Top posts

Every blog post that took off on Hacker News, ranked by the votes of its best submission. 2,851 posts.

Math & Algorithms
Any year
2344

Introduction to Category Theory

The aim of this course is to teach the basics of category theory, in a way that is accessible and relevant to computer scientists. The emphasis is on gaining a good understanding the basic definitions, examples, and techniques, so that students are equipped for further study on their own of more advanced topics if…

2356

What is Symbolic Computation?

I've been reading a lot of Lisp books lately, some more advanced than others. All of the introductory books I've seen cover the idea of symbolic computation, but most of them breeze past it with just a few pages about "symbols" and "quoting". For many programmers coming from non-Lisp languages these are new, foreign…

2361

Towards a Better Pythagorean Cup

There was an article on Hacker News the other day by David Richeson entitled Make Your Own Pythagorean Cup . A Pythagorean cup is a cup with a built-in siphon. Supposedly invented by Pythagoras, the cup functions just like an ordinary cup as long as it is only filled to a certain level. If anyone gets greedy and tries…

2366

Perlin noise

I used Perlin noise for the fog effect and title screen in Under Construction. I tweeted about my efforts to speed it up, and several people replied either confused about how Perlin noise works or not clear on what it actually is. I admit I only (somewhat) understand Perlin noise in the first place because I’ve…