A quick note from Hacker News about why we want optional types but why ’null’ is unintuitive.

A quick note from Hacker News about a beautiful proof of the uncountability of the reals.

How to write loops immutably and safely.

A quick note from Hacker News about my preference for static config rather than dynamic.

An underappreciated tool for writing good software.

Photos from the Mystery Hunt.

A couple of solution documents I made during the progress of the 2020 MIT Mystery Hunt.

A quick note from Hacker News about my thoughts on teaching cookery.

A quick note from Hacker News about the various stages of learning and teaching in mathematics.

A couple of solution documents I made during the progress of the 2019 MIT Mystery Hunt.

Notes from a chat with the creator of F#, about how to contribute to the compiler.

A quick overview of dependent types.

A quick note from Hacker News about why the comment-handling situation in JSON is bad.

Answering the question, “What is lost when we move from the reals to the complex numbers?”.

Answering the question, “Which mathematical ideas took a long time to define rigorously?”.

Answering the question, “Are these examples of abuses of notation?”.

Answering the question, “does the International Maths Olympiad help research mathematics?”.

This is just a link to a beautiful proof of the Cauchy-Schwarz inequality. There are a number of elegant proofs, but this is by far my favourite, because (as pointed out in the paper) it “builds itself”.

Answering the question, “Why does WolframAlpha say that a quantity is ComplexInfinity?”.

Answering the question, “how far back in time would maths be understandable to a modern mathematician?”.