Tech In Plain Sight: Super Glue

Many inventions happen not by design but through failure. They don’t happen through the failure directly, but because someone was paying attention and remembered the how and why of the failure, and learns from this. One of these inventions is Super Glue, the adhesive that every tinkerer and engineer has to hand to stick pretty much anything to anything, quickly. Although it was a complete failure for the original uses it was developed for, a chemist with good memory and an eye for a helpful product created it in a process he described as “one day of synchronicity and ten years of hard work.”

Super Glue was initially invented in 1942, when the chemist Harry Coover was working on a team trying to develop a clear plastic gun sight that would be cheaper than the metal ones already in use. The team cast a wide net, trying a range of new materials. Coover was testing a class of chemicals called cyanoacrylates. They had some promise, but they had one problem: they stuck to pretty much everything. Every time that Coover tried to use the material to cast a gun sight, it stuck to the container and was really hard to remove. 

When the samples he tried came into contact with water, even water vapor in the air, they immediately formed an incredibly resilient bond with most materials. That made them lousy manufacturing materials, so he put the cyanoacrylates aside when the contract was canceled. His employer B. F. Goodrich, patented the process of making cyanoacrylates in 1947, but didn’t note any particular uses for the materials: they were simply a curiosity. 

It wasn’t until 1951 when Coover, now at Eastman Kodak, remembered the sticky properties of cyanoacrylates. He and his colleague Fred Joyner were working on making heat-resistant canopies for the new generation of jet fighters, and they considered using these sticky chemicals as adhesives in the manufacturing process. According to Coover, he told Joyner about the materials and asked him to measure the refractive index to see if they might be suitable for use. He warned him to be careful, as the material would probably stick in the refractometer and damage it. Joyner tested the material and found it wasn’t suitable for a canopy but then went around the lab using it to stick things together. The two realized it could make an excellent adhesive for home and engineering use. Continue reading “Tech In Plain Sight: Super Glue”

Books You Should Read: David Macaulay’s Architecture Series

For a lot of us, there’s a bright line separating the books we enjoyed as children from the “real” books of our more mature years. We all eventually age out of the thin, brightly illustrated picture books we enjoyed in our youth, replacing them with thicker, wordier volumes with fewer and fewer illustrations, until they become so dense with information that footnotes and appendices are needed to convey all the information, and a well-written index is a vital necessity to make use of any of it.

Such books seem like a lot less fun than kids’ books, and they probably are, but most of us adjust to the change and accept the fact that the children’s section of the library doesn’t hold much that’ll interest us anymore. But not all the books that get a “JUV” label on their spines are created equal. Some are far more than picture books, even if the pictures are the main attraction. The books of British-born American author David Macaulay come to mind, particularly the books comprising his Architecture Series.

Macaulay’s books were enormously influential in developing my engineering sensibilities, and are still a pleasure to thumb through these many years later. I still learn something about the history of construction and engineering when I pull one of these books off the shelf, which makes them Books You Should Read.

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Multispectral Imaging Shows Erased Evidence Of Ancient Star Catalogue

Ancient Greek astronomer Hipparchus worked to accurately catalog and record the coordinates of celestial objects. But while Hipparchus’ Star Catalogue is known to have existed, the document itself is lost to history. Even so, new evidence has come to light thanks to patient work and multispectral imaging.

Hipparchus’ Star Catalogue is the earliest known attempt to record the positions of celestial bodies (predating Claudius Ptolemy’s work in the second century, which scholars believe was probably substantially based on Hipparchus) but direct evidence of the document is slim. Continue reading “Multispectral Imaging Shows Erased Evidence Of Ancient Star Catalogue”

A brass-and-wood replica of Faraday's motor

Replicating Faraday’s 200-Year-Old Electric Motor

Although new electric motor types are still being invented, the basic principle of an electric motor has changed little in the past century-and-a-half: a stator and a rotor built of magnetic materials plus a bunch of strategically-placed loops of wire. But getting even those basic ingredients right took a lot of experimentation by some of the greatest names in physics. Michael Faraday was one of them, and in the process became the first person to turn electricity into motion. [Markus Bindhammer] has recreated Faraday’s experiment in proper 19th century style.

