Scattering of light

                                   Scattering of light

When light rays fall on tiny dust particles present in the atmosphere they completely absorb the light energy and disperse the light in all directions. The velocity of light does not change during this process.Also refer  Lord Rayleigh scattering

 

Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more localized non-uniformities in the medium through which they pass. In conventional use, this also includes deviation of reflected radiation from the angle predicted by the law of reflection. Reflections that undergo scattering are often called diffuse reflections and unscattered reflections are called specular (mirror-like) reflections.

Wonders of Scattering of light

1. The sky appears blue to us due to scattering of light.

2. The sky appears black to astronauts as there is no scattering of light.

3. The objects are not seen clearly during winter due to more scattering of light.

4. Glass pieces appear as silver when seen from a far place.

AMAZING FACTS

                 AMAZING FACTS

In a single drop of water there are 2 sextillion –that’s 2,000,000,000,000,000,000,000 –Oxygen atoms and twice the number of Hydrogen atoms

Hydrogen is the simplest and lightest of all the elements. If it is not attached to other elements, hydrogen on earth floats away into space.

A 30-cm (1ft) cube of osmium weighs 640kg (1,410lb). That’s the same as ten 64 kg adults (140lb)!

 Lithium is soft it can be cut a knife, and is light                Osmium

enough to float on water.

Lithium

If you want to buy some of the element californium? You will need a lottery win as it costs US$27 million for just one gram! Because it have to be artificially created in a nuclear reactor and some it only last for a fraction of a second, hence high price tag.                                                                                                                                           Californium

                                                                                                                        

Amazing facts 3 (about Lanka)

All believe that Lanka in Ramayana is Srilanka.

But based on Valmiki Ramayana Lanka is not present day Srilanka (Ceylon).During those times Lanka was situated in the Indrana hills, also called 'Trikutia hill’, now surrounded by Hiran river (about 100 kms from what is now, Jabalpur) near Amarkarnataka in the vindhya mountains .The sagar (sea) mentioned in the original ramayana is the lake between the Indrana hill and Lanka of the Vindhyas, which is now a marshy land. The monkeys we read about in Ramayana were actually not monkeys but tribal people belonging to ‘Monkey tribes’ as the tribes in that area are called by the names of animals such as ‘Monkeys’,’ Serpents’, ’Jatayus’, ’Balus’ and ‘Vanaras’

All believe that Lanka in Ramayana is Srilanka.

This is not my opinion,but i have found it in my research in the book "India in Pocket size"

History of Touchscreens

                               History of Touch screens

The first touch screen was a capacitive touch screen developed by E.A. Johnson at the Royal Radar Establishment, Malvern, UK. The inventor briefly described his work in a short article published in 1965 and then more fully - along with photographs and diagrams - in an article published in 1967. A description of the applicability of the touch technology for air traffic control was described in an article published in 1968.

Note: Contrary to many accounts, while Dr. Sam Hurst played an important role in the development of touch technologies, he neither invented the first touch sensor, nor the first touch screen.)

Touchscreens first gained some visibility with the invention of the computer-assisted learning terminal, which came out in 1975 as part of the PLATO project. Touchscreens have subsequently become familiar in everyday life. Companies use touchscreens for kiosk systems in retail and tourist settings, point of sale systems, ATMs, and PDAs, where a stylus is sometimes used to manipulate the GUI and to enter data.

From 1979–1985, the Fairlight CMI (and Fairlight CMI IIx) was a high-end musical sampling and re-synthesis workstation that utilized light pen technology, with which the user could allocate and manipulate sample and synthesis data, as well as access different menus within its OS by touching the screen with the light pen. The later Fairlight series III models used a graphics tablet in place of the light pen.

The HP-150 from 1983 was one of the world's earliest commercial touchscreen computers. Similar to the PLATO IV system, the touch technology used employed infrared transmitters and receivers mounted around the bezel of its 9" Sony Cathode Ray Tube (CRT), which detected the position of any non-transparent object on the screen.

