Saturday, March 28, 2015


In 1938 Xerography, a dry printing process was invented by the American inventor Chester Carlson.

The word ‘Xerography’ comes from the Greek word which means ‘dry writing’. It was the foundation technology for copiers and laser printers.

Carlson applied for patent in 1939 and in 1942 the patent was granted to him.

But he was not successful to catch the interest of companies towards his invention. Later on, Carlson succeeded to negotiate commercial rights of his invention to Haloid Company in 1947.

This was the biggest deal of the life both for Carlson and for the company Haloid, which became one of biggest companies in the world due to this invention. Later on this company was renamed as ‘Xerox’.

In 1967 a young researcher in Xerox's Webster Research Center in Rochester, Gary K. Starkweather was sitting in his lab thinking instead of copying someone else's original, if we use a computer to generate the original and here only the idea of the laser printer was born.

At that time, the lasers were expensive devices, but convinced that the cost of lasers would drop over time and also there was a market for laser printing technology, Starkweather stuck to his guns.

His ideas were not meeting the requirements from Xerox management. Hewas told to stop working on the laser printer project. But he couldn't.

He just go through with his idea ignoring all ifs and but. He convinced people to get different parts for building it. The prototype was ready in 1969. It was built by modifying an existing xerographic copier.

Starkweather disabled the imaging system and created a spinning drum with 8 mirrored sides, with a laser focused on the drum. Light from the laser would bounce off the spinning drum, sweeping across the page as it moved through the copier.

The hardware was completed in just two weeks, but the computer interfacing and software took almost 3 months to get completed.

Printers were now a pillar of the company's growth strategy. Starkweather's drive to create the laser printer eventually transformed a small copier company into one of the world's imaging powerhouses, and revolutionized the computer printing industry.

When Xerox build the Palo Alto Research Center (PARC) in California in 1970, Starkweather came for salvation. 

Out of hostile territory,  he was finally given the freedom to conduct his research without fear of retribution. Starkweather went to work on building the laser printer.

In 1971, just nine months after joining PARC, Starkweather completed the first working laser printer.
He named it as ‘SLOT’, an acronym for Scanned Laser Output Terminal.

The digital control system and character generator for the printer were developed by Butler Lampson and Ronald Rider in 1972.

 The combined efforts resulted in a printer named EARS (Ethernet, Alto, Research character generator, Scanned laser output terminal).

 The EARS printer was used with the Alto computer system network and subsequently became the Xerox 9700 laser printing system.

Xerox 9700 was introduced in 1977, it was the industry's first commercial laser printer.
It was a wild success, few customers would produce the 200000 to 300000 prints per month needed for the unit to be profitable.

Starkweather shifted his research onto personal laser printers, and again worked against Xerox.
Xerox was a company that liked large, fast laser printers. They saw departmental units as the profit center for laser printer technology.

Xerox failed to realize that the profit wasn't in the printer but in the ink toner and the paper. As a result, the company was beaten up by Hewlett-Packard, which introduced the first personal laser printer in 1980.

Xerox always encouraged new ideas but never really liked to pursue them for very long. Things like Postscript, the laser printer, the personal computer, the bitmapped screen, the iconic interface, Ethernet, packet switching, all of this came out of PARC. And none of it, ended up as a product of Xerox.

In 1985, Office laser printers become available with high quality text and graphics. One of them is the Apple LaserWriter, a PostScript laser printer.

 HP LaserJet is introduced around the same time and uses the same Canon engine as the LaserWriter.
In 1987 Starkweather however left the company after 24 years of service. Following a 10-year stint at Apple Computer, Starkweather joined Microsoft Research in 1997. These days, his main area of research is display technology.

During mid-1990s, Xerox Majestik offers comparable image quality and colour to Canon CLC range and the color laser printing market becomes competitive in the market.

Tuesday, March 17, 2015


A capacitor is a device for temporarily storing electric charge.

In October 1745, Ewald Georg Von Kleist of Pomerania in Germany found that charge could be stored by connecting a generator by a wire to a volume of water in a hand-held glass jar.

