In the context of the Turing Year 2012, Professor David Harel
from the Weizmann Institute of Science in Rehovot (Israel) received
an honorary doctorate from the Technical University Eindhoven.
Renowned researcher and thinker in computer science, Harel invented
Statecharts, a computing language used broadly for the
specification and development of software and systems.
During his visit to the Netherlands he said to ScienceGuide that
he feels extremely grateful to receive an honorary doctorate from
the University of Eindhoven, the place where many years ago Edsger Dijkstra achieved great advancements for
"His work here at this university was very important for our
discipline. In fact, I believe that the research he conducted right
at this spot was far more relevant than what he did in his later
years at the University of Texas. He was a true pioneer, much more
so than I am. He is someone I really admire and in a way he is much
more like Turing, a brilliant mind himself."
Harel says that he was surprised how little Dijkstra's
achievements are known to the people in Eindhoven and the
Netherlands. "I am amazed that the TU Eindhoven doesn't publicize
this connection more. Dijkstra was a great inspiration and this is
something people need to be aware off. In contrast, I believe that
Stanford puts a great effort in publicizing the fact that
artificial intelligence pioneer John McCarthy worked there."
Not just a great scientist, but a visionary
For the occasion of Alan Turing's 100th birthday TU
Eindhoven organized a symposium during which Harel received his
honorary doctorate. Regarding the symposium's title 'From Turing to
Harel: Pioneers of Computer Science', Harel had some reservations.
"I actually found it embarrassing to be mentioned in one breath
with Turing. I wanted to change the title, but my appeal didn't
work. My contributions are much more modest. After all, I am
standing on the shoulders of Turing."
To the question why he felt so embarrassed about this, Harel cut
straight to the point: "Alan Turing was much more than a great
scientist, he was a true visionary! I am convinced that for at
least another 30 years we will be busy trying to understand what he
wanted to teach us.
His impact on the scientific community is tremendous, especially
given that he died at the age of 42, in the early 50's, and for
that matter under scandalous circumstances. The name of Alan Turing
will go down in history alongside names like Einstein, Galileo, and
Darwin. In a way, his impact on humanity is greater than that of
any of them."
Harel continues explaining that Turing was not a classic natural
scientist. That is also the reason why he or any of his successors
in computer sciences would never receive a Nobel Prize. "For our
discipline this prize simply doesn't exist. Instead, we invented
the 'Turing Award', which Edsger Dijkstra, for instance, received
long ago for his work. This is a distinction of similar importance
as the Nobel Prize, even though people may not be aware of
David Harel then talks with much empathy about Alan Turing's
life and the "outrageous" circumstances under which he died. Turing
was the first to theoretically conceptualize how a machine could be
designed that would solve any computable problem. He also worked on
cryptanalysis, and it was to a large extent Turing's work that
enabled the British to decipher the codes of Enigma, the infamous
Nazi cryptography machine.
Even though this work was a great aid to the Allied war efforts,
Turing received little praise afterwards. In the early 50's Turing
committed suicide following public prosecution due to his
homosexuality. "What happened to Alan Turing is outrageous. The
ingratitude of British society is shameful and it is a terrible
thing that something like that would happen to a brilliant mind
It reminds me of Galileo's fate who was stigmatized by the
church when he postulated that the world was not at the center of
the universe. The Turing Year is only a modest tribute to the
achievements of this man, and especially given what he had to
The world finally recognizes his meaning to scientific progress,
and there are numerous symposia, conferences, gatherings and many
other activities worldwide to mark this special year; in Israel
too. From my part, two of my expository books on the foundations of
computer science, in which Turing's work is central, will come out
this year in new printings."
All in his head
David Harel summarizes Alan Turing's contribution to computer
sciences in one sentence: "He made crystal clear the understanding
of what can and cannot be computed." According to Turing, all
computer languages and systems are equivalent in what they are able
"Whatever the largest, most complex supercomputer can do, any
laptop can do as well - it will only take more time and/or more
memory, etc. This is a radical insight and an extremely robust one
too. Alan Turing theorized this already in 1936, when no computer
had ever been built! He was able to establish this mathematically;
it was simply in his head."
This idea was so extraordinary because Turing's theoretical
computer, later to be called fondly the Turing machine, was
universal. Based on this fundamental concept, the first computers
were designed which could then do any calculation you can think
off. John von Neumann took this elementary idea, and used it in the
basic design of the first 'real' computers.
"It is possible that one day we will be able to build large
quantum computers and these will work differently from the ones we
have right now. Still, they will be only able to do exactly the
same things. They will probably be much, much faster, but they will
not be able to solve anything new.
