the reason of this developement

we should notice that the main reason for all that developement is edison that american scientist which born in febreuary,11 ,1987 he discoverd the lamp which give us the light
as aresult of that discovery many equiliprium discovered after that so we present respect for that great scientist

generation

Thales' experiments with amber rods were the first studies into the production of electrical energy. While this method, now known as the triboelectric effect, is capable of lifting light objects and even generating sparks, it is extremely inefficient.[49] It was not until the invention of the voltaic pile in the eighteenth century that a viable source of electricity became available. The voltaic pile, and its modern descendant, the electrical battery, store energy chemically and make it available on demand in the form of electrical energy. The battery is a versatile and very common power source which is ideally suited to many applications, but its energy storage is finite, and once discharged it must be disposed of or recharged. For large electrical demands electrical energy must be generated and transmitted in bulk.
Electrical energy is usually generated by electro-mechanical generators driven by steam produced from fossil fuel combustion, or the heat released from nuclear reactions; or from other sources such as kinetic energy extracted from wind or flowing water. Such generators bear no resemblance to Faraday's homopolar disc generator of 1831, but they still rely on his electromagnetic principle that a conductor linking a changing magnetic field induces a potential difference across its ends.The invention in the late nineteenth century of the transformer meant that electricity could be generated at centralised power stations, benefiting from economies of scale, and be transmitted across countries with increasing efficiency. Since electrical energy cannot easily be stored in quantities large enough to meet demands on a national scale, at all times exactly as much must be produced as is required. This requires electricity utilities to make careful predictions of their electrical loads, and maintain constant co-ordination with their power stations. A certain amount of generation must always be held in reserve to cushion an electrical grid against inevitable disturbances and losses.
Demand for electricity grows with great rapidity as a nation modernises and its economy develops. The United States showed a increase in demand during each year of the first three decades of the twentieth century, a rate of growth that is now being experienced by emerging economies such as those of India or China.Historically, the growth rate for electricity demand has outstripped that for other forms of energy.
Environmental concerns with electricity generation have led to an increased focus on generation from renewable sources, in particular from wind- and hydropower. While debate can be expected to continue over the environmental impact of different means of electricity production, its final form is relatively clean.

Electric potential

The concept of electric potential is closely linked to that of the electric field. we should notie that small electrical potenial is the main reason for the chemical progress because that small potential have amount of energy so we can use it in many daily needs such as in the watch,radio cassete,and other fields the reason of that discovery is the frog when an ascientist is passing akinfe over there in the presence of asolution he noticed that that frog although its died but it have avibrational movement after many research the scientist noticed that the reason of that movement is the electricity when there is ametal and abody conducting to electricity in the presence of acertain metal the electricity come throuth thatbody . A small charge placed within an electric field experiences a force, and to have brought that charge to that point against the force requires work. The electric potential at any point is defined as the energy ..
The electric field was formally defined as the force exerted per unit charge, but the concept of potential allows for a more useful and equivalent definition: the electric field is the local gradient of the electric potential. Usually expressed in volts per metre, the vector direction of the field is the line of greatest gradient of potential, and where the equipotentials lie closest together.

electric field

The concept of the electric field was introduced by Michael Faraday. . The electric field acts between two charges in a similar manner( in the same way ). to the way that the gravitational field acts between two masses, and like it, extends towards infinity and shows an inverse square relationship with distance. However, there is an important difference. while the electric field can result in either attraction or repulsion. Since large bodies carry no net charge. the electric field at a distance is usuallyequal null(0). Thus gravity is the dominant force at distance in the universe, despite being much weaker.we should notice that :
the electric field is the main reason for discovering the generation because when the mass cut amagnetic field an electric field is setting up during this process . we cant dent the main role of the electrical field in our life we use it in several ways such as light,fuel of many machines and instead of crude oil .

Field lines emanating from a positive charge above a plane conductor
An electric field generally varies in space, and its strength at any one point is defined as the force that would be felt by a stationary, negligible charge if placed at that point.The conceptual charge, termed a 'test charge', must be vanishingly small to prevent its own electric field disturbing the main field and must also be stationary to prevent the effect of magnetic fields. As the electric field is defined in terms of force, and force is a vector, so it follows that an electric field is also a vector, having both magnitude and direction. Specifically, it is a vector field.
The study of electric fields created by stationary charges is called electrostatics. The field may be visualised by a set of imaginary lines whose direction at any point is the same as that of the field. This concept was introduced by Faraday, whose term 'lines of force' still sometimes sees use. The field lines are the paths that a point positive charge would seek to make as it was forced to move within the field; they are however an imaginary concept with no physical existence, and the field permeates all the intervening space between the lines. Field lines emanating from stationary charges have several properties:(1)
that they originate at positive charges and terminate at negative charges; second, that they must enter any good conductor at right angles, and third, that they may never cross nor close in on themselves.
A hollow conducting body carries all its charge on its outer surface.

Electric charge

Electric charge is a property of certain subatomic particles, which gives rise to and interacts with, the electromagnetic force, one of the four fundamental forces of nature. elctric charge can form between two charges one of them is positive and the other Charge is negative. changes taking place within that system. Within the system, charge may be transferred between bodies, either by direct contact, or by passing along a conducting material, such as a wire. The informal term static electricity refers to the net presence (or 'imbalance') of charge on a body, usually caused when dissimilar materials are rubbed together, transferring charge from one to the other.