Von Kleist's hand and the water acted as conductors and the jar as a dielectric. Von Kleist found that touching the wire resulted in a spark even after removing the generator.

In a letter describing the experiment, he said "I would not take a second shock for the kingdom of France."

In 1746, the Leyden jar was invented by Pieter van Musschenbroek at the University of Leyden in Holland. It was a glass jar wrapped inside and out by a thin metal foil.

The two layers of electrically conducting material that is metal foil here were separated by layers of a non-conducting material that was glass in the case of the Leyden jar, but it can also be wax, mica, oil, paper, tantalum, plastic, ceramic material, or even air.

The outer foil was connected to the ground, and the inner foil was connected to a source of electricity such as an electrostatic generator.

The plates will become charged, one positively and one negatively. If the externally applied voltage is then removed, the plates of the capacitor remain charged, and the presence of the electric charge induces an electrical potential between the plates.

 Daniel Gralath was the first scientist to combine several Leyden jars in parallel into a "battery" to increase the charge storage capacity.

Benjamin Franklin checked the Leyden jar, and proved that the charge was stored on the glass, not in the water as it was assumed.

He used a Leyden jar to store electricity from lightning in his famous kite flying experiment in 1752. By doing so he proved that lightning was really electricity.

He deviced the idea of a parallel or flat plate capacitor & developed the first flat plate capacitor called the Franklin Square.

Leyden jars began to be made by coating the inside and outside of jars with metal foil, leaving a space at the mouth to prevent arcing between the foils.

The earliest unit of capacitance was the 'jar', equivalent to about 1 Nano farad.

Years later, Michael Faraday experimented and made the first practically viable capacitor. Faraday’s pioneering role in capacitor technology has been honoured by naming the SI unit of Capacitance as ‘Farad’.

Leyden jar or flat glass plate construction was used until about 1900.

The invention of wireless (radio) created a demand for standard capacitors, and the steady move to higher frequencies required capacitors with lower inductance.

A flexible dielectric sheet such as oiled paper sandwiched between sheets of metal foil, rolled or folded into a small package were constructed.

Early capacitors were also known as condensers, this term is still used occasionally now.

It was coined by Alessandro Volta in 1782.

 It was derived from the Italian word “condensatore”, with reference to the device's ability to store a higher density of electric charge than a normal isolated conductor. 

Monday, March 16, 2015


In Stanford Research Institute, scientists had to use pre-existing devices in order to interact with the computer including the light pen, joysticks and the trackball.

The first trackball consisted of a Canadian bowling ball that was supported by air bearings. It was invented by Tom Cranston and Fred Longstaff in 1952. The device was created for the Royal Canadian Navy.

The first light pen was invented by Ben Gurley in 1959.

In 1961, Douglas Engelbart was attending a computer graphics conference at Stanford Research Institute. He was disturbed with the computer graphics pointing devices available at that time. The basic idea for the computer mouse came to his mind there itself.

In 1964, the first prototype of computer mouse was made to be used with a graphical user interface (GUI), 'windows' of the computer. The primitive mouse had the cord in front, but they quickly connected it to the back end for a smooth motion.

In early 1967, Engelbart and Bill English published a paper having a discussion on a “knee-control” device that appeared challenging. That device was based on Engelbart's observation that the human foot was a good sensitive controller of the gas pedal in cars. 

They discovered that the knee offered even better control at little movements in all directions. In tests, it outperformed the mouse by a small margin.

After Engelbart got the idea, he hired Bill English who had been working in another lab at SRI, to make the hardware design of the mouse.

It was a simple mechanical device with two perpendicularly mounted discs on the bottom. The user could tilt the mouse to draw perfectly straight horizontal or vertical lines.

In 1967, Engelbart applied for a patent and received it as an assignor of SRI for the wooden shell with two metal wheels.

Mouse was originally referred to as a "X-Y Position Indicator for a Display System." This mouse was first attached with the Xerox Alto computer system in 1973. But it was not so successful.

The first widely used mouse was found on the Apple Lisa computer. Today, mouse is found and used on every computer.

