LighT

LIGHT

LIGHT IS A FORM OF ENERGY. It is a type of electromagnetic radiation, like X-rays  or radio waves. All electromagnetic radiation is produced by electric charges ; it is caused by the effects of oscillating electric and magnetic fields as they travel through space. Electromagnetic radiation is considered to have both wave and particle properties . It can be thought of as a wave of electricity and magnetism. In that case, the difference between various forms of radiations in their wavelength. Radiation can also be said to consist of particles, or packets of energy, called photons.The difference between light and -ray, for instance, is the amount of energy that each photon carries. The complete range of radiations is referred to as the electromagnetic spectrum, extending from low energy,long wave length  radio waves to high energy, short wave length gamma rays. Light is the only part of the electromagnetic spectrum that is visible. White light from the sun is made up of all the visible wave lengths of radiation, which can be seen when it is separated by using a prism. Light like  all forms of electromagnetic radiation, can be reflected (bounced back)   and refracted (bent). Different parts of the electromagnetic spectrum are produced in different ways. Sometimes visible light and  infra-red radiation - is generated by the vibrating  particles of warm or hot objects. The emission of light in this way is called incandescence, a phenomenon in which electrons gain and loss energy with in atoms.

ARTIFICIAL LIGHT SOURCES

DiesEL TRaiNs

DIESEL TRAINS

RUDOLF DIESEL FIRST DEMONSTRATED the diesel engine in Germany in 1898, but is was not until the 1940s that diesel locomotives were successfully established on both passenger and freight services, in the US. Early diesel locomotives like the "union Pacific" were more expensive to build than steam locomotives, but were more efficient and cheaper to operate, especially where oil was plentiful. One feature of diesel engines is that the power output cannot be coupled directly to the wheels. To convert the mechanical  energy produced by the diesel engines, a transmission system is needed. Almost all disel locomotives have electric transmissions and are known as "diesel-electric" locomotives. The diesel engine  works by drawing air into the cylinders and compressing it to increase its temperature; a small quantity of diesel fuel is then injected into it. The  resulting combustion drives the generator (more recently an alternator) to produce electricity, Which is fed to electric motors connected to the wheels. Diesel-electric locomotives are essentially electric locomotives that carry their own power plants, and are used world wide today. The "Deltic" diesel electric locomotive, the classic express steam locomotives and ran at speed up to 160 kph (100 mph)

FRONT VIEW OF "UNION PACIFIC"
 DIESEL-ELECTRIC LOCOMOTIVE 1950s

PROTOTYPE "DELTIC" DIESEL-ELECTRIC LOCOMOTIVE 1956

DIESEL ENGINE OF BRITISH RAIL CLASS 20
DIESEL-ELECTRIC LOCOMOTIVE

MusICaL PiLLarS

MUSICAL PILLARS



Temples often have some pillars portraying human figures playing musical instruments, but seldom do these pillars themselves  produce music. At the time Nellaiappar temple in Tamil Nadu , gentle taps on a cluster of pillars carved out of a single piece of rock produce the basic notes of Indian classical music, viz. Sa,Re,Ga,Ma,Pa,Dha,Ni,Sa. Vibrations of these pillars depend on elasticity of the stone used. Its density and shape .


                          Musical pillars are categorized into three types: the first  is called the Shruti pillar, as it can produce the basic notes-the "swaras'. The second type is the Gana Thoongal, which generates the basic tunes that make up the "ragas". The third variety is the Laya Thoongal pillars  that produce "taal"(beats) when tapped. The pillars at the Nellaiappar temple are a combination of the Shruti and Laya types.

                          
                           Archaeologists date the Nelliappar temple to the 7th century and claim it was built by successive rulers of the Pandyan dynasty.

                             The musical pillars of nelliappar and several other temples in southern India like those at Hampi  (Picture), KanyaKumari   and Thiruvananthapuram are unique to the country and have no parallel in any other part of world.

