Saturday, November 29, 2008

Changes in TCS

At the first BAM, I got an idea of how little complexity theory has changed in three decades: after I described Morgenstern's lower bound for arithmetic circuits with bounded constants, Christos noted that he gave a talk about the same paper in 1978, when he was a postdoc at Berkeley. We still have no clue how to prove a superlinear lower bound in the unrestricted model.

At the same meeting, I got to observe a change in the people that define our community, a change that fed right into my anxiety that "Theory of Computer Science" is becoming "Theory." After I defined and drew a butterfly graph, I asked how many people have seen this before; some 3 or 4 people raised their hands (which drops to a very small number once you subtract Christos and Dick Karp). But when I asked who knew that "Fourier characters are orthogonal," all but one had their hands up!

I, for one, grew up thinking supercomputers were cool, and knew all about routing messages, before I learned about those "linear systems" that people apparently wanted to solve on big machines. And, yes, I am suspicious of people who had a "theory is cool!" moment before 100 "CS is cool!" moments.

7 comments:

Anonymous said...

Yes, TCS is more like "Applied Maths" when I am introducing my major to the others.

Yajun said...

Math is cool! Otherwise, people ask you to fix their machines when they know you are in CS.

Anonymous said...

Otherwise, people ask you to fix their machines when they know you are in CS.

Whereas if you're in Math, they immediately give up all interest in you :)

David Klempner said...

It would have been 4 or 5, except I was too tired to drive up from Sunnyvale on Tuesday. :-(

When is the next BAM?

rgrig said...

I guess it depends where you go to school. In EE in Poli (Bucharest) you get to see the butterfly in three courses.

D. Eppstein said...

But Fourier transformations seem to be popular (with good reason) in the new TCS, and how can you understand FFTs if you don't understand butterfly graphs? Unless you care only about the mathematical behavior of the transform and not about performing it quickly...

Paul Beame said...

If you'd asked the same question about the butterfly graph 20 years ago almost everyone would have raised their hands. Many of them would not have had any idea about the FFT connection.