Today in History – February 1, 1972 – First scientific hand-held calculator, the HP-35, introduced for $395. I was an undergraduate in engineering when the HP-35 was released. I couldn’t afford to buy one and stuck with my slide rule. But the next year, I gave in and bought the next model, the HP-45 and it was well worth the money at the time. The calculators were easy to use, portable and reliable. The market responded by developing cheaper calculators, while Hewlett Packard kept the cost high and increased the functionality.

Check out the Engineering Pathway’s educational resources on the electronic calculators and history of computing. For more educational resources, see our electrical engineering education and computer engineering education community pages. The Engineering Pathway also hosts Engineering Education communities in all ABET-accredited disciplines.

Today in History – January 26, 1926 – Scottish Engineer John Baird gives first public demonstration of television in London. According to BBC News, his first prototype in 1924 was crudely made of a washstand, a tea chest and a project lamp in a biscuit tin, scanning disks made from carboard and lenses, all held together with srcap wood, darning needles, strings and sealing wax. Nevertheless, he managed to transmit a flickering image for a few feet. On 26 January 1926, he gave the first world’s demonstration to fifty scientists in London. By 1927 he was transmitting an image of over 438 miles between London and Glasgow and started the Baird Television Development Company. Other firsts include: first transmission of a human face in 1925 (see right photo above), first transatlantic television transmission between London and New York in 1928 and first demonstration of color and stereoscopic television.

Baird’s system was amazing in that it was entirely mechanical, but it couldn’t compete against new electronic systems, such as those being developed by Marconi in the United States. Marconi’s approach was ultimately adopted for early television systems, but Baird’s contributions paved the way by introducing the concept and providing the first proof of concept. Prior to this BBC (British Broadcasting Corporation) was concentrating on radio production because they thought television would be a passing fad. In 1936 they adopted a television service using the electronic television technology developed by Marconi and thus Baird’s contributions are less well known.

Check out the Engineering Pathway’s educational resources on the color television. For more educational resources, see our electrical engineering education and computer engineering education community pages. The Engineering Pathway also hosts Engineering Education communities in all ABET-accredited disciplines.

Also on this date in 1905, Cullinan Diamond (“Star of Africa”), the largest diamond ever found, is unearthed. On January 26, 1697,  Isaac Newton solves Bernoulli’s brachistochrone problem, inventing the “calculus of variations”. And in 1992, Americans with Disabilities Act went into effect.

Today in History – January 11, 1954 – Although radio weather broadcasts have been around since 1922, it was not until 1953 that BBC executives, gathered for a luncheon, introduced the idea of presenting a weather forecast on television. These BBC executives searched the Met Office and chose the 32-year-old George Cowling, a former Royal Air Force meteorologist, to take on this new idea. Cowling delivered the first televised weather forecast on January 11th, 1954 at 7:55 PM from BBC’s Lime Grove Studios. The broadcast lasted for only five minutes and cost 50 pounds to deliver, but it started a weather forecasting revolution. Today, the BBC’s Weather Center produces 100 forecasts each weekday, now with the help of modern computer, lighting, sound, and camera technology. This equipment was not available to Cowling, who relied on an easel to deliver his first broadcast.

Two months later RCA produced the first color television sets. See Lisa Huettel’s March 25 blog on this event.

Check out the Engineering Pathway’s educational resources on the color television. For more educational resources, see our electrical engineering education and computer engineering education community pages. The Engineering Pathway also hosts Engineering Education communities in all ABET-accredited disciplines.

Today in History – December 29, 1891 – Thomas Alva Edison patents “transmission of signals electrically” by radio. Close to a year later, on August 9, 1892, he received a patent for a two-way radio.

Also on this date in 1952, the first transistor hearing aid went on sale by the Sonotone Corporation.  This hearing aid was much larger than the miniature ones today as it was a hybrid of analog and digital technologies,  weighing 3.5-oz, measuring 3 inches and costing around $300 (which would be over $1500.00 today). Still it was a big improvement over the large amplifying horns and other devices used previously. Alexander Graham Bell was originally working on hearing aids for people with deafness when he invented the telephone using such a horn in 1876. Edison’s phonograph, invented in 1877, also used such a horn to amplify and broadcast sound.

