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From Computational Complexity

I was at the March for Science on Saturday

(Will blog on Harry Lewis's 70th Bday next week-- Today's post is more time sensitive.) I was on the March for Science on April 22. Here are some Kolmogorov random...

From Computational Complexity

Will talk about Harry Lewis 70th bday conference later but for now- that was then/this is now

On Wed April 19 I was at the Harry Lewis 70th birthday celebration! I will blog on that later. Harry Lewis was my thesis adviser. Odd to use the past tense- I...

From Computational Complexity

What is William Rowan Hamilton know for- for us? for everyone else?

I found the song William Rowan Hamilton that I used in my April fools day post because I was working on a song about Hamiltonian Circuits to the tune of Alexander...

From Computational Complexity

Proving Langs not Regular using Comm Complexity

(My notes on this are at my course website: here They are notes for my ugrad students so they may be longer and more detailed than you want.) While Teaching...

From Computational Complexity

William Rowan Hamilton- The Musical!

With the success of Hamilton,the musical on broadway (for all of the songs and the lyrics to them see here- I wonder who would buy the CD since its here for free)...

From Computational Complexity

If you want to help your bad students DO NOT give an easy exam

1) When I was a grad student TAing Formal Lang Theory we had a final ready to give out but noticed that one problem was too hard. So we changed it. But we made...

From Computational Complexity

Other fields of math don't prove barrier results- why do we?

Before FLT was solved did some people prove theorems like: FLT cannot be proven using techniques BLAH. This is important since all current proofs use BLAH. Ihere...

From Computational Complexity

why are regular expressions defined the way they are

BILL: The best way to prove closure properties of regular languages is to first prove  the equiv of DFA's, NDFA's and Reg Expressions. Then, if you want to prove...

From Computational Complexity

Should we learn from the Masters or the Pupils (Sequel)

A while back I had a blog entry Should we learn from the Masters of the Pupils? The Masters may have more insights but he Pupils may have a better view aided by...

From Computational Complexity

The benefits of Recreational Mathematics

Why study Recreational Mathematics? Why do recreational Mathematics? 1)  The line between recreational and serious mathematics is thin. Some of the problems in...

From Computational Complexity

Raymond Smullyan: Logician, Recreational math writer, Philosopher, passed away

Raymond Smullyan was born on May 25 1919 and passed away recently at the age of 97.  He was a logician (PhD from Princeton under Alonzo Church in 1959) who didThe...

From Computational Complexity

The Hardness of Reals Hierarchy

In my last post (here) I defined the following hierarchy (which I am sure is not original- if someone has a source please leave a comment on it) Z_d[x] is theProblems...

From Computational Complexity

What was the first result in complexity theory?

Let Z_d[x] be the set of polynomials of degree d over the integers. Let ALG_d be the set of roots of polys in Z_d. One can easily show that ALG_1 is a proper...

From Computational Complexity

My Once-Every-Four-Years Presidential Quiz/How Should Quizzes Work in the e-Era?

Every four years I post a PRESIDENTIAL QUIZ which I must update based on new information since we have a new prez and veep. The questions are here:here. I...

From Computational Complexity

My REU program/REU's in general/Flyers? Why do some Transcripts...

I run an REU program (Research Experience for Undergraduates) and I would normally urge you to urge undergrads who would benefit to apply to it and present both...

From Computational Complexity

Guest Post about the first Women in Computational Topology (WinCompTop) Workshop

The first Women in Computational Topology WinCompTop workshop was held in August at the Institute for Mathematics and its Applications (IMA) in Minneapolis, MN....

From Computational Complexity

Predictions for 2017

Lance's Complexity Year in Review, posted the last week of the year (lets hope that P vs NP is not resolved on Dec 31) is a tradition that goes back to 2002.  Bill...

From Computational Complexity

The very first Ramseyian Theorem

Many years ago I noticed that in several books on Ramsey Theory  mention that  Hilbert proved the first   Ramseyian theorem.  The theorem is the Hilbert Cube...

From Computational Complexity

Guest post by Samir Khuller on Humans, Machines, and the Future of Work (a workshop)

Guest Post from Samir Khuller on Humans, Machines, and the Future of Work (A Workshop) On Dec 5th and 6th I attended, at Rice University, a workshop on Humans...

From Computational Complexity

A students unusual proof might be a better proof

I asked a student to show that between any two rationals is a rational. She did the following: if x < y are rational then take δ << y-x and rational and use...
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