2022-02-14 5 min read


Note: A warm welcome to our new sponsor, Duro - the cloud PLM system for distributed hardware teams! We're very happy to have them :)

Notes, 2022-02-14.

I love bicycles. It’s one of the things I first bonded with Spencer about, before he invited me to write for The Prepared. Recently someone asked me to teach them how to ride a bicycle, assuming that I, a guy-who-really-likes-bicycles, might make a good instructor—but I don’t think knowing a lot about bicycles necessarily makes one a good instructor.

How to ride a bicycle belongs to a strange class of knowledge that feels incredibly obvious, but is fairly complex to articulate bottoms-up. This is illustrated well in this video from Veritasium, which shows that when people ride a bike exactly how they think it works bottoms-up, they generally fall.

The bicycle is a great human achievement, but our knowledge of it is messy and the way we communicate that knowledge is poorly specified. I’d bet that the average time it takes for someone to become comfortable on a bicycle is largely unchanged over the last century, despite leaping advances in our understanding of the physics behind them. And I’d also bet that most proficient riders are unable to explain how bicycle dynamics work bottoms-up without thinking really hard about it.

It’s really cool that people (even very young people!) can learn these “complex” things intuitively. To some extent, all the technical expertise of physics and mechanics and aerodynamics that we've developed over the past hundred years doesn't seem to have had any effect on how hard—or easy!—it is to learn to ride a bike. All this is to say: whatever it is you’ve been putting off trying, just go for it.

-Kane Hsieh

The most clicked link from last week's issue (~7% of opens) was an analysis of computer latency from 1977-2017. In the Members' Slack last week, we've been chatting about high powered model rockets, industrial sendoff gifts for colleagues, and the most practical (but still excellent) pepper mill.

Planning & Strategy.

  • NASA Jet Propulsion Laboratory has confirmed that it uses 15 decimal digits of pi for its most accurate calculations (interplanetary navigation). Our most distant spacecraft, Voyager 1, is ~12.5 billion miles from Earth; calculating the circumference of a circle with that radius using “only” 15 digits of pi has an error of ~​​1.5 inches or 1.9×10-13%.
  • I believe the proliferation of Earth observation satellite services available to consumers is going to unlock a lot of very cool projects. UC Berkeley graduate student Marcel Moran used satellite imagery to map and analyze crosswalk prevalence in San Francisco (academic results here). The results are unsurprisingly bleak: American urban planning tends to prioritize vehicles over walkability, and San Francisco is no different.

Making & Manufacturing.

Maintenance, Repair & Operations.

  • I really like McDonald’s McFlurries and dislike how often the machines are broken—a topic I wrote about in this newsletter on both ​​2020-12-21 and 2021-06-21. An ongoing lawsuit between Taylor (the manufacturer of the McFlurry machines) and Kytch (a third-party machine diagnostics vendor) has gotten more dramatic as newly released internal emails hint at corporate espionage, conspiracy, reverse engineering, and a turncoat franchisee—all in the name of delicious delicious soft serve.
  • In 2008, the MTA sunk 1,000 retired NYC subway cars into the Atlantic to create artificial reefs. The reefs were supposed to last 25 years, but they disintegrated in months. This came as a surprise because years before the MTA had sunk over 1,500 cars with no issues. As it turns out, the material and geometry of the 2008 “Brightliner” cars were significantly different and more corrosion prone than the earlier “Redbird” cars. This isn’t to say the modern cars were worse—survivability while submerged in salt water is hardly a reasonable design spec for subway cars—but it’s a good reminder of the inevitable march of entropy. The dramatically-titled Rust: the Longest War is a good overview on our history of battling corrosion.

Distribution & Logistics.

  • “Why are they called semi-trucks?” is one of those immortal questions. They are so named because they pull semi-trailers: trailers without front wheels. Despite agreeing on trailer standards, American and European semi-truck designs are wildly divergent, and the reason is regulation: Europe has maximum length limits for maneuverability in denser streets, resulting in “cab-over” trucks with square faces. While American truckers could use cab-over trucks, many drivers live out of their cabs during long drives and therefore prefer conventional cab designs, which have longer wheelbases and are effectively mobile apartments.

Inspection, Testing & Analysis.

  • My grandfather and his daughter (my mother) are both experts on fluid dynamics. To their dismay, I am not—but I do find it fascinating how weird and poorly understood fluids are. Case in point: some fluids suddenly become much thicker when they flow through a spongy material quickly—as if pouring water too fast turned it into syrup. Without getting too in the weeds (as this academic paper certainly does), we now understand that this is probably due to a unique type of “elastic turbulence.” Here’s where it gets weird: there is no general solution for turbulence. So the answer to a mystery is another mystery!
  • The wonderfully wholesome, volunteer-run Digital Museum of Plugs and Sockets is exactly what it sounds like: an illustrated overview of sockets past-and-present from around the world. No cookies or tracking or telemetry. Just sockets.
  • I was surprised when my friend Anton Troynikov mentioned that the USSR had landed ten probes on Venus, which made me feel like I had been proganadized-by-omission as an American student. Much of what we know about Venus is from these missions, but something hilarious happened during Venera 14: After traveling 37 million miles, and successfully navigating the corrosive Venusian atmosphere, and safely landing, it jettisoned its lens cap and extended its probe to sample the soil… only to find that the lens cap had landed directly under the probe, which proceeded to measure the compressibility of the lens cap.


Starlink antennas have a self-heating “Snow Melt Mode” to remove signal-attenuating water from its signal path. Unfortunately this can also attract cats, which happen to contain a lot of water.

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