Simple orbital mechanics

The Moon is slowly siphoning off the Earth’s rotational energy, in a phenomenon called tidal acceleration. This moves the Moon’s orbit farther from the Earth. According to Kepler’s laws of planetary motion, the Moon must orbit more slowly as it gets farther away. Well, which is it? Is the Moon speeding up, or slowing down?……

How to fix American football overtime

In American football, a neutral position is not really possible. There is no equivalent of a “jump ball” or a “face off”. One team, and not the other, must have possession of the ball, giving that team an advantage. This results in the overtime coin flip problem. I’ll assume that overtime is “sudden death”: The……

The half-life gap

If you sort all the nuclides (isotopes of elements) in order of increasing half life, there are a fairly steady supply of them (on a logarithmic scale) up to a half-life of about 10 million years. There are also about 250 that have a half-life so long that it has never been measured. (And for……

Points scored in overtime are not real points

I should know better than to write about college football, a sport that I pay little attention to. But it’s a particularly egregious example of an irritating phenomenon. On November 24, 2018, in American college football, Texas A&M and LSU were tied 31–31 at the end of regulation, and Texas A&M won in overtime. But……

The new record largest known prime number

A few days ago, the discovery of a new record largest known prime number (282,589,933−1) was announced, making my post on “finding” record prime numbers somewhat obsolete. I could update it, but that would be silly. Instead, I’ll discuss these record primes. It happens every couple of years: A new record large prime number is……

Win32 I/O character encoding part 3

This is the third, and possibly final, post in my series on Microsoft Windows console mode character encodings. It describes how to use Unicode reasonably cleanly, without the “chcp 65001” hack discussed in Part 2. Again, the idea is that you are writing a command-line computer program in C or C++, and you want it……

Why throwing a game is against the rules

On November 29, 2012 (six years ago today), there was an NBA basketball game that got some attention. It was a nationally televised game featuring two powerhouse teams: the San Antonio Spurs (Tim Duncan, etc.), versus the Miami Heat (Lebron James, etc.). To the dismay of many, Spurs coach Gregg Popovich more-or-less threw the game,……