
Vladimir Voevodsky has died - slbenfica
https://www.ias.edu/news/2017/vladimir-voevodsky
======
carlob
During grad school I had to spend a year at IAS, because my advisor was there
on sabbatical.

The Institute is not very grad-student-friendly (by design): there are a lot
of cultural and bureaucratic hurdles a student might find there, such as
refusing any affiliation, both for visa and academic purposes, not offering
proper office place, and a certain aloofness of the faculty.

My experience was a bit better than the norm at the then-new School for System
Biology, but I have a lot of great memories of discussion with Voevodsky over
lunch. He had found in me and another grad student from the same group two
people interested in the use of computers in science, and he didn't care that
we completely out of our depth discussing the foundations of mathematics. We
were both just very interested in how computers were transforming science, and
he kept telling us that the same revolution was going to happens for
mathematics as well, despite the resistance of some of his colleagues.

These discussions sparked an interest I still have for proof verification,
automatic theorem proving, and type systems.

Here's to hoping his legacy lives on and that the revolution he helped start
brings on a new era in mathematics.

~~~
mathgenius
[https://github.com/vladimirias](https://github.com/vladimirias)

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robinhouston
This interview (link below) gives some interesting insight into his work and
motivations. It’s in Russian, but Google Translate does a pretty good job with
it.

[http://baaltii1.livejournal.com/198675.html](http://baaltii1.livejournal.com/198675.html)

Among many other things, he describes some unusual experiences in 2006–7 that
clearly had a powerful impact on his thinking:

[Translation by Google] “I had in a few months acquired a very considerable
experience of visions, voices, periods when parts of my body did not obey me
and a lot of incredible accidents. The most intense period was in mid-April
2007 when I spent 9 days (7 of them in the Mormon capital of Salt Lake City),
never falling asleep for all these days.

Almost from the very beginning, I found that many of these phenomena (voices,
visions, various sensory hallucinations), I can control. So I was not scared
and did not feel sick, but perceived everything as something very interesting,
actively trying to interact with those "creatures" in the auditorial, visual
and then tactile spaces that appeared (themselves or by call) around me. I
must say, probably, to avoid possible speculations on this topic, that I did
not use any drugs during this period, tried to eat and sleep a lot, and drank
diluted white wine.”

~~~
gtt
I'm getting access denied on this entry. Could you copy-pase it somewhere
else?

~~~
jlgaddis
Try this (may have to run it through Translate):
[http://archive.is/b4gHd](http://archive.is/b4gHd)

~~~
stepik777
Second part: [http://archive.is/NtBiy](http://archive.is/NtBiy)

------
monort
Amusing anecdote from the life of Voevodsky
([https://lj.rossia.org/users/tiphareth/2097217.html](https://lj.rossia.org/users/tiphareth/2097217.html)):

 _Voevodsky was too lazy to search for an apartment, so he lived in his office
(at Harvard each graduate student gets a personal office) and slept on the
roof. Unfortunately, the windows of dean office (Willy Schmid) had direct view
at that roof. Volodya didn 't adhere to the usual day routine (and didn't
adhere to anything at all), sometimes he slept during the dean office hours.
Some day Schmid looked through the window and saw a roof and Voevodsky was
sleeping at the roof. It has to be said, that living and sleeping in the
office is a terrible taboo and social stigma in America, so Schmid was
outraged. Voevodsky was almost expelled, but everything turned out well,
though he was forced to rent an apartment and he has lived there from then
on._

~~~
ynotyman
I was a grad student at Harvard... let me correct a few things. First, Wilfred
Schmid would probably _never_ be called Willy. It's a funny idea though. Like
calling the Queen of England Lizzy. He wasn't the dean... he might have been
the dept chair at the time. As for living/sleeping at the office -- it's not a
"terrible taboo and social stigma in America". (I'm American). But it's not
allowed due to problems with hygiene (no showers in most bathrooms), smell,
clutter, disruption at odd hours, etc.. So it's not allowed in any workplace.
When it happens, the response of most departments is sympathy and an effort to
find the cause and find the person a place to live. And grad students at
Harvard are financially supported well enough to afford a decent room in the
area. I mean... I wasn't rich, but lived comfortably in apartments shared with
a few other grad students.

