Suppose I give you a bag of marbles and tell you that all the marbles are either green or black. You repeatedly reach in, pick out a random marble, and then put it back. You find that out of 100 draws, 70 of the marbles you took out of the bag were green. What's the probability that the next marble you'll draw will be green? Or, to put it another way, what's your best guess (expected value) of the fraction of marbles in the bag that are green?
A pragmatic guide to voting in the 2020 election
In this post I won't wax poetically about the importance of voting. Instead I'll tell you the most important things to know about voting in this election as efficiently as I can, and then talk a bit about what else you can do besides voting. Part A: The most important thing to know. Tell your … Continue reading A pragmatic guide to voting in the 2020 election
Your vote matters — probably more than you think
(This post is meant to persuade you to vote. If you already want to vote but don't have a concrete voting plan, check out this post.) In 10th grade civics class I learned about two moral arguments in favor of voting in elections. The first of these appeals to a notion of civic duty: as … Continue reading Your vote matters — probably more than you think
Puzzle: Losers and Winners
In May I wrote my first puzzle for this blog. If you tried that puzzle but didn't solve it, don't worry -- that was a really hard one. This one's easier -- I'd put its difficulty at around 3 out of 10. If you haven't done these sorts of puzzles before, this isn't a terrible … Continue reading Puzzle: Losers and Winners
Pooled COVID testing in the real world
[Thank you to Cathy Xue for proofreading and discussion.] In April I wrote about pooled testing. The basic idea is that instead of testing every swab individually, labs can pool samples together in groups of 10 (say) and test each mixture (pool) for the virus. For any pool that tests positive, they can then follow … Continue reading Pooled COVID testing in the real world
Jelle’s marbles have skill
Do you miss the pre-COVID excitement of watching sports? Are you bored right now, looking for some way to entertain yourself? Welcome to the world of Jelle's Marble Runs. https://www.youtube.com/watch?v=55iTYdRDG4s Round 1 of the 2020 Marbula One (intro ends at 1:45) https://www.youtube.com/watch?v=NPFVLLxhEI4 Round 1 of the 2020 Marble League (intro ends at 2:50) In the … Continue reading Jelle’s marbles have skill
Puzzle solution/hints: A Choral Arrangement
In May I published a puzzle called A Choral Arrangement. No one ended up solving it without additional hints, and so none of the prizes were claimed! I admit that this was disappointing; I knew the puzzle was hard, but expected at least one person to solve it. For those of you who worked on … Continue reading Puzzle solution/hints: A Choral Arrangement
An exploration of exploitation bias
This is a map of Nassau Street, the northern edge of Princeton University. It's a very standard sort of street; I imagine one quite like it exists in most college towns. It has lots of great places to eat, shown on the map in orange. During my senior year, because of Princeton's absurdly expensive meal … Continue reading An exploration of exploitation bias
Against “read or defer” norms
There's a particular pattern of discourse that I've seen, both in person and online, that has bothered me subconsciously for a while. It's a really easy trap to fall into even in a setting with good norms and intentions on both sides, so it may be helpful to articulate. Sophie is an anthropology major at … Continue reading Against “read or defer” norms
Puzzle: A Choral Arrangement
A few months ago I wrote about my favorite puzzles from the 2020 MIT Mystery Hunt, where I called the Mystery Hunt "one of my favorite things". Another one of my favorite things is actually writing these kinds of puzzles. I intend to occasionally post puzzles on this blog, and this is the first one! … Continue reading Puzzle: A Choral Arrangement
Unexpected Values 