How do keelboats sail upwind?

I was pretty sure I understood the basic principles.

Happily, Randall Munroe has clarified them for me!

Construction Physics on shipbuilding

Here's the sort of article that I used to send to my dad. And then we would discuss it when we were together. Improving Naval Ship Acquisition

My dad spent a bunch of his professional career working in the Armed Forces on analytic topics. He worked for several years for the Coast Guard working on logistics and operations problems. And then he worked for close to 20 years for the Navy on operations research problems. He spent a lot of time thinking about the details of why the military does things the way they do.

It's a deep, complex topic, and not easily accessible to outsiders like me.

But still, it was always interesting to get my dad's perspective on issues such as the ones in this essay:

Many of the US Navy’s recent ship designs are large, complex multi-role ships. The Navy expects the same ship to hunt pirates, counter ballistic missiles, track submarines, and more. Also common are high-end features unnecessary for a ship’s mission. These complex ships have many negative consequences on the ability to design ships, increase production throughput, and meet budget and schedule targets.

I really enjoy the Construction Physics newsletter. I have no idea how Brian Potter manages to write so many amazing articles so often, but they're great reading.

My dad and the new pope

I think my dad would have been happy that Leo XIV was a math major.

I think my dad might have liked this puzzle…

... although not because he liked Find-a-Word puzzles

Actually he much preferred cryptic crosswords when it came to puzzles.

He would watch me doing a Sudoku or a KenKen with some interest, but he never really enjoyed those either.

Although he had fun trying to work out the mathematics of Sudoku!

Anyway, i think he would have liked this puzzle because the theme was railroad trains and each word to be found was a type of train car.

One less commenter

My dad was the person who most often commented on my blog posts.

(I mean, besides the automated sparm marketing robots.)

I still have one or two long-time friends who occasionally comment on my posts.

But it's going to be a lot quieter in the comments section now.

Can you inherit interests?

Somehow, along the way, I came to find myself sharing certain interests with my father. I'm not exactly sure how this came to be, but it's something that I find I still have, even after he's gone>

The desert. When I was nine years old we moved from Lousiana to California, and came to live in a suburb of Los Angeles. But my dad wasn't really all that thrilled with the suburbs of Los Angeles. Instead, it came to be that he grew to love the desert. When we were young, he would take us on weekend trips into the high desert of inland California, and we would wander around its empty spaces, finding odd things to see and do.

Stamp collecting. I really have no idea how my dad came to be interested in collecting stamps, but I remember that when I was young, he would let me sit in his den with him, as we did things like soaking old envelopes to separate the stamp from the envelope, examining the resulting stamps under magnifying glasses, and looking up each stamp in a specialty catalog to learn more about whether this was a special and interesting stamp, in which case we would happily mount the stamp into its position in the album.

Cryptic crosswords. I came to this rather late, rather than as a child, when at some point I visited my parents and they had a cryptic crossword open on the breakfast table. Cryptics feature a blend of word play and puzzles that is quite hard to explain unless you've tried them. I'm really not very good at them, but I love to try to solve them, and when I got stuck I would just ask my dad and he would explain the answer.

The United States Coast Guard. Most Americans, I'd say, have pretty much no idea what the USCG is, and what it does, but my father was a career coastie, eventually rising to and retiring as a Captain in the Coast Guard Reserve. He helped me understand what the Coast Guard does, and why it is so unusual among all the US armed forces.

Things I already miss about my father

 It’s only been 48 hours so these aren’t particularly deep thoughts. But they are thoughts nonetheless.

• I just finished N K Jemisin's marvelous Broken Earth trilogy, and I really wanted to know what dad thought about it. He had zipped through all three volumes in barely 10 days, while it took me two months to finish them. He was a much faster reader than me. But he was waiting patiently until I finished the last volume before telling me. So now I'll never know.
• I played some golf, which I enjoy but don't do often, and am not very good at. But my dad loved golf and was remarkably good at it , so I wanted to tell him some stories from my golf trip. Don't get to do that and have no one else to tell.
• The golf courses were out in the desert and my dad had a phenomenal knowledge of desert plants; i wanted to tell him about the mesquite and the tamarisk and the locust and the acacia that were lining the course.
• I was learning a bit about prediction markets and they are pretty abstract and so I wanted to talk to my dad about them to see what he thought. I think he would have found them fascinating