Full Width 
Shortcuts 
Sign Up 
Log In 
Articles 
Reading List More from Tikalon Blog by Dev Gualtieri
Tikalon Blog is now in archive mode. Here's a directory of links to easily printed and saved articles. If you're willing to wait a while for the download, a zip file of all the blog articles can be found at the link below. Note, however, that these articles are copyrighted and can't be used to train artificial intelligent agents. Individuals are free to republish single articles on their personal websites.
Microphones convert sound into an electrical signal for subsequent amplification, as in auditorium public address systems; or transmission, as in landline and mobile phones. The most common types of microphones are carbon, used in early telephones, condenser, electret, dynamic, ribbon, crystal and MEMS. All these microphones operate as transducers that convert sound pressure into an electrical signal. This makes them also sensitive to noise caused by air molecules bouncing against their diaphragms. In an effort to solve this thermal noise problem, a team of mechanical engineers has investigated a sound sensing approach that uses viscous air flow rather than sound pressure. Viscous flow is what vibrates spiderwebs in gentle breezes. Air flow passing a thread of a spiderweb drags the thread. They demonstrated sound detection by a simulated spiderweb, an array of thin cantilever beams. The beams were 0.5 micrometer thick silicon nitride placed over a hole in a silicon wafer, and a laser was used to measure the displacement of the microbeams, first in response to thermal noise, and then in response to sound waves from 100 to 1000 Hz. The cantilever velocity matched that of the sound wave, irrespective of the length or width of the beam. The demonstrated cantilever microphone is about 50 dBa less sensitive than the best pressure-based microphones; but, pressure microphones have been perfected over a span of 150 years. As the lead author of the paper comments, "Detecting air flow as a way to sense sound has largely been ignored by researchers, but the principles show that it's worth considering."
"Form follows function" is a maxim that an object's shape and appearance should be defined only by its purpose or function. A quick perusal of any antique shop will show that this maxim is generally ignored. Humans (Homo sapiens) have been called "naked apes," but we and our close species cousins quickly adopted the concept of wearing the fur skins of animals for protection. Our ancestors were likely much more interested in how they would obtain their next meal than how stylish they appeared in hyena fur. As human culture progressed, people desired to distinguish themselves from others; and, what could be an easier way to do that than through dress. This is accomplished by the simple technique of dyeing drab natural fibers, but the simple sewing needle is a technical innovation that's lead to a means of producing more ornate dress. A recent open access article in Science Advances investigates the use of delicate eyed needles in the Paleolithic as the means for producing refined, ornamented dress. One argument for clothing's becoming a means of decoration is that traditional body decoration, such as body painting with ochre, weren't effective in cold climates, since clothing was needed all the time for survival. Homo sapiens arrived in Europe at around 45,000 BC, and the earliest known eyed needles appeared in Siberia around 40,000 BC, in the Caucasus around 38,000 BC, in West Asia around 30,000 BC, and in Europe around 26,000 BC. Clothing the human body regardless of climate is a social practice that's persisted to this day. The eyed needle combined the processes of hole puncture and threading to allow finer and more efficient sewing.
Deep thought is what distinguishes humans from other animals. The brain is the medium for thought; so, there's the idea that brain size is important, with larger brains allowing more profound thought. Larger brains in hominids appears to have an evolutionary advantage, but the largest animals do not have proportionally larger brains. For the last century, conventional wisdom was that body mass in mammals could be described by a power law. A British research team has created a large dataset of brain and body sizes from about 1,500 species to determine the trend in brain size evolution, finding that the trend is brain size and body mass is not log-linear, but rather log-curvilinear, plateauing at high body mass. The research team found that all groups of mammals demonstrated rapid bursts of evolutionary change, not only towards larger brain size, but smaller as well. Bats very rapidly reduced their brain size, suggesting that flight may have imposed an evolutionary constraint. Homo sapiens has evolved more than twenty times faster than all other mammalian species, resulting in the massive brain size of modern man. Primates, rodents, and carnivores show a tendency for increase in relative brain size as they evolved. It appears that there is something preventing brains from getting too big, perhaps because big brains beyond a certain size are simply too costly to maintain. This upper limit of brain size applies to animals with very different biology.