The first cordless mouse was shipped in September, 1984, with the Metaphor computer of David Liddle and Donald Massaro, former Xerox PARC engineers. The computer also had a cordless keyboard and function keypad.

The cordless mouse was built for Metaphor by Logitech and used infra-red (IR) signals to transmit mouse data to the computer. 

The problem with IR technology using devices was that they need a clear line of sight between the mouse and the computer's receiver which was too difficult.

This problem was solved by replacing IR with radio frequency (RF) communications.

Tuesday, March 10, 2015


The book Records of the Unworldly and the Strange, by Tao Gu, China in 950 AD gives the earliest descriptions of a match:
If there occurs an emergency at night it may take some time to make a light to light a lamp. But an ingenious man devised the system of impregnating little sticks of pinewood with sulphur and storing them ready for use. At the slightest touch of fire they burst into flame. This marvellous thing was earlier called a “light-bringing slave”, but afterwards when it became an article of commerce its name was changed to ‘fire inch-stick’.”

In 1669, Hennig Brandt in Hamburg was experimenting to transform an olio of base metals into gold, but accidentally produced the element phosphorous. He did not make use of his discovery.

In 1680, Robert Boyle, a British physicist coated coarse paper in phosphorous, and a splinter of wood in sulphur. When the wood was passed through the folded paper, it burst into flames. Due to the limited amount of phosphorous, this invention was little more than expensive.

In 1817, “the Ethereal Match” was invented by a French chemist in which a piece of paper coated with a compound of phosphorous got ignited when exposed to air. The paper was vacuum-sealed in a glass tube called the “match,” and whenever required it was ignited by smashing the tube.

In 1826, John Walker, an apothecary in Stockton-On-Tees, was conducting an experiment in his laboratory. He stirred a mixture of antimony sulphide, potassium chlorate, gum and starch with a wooden stick, and subsequently scraped the stick on the stone floor of the lab to remove a glob of the solution dried on the end of it.

When the stick burst into flames, Walker felt it very interesting and made several of the sticks. He demonstrated it again with Samuel Jones in London.

Samuel Jones realized the commercial potential of this sudden invention and set up a match business in London, and cleverly named his product “Lucifer’s”.  Lucifers became popular and following their introduction in London, tobacco smoking of all kinds greatly increased.

In 1831, Charles Sauria of France developed a match that used white phosphorus. These matches were strike-anywhere matches.

They were much easier to ignite and caused many unintentional fires. Also White phosphorus proved to be highly toxic. Workers in match plants inhaled white phosphorus fumes and hence suffered from a horrible degeneration of the jawbones known as "phossy jaw."

Inspite of this health hazard, white phosphorus continued to be used in strike-anywhere matches until the early 1900s, when government action in the United States and Europe forced manufacturers to switch to a nontoxic chemical.

A non-poisonous match using red phosphorous was invented in the mid-1800s; however it was more expensive to produce.

After agitation and worker actions like the London Match girl’s Strike in 1888, Government pass legislation against the use of white phosphorous, which forced match manufacturers to reform their dangerous product.

In 1844, Gustaf Pasch of Sweden placed some of the match's combustion ingredients on a separate striking surface, rather than adding them all into the match head, as an extra precaution against accidental ignition.

In 1855, J. E. Lundstrom of Sweden introduced safety matches coupling the idea of Gustaf Pasch with the discovery of less-reactive, nontoxic red phosphorus.

Although safety matches posed less of a hazard, but still many people preferred to use strike-anywhere matches, and both types continued to be used today.

In 1896, a brewing company ordered more than fifty thousand matchbooks to advertise a new product on it and the ubiquitous practice of matchbook advertising was born.

 In the 1940’s the psychological warfare branch of the U.S. government distributed thousands of matchbooks containing anti-Nazi slogans to occupied countries, and the French Resistance produced matchbooks containing instructions on how to derail Nazi trains printed on the inside cover.

Thirty thousand match heads will produce a 10-15 foot column of flame. A satchel of sixty thousand match heads has enough firepower to propel a 6 pound bowling ball 1500 feet.