Touch screens

                              Touch Screen

A special thanks goes to Jason Ford of Elo TouchSystems, the company whose founder invented touch screen technology, for providing the following historical information.

In 1971, the first "touch sensor" was developed by Doctor Sam Hurst (founder of  Elographics) while he was an instructor at the University of Kentucky. This sensor called the "Elograph" was patented by The University of Kentucky Research Foundation. The "Elograph" was not transparent like modern touch screens, however, it was a significant milestone in touch screen technology.

In 1974, the first true touch screen incorporating a transparent surface came on the scene developed by Sam Hurst and Elographics. In 1977, Elographics developed and patented five-wire resistive technology, the most popular touch screen technology in use today. On February 24, 1994, the company officially changed its name from Elographics to Elo TouchSystems

A touchscreen is an electronic visual display that can detect the presence and location of a touch within the display area. The term generally refers to touching the display of the device with a finger or hand. Touchscreens can also sense other passive objects, such as a stylus. Touchscreen is common in devices such as all-in-one computers, tablet computers, and smartphones.

The touchscreen has two main attributes. First, it enables one to interact directly with what is displayed, rather than indirectly with a cursor controlled by a mouse or touchpad. Secondly, it lets one do so without requiring any intermediate device that would need to be held in the hand. Such displays can be attached to computers, or to networks as terminals. They also play a prominent role in the design of digital appliances such as the personal digital assistant (PDA), satellite navigation devices, mobile phones, and video games.

                                History of television

John Logie Baird gave up his job as an electric-power engineer in 1922 and devoted himself to television research. He produced televised objects in outline in 1924 and recognizable human faces in 1925 and in 1926 became the first person to televise pictures of objects in motion. He demonstrated colour television in 1928. The German post office gave him facilities to develop a television service in 1929. When the BBC television service began  (1936) is system competed with that of Marconi Electric and Musical Industries; the BBC adopted the latter exclusively in 1937.

In its early stages of development, television employed a combination of optical, mechanical and electronic technologies to capture, transmit and display a visual image

In 1884 Paul Gottlieb Nipkow, a 23-year-old university student in Germany, patented the first electromechanical television system which employed a scanning disk, a spinning disk with a series of holes spiraling toward the center, for rasterization

Scottish inventor John Logie Baird demonstrated the transmission of moving silhouette images in London in 1925 and of moving,monochromatic images in 1926.

In 1926, Hungarian engineer Kálmán Tihanyi designed a television system utilizing fully electronic scanning and display elements, and employing the principle of "charge storage" within the scanning (or "camera") tube.

By 1927, Russian inventor Léon Theremin developed a mirror-drum-based television system which used interlacing to achieve an image resolution of 100 lines.

Also in 1927, Herbert E. Ives of Bell Labs transmitted moving images from a 50-aperture disk producing 16 frames per minute over a cable from Washington, DC to New York City, and via radio from Whippany, New Jersey. Ives used viewing screens as large as 24 by 30 inches (60 by 75 centimeters). His subjects included Secretary of Commerce Herbert Hoover.

In 1927, Philo Farnsworth made the world's first working television system with electronic scanning of both the pickup and display devices, which he first demonstrated to the press on 1 September 1928.

Television [T.V]

                                 TELEVISION (T.V)

Television (TV) is a telecommunication medium for transmitting and receiving moving images that can be monochromatic (shades of grey) or multicolored. Images are usually accompanied by sound. "Television" may also refer specifically to a television set, television programming, television transmission.

Electronic system for transmitting still or moving images and sound to receivers that project a view of the images on a picture tube or screen and recreate the sound.

Early versions (1900–20) of the cathode-ray (picture) tube, methods of amplifying an electronic signal, and theoretical formulation of the electronic scanning principle later became the basis of modern TV. RCA demonstrated the first all-electronic TV in 1932. Cable TV systems (introduced in the late 1940s), colour TV (in the 1950s), and recording or playback machines (in the 1980s; see VCR) followed. Digital high-definition (HDTV) systems (1990s) provide sharper, clearer pictures and sound with little interference or other imperfections and have the potential to merge TV functions with those of computers.