In today's bigger is better world, you don't order a large coffee, you order a 20 fluid ounce Venti coffee. From 1987 through 2004, McDonald's restaurants had a supersize option for larger than large portions of its French fries and soft drinks. The prefix, super, has been used to describe supercooling, the unexpected cooling without a phase change when liquids can be cooled below their freezing points without solidifying. Water has many unusual properties, and these are most probably the result of water molecule being small, and the force holding these molecules together in a liquid or solid arising from hydrogen bonding. Supercooled water is a hazard to aviation, since supercooled water droplets often existing in cumulus and stratus clouds will instantly freeze on aircraft surfaces and plug the Pitot tubes that indicate airspeed. It's easy to create supercooled water in the laboratory. You just need to purify the water to remove contained minerals. The mineral crystals act as nucleation sites. Bacteria and fungi are efficient natural ice nucleators because of the way their proteins act as ice templates. The best such natural ice nucleators the Pseudomonas syringae bacterium, which is used to make artificial snow. Larger protein molecules are usually better at ice nucleation, but small fungal proteins are good at ice nucleation when they clump into larger aggregates. Scientists at the University of Utah have developed a model for prediction of the nucleation temperature of ice on a given surface. Model parameters include the shapes of surface defects, and appropriately sized and shaped surface bumps and depressions can squeeze water molecules into configurations that make it easier or harder for ice to form.
More in science
A better understanding of human smell is emerging as scientists interrogate its fundamental elements: the odor molecules that enter your nose and the individual neurons that translate them into perception in your brain. The post How Smell Guides Our Inner World first appeared on Quanta Magazine
As I try to write this article, my friend and I have six different screens attached to three types of devices. We’re working in the same room but on our own projects—separate yet together, a comfortable companionship. I had never really thought of the proliferation of screens as a peacekeeping tool until I stumbled across one of Allen B. DuMont’s 1950s dual-screen television sets. DuMont’s idea was to let two people in the same room watch different programs. It reminded me of my early childhood and my family’s one TV set, and the endless arguments with my sisters and parents over what to watch. Dad always won, and his choice was rarely mine. The DuMont Duoscopic Was 2 TVs in 1 Allen B. DuMont was a pioneer of commercial television in the United States. His eponymous company manufactured cathode-ray tubes and in 1938 introduced one of the earliest electronic TV sets. He understood how human nature and a shortage of TV screens could divide couples, siblings, and friends. Accordingly, he built at least two prototype TVs that could play two shows at once. In the 1945 prototype shown at top, DuMont retrofitted a maple-finished cabinet that originally held a single 15-inch Plymouth TV receiver to house two black-and-white 12-inch receivers. Separate audio could be played with or without earpieces. Viewers used a 10-turn dial to tune into TV channel 1 (which went off the air in 1948) and VHF channels 2 through 13. As radio was still much more popular than television, the dial also included FM from 88 to 108 megahertz, plus a few channels used for weather and aviation. The lower left drawer held a phonograph. It was an all-in-one entertainment center. To view their desired programs on the DuMont Duoscopic TV set, this family wore polarized glasses and listened through earpieces.Allen DuMont/National Museum of American History/Smithsonian In 1954, DuMont introduced a different approach. With the DuMont Duoscopic, two different channels were broadcast on a single screen. To the naked eye, the images appeared superimposed on one another. But a viewer who wore polarized glasses or looked at the screen through a polarized panel saw just one of the images. Duoscopic viewers could use an earpiece to listen to the audio of their choice. You could also use the TV set to watch a single program by selecting only one channel and playing the audio through one speaker. DuMont seemed committed to the idea that family members should spend time together, even if they were engaged in different activities. An image of the Duoscopic sent out by the Associated Press Wirephoto Service heralded “No more lonely nights for the missus.” According to the caption, she could join “Hubby,” who was already relaxing in his comfy armchair enjoying his favorite show, but now watch something of her own choosing. “Would you believe it?” a Duoscopic brochure asks. “While HE sees and hears the fights, SHE sees and hears her play…. Separate viewing and solo sound allows your family a choice.” The technology to separate and isolate the images and audio was key. The Duoscopic had two