WooDWiNd INsTRuMEntS

WOODWIND INSTRUMENTS

WOODWIND INSTRUMENTS ARE wind instruments that are generally made of wood, although some are made of metal or plastic. The sound of a woodwind instrument is produced  by the vibration of air in hollow tube. The air is made to vibrate by blowing  across a blow hole-as in the flute and piccolo or by blowing through a single reed as in the clarinet and saxophone or a double reed-as in the bassoon, cor anglais, and oboe. The pitch of a  woodwind instrument can be changed by opening or closing holes cut into the tube of the instrument.

                                                                     

              

EaRLy SignS oF LiFE

EaRLy SignS oF LiFE

                                              FOR ALMOST A THOUSAND MILLION YEARS after its formation, there was no known life on earth. The first simple , sea-dwelling organic structures appeared about 3,400 years ago ; they may have form when certain chemical molecules jointed together. Prokaryotoe, single celled micro-organisms such as blue-green algae, were able to photosynthesize, and  thus produce oxygen. A thousand millions years later , sufficient oxygen had built in  the earth's atmosphere to allow multicellular organisms to proliferate in the Precambrian seas. Soft-bodied  jelly fish, corals and sea worms flourished about 700 million years ago. Trilobites, the first animals with hard body frames , developed during the Cambrian period (570-510 million years ago). How ever it  was not until the beginning   of  the Devonian period (409-363 million years ago) that early land plants, such as Asteroxylon, formed water-retaining cuticle, which ended their dependence on an aquatic environment. About 363 million years ago, the first  amphibians crawled onto the land, although they still returned to the water to lay their soft eggs. Not until the emergence of the first reptiles would animals appear that were independent of water in this way.

MINERALS

MINERALS

A MINERAL IS A NATURALLY OCCURRING  SUBSTANCE that has a characteristic chemical compositions and specific physical properties, such as habit and streak  .A rock,by comparison , is an aggregate of minerals and need not have a specific chemical composition . Minerals are made up of elements (substance that cannot be broken down chemically in to simpler substances), each of which can be represented by a chemical symbol. Minerals can be divided in to two main groups: native elements and compounds. Native elements are made up a pure element. Example include gold(chemical symbol Au), silver (Ag), copper (Cu) and carbon (C) ; carbon occurs as a native element in two forms, diamond and graphite. Compounds are combinations of two or more elements. For example, sulphides are compounds of sulphur (S) and one or more other elements, such  as lead (Pb) in the mineral galena, or antimonv  (Sb) in the mineral stibnite. 

HELP THE POOR, GOD WILL ALWAYS BLESS YOU

HELP THE POOR , GOD WILL ALWAYS BLESS YOU

Hi guys,

      We know that most of the people in this world enjoy their luxurious life in each second. They use to spent more money  even for a simple thing. While people live in this luxurious life style, most  of the people don't care or thing about the people Who suffer each second of their life.We have to help them as we can.We have to pray for them. Any thing may happen to our life at any time so be thank full to god and also try to help the poor people as you can.........

SHAPE OF S-ORBITALS, SHAPE OF P-ORBITALS, SHAPE OF D-ORBITALS

SHAPE OF S-ORBITALS : The probability  of finding the electron belonging to s-orbital is found  to be equal in all directions at a particular distance from the nucleus . In other words, s-orbitals are non-directional and spherically symmetrical in shape. As the value of n increases, the size s-orbital increases. 
Example, 2s orbital is larger than the 1s orbital.

Charge cloud pictures of 1s orbital

Charge cloud pictures of 2s orbital

 SHAPE OF P-ORBITALS: For p-orbitals there are three possible orientations of electron cloud. These three orientations or orbitals of a p-subshell are designated as px,py and pz depending upon the axis along which they orient. p-orbitals are dumb-bell shaped.

SHAPE OF D-ORBITALS:  For d-orbitals there are five possible orientations of the electron cloud. These orientations or orbitals are designated as dxy,dyx,dx2-y2 and dz2. The shapes of five 3d-orbitals (boundary surface diagrams) are shown.