~~~
arkvet
I was a grad student at Harvard in the math department too. In my time there
was a student who decided he was going to sleep in his office (I don't think
sleeping outside is such a great option in the New England winter). These
offices are small - there's a desk, then room for a chair, and shelves for
books above the desk. They are essentially for solo work. Anyway, this student
was handling it fine - showering in the university gym and doing laundry in
the basement of the nearby graduate residence halls, and rolling his bed up in
the morning so as not to be reported by the cleaning staff. Then his
girlfriend visited from abroad and she was so appalled with the suggestion
that they bed down together essentially under his desk, that he ended up
having to pay for them to stay for a week in a decent hotel. After that he
found himself an apartment-share pretty quick.

------
j-pb
F __*. This is an unfatomable loss both him as a amazing person and him as an
outstanding mathematician.

We just lost the Hilbert of the new Hilbert program.

------
danharaj
This is a massive loss for mathematics and the world :(

Although I've never met him, I've been strongly influenced by his writings and
contributions to math, especially his down to earth blog posts.

~~~
defen
That's two Fields Medalists taken entirely too early in the past 3 months (the
other being Maryam Mirzakhani). Very sad.

------
fermigier
From
[http://www.mathunion.org/ICM/ICM2002.1/Main/icm2002.1.0099.0...](http://www.mathunion.org/ICM/ICM2002.1/Main/icm2002.1.0099.0104.ocr.pdf)
(2002):

"Among his main achievements are the following: he defined and developed
motivic cohomology and the A1-homotopy theory of algebraic varieties; he
proved the Milnor conjectures on the K-theory of fields."

Quite an achievement, indeed...

------
fermigier
A great video interview of VV (2014) discussing his career, in english
(subtitled in French) is available here:
[https://vimeo.com/99586217](https://vimeo.com/99586217)

French transcription here:
[http://smf4.emath.fr/Publications/Gazette/2014/142/smf_gazet...](http://smf4.emath.fr/Publications/Gazette/2014/142/smf_gazette_142_87-94.pdf)

------
marchdown
Oh no! I was following his work closely and had high hopes for him delivering
on his vision: type theory and constructive notion of equality not getting in
the way of doing mathematics with computer, but helping us along. It will
hopefully will be picked up by his collaborators.

------
doall
Comments from the members of Homotopy Type Theory - Google Groups.

[https://groups.google.com/forum/#!topic/homotopytypetheory/K...](https://groups.google.com/forum/#!topic/homotopytypetheory/K_4bAZEDRvE)

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dkural
:( Such a huge loss to the world. What a terrible year, to lose such bright
and young mathematicians.

------
cdetrio
Reading the story[1] about Voevodsky, I was reminded of how Bertrand Russell
described Gottlob Frege as "almost superhuman":

> _As I think about acts of integrity and grace, I realise that there is
> nothing in my knowledge to compare with Frege’s dedication to truth. His
> entire life’s work was on the verge of completion, much of his work had been
> ignored to the benefit of men infinitely less capable, his second volume was
> about to be published, and upon finding that his fundamental assumption was
> in error, he responded with intellectual pleasure clearly submerging any
> feelings of personal disappointment. It was almost superhuman and a telling
> indication of that of which men are capable if their dedication is to
> creative work and knowledge instead of cruder efforts to dominate and be
> known._ [2]

And how rare it is to see such "exceptionally honest" academic dialogue as
Frege's:

> _Frege starts his analysis by this exceptionally honest comment : "Hardly
> anything more unfortunate can befall a scientific writer than to have one of
> the foundations of his edifice shaken after the work is finished. This was
> the position I was placed in by a letter of Mr Bertrand Russell, just when
> the printing of this volume was nearing its completion"_ [3]

Voevodsky too, upon finding himself in the same position as Frege, reacted
with a super-human level of integrity and intellectual honesty:

> In 1998, the American mathematician Carlos Simpson published a paper
> indicating there might be a mistake in Voevodsky and Kapranov’s 1990 result.
> For years Voevodsky sifted through the details without making much progress.
> He remained convinced the result was right. Then, in the autumn of 2013, as
> the leaves changed color and summer gave way to autumn, he made a
> breakthrough. Of sorts. He confirmed the error. The important result was no
> longer quite so important.

> “It is plainly wrong. The main theorem is incorrect,” he says. “It’s not
> that there is some gap in the proof. It’s that the main theorem is plainly
> wrong.” The mistake, he explains, was in failing to question the obvious.
> “We had proved that an assertion was indeed true in all of the difficult
> cases, but it turned out to be false in the simple case. We never bothered
> to check.” In confirming the error, he added an addendum to the original
> citation in his official publications list—“Warning: The main theorem of
> this paper was shown by Carlos Simpson to be false.” [1]

It is all the more remarkable that he spent years of working through
painstaking details to prove to himself that he was wrong. And rather than
quietly issuing a retraction, he shouted it from the rooftops, leading a
heroic charge to get mathematicians to stop hand-waving with English-language
proofs, and start writing code. [4]

> _And I now do my mathematics with a proof assistant. I have a lot of wishes
> in terms of getting this proof assistant to work better, but at least I
> don’t have to go home and worry about having made a mistake in my work. I
> know that if I did something, I did it, and I don’t have to come back to it
> nor do I have to worry about my arguments being too complicated or about how
> to convince others that my arguments are correct. I can just trust the
> computer. There are many people in computer science who are contributing to
> our program, but most mathematicians still don’t believe that it is a good
> idea. And I think that is very wrong._ [5]

1\. [https://nautil.us/issue/24/error/in-mathematics-mistakes-
are...](https://nautil.us/issue/24/error/in-mathematics-mistakes-arent-what-
they-used-to-be)

2\. [https://plato.stanford.edu/entries/russell-
paradox/](https://plato.stanford.edu/entries/russell-paradox/)

3\.
[https://en.wikipedia.org/wiki/Russell%27s_paradox#cite_note-...](https://en.wikipedia.org/wiki/Russell%27s_paradox#cite_note-12)

4\. [https://www.quantamagazine.org/univalent-foundations-
redefin...](https://www.quantamagazine.org/univalent-foundations-redefines-
mathematics-20150519/)

5\.
[https://www.ias.edu/sites/default/files/pdfs/publications/le...](https://www.ias.edu/sites/default/files/pdfs/publications/letter-2014-summer.pdf)