CRTs, each with its own feed, set at right angles to each other. A half-silvered mirror superimposed the two images onto a single screen, which could then be filtered with polarized glasses or screens. TV pioneer Allen B. DuMont designed and manufactured cathode ray tubes and TV sets and launched an early TV network.Science History Images/Alamy A separate box could be conveniently placed nearby to control the volume of each program. Users could toggle between the two programs with the flick of a switch. Each set came with eight earpieces with long cords. A short note in the March 1954 issue of Electrical Engineering praises the engineers who crafted the sound system to eliminate sound bleed from the speakers. It notes that a viewer “very easily could watch one television program and listen to the audio content of a second.” Or, as a United Press piece published in the Panama City News Herald suggested, part of the family could use the earpieces to watch and listen to the TV while others in the room could “read, play bridge, or just sit and brood.” I suspect the brooders were the children who still didn’t get to watch their favorite show. Of course, choice was a relative matter. In the 1950s, many U.S. television markets were lucky to have even two channels. Only in major metropolitan areas were there more programming options. The only known example of DuMont’s side-by-side version resides at the South Carolina State Museum, in Columbia. But sources indicate that DuMont planned to manufacture about 30 Duoscopics for demonstration purposes, although it’s unclear how many were actually made. (The Smithsonian’s National Museum of American History has a Duoscopic in its collections.) Alas, neither version ever went into mainstream production. Perhaps that’s because the economics didn’t make sense: Even in the early 1950s, it would have been easier and cheaper for families to simply purchase two television sets and watch them in different rooms. Who Was Early TV Pioneer Allen DuMont? DuMont is an interesting figure in the history of television because he was actively engaged in the full spectrum of the industry. Not only did he develop and manufacture receivers, he also conducted broadcasting experiments, published papers on transmission and reception, ran a television network, and produced programming. After graduating from Rensselaer Polytechnic Institute in 1924 with a degree in electrical engineering, DuMont worked in a plant that manufactured vacuum tubes. Four years later, he joined the De Forest Radio Co. as chief engineer. With Lee de Forest, DuMont helped design an experimental mechanical television station, but he was unconvinced by the technology and advocated for all-electric TV for its crisper image. RELATED: In 1926, TV Was Mechanical When the Radio Corporation of America acquired De Forest Radio in 1931, DuMont started his own laboratory in his basement, where he worked on improving cathode ray tubes. In 1932 he invented the “magic eye,” a vacuum tube that was a visual tuning aid in radio receivers. He sold the rights to RCA. In 1935, DuMont moved the operation to a former pickle factory in Passaic, N.J., and incorporated it as the Allen B. DuMont Laboratories. The company produced cathode ray oscilloscopes, which helped finance his experiments with television. He debuted the all-electronic DuMont 180 TV set in June 1938. It cost US $395, or almost $9,000 today—so not exactly an everyday purchase for most people. Although DuMont was quick to market, RCA and the Television Corp. of America were right on his tail. RELATED: RCA’s Lucite Phantom Teleceiver Introduced the Idea of TV Of course, if companies were going to sell televisions, consumers had to have programs to watch. So in 1939, DuMont launched his own television network, starting with station W2XWV, broadcasting from Passaic. The Federal Communications Commission licensed W2XWV as an experimental station for television research. DuMont received a commercial license and changed its call sign to WABD on 2 May 1944, three years after NBC’s and CBS’s commercial stations went into operation in New York City. Due to wartime restrictions and debates over industry standards, television remained mostly experimental during World War II. As of September 1944, there were only six stations operating—three in New York City and one each in Chicago, Los Angeles, and Philadelphia. There were approximately 7,000 TV sets in personal use. The DuMont Television Network’s variety show hosted by Jackie Gleason [left, hands raised] featured a recurring skit that later gave rise to “The Honeymooners.”Left: CBS/Getty Images; Right: Garry Winogrand/Picture Post/Hulton Archive/Getty Images While other networks focused on sports, movies, or remote broadcasts, the DuMont Television Network made its mark with live studio broadcasts. In April 1946, WABD moved its studios to the Wanamaker Department Store in Manhattan. DuMont converted the 14,200-cubic-meter (500,000-cubic-foot) auditorium into the world’s largest television studio. The network’s notable programming included “The Original Amateur Hour,” which started