Author Archives: possiblywrong

History of COVID-19 cases

All of the raw data presented here was retrieved from this GitHub repository, which, as described there, is maintained by and thanks to the Johns Hopkins University Center for Systems Science and Engineering (JHU CSSE), with support by ESRI Living … Continue reading

Posted in Uncategorized | 1 Comment

Fair dice: some isohedra are less fair than others

Introduction What makes dice fair? Intuitively, when we roll a fair die with sides, we expect each of its possible outcomes to have the same probability of occurring. What shapes have this property? I think this is an interesting problem, … Continue reading

Posted in Uncategorized | 2 Comments

Solving the 2x2x2 Rubik’s cube (revisited)

Introduction Years ago I wrote an article about solving the 2x2x2 Rubik’s cube, using an efficient representation of the scrambled states of the cube, and using VPython as a means of visualizing the cube and rotations of its faces. The … Continue reading

Posted in Uncategorized | Leave a comment

Another dice puzzle

Introduction The dice game craps is played by repeatedly rolling two six-sided dice, and making various wagers on the outcomes of the sequence of rolls. The details of the wagers don’t concern us here– instead, let’s consider just one particular … Continue reading

Posted in Uncategorized | Leave a comment

Tracking a card through a shuffled deck

Introduction Riffle shuffle a deck of cards once. What is the probability that the original top card ends up on the bottom of the shuffled deck (or vice versa)? This is very unlikely… but suppose that we shuffle again… and … Continue reading

Posted in Uncategorized | 4 Comments

A different sock matching problem

When I take a load of laundry from the dryer, there are socks mixed in with all of the other clothes. Suppose that there are pairs of socks, socks in total, that I match and fold by randomly drawing one … Continue reading

Posted in Uncategorized | 9 Comments

The hot hand

The wager described in the previous post was motivated by an interesting recent paper (Miller and Sanjurjo, reference below) discussing the hot hand, or the perception in some sports, particularly basketball, that a player with a streak of successful shots … Continue reading

Posted in Uncategorized | Leave a comment