This greater speed of calculation can be a very handy thing, but
it still does not compare to Turing's fundamental insight that all
computers are equivalent." Meanwhile, the possibility of creating
quantum computers itself has made a leap forward. Recently, a team
surrounding Leo Kouwenhoven discovered the Majorana particle, which could
be a major step towards realizing such a machine.
Modeling biological systems
Now imagine that Alan Turing would have had a better fate,
growing old as a professor in his discipline, what could he have
changed for science? Harel: "It is very hard to tell. The only
thing that I can predict is that he would no doubt have done a lot
more in the field of computational biology.
In his final years, he was particularly fascinated by the
possibility of constructing mathematical models that could analyze
and recreate biological patterns. I think that with his help we
would be 20 years ahead of where we are right now." David Harel
himself has developed a similar passion in combining computer
science and biology. "Analyzing growth patterns in biology is a
vast research field. Just think about what we still have to learn
about biological process like how cancers come about and
For the future, Harel has a clear vision: "Computer science will
become vital to the leading sciences of the 21st century, namely
biology, biochemistry and medicine. This compares to the important
the role mathematics had for breakthroughs in physics in the
20th century." He forecasts that within 15 years a
biologist will have to know almost as much about computer science
as your typical computer scientist. Manipulating biochemical
processes with the help of complex algorithms will be fundamental
to 21st century sciences.
Where then will humanity be during the next Turing Centennial
Year, 2112? What will science be like in 100 years from now? Harel
begins his answer with a quote: "You know there is an old Jewish
saying: 'Prophecy is given to the fools', which is why I am not
going to try to predict what will happen in the future. But there
is something that I would really like to see. But before I begin to
explain, please take a moment and watch this video:
"What you are seeing is the embryo of aC. elegansworm that grows
from a 2 cell organism to an almost mature creature. But this is
only the beginning. Within a couple of years we will be able to
model biological growth processes in much greater detail. At some
point, we will be able to digitally manipulate individual
characteristics like a creature's DNA. What starts with a simple
simulation of a maturing worm could lead to complete, manipulable
computer models of human beings. This way we could decide how to
best detect and cure diseases simply by altering aspects of
realistic computer models."
Outside the lab thick skin needed
David Harel is not only active as a scientist, but has become a
fervent advocate of the Near East peace process. Together with
other intellectuals he advocates for a diplomatic solution and a
fair retreat from most of the territories occupied by Israel in
1967, a stance that is much disliked by Israel's Prime Minister
Netanyahu. "Peace can only exist if both parties come to an
Recently, I have spent around 20% of my time trying to influence
the peace process in Israel. Within computer sciences, there is a
very clear and clean way of thinking. Doing work for the public,
especially in Israel, is much more frustrating and you need
different talents. Above all, what you need is thick skin. Many
people will criticize you as arrogant when you try to use rational
arguments. What I am trying to do with my colleagues is to be
realistic and to take some of the emotions out of the debate."
"Our premise is that fear is one of the reasons that the peace
process is not moving forward. Israelis are afraid of Palestinians
planning to drive them into the sea and Palestinians fear being
thrown out of the country and into Jordan. So we devised a poll
where we asked our citizens whether they would support the peace
process if they became convinced that their fears were
Give Netanyahu the Nobel Prize
83% of all Israelis answered 'Yes'; and even more surprisingly,
76% of those who support Netanyahu's right wing policies responded
with 'Yes'. What we really have to do, is finding a way to
eliminate the fear on both sides of the border. Europe, President
Obama and all the other parties involved can help with this by
Not without irony, Harel then talks about a recent news article
he wrote in the aftermath of an Israeli Chemist winning a Nobel.
Harel asked in his article who would be the next Israeli in line to
receive this distinction in Stockholm. "I wrote that I do in fact
know someone who would very well deserve this award. The only thing
he would have to do for this is to be bold.
I pray that Benjamin Netanyahu will be the next Nobel laureate.
For this to happen, he would really have to do something courageous
and bold, just like De Gaulle or Churchill. I do not have to agree
with what a politician like Netanyahu stands for, but the day he
receives the Nobel Prize I will tip my hat to him and celebrate him
as a hero."
Scientists have the great responsibility to advance our world
with their thoughts, and this is also a maxim David Harel lives by.
But one of the things that fascinate him about Alan Turing is that
he showed that working in many areas can be fruitful too. Harel can
tell enthusiastic stories of how it should actually be possibly to
experience the smell of herbs and flowers when you view a video of
a market in the French Provence.
"I know, this says much about me spreading my interests in an
irresponsible fashion. Often I hear from others that I 'spread my
butter thin'. But this is the price I need to pay, just like Alan
Turing did. Of course it can be very productive to focus all your
attention on one great project. The only problem is that I am
afraid that if I did so I might die of boredom."