~~~
cdetrio
Univalent Foundations is apparently controversial. It appeared to come to a
head a couple years ago when a lively debate played out in the comments of a
blog (including a comment by Voevodsky himself):
[https://mathematicswithoutapologies.wordpress.com/2015/05/13...](https://mathematicswithoutapologies.wordpress.com/2015/05/13/univalent-
foundations-no-comment/#comment-270)

~~~
iheartmemcache
(To contextualize [hopefully without misrepresenting their positions], Lurie
and Vlad both think/thought that axiomatic set theory is not a proper
mathematical foundation. Their disagreement lays in how to construct the
reformalization of mathematics (Univalent Foundations vs Higher Topos Theory).

A (very rough) analogy would be the general consensus of climate change
scientists agreeing on global warming being the result of the rapid re-release
of fossil fuels into the ecosystem but disagreeing on whether the cause is
from shipping container barges or the rapid industrialization of the BRIC
nations.)

Here's what's regarded as the seminal resource[1] on Univalent Foundations.
"Homotopy Type Theory: Univalent Foundations of Mathematics" which Vlad was
working on at IAS. Not only mathematicians but logicians and computer
scientists have made large contributions to this work. Names like Awodey and
Robert Harper will certainly sound familiar to the C.S. crowd here.

[1][https://homotopytypetheory.org/book/](https://homotopytypetheory.org/book/)

------
doall
What a huge loss :(

I have been dreaming that one day we will have a fully developed type system
for programming languages based on HoTT and I can develop a new language based
on that.

------
tuxguy
Does anyone know what happened ?

Was he sick ? Was it cancer ?