For more information, see the Engineering Pathway‘s resources on Edison and radios or hearing aids. For curricular resources, browse our resources for persons with disabilities, or visit the Electrical Engineering Education or Engineering Diversity community sites.

Today in History – December 21, 1807 – Fourier introduces his series at the Paris Institute. Joseph Fourier’s memoir, On the Propagation of Heat in Solid Bodies, was read to the Paris Institute. It introduced the expansion of functions into trigonometric series which are now called Fourier series.

The Fourier series allows periodic functions to be represented as a weighted sum of much simpler sinusoidal component functions sometimes referred to as normal Fourier modes, or simply modes for short. The weights, or coefficients, of the components, arranged in order of increasing frequency, form a sequence (or function) called Fourier series. Fourier analysis provides a frequency domain representation of a time domain function. The mapping between the two functions is one-to-one, so the transform is reversible. A common visualization of this transformation is the audio equalizer, which is a dynamic representation of a time signal converted to the frequency domain. An audio spectrum of both time and frequency is shown below.

Preliminary work by Madhava, Nilakantha Somayaji, Jyesthadeva, Leonhard Euler, Jean le Rond d’Alembert, and Daniel Bernoulli would serve as the foundation for Fourier’s work. He applied his studies of trigonometric series to a solution of the partial differential heat equation to produce the series below:

Fourier’s initial series lacked the precision of a function, and Dirichlet and Riemann would later express the series as a formal integral.

Fourier series applications include electrical engineering, vibration analysis, acoustics, optics, signal and image processing, and data compression. Using the tools and techniques of spectroscopy, astronomers can deduce the chemical composition of a star by analyzing the frequency components, or spectrum, of the star’s emitted light. Similarly, engineers can optimize the design of a telecommunications system using information about the spectral components of the data signal that the system will carry.

For more information, see the Engineering Pathway‘s resources on Fourier and the Fourier series For related educational resources, visit the Electrical Engineering Education disciplinary community.

Today in History – December 20, 1899 – Carbon Arc Lamps generate light by way of a spark between two carbon nodes. However, they also produce a constant humming noise while running. Since they were widely used in Europe (installed before the invention of the electric light bulb in the United States), a British physicist and electrical engineer, William Duddell was appointed to solve the noise problem in 1899. During his experiments, Duddell found that he could control the audible frequencies by varying the voltage supplied to the lamps. It’s possible that Duddell was aware of similar findings by a Dr. Simon of Frankfurt, Germany a year earlier (who showed that the modulated arc produced modulated light as well as sound, allowing the German Navy to make telephone calls between ships with an arc searchlight and a photosensitive selenium cell). However, it was Duddell that attached a keyboard to the arc lamps, creating one of the first electronic instruments, The Singing Arc, that was audible without the use of an amplifying system (which had yet to be invented). Other pre-20th-century electronic instruments include the Clavecinlectrique, the Musical Telegraph, and the Telharmonium.

Also on this date in 1951, the first electricity generated by nuclear power powers four lightbulbs. And in 1977, the first space walk was made by Cosmonaut Grechko of the Salyut.

For more information, see the Engineering Pathway‘s resources on electronic music; breeder reactors and nuclear power; and the Salyut, space exloration and aerospace engineering. For related educational resources, visit the Electrical Engineering Education, Aerospace Engineering Education,or Nuclear Engineering Education disciplinary communities.

Today in History – December 19, 1972 – Apollo 17, last of Apollo Moon landing series, returns to Earth. It was the sixth and last Apollo mission in which humans walked on the lunar surface.

Also on this date in 1958, the first radio message was broadcast from space from the U.S. launched Explorer-1. Later that year, the U.S. SCORE spacecraft became the first communication satellite in Earth orbit. It was a one-way communication system with a transmitter that broadcast to Earth a pre-recorded message, taped on the ground before launch by President Dwight D. Eisenhower – “To all mankind, America’s wish for Peace on Earth and Good Will to Men Everywhere”.

For more information, see the Engineering Pathway;s resources on the Apollo mission and space exploration, communications satellites or GPS and geomatics systems. For related educational resources, visit the Aerospace Engineering Education, Electrical Engineering Education , or Surveying and Geomatics Engineering Education disciplinary communities.