The 3d orbitals

JURASSIC PERIOD

JURASSIC PERIOD

THE JURASSIC PERIOD, the middle part of the Mesozoic era, lasted from 208 to 146 million years ago. During Jurassic times, the land -mass of Pangaea  broke  up into the continents of Gondwanaland and Laurasia , and sea levels rose, flooding area of lower land. The Jurassic climate was warm and moist . plants such as ginkgos, horsetails and conifers thrived and giant redwood tree appeared , as did the first flowering plants. The abundance of plant food coincided with the proliferation of herbivorous (plant-eating) dinosaurs, such as the large sauropods (eg. Diplodocus) and stegosaurs (eg.Stegosaurus). Carnivorous (Flesh-eating) dinosaurs, such as Compsognathus  and Allosaurus, also flourished by hunting the many animals that existed-among them other dinosaurs. Further  Jurassic animals included shrew-like mammels, and pterosaurs (flying reptiles) as well as plesiosaurs and ichthyosaurs (both marine reptiles)

THE BRAIN AND THE MEMORY

THE BRAIN AND THE MEMORY

Weighing 1.5 kg with an astronomical number of neurons and billions of connections, the brain - the most crucial part of your central nervous system-controls everything, from a moving a little finger and solving mathematical equation to remembering happy days. But what is the connection between your brain and your memory? the brain is in fact where your memory is located , and most of your activities bring in to play. Memory forms part of your identity , your intelligence and your emotions. But where is exactly ?

That unknown entity, the brain

Test your knowledge of the brain's structure and function.

1)  the brain is made up of several thousand cells. true or false . why ?

        FALSE. The brain is composed of nearly 100 billion cells, called neurons and each neuron can rapidly from connections with 10,000 others.

2) You are born with a fixed number of neurons. true or false . why ?

        TRUE. The initial of neurons can't be replaced at the age of 80, how ever under the normal health conditions, you will have lost only 10% .The remaining 90% still available does not  degenerate and can establish new connections with other neurons.

3) The two hemispheres of the brain are divided in to many lobes.true or false . why ?

            FALSE. Each hemisphere of the brain is divided into four zones, the cerebral lobes, each of which controls specific activities. There are connections ensuring   contact between these various lobes.


4) You make use of your full complement of neurons in everyday life.true or false . why ?

          FALSE. We make use only 30 to 40 percent of our neurons because we usually repeat the same activities. If you don't make proper use of the brain, if you underutilized or fail to stimulate it, you may experience memory problems or difficulties in finding the right word. There fore, it is advisable to have as wide range of activities as possible-for example, reading, writing, gardening or sport- to make your brain work in a variety of ways.


5) Glucose is the main source of  brain energy.true or false . why?


        TRUE. the brain consume 5 g of glucose  (or sugar) an hour.To ensure an adequate supply of this fuel, you need a continuous supply of glucose in your bloodstream. So you should not exclude, rapid-release sugars from your diet.


6) The memory works less efficiently when you grow older. true or false . why ?

          FALSE. One out two people over 50 complains of memory problems . Although it might be true that we acquire information less rapidly and find it more difficult to retrieve our memories as we get older, the ability to store new information remains unimpaired.

7) Cerebral activity continues during sleep.true or false . why ?

           TRUE. we now know that cerebral activity is intense while we sleep. During the dream stage ( or REM- Rapid Eye Movement-sleep) the brain fixed and consolidates  information registered during the day.


8) Stress, anxiety and fatigue affect brain function.true or false . why ?

             True. At times of stress, fatigue you will find it much more difficult to concentrate and remain alert. As a result   information reaching your memory will be less efficiently registered and thus more easily forgotten.


9) Certain pathological conditions that affect the brain  are irreversible.true or false . why ?

              TRUE. The most wide spread brain disorder is ALZHEIMER'S disease. It is characterised by a orogressive , continuous and irreversible loss  of intellectual ability and is first manifested in specific memory problems. Medical treatment available at present can slow down its progress but cannot reverse it.


10) Memories are located in a specific part of the brain.true or false . why ?


                  FALSE.Memories are not localised in one specific place in the brain, although we know that one section the hippo campus plays a key role in retrieving memories. Memory function involves different zones of the brain.  
           

BELL FRUIT WHICH GREW IN MY BEAUTIFUL VILLAGE CHETTIKULAM

These images view  the fresh and  tasty bell fruit which grew in my beautiful village CHETTIKULAM (India/Kerala/Trissur/Chalakudy/Chettikiulam). Its really tasty fruit.Even the small kids to oldage people likes it. People use this fruit to make juice, pickle,wine and also many other things. In malayalam we call it  "CHAMBAKKA" Its really nice try it you will like it..........

