Quantum mechanics as a generalization of probability (2007)
There are two ways to teach quantum mechanics. The first way -- which for most physicists today is still the only way -- follows the historical order in which the ideas were discovered. So, you start with classical mechanics and electrodynamics, solving lots of grueling differential equations at every step. Then you…
World Cup Follow-Up: Update of Winning Probabilities and Betting Results
An update on the winning probabilities for the remaining World Cup teams, and an analysis of how our predictor performed on the group-phase matches.
Overkilling the 8-queens Problem
Last night, a fellow Hacker Schooler challenged me to a running-time contest on the classic eight queens puzzle. Naturally, I pulled up my trusty …
Gridlock vs. Bottlenecks: A visual explanation
"Emails show [Chris Cristie]'s aides did plan bridge gridlock," says Salon . To a transportation engineer, the aides are innocent: bridges can't have gridlock. While we often say "gridlock" to mean "bad traffic," it has a technical meaning.
Why are roller coaster loops not circular?
Why are the loops on roller coasters never circular?
How I created two images with the same MD5 hash
I posted the following images the other day which although looking totally different have exactly the same MD5 hash ( e06723d4961a0a3f950e...
Why cans of soup are shaped the way they are
What is special about cylinders, and why do they have specific aspect ratios?
Analysis of suspected MH370 pings recorded by Ocean Shield
So this is a bit of a deviation from my normal MATLAB oriented posts. In-fact MATLAB was not used once in this analysis! I've been followi...
Zero Knowledge Proofs: An illustrated primer
One of the best things about modern cryptography is the beautiful terminology. You could start any number of punk bands (or Tumblrs) named after cryptography terms like ‘hard-core predicate&#…
Elsevier journals – some facts
Update: figures now in from Imperial. See below. Further update: figures in from Nottingham too. Further update: figures now in from Oxford. Final update: figures in from LSE. A little over two yea…
Levels of Excellence
Over on Google+, a computer scientist at McGill named Artem Kaznatcheev passed on this great description of what it’s like to learn math, written by someone who calls himself ‘man aft…
Dual_EC_DRBG backdoor: a proof of concept
Dual_EC_DRBG is an pseudo-random number generator promoted by NIST in NIST SP 800-90A and created by NSA. This algorithm is problematic because it has been made mandatory by the FIPS norm (and should be implemented in every FIPS approved software) and some vendors even promoted this algorithm as first source of…
Evolutionary algorithm to find Quake III's fast inverse square hack with Python
Curiosity killed the cat I've always been amazed by early game developers. Unlike today, they had to bend and twist software to its extre...
Fast and easy Levenshtein distance using a trie (2011)
<img src="http://stevehanov.ca/blog/images/acer.jpg"/> If you have a web site with a search function, you will rapidly realize that most mortals are terrible typists. Many searches contain mispelled words, and users will expect these searches to magically work. This magic is often done using levenshtein distance. In…
The Lambda Calculus for Absolute Dummies (2012)
If there is one highly underrated concept in philosophy today, it is computation . Why is it so important? Because computationalism is t...
The most common errors in undergraduate mathematics
This page describes the errors that I have seen most frequently in undergraduate mathematics, the likely causes of those errors, and their remedies.
The Traveling Salesman with Simulated Annealing, R, and Shiny
I built an interactive Shiny application that uses simulated annealing to solve the famous traveling salesman problem. You can play around with it to create and solve your own tours at the bottom of …
How to Conquer Tensorphobia
A professor at Stanford once said, If you really want to impress your friends and confound your enemies, you can invoke tensor products… People run in terror from the $ \otimes$ symbol. He was explaining some aspects of multidimensional Fourier transforms, but this comment is only half in jest; people get confused by…