Saturday, March 7, 2015


In 1938, Ruth married Elliot Handler.

In 1945, Mattel Co. was founded by Harold Matson, Elliot Handler and Ruth Handler to make picture frames. But in 1946, Matson sold his interest to the Handlers. Mattel started making and selling doll house furniture.

During early 1950s, Handler observed that her young daughter, Barbara, and her girlfriends enjoyed playing with adult female dolls as compared to baby dolls.

Handler returned from a trip to Europe with introducing "Lilli" doll which was modelled after a cartoon character in a German comic strip and in a daily newspaper called the Bild-Zeitung.

This character was known for her large breasts and sexy clothing, was originally created for adult entertainment as a symbol of sex and pornography for the men of Germany.

Ruth Handler encountered the Lilli doll on her vacation in Switzerland and now the toy company that she and her husband founded i.e. Mattel had started turning a profit.

While she watched her daughter, Barbara playing with adult dolls, Ruth Handler formulated the idea of creating an affordable adult doll for little girls.

Jack Ryan, executive of Mattel, purchased the rights for Lilli and negotiates with a company of Tokyo to create an inexpensive doll like Lilli for little girls.

American male designers challenged Handler that it would be impossible to make a doll with stylish clothing and accessories with an affordable price. But Handler accepted this challenge and created a new doll with softer look by the "rotation-moulding" process and named it “Barbie” as her daughter’s name.

Finally in 1958, Barbie was born with 11 1/2 inches height and weight 11 ounces. She debuted as a teenage model in a black and white striped swimsuit along with sunglasses, high-heeled shoes, and gold-colour hoop earrings.

Her body was shaped with movable head, arms, and legs. Barbie was the first doll in America with an adult body.

Barbie was used as a "teaching tool for femininity". As the ideal western woman with long legs and arms, a small waist, and high round chest, Barbie represented every little girl's dream of the perfect mature body.

Barbie was accompanied with an original box and a fashion booklet. The box is covered in haute-couture style drawings representing Barbie a very fashionable figure. The cover of the booklet is of Barbie's profile.

Her side-ways glancing look was set against a pink background creating an air of "remarkable sophistication".

Barbie has a pleasant attitude toward cleanliness. Barbie is seen in a Bar-B-Q outfit showing the homemaking skills required for being a good wife.

Barbie also wore undergarments that symbolized adulthood. She had a girdle, which was a necessary garment to encourage good posture in women. Barbie's first wardrobe also included two straps-less bras, one half-slip, and one floral petticoat. All private and embarrassing questions about growing up could be answered by dressing Barbie.

Another popular outfit of the first Barbie was the wedding dress. She also owned clothing for recreational activities such as playing tennis and dancing ballet.

Fashion of the 1950's was up-to-date in Barbie's wardrobes. Latest fabric innovations such as nylon tricot, nylon tulle, sheer nylon, and nylon net were used as materials for Barbie's clothing.  As women were purchasing tights, Barbie was given her first pair in 1961 to keep up with current feminine trends.

Mattel wanted to keep Barbie's image too perfect so they decided to create a more personal side of Barbie. Society's emphasis was on a family, therefore in the 1960's Barbie's parents were identified as Robert and Margareth Roberts from Willows, Wisconsin.

Along with parents, Mattel developed a boyfriend and female friend for Barbie. Ken, named after the Handler's son, was introduced as Barbie’s boyfriend in 1961 and Midge, Barbie's freckle faced friend, debuted in 1963.

Ken also came with teenage male essentials, such as a letter sweater, tuxedo, and a grey flannel suit. They believed that young girls did not need to know some realities of adulthood; therefore Ken was born with permanent underwear.

Midge was less glamorous and less intimidating. She had Barbie's body but a wider, friendly face covered in freckles. Her look was intended to be "thoughtful".

Barbie has been able to maintain her status as "the most popular fashion doll ever created". The talented staff at Mattel researches societal trends to keep Barbie current.