ABOUT THE NOVEL "PRIDE AND PREJUDICE" AND ABOUT THE AUTHOR

PRIDE AND PREJUDICE

About the novel:

'Its is a truth universally acknowledged that a single man in possession of a good fortune must be in a want of a wife.'  This famous opening sentence defines the plot of PRIDE AND PREJUDICE. Mrs. Bennet has only one aim in her life-to see her daughters married. Her husband Mr. Bennet, a gentleman, and the elder daughters, the beautiful and meek Jane and the lively and intelligent Elizabeth  don't much like her efforts at match making. With the arrival of several young men the town of Meryton is roused into a flutter of activities-balls, dances and visits.

                   Mr.Bingley , a good looking and gentlemanly young man comes to Nether field, in the company of his two sisters and his friend Darcy. Even though Darcy has a strong personality, handsome features and a huge income, he is bad mannered and suffers from the sin of pride. Elizabeth eventually makes up her mind that she would never like Mr.Darcy. Her sin is prejudice.

                    Bingley becomes attached to Jane.But Darcy persuades him not to marry Jane, as he think Mrs.Bennet to be coarse and unrefined. Even though Darcy declares his love to Elizabeth, she rejects him outright. Later Darcy comes to help Elizabeth at a crucial period and she begins to love him. The story ends with the much awaited union of Elizabeth and Darcy, and Jane and Bingley too.

RELATIONS BETWEEN CHARACTERS IN JANE AUSTEN'S PRIDE AND PREJUDICE

About the author:

Portrait of  JANE AUSTEN, drawn by her
 sister Cassandra (c.1810)

Jane  Austen was born in Hampshire, England on 16th December 1775 in a well to do family as the seventh child. She left school after three years of study to complete education at home.Though she never travelled beyond her locality, she had many opportunities to study the habits of the middle class, the gentry and the aristocracy of the early 19th century England. She gay and witty, a keen observer of people , a brilliant conversationalist and an accomplished dancer. Before she had reached the age of 17, she had written many sketches , short stories and tales. She began her first novel, LADY SUSAN in 1974.In 1976 she wrote FIRST IMPRESSIONS which she later developed in ti PRIDE AND PREJUDICE. Her  major novels apart from Pride and prejudice are sense and sensibility, north anger Abbey,Persuasion, Mansfield Park and Emma.Though her novels were published anonymously, the fact of her authorship had become known by 1814. She has many admirers by that time, including sir Walter Scott. Early in 1816, Jane Austen's health began to fail, but her spirit remained strong and her mental powers intact. In may 1817 she became seriously ill. The end came on July 18th,1817.

MEASURING TIME

M E A S U R I N G   T I M E 

ALL TIME KEEPING DEVICES depends on counting a regularly-repeated phenomenon. The earliest time keeping devices were based on daily , monthly, or yearly cycles of the sun or moon. Most modern clocks are based on repeated mechanical or electrical oscillations (vibrations). The more frequent the vibrations , the greater the potential accuracy of the clock. The crystal in a quartz watch typically vibrates at 32,768 hertz (32,768 times in a second), so it keeps better time than a pendulum clock, whose pendulum typically swings twice a second. The most accurate time keeping devices are atomic fountains, which are based on oscillations of caesium atoms. Global communication technologies, such as computer networks and broadcasting, rely on the world using one accurate time standard. This is called UCT (Universal Coordinated Time) , and is based on the average time signal received from over 200 atomic clocks world wide. The more we  rely on high technology for precise time keeping, the more vulnerable we become to problems with that technology, for example the bug that threatens to strike at the beginning of the new millennium.

PENDULUM CLOCK

 In the 16th century, the Italian scientist Galileo Galilei  used the regular swing of a pendulum to measure periods of time. He suggested that a pendulum could be connected to the hands of a clock to turn them in regular steps. 

