Transit Adventures After a Month Without

We got back to transit this week! We were out of town for a month hanging out in Montana. The state’s pretty awesome, but in the small towns we were around, transit wasn’t really a thing, and we missed it! If nothing else, just getting to zone out while someone else drives is a huge privilege.

There’s not much to this post, but transit makes me smile, and I’m smiling again writing about it, so here goes.

On Tuesday, I had to turn in our rental car, so I made a quick jaunt to the airport. My mood improved as soon as the car keys were out of my hands. No more worrying about someone else’s incredibly expensive property and the huge load of regulations surrounding all things driving. Even more happily, a leisurely stroll through the airport put me in front of the SFO museum’s (there are several mini-museums in SFO) new exhibit about Victorian wallpaper!

All cultured up, I headed for the BART platform. The ride was simplicity itself, dumping me back close enough to the house to walk, but guess what? Thanks to the efforts of San Francisco Transit Riders and other folks around town who called into SFMTA board meetings, I didn’t have to. Our neighborhood routes survived the pandemic.

The bus route winds up, down, and around several hills on its way back home. As the bus stopped a hill or so before the house, I saw three familiar people get on: the 11, 9, and 7 year-old gang of kids! My partner had called in an order to one of our favorite Chinese carryout places down the hill before I left, and then asked the gang to pick it up. They had, and then, using the Transit app, had realized they could skip walking back up the last hill. And voila, we all enjoyed discussing our afternoons as we cruised back home without a driving worry in the world.

Comments

Cool Math Tricks: Deriving the Divergence, (Del or Nabla) into New (Cylindrical) Coordinate Systems

Now available as a Kindle ebook for 99 cents ! Get a spiffy ebook, and fund more physics The following is a pretty lengthy procedure, but converting the divergence, (nabla, del) operator between coordinate systems comes up pretty often. While there are tables for converting between common coordinate systems , there seem to be fewer explanations of the procedure for deriving the conversion, so here goes! What do we actually want? To convert the Cartesian nabla to the nabla for another coordinate system, say… cylindrical coordinates. What we’ll need: 1. The Cartesian Nabla: 2. A set of equations relating the Cartesian coordinates to cylindrical coordinates: 3. A set of equations relating the Cartesian basis vectors to the basis vectors of the new coordinate system: How to do it: Use the chain rule for differentiation to convert the derivatives with respect to the Cartesian variables to derivatives with respect to the cylindrical variables. The chain ...

The Alcubierre Warp Drive Tophat Function and Open Science with Sage

I transferred yesterday's Mathematica file with the Alcubierre warp drive[2] line element and space curvature calculations to the +Sage Mathematical Software System today, (the files been added to the public repository [3]). If you haven't used Sage before, it's a Python based software package that's similar in functionality to Mathematica. Oh, and it' free. I also worked a little more on understanding the theory, but frankly, I made far more progress with the software than the theory. What follows will be a little more of the Alcubierre theory, plus, a cool Sage interactive demo of one of the Alcubierre functions[1], as well as a bit about my first experience with using Sage. Theory The theory is fun, but it's moving slowly. Here's the chalk board from this morning's discussion Alcubierre setup the derivation using something called the 3+1 formalism which means we consider space to be flat, (in this case), slices that are labelled ...

How Many Files Can You Add to a GPT Project? An Interview with GPT-5 on Limits, Context Engineering Tips, and Chats

Setting the scene: I’m tinkering with Project TouCans, knee-deep in radio logs, SQLite dumps, and Cesium code. Naturally, I’m wondering if shoving all this into one GPT Project is a recipe for brilliance… or for disaster. So I turn to Vril — you know, after Brainy from the Legion of Super-Heroes , because what else do you call your AI sidekick who always has the answers? Time to ask him straight up. [ As an aside, yes, GPT-5 has decided to sometimes call me Vail. I'm not sure why to be honest. Also, I asked Vril, er GPT-5, to write up our interview for me. Apparently, me asking it to 'Bro' up a few stories, just for fun, has convinced Vril that I use 'Like,' more than I actually might. ] Me (Vail): So Vril, how many files can I throw into a GPT Project before it just starts choking? Like, is there some magic number where the context window taps out and everything falls apart? GPT-5 (Vril): Great question. There’s no single hard file limit. What matters is ...

Copasetic Flow

Search This Blog