She has now appeared as a doctor, astronaut, businesswoman, police officer, UNICEF volunteer, and athlete. Over the years, Barbie had achieved the title of the most popular fashion doll ever since created.

Wednesday, March 4, 2015


The word ‘LASER’ stands for "Light Amplification by Stimulated Emission of Radiation".

In 1917, Albert Einstein first explained the theory of stimulated emission, which became the basis of Laser.

When a photon interacts with an excited molecule or atom, it causes the emission of a second photon having the same frequency, phase, polarization and direction.

During late 1940s or 50s, scientists and engineers work hard to realize a practical device working on the principle of stimulated emission

In 1954, a predecessor of the laser, called the MASER was independently developed at Columbia University by Charles Townes and Jim Gordon and in Russia by Nicolay Basov and Alexsandr Prokhorov.

MASER stands for "Microwave Amplification by Stimulated Emission of Radiation",

The ammonia masers were two-energy-level gaseous systems that could continuously retain a population inversion and oscillation.

Nicolaas Bloembergen proposed a three-level solid state maser at Harvard in 1956. It was demonstrated by researchers at Bell Labs that same year.

After the masers, Arthur Schawlow and Charles Townes thought to make infrared or visible light masers.

In 1957 Schawlow and Townes developed an optical cavity by placing two highly reflecting mirrors parallel to each other, and positioned the amplifying medium in between the cavity.

In 1960, Maiman realized first working LASER based on Ruby at Hughes Research Laboratories.

In 1961, Javan, Bennet, and Herriot invented first gas laser using Helium- Neon gases called as He-Ne laser at Bell Laboratories.

In 1962, Johnson, Boyd, Nassau and Sodden developed continuous wave solid-state laser.

During 1964, Geusic, Markos and Van Uiteit together led to the development of first working Nd:YAG LASER at Bell Labs.

CO2 LASER was invented by Patel during 1964 at Bell Labs.

Argon Ion LASER was developed by Bridges in 1964 at Hughes Labs.

In 1965, Pimentel and Kasper made first chemical LASER at University of California, Berkley.

In 1965, Wave propagation in nonlinear media was observed.

First metal vapor LASER i.e. Zn-Cd Laser was developed at University of Utah by Silfvast, Fowles and Hopkins in 1966.

In 1966, first Dye Laser action was demonstrated by Sorokin and Lankard at IBM Labs.

In 1970, First Excimer LASER based on Xenon (Xe) only was developed by Nikolai Basov's Group at Lebedev Labs, Moscow.

It was in 1980 that Geoffrey Pert's Group gave first report of X-ray lasing action at Hull University, UK.

During 1984, Dennis Matthew's Group demonstrated "laboratory" X-ray laser from Lawrence Livermore Labs.

Monday, March 2, 2015


It is believed that the concept of parachute was firstly given by Leonardo da Vinci(1452-1519). The description of a parachute concept is found in da Vinci's notebooks along with a sketch.

Although da Vinci never made the device but his sketch consisted of a cloth material pulled tightly over a rigid pyramidal structure.

He is credited for the concept of lowering man to the ground safely using a maximum drag decelerator.
Croatian Faust Vrancic constructed a device based on Da Vinci's drawing and jumped from a Venice tower in 1617.

Faust Vrancic published Machinae Novae magazine in which he described in text and in picture form fifty-six advanced technical constructions, including Vrancic's parachute called the Homo Volans.

In 1783, Sebastian Lenormand jumped from a tower using a 14-foot diameter parachute. The first emergency use of a parachute was made by Jean Pierre Blanchard in 1785 after the hot air balloon exploded in which he was present.

Blanchard also worked on a foldable silk parachute, before then all parachutes were constructed with a rigid frame so cannot be folded.

On October 22, 1797, Andrew Garnerin become the first person to jump from hot air ballons as high as 8,000 feet in the air with a parachute without a rigid frame.

 As the parachute was coming down, severe oscillations were induced in the canopy. So he designed the first air vent in a parachute to reduce oscillations as suggested by Lalandes.