THE ATOMIC FOUNTAIN

At present , the most accurate timekeeping devices is the atomic fountain. It was developed by Nobel prize winning scientists in the early 1990s and is far more accurate than a standard atomic clock, such as NIST-7. The atomic fountain enables us to measure time with greater accuracy, mainly because it uses cooler , slower-moving atoms than the atomic clock. Atomic fountain devices are accurate to within one ten-billionth of a second per day.

HOW THE ATOMIC FOUNTAIN WORKS

1) Three pairs of laser beams (AB,CD,EF) trap and cool a ball of several million caesium atoms, all in one of two energy states.

2)  The laser are detuned slightly to slowly launch the bell upward through a field of microwave radiation.

3)As the atoms fall through the microwave cavity, many of them are "EXITED" and change energy state.

4) A detector unit measure the fluorescence of the atoms and calculates how many have changed state.

5) the microwave frequency is fine-tuned to excite a greater proportion of the atoms to change energy state.

6)When this proportion is greatest, the microwave  frequency is closest to the true resonant frequency of the atom.

MEASURING THE SECOND

Atomic devices keep time using caesium atoms, which flips between two energy states when they are hit with microwave radiation of a specific, fixed frequency. One second is defined as exactly 9,192,631,770 oscillations of this radiation. Atomic clocks measure time by producing radiation with a frequency as close as possible to the resonant frequency of the cesium atom, and then counting the oscillations.

NIST-7 ATOMIC CLOCK

                                          

This laser forms part an early-1990s atomic clock, developed by the US National Institute of Standard and Technology. At that time,the clock was the most accurate timekeeping device in the world, precise to within one billionth of a second per day (one second in three million years). Above, a scientist observe the laser as it "excites" caesium atoms. The atoms oscillate between two energy states, and the clock counts the oscillations.

THE MILLENNIUM BUG

The millennium or Y2K (year 2000) bug is a threat to computer systems that store dates using just two digits. Thus, the year after  1999 would be represented as 00, which could be interpreted as 99 years earlier rather than one year later. Systems that store dates in this way are danger of crashing on 1 January 2000. Although th Millennium bug may affect the personal computers, the greatest threats come to embedded systems - custom-built that are used in vital service industries such as banking, utilities, transport, telecommunications, the medical sector, and air traffic control. Severe problems could occur if equipment affected by the bug is not modified. The true extent of the problem will, however, only be known on 1 January 2000.

INTERACTIVE TELEVISION

I N T E R A C T I V E      T E L E V I S I O N

THE FUTURE OF TELEVISION is undoubtedly digital. Television or video signals can be converted from their normal analogue form (continuously varying) into digital form, Which consists of a series of definite pulses rather like Morse code. Digital signals  can be transmitted' compressed , and manipulated by computers without any unwanted "noise"affecting the data. One of the advantage of digital technology is that video data can be manipulated to make interactive television possible. Interactive "video-on-demand" (VOD) services allow users to watch the material of their choice from a large central video vault. A digital server enables many users to watch the same film, starting  at different times, by sending the video data in small "packets" to them. Other services include news programmers, games, music, and electronic shopping. With the latter, the user "strolls" through a virtual shop and uses a  credit card to buy items, Which are then delivered to the within days.

NEIGHBOURHOOD  NODE:                                                            MODULATOR :

The junction box , or neighbourhood node,                                The information  received by the  

 converts the fibre-optic cable's  optical                                      modulator is converted to the correct

signals into an electrical signal, which is                                     frequency for its journey to the home.

transmitted via coaxial cable to different

 homes in the neighbourhood.

STORAGE VAULTS

Digital video data is compressed before being stored in vaults. A typical vault may house up to 100 magnetic hard drives.

VIDEO-ON-DEMAND

Allowing viewers to choose a film or television programme  from a vast selection whenever desired, video-on-demand comes complete with all the flexibility of a  video recorder (including fast- forward, rewind and pause facilities). A typical VOD system consists of video vaults containing compressed digital video data, a sophisticated digital server that sends the requested material to the correct destination, and decoder and remote control units in the home.