~~~
sillysaurus3
Can we not? Do you think that they would have wanted the thread about their
death to be filled with speculation about whether he killed himself or drank
himself to death? No one knows anything, and even if they did it would be
impolite to offer up that information.

He was a great mathematician. RIP.

~~~
widdma
I think if he did have mental health problems, like many others in the field,
it's now more than ever to raise the point. If he didn't it doesn't hurt to
raise the issue, because it is genuine.

If you suffer from anxiety and/or depression, there is help. Talk to someone.
You're not alone, and you don't need to suffer alone.

------
SomeStupidPoint
A great loss for mathematics!

I became familiar with his work through HoTT --

> More recently he became interested in type-theoretic formalizations of
> mathematics and automated proof verification. He was working on new
> foundations of mathematics based on homotopy-theoretic semantics of Martin-
> Löf type theories. His new "Univalence Axiom" has had a dramatic impact in
> both mathematics and computer science.

And some of his online lectures outlining his reasoning and motivations became
greatly influential on my own interests.

~~~
saganus
Could you expand on his work, related to CS and/or his influence in your work?

I've never heard of him so I'm curious, being a Field medalist and all.

~~~
danharaj
Voevodsky won the Fields medal for A^1 homotopy theory:
[https://en.wikipedia.org/wiki/A%C2%B9_homotopy_theory](https://en.wikipedia.org/wiki/A%C2%B9_homotopy_theory)

It's quite technical to describe what that is, but the general idea is that he
imported homotopy theory, a fundamental concept in mathematics which allows
you to describe topology with an algebra of paths in that geometry, to
algebraic geometry. This allowed him to solve some major open problems in the
field.

Topology is essentially the study of continuity and the properties that are
invariant of objects under continuous deformation. The prototypical example of
a topological space is the continuum although the concept of continuity has
been generalized a great deal. Homotopy is the study of continuous paths which
are defined as continuous functions from the unit interval into topological
spaces, as well as higher dimensional "paths". It turns out that these paths
have a rich algebraic structure which give you a strong idea of what the
"shape" of the space is like.

Classically algebraic geometry is the study of solutions to systems of
polynomial equations over systems of numbers related to the integers,
rationals, reals, and complex numbers. More modernly, it is the study of
models of theories that resemble the previously mentioned theory in
fundamental ways. For example, the theory of elliptic curves which underlies
some of our modern cryptography is part of algebraic geometry.

~~~
johnvega
I think topology is mentioned in recent Microsoft Ignite Quantum Computing
discussions from at least 1 panel who is a mathematician. I wonder how it
might be related.

~~~
danharaj
Topology of course is fundamental to all of physics, but in that context my
guess would be on topological quantum computing:
[https://en.wikipedia.org/wiki/Topological_quantum_computer](https://en.wikipedia.org/wiki/Topological_quantum_computer)

I once attended a talk on the subject by Michael Freedman who is with
Microsoft Station Q. They are trying to build just such a computer.

~~~
SomeStupidPoint
Since you didn't include it, but it's relevant to the topic at hand -- Michael
Freedman is also a Fields medalist that did substantial work in topology.
Which is, ultimately, why he's involved with Station Q -- he was part of the
group that realized you could use the topological structure of certain
interactions to encode general computations, and was part of convincing MS to
pursue that.

[https://en.wikipedia.org/wiki/Michael_Freedman](https://en.wikipedia.org/wiki/Michael_Freedman)

~~~
johnvega
Vladimir Voevodsky's legacy could be part of Quantum Computer design if it
pans out in the future.

------
mathgenius
The name Voevodksy comes from two old russian words: vodit, which means "to
lead", and voena which means war. So, voevod, would mean something like "war
leader", or general. (Source: russian friend that I just consulted.)

~~~
iagooar
In Polish, there is the word "wojewoda" (Polish uses "w" where in English or
Latin languages you would use a "v"). Historically it meant the same as in
Russian, but nowadays it is the title of the governor of a province.

To make things even more interesting, Poland is actually divided in regions /
provinces called "województwa" (plural), or literally "lands that belong to
the wojewoda". A "województwo" (singular) is more or less the equivalent of a
German "Land" or US American "states".

------
grondilu
That's young. What happened?

