Notes, 2023-02-06

I’ve always been fascinated with the co-evolution of computation and textiles. Some of the first industrialized machines produced elaborate textiles on a mass scale, the most famous example of which is the jacquard loom. It used punch cards to create complex designs programmatically, similar to the computer punch cards that were used until the 1970s. But craft work and computation have many parallel processes. The process of pulling wires is similar to the way yarn is made, and silkscreening is common in both fabric and printed circuit board production. Another of my favorite examples is rubylith, a light-blocking film used to prepare silkscreens for fabric printing and to imprint designs on integrated circuits.

Of course, textiles and computation have diverged on their evolutionary paths, but I love finding the places where they do converge – or inventing them myself. Recently, I’ve had the opportunity to work with a gigantic Tajima digital embroidery machine. This room-sized machine, affectionately referred to as The Spider Queen by the technician, loudly sews hundreds of stitches per minute – something that would take me months to make by hand. I’m using it to make large soft speaker coils by laying conductive fibers on a thick woven substrate. I’m trying to recreate functional coils – for use as radios, speakers, inductive power, and motors – in textile form. Given the shared history, I can imagine a parallel universe where embroidery is considered high-tech and computers a crafty hobby.

-lee wilkins

The most clicked link from last week's issue (~4% of opens) was a history of drug smuggling birds. In the Members' Slack, we love keeping the conversation about each Monday's issue going. One Member shared that if you, like Anna and Kelly, dream of riding down an airplane's escape slide, you should look into volunteering for Citizen Corps emergency preparedness drills.

JOBS.

Charm Industrial is hiring a senior mechanical engineer in SF.
Charm Industrial is hiring a field operations engineer in SF.
Places Journal is hiring a public engagement editor in SF.
Autodesk is hiring a senior manager for industry engagement strategy in Copenhagen.
The City of Toronto is hiring senior project managers for transportation services.
More jobs on Scope of Work's job board; you can promote the role you're hiring for here.

Scope of Work is supported by our awesome Members , and through generous support from:

PLANNING & STRATEGY.

In 1970, the British Railway filed a patent for a flying saucer, or as they put it “a power supply for a space vehicle which offers a source of sustained thrust for the loss of a very small mass of fuel.” The project started out as a lifting platform, but quickly got out of hand. Fuel was to be injected into a magnetic accelerator, and high-energy lasers would accelerate hydrogen atoms into collisions. Then, some of the atoms would undergo nuclear fusion and generate helium, releasing a ton of energy. Any observer would have seen a brilliant glow of light before being promptly irradiated. The engineer who designed it, Charles Frederick, did so on his own time and only brought it to British Rail once the design was complete. Since the British patent system allows for not-yet practical entries, the patent was granted. Soon after, the word “nuclear” hit a nerve with the cold war mindset of the government and it was labeled as top secret. On the subject of bizarre patents, I love this one granted for “pet display clothing,” which reminds me of this wearable ant farm.

MAKING & MANUFACTURING.

Traditionally, one might pour concrete into a box-like structure and wait for it to dry. This overview of concrete forming technology elaborates on a few other ways of forming concrete, such as fabric or inflatable forms that allow for more organic or unique shapes. Also see these CNC-manufactured knit forms for intricate glass-fiber-reinforced concrete, which eliminate the need for traditional concrete molding materials like wood or foam.

I love unique media storage devices, and some of my favorites are variations of feeling bumps along a surface. Gramophone wax cylinder recorders, popular in the early 1900s, use a sapphire needle, gently pressed along the wax, to record and play back sound. Another favorite is the capacitance electronic disc, which played video on a record-like device, but had a few fatal flaws: it was extremely fragile, and about half a decade too late. While the idea was first imagined by RCA in the mid-1960s, it wasn’t released until 1981, well after VHS.
Best of all might be TIM, the mechanical speaking clock the British Post Office put into service in 1937. If someone wanted to set their pocket watch, they could phone up TIM (so named because you dialed 846, or TIM) to hear the exact time. While the TIM wasn’t the first speaking clock, its design was fascinating. It used glass disks, like gramophone records, with recordings by Jane Cain, who was known as The Girl With The Golden Voice. Her pre-recorded messages told the correct time, down to the second, thanks to a series of cams and ratchet wheels that rotated the disks for playback.