DIGITAL VIDEO DISC

The video format set replace tapes and laser discs in the home looks exactly like an audio compact disc (CD)- a silver platter 12 cm(4 3/4 in) in diameter. (To avoid a repetition of the 1980s VHS/Beta video-cassette war, electronic companies involved have agreed on one format.) However, the digital video disc can hold up to 9 hours of data on its 2 sides, with each side containing 133 minutes of programme time. This is compared with the 74 minutes held by a CD. In addition, DVD's interactivity means that certain programmes can be viewed from a variety of camera angles. 

CINEMA BY COMPUTER 

Disney productions TOY STORY (1995) was the world's first feature film to be generated entirely on computer. A team of 27 animators worked on the film, producing an average of 3 1/2 minutes of footage per week. Some of the  characters and scenes were created solely on computer, whereas others were set up with models and props before being scanned in the computer  for digitization.

SIMILARITIES AND DIFFERENCES BETWEEN FRICTION AND VISCOSITY

Similarities:

• Both came in to play when ever there is relative motion.
• Both opposes relative motion.
• Both erase from intermolecular force.
• Both depend on the nature of surface.

Difference:

• Viscous force depends on the velocity gradient and area of contact and frictional force independent of area of contact and relative velocity.
• Viscosity of liquid decrease with increase in temperature, Where as friction independent of temperature.
• In friction heat is generated at the surface between the solids. When a fluid moves over a solid heat is generated within the fluid.  

GLOBAL TELECOMMUNICATIONS

G L O B A L

   T E L E C O M M U N I C A T I O N S

CONSTELLATIONS OF LAW-ORBITING  satellite hold the key to today's flexible global telephone networks . These systems integrate satellite communication with existing land-line and cellular networks to provide truly global coverage from a mobile phone. This enables people in remote areas, even those on tiny pacific islands or high in the Himalayas, to keep in touch with the rest of the world. Satellite systems are the next logical step in the mobile-phone revolution that swept the world in the late 1990s. Iridium was the first system to offer a commercial service. It was conceived and developed by the US electronics company Motorola, and began operation on 1 November 1998. The system was named after the 77th chemical element in the periodic table, as there were originally to be 77 satellites in the network. Other networks offering a similar service include Globalstar, which operates with a constellation of 48 satellites. 

 The iridium network consist of 66 satellites, each providing a coverage of 16 million square km (6 million square miles). Its offers a constant service, as there will always be one or more satellites over the horizon. The network operates as a constellation, which means that a failed or malfunctioning satellite will not impede the system's ability to provide global coverage . When a call is made it is routed to the nearest satellite , and then relayed around the world to its destination is a land-based telephone , the last satellite in the chain feeds the signal to a "gateway" ground station. This gateway then connects with the existing land-line telephone system.

ENVIRONMENTAL CONCERNS

Mobile phones operate using radio signals. They have a transmitter that sends a signal to an aerial, which is part of a nationwide communication  network. These radios work at low power, so mobile users need to be within a few kilometres of an aerial for their signal to be received. The mobile-phone revolution of the late 1990s has resulted in hundreds of millions of users worldwide, and thousands of aerials have been built, both in town and country, to receive the ever-increasing number of signals. In environmentally sensitive areas, unsightly aerial masts are sometimes disguised as tress or flagpoles. They have been sited on buildings and church towers, and then camouflaged.

 MICROWAVE RELAY TOWER

The Iridium communications system can route calls through an ordinary mobile telephone network, if available, and also interconnected with conventional telephone networks. Land links, such as this microwave relay tower , are often needed to route  calls to their final destination.


                             

                    IRIDIUM HAND SET

Early satellite phones required briefcase-sized units to receive and process signals from communication satellites. The Iridium hand set has a similar features to a conventional mobile phone but is slightly large in size. It is also more expensive to purchase and operate but, unlike an ordinary mobile phone, can be used in any location on Earth.  

FLOATATION AND LAWS OF FLOATATION.

Consider a body just placed on the surface of the liquid. As the body starts  sinking upward thrust gradually increases. If the weight of the body is greater than the upward thrust the body continues to sinks. When the upward thrust is equal to the weight of the body, the body floats.

Laws of floatation :

1. The weight of floating body is equal to the liquid displaced.
2. The center of gravity of the floating body and the center of buoyancy lie in the same vertical line.