Orbiting Earth is just moving sideways so fast that you move away from Earth as fast as you fall back towards it. Just getting up there is easy, but it isn’t enough — you’d just fall straight back down. It’s the sideways speed which is so hard to reach.

You could do this in our atmosphere as well, if the atmosphere wasn’t slowing you down so much.

A card problem

I was recently party to a very simple, but nonetheless interesting card game. In the game, four players begin the game holding one suit of cards each from a single deck. Then, for thirteen rounds (until the players have run out of cards) every player discards one of their cards simultaneously into the centre, with the player who discards the highest-value card winning the round. If two or more players discard cards of the same face value, then the round is a draw. The winner of the most rounds at the end then wins the game.

While this game is pretty simple and at first glance largely up to luck, it did make me wonder whether there were any strategies that could increase a player’s chance of winning. It would seem so, especially since the starting hands are constant. Therefore, it would be interesting to find both the optimal strategy assuming everyone else plays randomly (i.e. equal probability to play any remaining card), as well as the optimal strategy assuming everyone else plays optimally.

Functional Python

Ever tried to learn Haskell? Confused? Know Python? How about trying to write some functional code in Python? And no, I don’t even mean just using functional principles in Python as the docs describe, I mean actually writing Python like you write Haskell.

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The book of Synook

“Why are you burying that notebook in the ground?”

“I want to start a religion.”

Comic Neue

Random sampling job applicants

Recently, one of my friends told me of her job application, which had been rejected before even the second stage of the recruitment process, which was an entirely automated cognitive aptitude test. I joked that maybe the company randomly sampled their applicants, due to high demand for employment. This made me wonder, however, whether such a procedure was in fact reasonable. After all, processing candidates is expensive and time-consuming, right?

Consider a job application process: there are a certain number of applicants n, of which only some proportion p are “suitable” for the position (in this case, we will consider all suitable candidates equally so). Fortunately, the company only has some t < np* positions open, and thus does not need to find all the suitable candidates. Say they wanted to have a 90% chance of finding at least t suitable candidates — how much of the applicant population would they need to sample?

Of the answer, I’m not sure… perhaps someone can enlighten me. An interesting question though, no?


Let the ephemeral sunlight shine through the gathering clouds onto the waves crashing upon the shores of our hearts; and in the last moments of our day shall we be called to travel beyond the endless seas to the place where time is no more, a place forever waiting for those who remain to join us who have gone, in the eternal sunlight of the perfect day.

Fez impressions

Fez is a compelling game. The combination of the art style and music, exploration mechanics, and puzzles come together to create a platformer with a much deeper appeal than most. Many hours into the game, with almost of all objectives complete, I am still encouraged to continue and solve the last secrets within the game.

Perhaps what surprised me most about the game is what the main gameplay actually turned out to be like. For any of you that have seen any gameplay footage from the game, it would seem that the complexity comes mainly from the ability to rotate to 2D world in a “2.5D” manner, and the confusion that arises from that. While the rotation is a major gameplay mechanic the game does not rest long on exploiting it by itself, and introduces many other puzzles and tricks that build upon the original mechanic. By the end of the game, rotating the world seems like a natural action, necessary, but done without thinking twice — it ends up just being how the world of Fez works.

Instead, scattered throughout the game are a vast number of puzzles of all kinds, requiring a broad range of methods in order to solve. From the first, simple manipulation puzzles to end-game, cryptic enigmas the game builds, bit by bit, upon what the player has already completed in order to craft a mystery of a proportion quite incredible for the game of its size, and one that takes a long time to solve. The world is incredibly detailed, with a well-designed code language and many small details that all contribute to the overall solution. There are many surprises, too, such as timed jumping puzzles, that continue to push the boundary even long into the game when everything seems to have been already discovered. It’s never possible to know just what is behind the next closed door.

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Spot Pricing

Imagine your city passes a law requiring that all hotels in town, from the fleabag on Mediterranean Avenue to the Four Seasons on Boardwalk, charge $100 a night. You don’t have to be an economist to know what will happen: the best hotels will be booked to capacity every night, and no one will ever stay at the CheapSleep.

No city price-fixes its hotels, but plenty make the same mistake with curbside parking spaces. Make them all the same price, and you’ll never get a spot on chichi Hayes Street unless you drive around (and around, and around) waiting for one to open up.

A promising method of reducing parking prices and increasing availability in San Francisco. Fixed meter pricing (at least here in Melbourne) is getting ridiculously high.