Full Width 
FOCUS MODE
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."
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
Belting your favorite song over prerecorded music into a microphone in front of friends and strangers at karaoke is a popular way for people around the world to destress after work or celebrate a friend’s birthday. The idea for the karaoke machine didn’t come from a singer or a large entertainment company but from Nichiden Kogyo, a small electronics assembly company in Tokyo. The company’s founder, Shigeichi Negishi, was singing to himself at work one day in 1967 when an employee jokingly told him he was out of tune. Figuring that singing along to music would help him stay on pitch, Negishi began thinking about how to make that possible. He had the idea to turn one of the 8-track tape decks his company manufactured into what is now known as the karaoke machine. Later that year, he built what would become the first such machine, which he called the Music Box. The 30-centimeter cube housed an 8-track player for four tapes of instrumental recordings and included a microphone to sing into. He sold his machine in 1967 to a Japanese trading company, which then sold it to restaurants, bars, and hotel banquet halls, where they used it as entertainment. The machine was coined karaoke in the 1970s to describe the act of singing along to prerecorded music. The term is a combination of two Japanese words: kara, meaning empty, and okesutora, meaning orchestra. In a few years, dedicated establishments known as karaoke bars began to open across Japan. Today the country has more than 8,000, according to Statista. The karaoke machine has been commemorated as an IEEE Milestone. The dedication ceremony was held in June in the area that houses karaoke booths connected to the Shinagawa Prince Hotel in Tokyo. Negishi’s family attended the event along with IEEE leaders. Negishi died last year at the age of 100. He was grateful that people enjoy karaoke around the world, his son, Akihiro Negishia, said at the ceremony, “though he didn’t imagine it to spread globally when he created it.” Accidentally inventing one of the world’s favorite pastimes Shigeichi Negishi grew up in Tokyo, where his mother ran a tobacco store and his father oversaw regional elections as a government official. After earning a bachelor’s degree in economics from Hosei University in Tokyo, he was drafted into the Imperial Japanese Army during World War II. He became a prisoner of war and spent two years in Singapore before being released in 1947. He returned to Tokyo and sold cameras for electrical parts manufacturer Olympus Corp. In 1956 he started Nichiden Kogyo, which manufactured and assembled portable radios for the home and car, according to the Engineering and Technology History Wiki entry about the karaoke machine. Negishi would start each morning singing along to the “Pop Songs Without Lyrics” radio show, according to a Forbes article. He typically didn’t sing in the office, but one fateful day he did. Negishi was inspired to engineer one of the 8-track tape decks his company manufactured into what is now known as the karaoke machine An 8-track tape deck can play and record audio using magnetic tape cartridges. Nichiden Kogyo’s Music Box was a 30-centimeter cube with slots to insert four 8-track tapes on the top panel, with control buttons to play, stop, or skip to the next song. Inside each 13-centimeter-long rectangular 8-track cartridge is a loop of almost 1 cm-wide magnetic tape that is coiled around a circular reel, as explained in an EverPresent blog post on the technology. A small motor inside each cartridge pulls the tape across an audio head inside the player, which reads the magnetic patterns and translates them into sound. Each tape had a metal sensing strip that notified a solenoid coil located in the player when a song had ended or if a person pressed the button to switch to the next song, according to an Autodesk Instribules blog post. The coil created a magnetic field when electricity passed through it—which rotated the spindle on which the audio head was mounted to move to the next track on the tape. Each tape could hold about eight songs. Negishi added a microphone amplifier to the player’s top panel, as well as a mixing circuit. The user could adjust the volume of the music and the microphone. He also recorded 20 of his favorite songs onto the tapes and printed out the lyrics on cardstock. He tested the machine by singing a popular ballad, “Mujo no Yume” (“The Heartless Dream”). “It works! That’s all I was thinking,” Negishi told reporter Matt Alt years later, when asked what his thoughts were the first time he tested the Music Box. Alt wrote Pure Invention: How Japan Made the Modern World. In 1969 engineers at Tokyo-based trading company Kokusai Shohin added a coin acceptor to the machine, renaming the Music Box the Sparko Box.Dr. Tomohiro Hase The fees to file a patent were too expensive, according to the ETHW entry, so in 1967 Negishi sold the rights to the machine to Mitsuyoshi Hamasu, a salesman at Kokusai Shohin. The Tokyo-based trading company began selling and leasing the machines by the end of the year. In 1969 engineers at Kokusai Shohin added a coin acceptor to the machine. The company renamed the Music Box the Sparko Box. In six years, about 8,000 units were sold, Hamasu said in an interview about the rise of karaoke. Karaoke became so popular that in the 1980s, venues and bars specializing in soundproofed rooms known as karaoke boxes emerged. Groups could rent the rooms by the hour. Negishi’s family owns the first Music Box he made. It still works. The Milestone plaque recognizing the karaoke machine is on display in front of the former headquarters of Nichiden Kogyo, which Negishi turned into a tobacco shop after he retired. The shop is now owned by his daughter. The plaque reads: “The first karaoke machine was created in 1967 by mixing live vocals with prerecorded accompaniment for public entertainment, leading to its worldwide popularity. Created by Shigeichi Negishi of Nichiden Kogyo, and originally called Music Box (later Sparko Box), it included a mixer, microphone, and 8-track tape player, with a coin payment system to charge the singer. An early operational machine has been displayed at the original company site in Tokyo.” Administered by the IEEE History Center and supported by donors, the Milestone program recognizes outstanding technical developments around the world. The IEEE Tokyo Section sponsored the nomination.
How Canada's largest city developed a 30 kilometer network of pedestrian tunnels
Bison have made a remarkable comeback in Yellowstone National Park, going from fewer than two dozen animals at the turn of the last century to roughly 5,000 today. Their return, a study finds, has had a remarkable impact on grasslands in the region. Read more on E360 →
An updated evolutionary model shows that living systems evolve in a split-and-hit-the-gas dynamic, where new lineages appear in sudden bursts rather than during a long marathon of gradual changes. The post The Sudden Surges That Forge Evolutionary Trees first appeared on Quanta Magazine
Back in the dawn of the 21st century, the American Chemical Society founded a new journal, Nano Letters, to feature letters-length papers about nanoscience and nanotechnology. This was coincident with the launch of the National Nanotechnology Initiative, and it was back before several other publishers put out their own nano-focused journals. For a couple of years now I've been an associate editor at NL, and it was a lot of fun to work with my fellow editors on putting together this roadmap, intended to give a snapshot of what we think the next quarter century might hold. I think some of my readers will get a kick out of it.
