lectures on computer science are today compared to only 15 years ago.
Today, he is far more focused on reasoning and computing in high-di-mensionality data rather than operating systems, programming languages,
and data structures. What completely
surprised me was the reasoning that
leads to the conclusion that the unit
sphere in extremely high-dimension-ality spaces has vanishing volume.
There were surprises like this laced
throughout an entertaining but very
thought-provoking examination of
the modern computer science curriculum as he sees it.
A visit to the European Molecular Biology Laboratory (EMBL) on
the outskirts of Heidelberg proved
to be very stimulating. Surrounded
by energetic and thoughtful mathematics and computer science graduates, post-docs, and junior faculty,
we heard a remarkable lecture about
what is known about the complex
operation of cells and the particularly interesting way in which micro-tubules are used to guide the transport of complex biochemicals within
the cell. Computational biology was
“in the air” at EMBL and the HLF. If
anything stood out for me, it was the
increasing role of computing and
mathematics in diverse subjects including astrophysics, biochemistry,
and mathematical topology among so
many other modern interests.
The Heidelberg Laureate Forum is
one of the best new activities in which
ACM is engaged and I predict it will become a strong and new tradition among
the many ways in which ACM contributes to and reinforces the importance
of computing in our society.
Vinton G. Cerf is VP and Chief Internet Evangelist at Google.
He served as ACM president from 2012–2014.
Copyright held by author
The primary mover, Klaus Tschira
(a founder of the German software
firm SAP), has again generously supported this weeklong event through
his personal foundation. ACM (Turing
Award), the International Mathematics Union (Fields Medal and Nevanlin-na Prize) and the Norwegian Academy
of Science and Letters (Abel Prize) are
additional sponsors and organize the
selection of the 200 young researchers who join the laureates for the
week. There were plenty of opportunities for formal lectures and informal
small group gatherings to link the 100
mathematics and 100 computer science researchers to each other and the
laureates in attendance. The HLF staff
provided superb planning, operational and logistical support throughout
this event, adapting in real time to
suggestions for improvement.
It would be difficult to overstate the
energy levels reached at this event. If
we had been arranged in a circle, we
might have outdone the Large Hadron
Collider at CERN! As usual, I learned
many new things from both the mathematicians and the computer scientists. While I have only limited space
in this column, I would like to share
some of the interesting surprises that
came my way.
Ivan Sutherland was in attendance
again this year and while discussing
computer architecture using asyn-
chronous circuits, he told me about a
very interesting idea that has implica-
tions for improving software safety.
We all know a register of N bits has 2N
values, 0–2N– 1. Right? Wrong! Turns
out, as Ivan grinningly reported, there
is another value, “empty.” That is, if
nothing has been stored in the reg-
ister, the hardware should produce
an exception to any attempt to make
use of the (non)value in that register.
Flagging such an event should reduce
the incidence of using the contents
of an uninitiated register that could
lead to any of a variety of bad effects.
This begs the question, “When does
the ‘empty’ flag get set?” It is obvious
that it must be reset when something
is stored in the register. One might set
the bit when a “new” register is created
in a push-down stack, for instance. Or
when memory is returned to the “free
pool” in a garbage-collecting system.
When a register is popped off the
push-down stack it should be treated
as empty of any value. This idea rein-
forces the more general sense that
safety and security of programs might
be improved by creating a partnership
in the form of hardware-reinforced
security or safety measures.
Leslie Lamport, recipient of the
2013 Turing award, gave one of the
lectures. He spoke eloquently on the
topic of proofs (not just of program cor-
rectness but of any proofs). He made a
strong and vivid case for changing from
the 17th-century style of narrative proofs
to a 21st-century style in which it is clear
at each step what precedents are being
invoked for each step in the proof. The
use of a terse symbolic representation
versus a narrative made the basis for
each assertion far more apparent.
John Hopcroft gave an example-rich talk illustrating how different his
The second Heidelberg Laureate Forum
(HLF) has just ended. Taking place annually
in this historic city, this conference was
even better than the first, if that is possible.
Heidelberg Laureate Forum II
DOI: 10.1145/2674716 Vinton G. Cerf