In 1890, Paul Letteman and Kathchen Paulus invented the method of folding or packing the parachute in a knapsak to be worn on the back before its release.

Kathchen Paulus was also behind the invention of the intentional breakaway, which is when one small parachute opens first and pulls open the main parachute.

The development of modern parachutes deployed at high speeds and high altitudes started in the 1930's. Knacke and Madelung developed the ribbon parachute in Germany for Ring sail parachute decelerating heavy high speed payloads.

After World War II,  Knacke invented the ring slot parachute which is used for moderate subsonic speeds. This parachute is used primarily for cargo delivery and aircraft deceleration.

By the late 1970's the parawing was replaced by the parafoil, invented in the middle 1960's by Domina Jalbert, a kite maker.

The parafoil or ram-air parachute is a deformable airfoil that maintains its shape by trapping air between two rectangle shaped membranes, sewn together at the trailing edge and sides, but open at the leading edge.

Several ribs are sewn to the inside of the upper and lower surfaces, maintaining an airfoil cross section in the spanwise direction.

Sunday, March 1, 2015


·         Mobile phones have become an indispencible part of our lives. Due to the fast growing technology and innovations over a period of time, mobile phones are now affordable to everyone.

·         It was Charles Stevenson who invented radio communication in early 1890s for keeping contacts with the offshore lighthouses.

·         In 1894, Marconi transmitted signals over the distance of 2 km and Fessenden capably broadcasted music through radio by 1906.

·         In 1908, Nathan B. Stubblefield lived in Murray, Kentucky applied for the U.S. Patent 887,357 for a wireless telephone but he originally applied only for radio telephones.

·         The radio telephones were used for air traffic safety as well as in the passenger airplanes. At the time of Second World War, German tanks made great use of these radio telephones too.

·         Two way radios were an ancestor of the mobiles phones. These mobile phones are referred to as 0G mobile phones, or Zero Generation mobile phones.

·         Later these radio phones incorporated cigarette lighter plugs and were called bag phones. They were fixed in the vehicles to be used either as portable two way radios or mobile phones.

·         In 1940s, Motorola came with new developments in mobile phones called as Walkie Talkie. It was large, bulky and battery operated and was used by US military.

·         In 1956, Ericsson Company released the earliest full automatic cellular phone system called MTA in Sweden. It was operated automatically but too much bulky, weighed around 40 kgs. Its lighter version was introduced in 1965. This was known as MTB and used the DTMF signaling.

·         In 1957, Leonid Kupriyanovich developed experimental model of wearable mobile phones in Moscow, operating with the help of base station. He developed the radio phone known as LK-1 whose battery lasted for around 20-30 hours, weighing 3 kg, and worked within the distance of 20 to 30 km from the station.

·         In 1966, another automatic pocket mobile phone was developed in 1966 at Bulgaria called RAT-0.5, phone coordinated with the base station known as RATZ-10.

·         Invention of mobile phones that closely resembles today’s mobile phones is credited to Martin Cooper, employer and researcher of Motorola.  He initially developed cellular phone named Motorola Dynatac in 1973.

·         It was 5 inches width and 9 inches in length, 2.5 pounds in weight having around 30 circuit boards in it. It had recharge time of around 10 hours, talk time of 35 minutes. One could listen, dial and talk on this mobile phone but display screen was still missing.

·         The next major step in mobile phone history was in the mid-eighties with the First Generation (1G) fully automatic cellular networks were introduced.

·         Motorola DynaTac was the first ever mobile phone to be approved by the FCC (Federal Communications Commission) in the USA in 1983.

·         In 1993, the birth of the Second Generation (2G) mobile phones was found in Finland. In the same year, first SMS text messages were sent and that data services began to appear on mobile phones.
·         Mobiles that we use today are 3G mobiles, or Third Generation mobiles, or even more advanced 4G handsets.

·         3G launched was launched in 2001 and allowed operators to enjoy a huge range of advanced services such as video calling and HSPA data transmission.

·         4G became commercially available in the UK in late 2012 and offers superfast connections and similarly speedy downloads.