Back in 1821, the very nature of electricity and its relation to magnetism were active areas of research. Tasked with writing an article about the new science of eletromagnetics, Faraday decided to test out the interaction between a current-carrying wire and a permanent magnet, in a setup very similar to [Markus]’s design. A brass wire is hanging freely from a horizontal rod and makes contact with a conductive liquid, inside of which a magnet is standing vertically. As an electric current is passed through the wire, it begins to rotate around the magnet, as if to stir the liquid.

[Markus]’s video, embedded after the break, shows the entire construction process. Starting from rods and sheet metal, [Markus] uses mostly hand tools to create all basic parts that implement the motor, including a neat knife switch. Where Faraday used mercury as the conductive liquid, [Markus] uses salt water – cheaper and less toxic, although it does eventually eat up the brass wire through electrolysis.

While not particularly useful in itself, Faraday’s motor proved for the first time that electric energy could be converted into motion through magnetism, leading to a whole class of ultra-simple motors called homopolar motors. It would be a while before experiments by the likes of Tesla and Ferraris led to modern AC motors. If you don’t like your motors magnetic, you can use electrostatics instead.

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Two nearly-identical black and white images of a solar installation on top of a roof in NYC. The left image purports to be from 1909 while the other says it is from 1884. Both show the same ornate building architecture in the background and angle of the panels.

The Mysterious Case Of The Disappearing Inventor

When combing through the history of technological innovation, we often find that pinning down a given inventor of something can be tricky. [Foeke Postma] at Bellingcat shows us that even the Smithsonian can get it wrong when given faulty information.

The mystery in question is the disappearance of inventor [George Cove] from a photograph of his solar panel system from 1909 and its reuse as evidence of the first photovoltaic solar panel by another inventor, [Charles Fritts], around 1884. Questions first arose about this image in 2021, but whether this was an example of photo manipulation was merely speculation at the time.

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Clipper Windpower: Solutions In Search Of Problems

The first modern wind turbines designed for bulk electricity generation came online gradually throughout the 80s and early 90s. By today’s standards these turbines are barely recognizable. They were small, had low power ratings often in the range of tens to hundreds of kilowatts, and had tiny blades that had to rotate extremely quickly.

When comparing one of these tiny machines next to a modern turbine with a power rating of 10 or more megawatts with blades with lengths on the order of a hundred meters, one might wonder if there is anything in common at all. In fact, plenty of turbines across the decades share fundamental similarities including a three-blade design, a fairly simple gearbox, and a single electric generator. While more modern turbines are increasingly using direct-drive systems that eliminate the need for a gearbox and the maintenance associated with them, in the early 2000s an American wind turbine manufacturer named Clipper Windpower went in the opposite direction, manufacturing wind turbines with an elaborate, expensive, and heavy gearbox that supported four generators in each turbine. This ended up sealing the company’s fate only a few years after the turbines were delivered to wind farms.

Some history: the largest terrestrial wind turbines were approaching the neighborhood of 2 megawatts, but some manufacturers were getting to these milestones essentially by slapping on larger blades and generators to existing designs rather than re-designing their turbines from the ground up to host these larger components. This was leading to diminishing returns, as well as an increased amount of mechanical issues in the turbines themselves, and it was only a matter of time before the existing designs wouldn’t support this trend further. Besides increased weight and other mechanical stresses on the structure itself, another major concern was finding (and paying for) cranes with enough capacity to hoist these larger components to ever-increasing heights, especially in the remote locations that wind farms are typically located. And cranes aren’t needed just for construction; they are also used whenever a large component like a generator or blade needs to be repaired or replaced. Continue reading “Clipper Windpower: Solutions In Search Of Problems”

How Duck Tape Became Famous

If you hack things in the real world, you probably have one or more rolls of duck tape. Outside of the cute brand name, many people think that duck tape is a malapropism, but in truth it is the type of cloth traditionally used in our favorite tape: cotton duck. However, as we’ll see, it’s not entirely wrong to call it duct tape either. Whatever you call it, a cloth material has an adhesive backing and is coated with something like polyethylene.

Actually, the original duck tape wasn’t adhesive at all. It was simply strips of cotton duck used for several purposes, including making shoes and wrapping steel cables like the ones placed in 1902 at the Manhattan Bridge. By 1910, the tape was made with adhesive on one side and soaked in rubber, found use in hospitals for binding wounds. In May 1930, Popular Mechanics advised melting rubber from an old tire and adding rosin to create a compound to coat cotton tape, among other things.

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