Today in History – December 18, 1958 – SCORE (Signal Communication by Orbital Relay Equipment) was the world’s first communications satellite to be put into orbit. As the first American satellite to relay communications from one ground station to another, SCORE used a tape recorder to store and forward voice messages. It was used to send a Christmas greeting via short wave frequency to the world from U.S. President Dwight D. Eisenhower.

The SCORE satellite was designed and built by Kenneth Masterman-Smith, a military communication research engineer, along with other personnel with the U.S. Army Signal Research and Development Laboratory (SRDL) at Fort Monmouth, New Jersey. Launched in an Atlas rocket, SCORE provided a first test of a communications relay system in space. The technical objectives were to demonstrate the capabilities of satellite launch from an Atlas missile and the feasibility of transmitting messages through the upper atmosphere from one ground station to one or more ground stations. Score placed the United States at an even technological par with the Soviet Union as a highly functional response to the Sputnik satellites. The payload weighed 150 pounds, and was built into the fairing pods of the 9000 pound Atlas missile. Any of four ground stations in the southern United States could command the satellite into playback mode to transmit the stored message or into record mode to receive and store a new message. Its batteries lasted 12 days and it reentered the atmosphere on 21 January 1959.

SCORE was an early research endeavor for the Advanced Research Projects Agency (ARPA), which eventually evolved into the Defense Advanced Research Projects Agency (DARPA). It was developed during the dawn of satellite communication innovation in the U.S. and abroad. The first satellite equipped with on-board radio-transmitters was the Soviet Sputnik 1, launched in 1957. NASA launched an Echo satellite in 1960; the 100-foot aluminized PET film balloon served as a passive reflector for radio communications. Courier 1B, (built by Philco) also launched in 1960, was the world’s first active repeater satellite. Telstar was the first active, direct relay communications satellite. Belonging to AT&T as part of a multi-national agreement between AT&T, Bell Telephone Laboratories, NASA, the British General Post Office, and the French National PTT (Post Office) to develop satellite communication, it was launched by NASA from Cape Canaveral on July 10, 1962, the first privately sponsored space launch.

For more information, see the Engineering Pathway’s educational resources on communications satellites or GPS and geomatics systems. For related curricula, visit the Information Technology Education, Electrical Engineering Education , Surveying and Geomatics Engineering Education disciplinary communities.

Today in History – December 12, 1901 – Marconi sends first transatlantic radio signal. Guglielmo Marconi and his assistant, George Kemp heard the faint clicks of Morse code this day, signifying the first reception of transatlantic radio signals. This experiment in “wireless telegraphy” at a global dimension eventually transformed radio into a major form of communication in the twentieth century. Photo citation (left): Guglielmo Marconi with his assistant George Kemp pictured with a 10-inch induction coil spark transmitter and a Morse inker during the 1901 transatlantic test at Signal Hill. Center photo: Marconi’s antenna system at Poldhu, Cornwall. Right photo: BBC article and audio file.

Readers may be interested in the Engineering Pathway’s related educational resources on Marconi, telecommunications and our Electrical Engineering Education Community site.

Also on this date, Tide detergent introduced by Proctor and Gamble in 1946, the U.S. copyright law amended to include computer programs in 1980, and first prototype of hovercraft patented by British Engineer Christoper Cockerell in 1955.

Today in History – December 8, 1993 – First functional GPS (Global Positioning System) was developed. The technology initially developed for military use eventually made its way into our daily lives- most notably in cars and cell phones. Using information from a number of satellites orbiting the Earth (originally with 24, now a total of 30), a GPS receiver can pinpoint your location in real time with the help of atomic clocks, which makes this accurate to one billionth of a second. The GPS manufacturing and development industry has launched into a multi-billion dollar industry with its vast number of practical applications- from locating lost ships at sea to studying earthquakes by monitoring plate tectonics like the people at SCIGN (Southern California Integrated GPS Network). Soon enough, they will be available in credit card sizes, making it even more convenient to carry one around.

For more information, see the Engineering Pathway’s educational resources on GPS and geomatics. For related curricula, visit the Information Technology Education, Computer Engineering Education, Electrical Engineering Education , Surveying and Geomatics Engineering Education disciplinary communities.

Also on this date in 2004- After popularizing the PC in the ’80s, IBM sells its PC business to a Chinese company. The computer industry giant decided to let go of its retail computer division in order to concentrate on software development and providing services at a larger scale.