Some unknown inventors

Some unknown inventors of some well known and well used things

The electric fan was invented in 1882 by Schuyler Skaats Wheeler

Philip H. Diehl (29 January 1847 – 7 April 1913) was a German-American engineer and inventor of ceiling fan.

Schuyler Skaats

Together with Lebbeus B. Miller, Diehl invented and patented the "oscillating shuttle" bobbin driver design and a sewing machine build around it.                                   Philip H. Diehl  

Lin; Tak-Huei is the inventor of the tube light

A Binoculars [Explaination]

Optical instrument for providing a magnified view of distant objects, consisting of two similar telescopes, one for each eye, mounted on a single frame.

In most binoculars, each telescope has two prisms, which reinvert the inverted image provided by the eyepiece of each telescope. Light rays travel along a folded path inside the telescopes, so the instrument has a shorter overall length. The prisms also provide better depth perception at greater distances, by allowing the two objectives (object lenses) to be set farther apart than the eyepieces. Binocular eyepieces are often fitted to microscopes or other optical instruments.

Radio Telescopes

Radio telescopes vary widely, but all have two basic components: a large radio antenna or an antenna array and a radiometer or radio receiver. Because some astronomical radio sources are extremely weak, radio telescopes are usually very large, and only the most sensitive radio receivers are used. The first large fully steerable radio telescope was completed in 1957 at Jodrell Bank, Eng. The world's largest fully steerable radio telescope is the 360 × 330-ft (110 × 100-m) off-axis antenna operated by the National Radio Astronomy Observatory in Green Bank, W.Va. The largest single radio telescope is the 1,000-ft (305-m) fixed spherical reflector at the Arecibo Observatory in Puerto Rico. The world's most powerful radio telescope is the Very Large Array in New Mexico, made up of 27 separate mobile parabolic antennas that together provide the angular resolution of a single antenna 22 mi (35 km) in diameter.

Combination of radio receiver and antenna, used for observation in radio and radar astronomy

Hubble space telescope (HST)

                                          Hubble space telescope(HST)
Most sophisticated optical observatory ever placed into orbit around Earth.

Because it is above Earth's obscuring atmosphere, it can obtain images much brighter, clearer, and more detailed than ground-based telescopes can. Named for Edwin Hubble, it was built under NASA supervision and deployed on a 1990 space-shuttle mission. The reflector telescope's mirror optics gathers light from celestial objects and directs it to an array of cameras and spectrographs (see spectroscopy). A defect in the primary mirror initially caused it to

 produce fuzzy images; in 1993 another shuttle

mission corrected this and other problems. Subsequent missions to the HST have been for maintenance, repairs, and instrument upgrades.

History of Telescopes

The earliest known working telescopes appeared in 1608 and are credited to Hans Lippershey. Among many others who claimed to have made the discovery were Zacharias Janssen, spectacle-maker in Middelburg, and Jacob Metius of Alkmaar. Galileo used this design the following year. In 1611, Johannes Kepler described how a telescope could be made with a convex objective and eyepiece lens and by 1655 astronomers such as Christiaan Huygens were building powerful but unwieldy Keplerian telescopes with compound eyepieces. Hans Lippershey is the earliest person documented to have applied for a patent for the device. Isaac Newton is credited with building the first "practical" reflector in 1668. Writings by John Dee and Thomas Digges in England in 1570 and 1571, respectively ascribe the use of both reflecting and refracting telescopes to Thomas' father Leonard Digges, and it is independently confirmed by a report by William Bourne in approximately 1580. They may have been experimental devices and were never widely reported or reproduced.

Early inventions on Gear Box

All think that Leonardo davince is just a painter.

He is a great scientist also. He had prepared the model of aero plane even before 100 years of its invention. He had also prepared a model of gear box of a car in those days. But his models were of small defects. His gear wheel used to rotate back instead of rotating front. This is corrected by the today’s scientists

In 1834, Vermont blacksmith Thomas Davenport, the inventor of the first gear box.

