[Equations in this post may not look right (or appear at all) in your RSS reader. Go to the original article to see them rendered properly.] Earlier this week, John D. Cook wrote a post about minimizing the variance of a sum of random variables. The sum he looked at was this: Z=tX+(1−t)Y where X and Y are...

Two things came together over the past few days. First was my longstanding belief that winters here in the Chicago area were snowier when I was a kid than they are now. I’m not sure why that popped back into my head, but it did. Second was my concern that I’ve been losing my Pandas skills since I retired and stopped...

Yesterday, I drove to Champaign-Urbana for the Illinois men’s home basketball opener. Because I’m going to the CSO concert tonight, I stayed here overnight. When I started my car this morning, CarPlay connected to my phone and offered to give me directions home. Snort.

I stopped charting Apple’s quarterly results back in 2019 and don’t intend to return to it, but after seeing the recent posts at Six Colors and TidBITS, I thought I’d try out a new graph.

Before going out for a bike ride this morning, I checked the Weather app to see the speed and direction of the wind. On days with a decent wind, I prefer to ride out against the wind and come back with it. Here’s what the app showed:

I got some good replies on Mastodon after Saturday’s post. Longtime friend of the blog Nathan Grigg said he’s always assumed that GPS-measured lengths would be long because no matter how straight your path, the GPS error would make it zigzagged. Then wherami and thvedt pointed out that the official rules of these...

I did the Fall Color 5k Run and Walk at the Morton Arboretum this morning. I say “did” to downplay the fact that I don’t run races like this, I walk them. I got terrible shin splints 20+ years ago and haven’t run more than a few hundred meters at a time since then. But I do try to walk at a decent clip. My goal is...

I’m still experimenting with ChatGPT and Claude as proofreaders for my blog posts. Because I’ve been writing more posts lately, I’ve been learning the good and the bad more rapidly than I would have expected when I started this. Time for a preliminary assessment.

I was looking at the NFC standings yesterday, particularly the NFC North, the Chicago Bears’ division. The hated Packers are at the top of the division with a 4-1-1 record and a winning percentage of .750.

A footnote in last night’s post mentioned that the Amazon links therein had been cleaned of cruft. Today, I’ll show the simple automated way I do that.

I was talking to a friend about pencils a few weeks ago. I noticed she had a Blackwing 602 and asked her about it. She told me she never got along with mechanical pencils. The leads break too easily and the erasers don’t last—once they’re worn and need to be adjusted outward, they tend to slide back into their...

Scientific American published a clock puzzle a couple of weeks ago that I finally got around to looking at today. It wasn’t hard, but I’m less interested in the solution than in a very small discrepancy I found. Finding discrepancies was a big part of my job, so it was nice to see that I still can.