice to the budding TCS researcher, I am posting the contribution by Wolfgang Thomas. Happy reading!
As
one of the EATCS fellows I have been asked to contribute some
personal words of advice for younger people and on my research
interests. Well, I try my best.
Regarding
advice to a student and young researcher interested in TCS, I start
with two
short sentences:
And
then I add some words on what influenced me
when I started research - you may judge whether my own experiences
that go back to „historical“ times would still help you.
By
the way, advice from historical times, where blackboards and no
projectors were used, posed in an entertaining but clearly wise way,
is Gian-Carlo Rota’s paper „Ten Lessons I Wish I Had Been Taught“
(http://www.ams.org/notices/199701/comm-rota.pdf).
This is a view of a mathematician but still worth reading and
delightful for EATCS members. People like me (68 years old) are also
addressed - in the last lesson „Be Prepared for Old Age“…
Back
in the 1970’s when I started I wanted to do something relevant. For
me this meant that there should be some deeper problems involved, and
that the subject of study is of long-term interest. I was attracted
by the works of Büchi and Rabin just because of this: That was
demanding, and it treated structures that will be important also in
hundred years: the natural numbers with successor, and the tree of
all words (over some alphabet) with successor functions that
represent the attachment of letters.
The
next point is a variation of this. It is a motto I learnt from Büchi,
and it is a warning not to join too small communities where the
members just cite each other. In 1977, when he had seen my
dissertation work, Büchi encouraged me to continue but also said:
Beware of becoming member of an MAS, and he explained that this means
„mutual admiration society“. I think that his advice was good.
I
am also asked to say something about principles for the postdoctoral
phase. It takes determination and devotion to enter it. I can say
just two things, from my own experience as a young person and from
later times. First, as it happens with many postdocs, in my case it
was unclear up to the very last moment whether I would get a
permanent position. In the end I was lucky. But it was a strain. I
already prepared for a gymnasium teacher’s career. And when on a
scientific party I spoke to Saharon Shelah (one of the giants of
model theory) about my worries, he said „well, there is
competition“. How true. So here I just say: Don’t give away your
hopes - and good luck. - The other point is an observation from my
time as a faculty member, and it means that good luck may be actively
supported. When a position is open the people in the respective
department do not just want a brilliant researcher and teacher but
also a colleague. So it is an important advantage when one can prove
that one has more than just one field where one can actively
participate, that one can enter new topics (which anyway is necessary
in a job which lasts for decades), and that one can cooperate (beyond
an MAS). So for the postdoc phase this means to look for a balance
between work on your own and work together with others, and if
possible in different teams of cooperation.
Finally,
a comment on a research topic that excites me at this moment. I find
it interesting to extend more chapters of finite automata theory to
the infinite. This has been done intensively in two ways already - we
know automata with infinite „state space“ (e.g., pushdown
automata where „states“ are combined from control states and
stack contents), and we know automata over infinite words (infinite
sequences of symbols from a finite alphabet). Presently I am
interested in words (or trees or other objects) where the alphabet is
infinite, for example where a letter is a natural number, and in
general where the alphabet is given by an infinite model-theoretic
structure. Infinite words over the alphabet N are well known in
mathematics since hundred years (they are called points of the Baire
space there). In computer science, one is interested in algorithmic
results which have not been the focus in classical set theory and
mathematics, so much is to be done here.