First Image ove Mercury orbit

First Image Ever Obtained from Mercury Orbit

5:20 am EDT on Mar. 29, 2011, MESSENGER captured this historic image of Mercury. This image is the first ever obtained from a spacecraft in orbit about the Solar System's innermost planet. Over the subsequent six hours, MESSENGER acquired an additional 363 images before downlinking some of the data to Earth. The MESSENGER team is currently looking over the newly returned data, which are still continuing to come down

Lcd's

Opto electronic device used in displays for watches, calculators, notebook computers, and other electronic devices.

Current passed through specific portions of the liquid crystal solution causes the crystals to align, blocking the passage of light. Doing so in a controlled and organized manner produces visual images on the display screen. The advantage of LCD’s is that they are much lighter and consume less power than other display technologies (e.g., cathode-ray tubes). These characteristics make them an ideal choice for flat-panel displays, as in portable laptop and notebook computers.

Liquid crystal display

                                    History of Lcd's

In 1888, liquid crystals were first discovered in cholesterol extracted from carrots by Austrian botanist and chemist, Friedrich Reinitzer.

In 1962, RCA researcher Richard Williams generated stripe-patterns in a thin layer of liquid crystal material by the application of a voltage. This effect is based on an electro-hydrodynamic instability forming what is now called “Williams domains” inside the liquid crystal.

According to the IEEE, "Between 1964 and 1968, at the RCA David Sarnoff Research Center in Princeton, New Jersey, a team of engineers and scientists led by George Heilmeier with Louis Zanoni and Lucian Barton, devised a method for electronic control of light reflected from liquid crystals and demonstrated the first liquid crystal display. Their work launched a global industry that now produces millions of LCDs."

Electroluminesense and its discovery

French scientist Georges Destriau discovered electroluminescence (EL) as early as 1936.

The format was first discovered and produced by sandisk in 1994. ... These symptoms include electroluminesense form.

Electroluminescence is the result of radioactive recombination of electrons and holes in a material, usually a semiconductor. The excited electrons release their energy as photons - light. Prior to recombination, electrons and holes may be separated either by doping the material to form a p-n junction (in semiconductor electroluminescent devices such as LEDs), or through excitation by impact of high-energy electrons accelerated by a strong electric field (as with the phosphors in electroluminescent displays).

Discovery of LED's

                                Discovery of LED’s

Electroluminescence as a phenomenon was discovered in 1907 by the British experimenter H. J. Round of Marconi Labs, using a crystal of silicon carbide and a cat's-whisker detector. Russian Oleg Vladimirovich Losev reported on the creation of a first LED in 1927. His research was distributed in Russian, German and British scientific journals, but no practical use was made of the discovery for several decades. Rubin Braunstein of the Radio Corporation of America reported on infrared emission from gallium arsenide (GaAs) and other semiconductor alloys in 1955.[10] Braunstein observed infrared emission generated by simple diode structures using gallium antimonide (GaSb), GaAs, indium phosphide       Hj Round

(InP), and silicon-germanium (SiGe) alloys at room temperature

and at 77 kelvin. 

In 1961, American experimenters Robert Biard and Gary Pittman working at Texas Instruments, found that GaAs emitted infrared radiation when electric current was applied and received the patent for the infrared LED

Light emitting diodes[LED"S]

Semiconductor diode that produces visible or infrared light when subjected to an electric current, as a result of electroluminescence.

Visible-light LEDs are used in many electronic devices as indicator lamps (e.g., an on/off indicator) and, when arranged in a matrix, to spell out letters or numbers on alphanumeric displays. Infrared LEDs are used in optoelectronics (e.g., in auto-focus cameras and television remote controls) and as light sources in some long-range fibre-optic communications systems. LEDs are formed by the so-called III-V compound semiconductors related to gallium arsenide. They consume little power and are long-lasting and inexpensive