This recent Practical Engineering video explains how different spillway gates hold back and release water on dams. I was particularly impressed with the 3D printed examples of gate designs, which are demonstrated in a clear acrylic box with dyed water.

A great video of the last fake flower factory in NYC, where hand dyed materials are crafted into unique blooms with die presses.

MAINTENANCE, REPAIR & OPERATIONS.

This YouTube playlist features antique (and ancient) counting and calculating devices with a huge variety of mechanisms. One of my favorites is the 1844 Palmers Pocket Scale, a small book with a circular slide rule in the back cover – perfect for making your calculations on the go. The ornate flowers are also a nice touch. The full text is available through Google Books, slide rule not included.

In the 1960s, ferrite cores were used as nonvolatile memory. This meant that even if power was discharged from the unit, the memory remained intact, but the cores were big and slow. Looking for a more powerful and easier to manufacture solution, Bell Labs invented bubble memory in the 1970s. The design used magnetic bubble-like parts of a silicon chip to physically store memory. While it offered robust storage, bubble memory had low capacity, slow speed, and was expensive to produce – the volatile competitor DRAM was less robust but had better performance. DRAM gained more market share but a 1988 shortage, caused by a Japanese-American trade agreement that limited production of ICs, resulting in a brief spike in popularity for bubble memory. Ultimately, bubble memory was used for niche applications in rugged environments such as factory automation, satellites, and military hardware. Nonetheless, this obscure storage technique played a role in the Persian Gulf War where its cost and performance were a reasonable trade-off for reliable data security.

DISTRIBUTION & LOGISTICS.

Ken Shirriff details the intricate mechanical systems of the Globus INK – a gorgeous navigation system for soviet spacecraft. It features a rotating globe inside a metal housing, and let Soyuz cosmonauts see their position above Earth.

In the summer, I love Montreal’s twisted wrought iron staircases, but in the winters, they’re treacherous. I’d always wondered why a city that gets so much snow has so many external staircases. It turns out there were several factors. Due to a sudden increase in population in the early 20th century, the city limited the width of multiplexes and introduced requirements for green spaces out front. To maximize the limited interior space, architects began putting staircases outside buildings. The Catholic Church, which wielded political clout, also asserted a moral stance: people shouldn’t be able to enter a house in secret. It's not the only odd regulation that has shaped the city: There is also a law that buildings can’t be taller than Mount Royal, the mountain at the heart of, and the namesake of Montreal.

INSPECTION, TESTING & ANALYSIS.

An informative chart on the electromagnetic spectrum, with sidebars on cosmic microwave background radiation, television, gamma rays, and more.

Open source hardware is great, but if you wanted to have truly trusted systems, you would have to design and manufacture your own silicon chips. In the process of manufacturing an IC, there are opportunities for malicious actors to insert security vulnerabilities that can compromise your machine. This detailed article explains how to spot hardware Trojans – malicious circuitry that impairs the function or trustworthiness of an IC – under a microscope. Some examples of hardware vulnerabilities include a hack that would reduce the effectiveness of random number generators or leak information about the processor to an attacker. The wildest thing to me is that these behaviors can be masked during security testing by IC tape-out design modification – changing the IC photomask post-signoff – to flip transistor polarity and make the chip appear to function normally.

Most telescopes use traditional optics like lenses and mirrors, but some have used rotating liquid to focus light. In 1850, Ernesto Capocci proposed spinning liquid mercury to focus light, and the concept was first realized in 1872 by Henry Skey who built a 35 cm diameter liquid mirror in his laboratory. However, many contemporary liquid telescopes aren’t very practical as vibrations disrupt the surface, making images difficult to capture. In 1982, Canadian physicist Ermanno F. Borra used a solid-state sensor known as a charge-coupled device to cut down vibrations and capture images more efficiently. There are several attempts to revive liquid mirror telescopes today, as they can be easier to manufacture and more cost effective than large scale mirrors. Mirror telescopes can be extremely expensive – it costs roughly $10 million for a 6-meter mirror, and the JWST mirrors cost almost $10 billion!