as a radio program; “The Johns Hopkins Science Review,” which had a surprisingly progressive take on women’s health; “Life Is Worth Living,” a devotional show hosted by Catholic Bishop Fulton Sheen (that garnered DuMont’s only Emmy Award); “Cavalcade of Stars,” a variety show hosted by Jackie Gleason that birthed “The Honeymooners”; and “Captain Video and His Video Rangers,” a children’s science fiction series, the first of its genre. My grandmother, who loved ballroom dancing, was a big fan of “The Arthur Murray Party,” a dance show hosted by Arthur’s wife, Kathryn; my mom fondly recalls Kathryn’s twirling skirts. While NBC, CBS, and the other major television players built their TV networks on their existing radio networks, DuMont was starting fresh. To raise capital for his broadcast station, he sold a half-interest in his company to Paramount Pictures in 1938. The partnership was contentious from the start. There were disputes over money, the direction of the venture, and stock. But perhaps the biggest conflict was when Paramount and some of its subsidiaries began applying for FCC licenses in the same markets as Dumont’s. This ate into the DuMont network’s advertising and revenue and its plans to expand. In August 1955, Paramount gained full control over the DuMont network and proceeded to shut it down. DuMont continued to manufacture television receivers until 1958, when he sold the business to the Emerson Radio & Phonograph Corp. Two years later, the remainder of DuMont Labs merged with the Fairchild Camera and Instrument Corp. (whose founder, Sherman Fairchild, had in 1957 helped a group of ambitious young scientists and engineers known as the “Traitorous Eight” set up Fairchild Semiconductor). Allen DuMont served as general manager of the DuMont division for a year and then became a technical consultant to Fairchild. He died in 1965. One Thing Allen DuMont Missed My family eventually got a second and then a third television, but my dad always had priority. He watched the biggest set from his recliner in the family room, while my mom made do with the smaller sets in the kitchen and bedroom. He was relaxing, while she was usually doing chores. As a family, we would watch different shows in separate places. An ad for the DuMont Duoscopic touted it as a device for household harmony: “While HE sees and hears the fights, SHE sees and hears her play.” National Museum of American History/Smithsonian These days, with so many screens on so many devices and so many programming options, we may have finally achieved DuMont’s vision of separate but together. While I was writing this piece, my friend was watching the French Open on the main TV, muted so she didn’t disturb me. She streamed the same channel on her tablet and routed the audio to her headset. We both worked on our respective laptops and procrastinated by checking messages on our phones. But there’s one aspect of human nature that DuMont’s prototypes and promotional materials failed to address—that moment when someone sees something so exciting that they just have to share it. Sarah and I were barely getting any work done in this separate-but-together setting because we kept interrupting each other with questions, comments, and the occasional tennis update. We’ve been friends too long; we can’t help but chitchat. The only way for me to actually finish this article will be to go to a room by myself with no other screens or people to distract me. Part of a continuing series looking at historical artifacts that embrace the boundless potential of technology. An abridged version of this article appears in the July 2025 print issue as “The 2-in-1 TV.” References I first learned about the Duoscopic in a short article in the March 1954 issue of Electrical Engineering, a precursor publication to Spectrum. My online research turned up several brochures and newspaper articles from the Early Television Museum, which surprisingly led me to the dual-screen DuMont at the South Carolina State Museum in my hometown of Columbia, S.C. Museum objects are primary sources, and I was fortunate to be able to visit this amazing artifact and examine it with Director of Collections Robyn Thiesbrummel. I also consulted the museum’s accession file, which gave additional information about the receiver from the time of acquisition. I took a look at Gary Newton Hess’s 1960 dissertation, An Historical Study of the Du Mont Television Network, as well as several of Allen B. DuMont’s papers published in the Proceedings of the IRE and Electrical Engineering.
Last year Meta identified 135 materials that could potentially be used to draw down carbon dioxide, work it described as "groundbreaking." But when scientists tried to reproduce the results, they found that none of the materials could perform as promised and that some did not even exist. Read more on E360 →
The precursors of heavy elements might arise in the plasma underbellies of swollen stars or in smoldering stellar corpses. They definitely exist in East Lansing, Michigan. The post Physicists Start To Pin Down How Stars Forge Heavy Atoms first appeared on Quanta Magazine
