Skip to content

A Quantum Two-Finger Exercise

April 8, 2015


More mileage than expected from a little example

CarrollBlackboard
Cropped from World Science Festival source

Sean Carroll is a cosmologist in the Department of Physics at Caltech. He also maintains a blog, “Preposterous Universe,” and writes books promoting the public understanding of science. I have recently been enjoying his 2010 book From Eternity to Here: The Quest for the Ultimate Theory of Time.

Today—yes, Carroll would agree that there is a today—I would like to share an interpretation of a little quantum computing example that occurred to me while reading his book.
Read more…

April Fool

April 1, 2015


Non-jokes on April Fool’s Day

nunspriest
Nun’s Priest’s Tale source

Faadosly Polir is the older brother of Lofa Polir. You may recall he invented new ways to apply powerful mathematical techniques to prove trivial theorems, and she once claimed a great result on integer factoring. We have heard from both since, but they haven’t given us any new April Fool’s Day material, mainly because they weren’t fooling to begin with.

Today Ken and I wished to help you enjoy April Fool’s day.
Read more…

Is It New?

March 24, 2015


How to tell algorithms apart

egdaylightSummerPic

Edgar Daylight was trained both as a computer scientist and as a historian. He writes a historical blog themed for his near-namesake Edsger Dijkstra, titled, “Dijkstra’s Rallying Cry for Generalization.” He is a co-author with Don Knuth of the 2014 book: Algorithmic Barriers Failing: P=NP?, which consists of a series of interviews of Knuth, extending their first book in 2013.

Today I wish to talk about this book, focusing on one aspect.
Read more…

Leprechauns Will Find You

March 17, 2015

And perhaps even find your hidden prime factors

 

leprechaun_256

Neil L. is a Leprechaun. He has visited me every St. Patrick’s Day since I began the blog in 2009. In fact he visited me every St. Patrick’s Day before then, but I never talked about him. Sometimes he comes after midnight the night before, or falls asleep on my sofa waiting for me to rise. But this time there was no sign of him as I came back from a long day of teaching and meetings and went out again for errands.

Today Ken and I wish you all a Happy St. Patrick’s Day, and I am glad to report that Neil did find me.
Read more…

The Other Pi Day

March 14, 2015


It’s 3/14/15, do you know how much your Π costs?

pi-tag-usa-artikel-410
source

Larry Shaw apparently created the concept of Pi Day in 1988. He was then a physicist who worked at the San Francisco Exploratorium. He and his colleagues initially celebrated by marching around in circles, and then eating pies—that is fruit pies. As Homer Simpson would say: hmm.

Today Ken and I want to add to some of the fun of Pi Day, and come back to a different Pi that has occupied us.
Read more…

Lint For Math

March 8, 2015


Can we remove simple errors from math proofs?

825-SteveJohnson
simple-talk interview source

Stephen Johnson is one of the world’s top programmers. Top programmers are inherently lazy: they prefer to build tools rather than write code. This led Steve to create some of great software tools that made UNIX so powerful, especially in the “early days.” These included the parser generator named Yacc for “Yet Another Compiler Compiler.”
Read more…

News on Intermediate Problems

March 5, 2015


The Minimum Circuit Size Problem goes front and center

EricDasRyanCody

Eric Allender, Bireswar Das, Cody Murray, and Ryan Williams have proved new results about problems in the range between {\mathsf{P}} and {\mathsf{NP}}-complete. According to the wide majority view of complexity the range is vast, but it is populated by scant few natural computational problems. Only Factoring, Discrete Logarithm, Graph Isomorphism (GI), and the Minimum Circuit Size Problem (MCSP) regularly get prominent mention. There are related problems like group isomorphism and others in subjects such as lattice-based cryptosystems. We covered many of them some years back.

Today we are delighted to report recent progress on these problems.
Read more…

Follow

Get every new post delivered to your Inbox.

Join 2,482 other followers