Posts in category Roots of Unity
Eight Degrees North
Eight degrees doesn’t sound like much. It’s only 1/45 of the way around a circle. On a globe, it’s about nine percent of the angular distance between the Equator and the North Pole.
Today, I live eight degrees farther north than where I grew up. As one would expect, the climate is a bit different. Latitude is part of that: on any given day, i [...]
The Ditherer’s Mean
So you’ve got some numbers, and you want to produce one number that represents their typical value. If you’ve taken a little bit of math or statistics, you might reach for the mean—the arithmetic mean, to be precise. Add the numbers together and divide by the number of numbers you have. Easy enough.
But perhaps you’re a bit of a Chidi, and fu [...]
A Mathematical Companion for Your Yea...
If you’re looking for a holiday gift for a mathematician, STEM student, teacher, or other math-interested person in your life (including yourself), I’ve got good news for you! I am excited to announce the availability of a product I am particularly proud of: the AMS Page-a-day calendar, published by the American Mathematical Society. You can [...]
Self-Referential Podcasting
This post originally appeared at scientificamerican.com.
On our most recent episode of My Favorite Theorem, Kevin Knudson and I talked with University of Nebraska mathematician Judy Walker, who works in the field of coding theory. You can find the audio, transcript, and show notes at kpknudson.com.
Walker’s field, coding theory, is about how [...]
Farewell to the Fractional Foot
This post originally appeared at scientificamerican.com.
What an exciting year it has been for units of measure! (Granted, it doesn’t take a lot to be an exciting year for units of measure.) In May, the kilogram got a makeover. The old standard, a piece of platinum-iridium alloy housed at the International Bureau of Weights and Measures in Fr [...]
It’s Factoradical!
This post originally appeared on scientificamerican.com.
The word “factoradic” jumped out to me when I peeked over a new math friend’s shoulder and saw it in the title of the paper she was revising. What a great word! I had no idea what it meant.
My new friend showed me with an example: the number 2019 is 2(6!)+4(5!)+4(4!)+2!+1. Or more forma [...]
Hilbert Walked So the Clay Institute ...
This post originally appeared on scientificamerican.com.
I’ve been reading up on Hilbert’s problems recently. They’re the 23 problems presented by German mathematician David Hilbert at the International Congress of Mathematicians held in Paris in 1900. (To be more precise, Hilbert presented 10 of them in a talk at the congress. The full list [...]
Law & Order: MVT
This post first appeared on scientificamerican.com.
In the criminal justice system, velocity-based offenses are considered especially unimportant. In New York, the dedicated detectives who investigate these minor misdemeanors are members of an elite squad known as the Moving Violation Team. These are their stories.
[Open with aerial shot of t [...]
An Airtight Proof That There Are More...
This post first appeared at scientificamerican.com.
In our latest episode of My Favorite Theorem, my cohost Kevin Knudson and I talked with Bates College mathematician Adriana Salerno about one of the prettiest theorems there is, Georg Cantor’s proof that there are more real numbers than there are whole numbers. You can listen at kpknudson.co [...]
Ping-Pong for Introverts
This post originally appeared on scientificamerican.com.
Ping-pong is great, but there’s a catch: you have to play with someone else. What is a committed introvert to do?
You could always hit the ball against some fixed object, but as Mitch Hedberg observed about tennis (easily generalized to other hit-a-ball games), you’ll never be as good a [...]
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