Charge on a gold-leaf electroscope causes the leaves to visibly repel each other
The presence of charge gives rise to the electromagnetic force: charges exert a force on each other, an effect that was known, though not understood, in antiquity. A lightweight ball suspended from a string can be charged by touching it with a glass rod that has itself been charged by rubbing with a cloth. If a similar ball is charged by the same glass rod, it is found to repel the first: the charge acts to force the two balls apart. Two balls that are charged with a rubbed amber rod also repel each other. However, if one ball is charged by the glass rod, and the other by an amber rod, the two balls are found to attract each other. These phenomena were investigated in the late eighteenth century by Charles-Augustin de Coulomb, who deduced that charge manifests itself in two opposing forms. This discovery led to the well-known axiom: like-charged objects repel and opposite-charged objects attract.
The force acts on the charged particles themselves, hence charge has a tendency to spread itself as evenly as possible over a conducting surface. The magnitude of the electromagnetic force, whether attractive or repulsive, is given by Coulomb's law, which relates the force to the product of the charges and has an inverse-square relation to the distance between them. The electromagnetic force is very strong, second only in strength to the strong interaction but unlike that force it operates over all distances.In comparison with the much weaker gravitational force, the electromagnetic force pushing two electrons apart is 1042 times that of the gravitational attraction pulling them together.
The charge on electrons and protons is opposite in sign, hence an amount of charge may be expressed as being either negative or positive. By convention, the charge carried by electrons is deemed negative, and that by protons positive, a custom that originated with the work of Benjamin Franklin. The amount of charge is usually given the symbol Q and expressed in coulombs; each electron carries the same charge of approximately −1.6022×10−19 coulomb. The proton has a charge that is equal and opposite, and thus +1.6022×10−19 coulomb. Charge is possessed not just by matter, but also by antimatter, each antiparticle bearing an equal and opposite charge to its corresponding particle.
Charge can be measured by a number of means, an early instrument being the gold-leaf electroscope, which although still in use for classroom demonstrations, has been superseded by the electronic electrometer.

; most commonly these are electrons, but any charge in motion constitutes a current.
By historical convention, a positive current is defined as having the same direction of flow as any positive charge it contains, or to flow from the most positive part of a circuit to the most negative part. Current defined in this manner is called conventional current. The motion of negatively-charged electrons around an electric circuit, one of the most familiar forms of current, is thus deemed positive in the opposite direction to that of the electrons. However, depending on the conditions, an electric current can consist of a flow of charged particles in either direction, or even in both directions at once. The positive-to-negative convention is widely used to simplify this situation.

An electric arc provides an energetic demonstration of electric current
The process by which electric current passes through a material is termed electrical conduction, and its nature varies with that of the charged particles and the material through which they are travelling. Examples of electric currents include metallic conduction, where electrons flow through a conductor such as metal, and electrolysis, where ions (charged atoms) flow through liquids. While the particles themselves can move quite slowly, sometimes with an average drift velocity only fractions of a millimetre per second, the electric field that drives them itself propagates at close to the speed of light, enabling electrical signals to pass rapidly along wires.
Current causes several observable effects, which historically were the means of recognising its presence. That water could be decomposed by the current from a voltaic pile was discovered by Nicholson and Carlisle in 1800, a process now known as electrolysis. Their work was greatly expanded upon by Michael Faraday in 1833.[28] Current through a resistance causes localised heating, an effect James Prescott Joule studied mathematically in 1840.One of the most important discoveries relating to current was made accidentally by Hans Christian Ørsted in 1820, when, while preparing a lecture, he witnessed the current in a wire disturbing the needle of a magnetic compass.He had discovered electromagnetism, a fundamental interaction between electricity and magnetics.
In engineering or household applications, current is often described as being either direct current (DC) or alternating current (AC). These terms refer to how the current varies in time. Direct current, as produced by example from a battery and required by most electronic devices, is a unidirectional flow from the positive part of a circuit to the negative. If, as is most common, this flow is carried by electrons, they will be travelling in the opposite direction. Alternating current is any current that reverses direction repeatedly; almost always this takes the form of a sinusoidal wave.Alternating current thus pulses back and forth within a conductor without the charge moving any net distance over time. The time-averaged value of an alternating current is zero, but it delivers energy in first one direction, and then the reverse. Alternating current is affected by electrical properties that are not observed under steady state direct current, such as inductance and capacitance.These properties however can become important when circuitry is subjected to transients, such as when first energised.

History

Main articles: History of electromagnetism and History of electrical engineering
See also: Etymology of electricity
Long before any knowledge of electricity existed people were aware of shocks from electric fish. Ancient Egyptian texts dating from 2750 BC referred to these fish as the "Thunderer of the Nile", and described them as the "protectors" of all other fish. They were again reported millennia later by ancient Greek, Roman and Arabic naturalists and physicians. Several ancient writers, such as Pliny the Elder and Scribonius Largus, attested to the numbing effect of electric shocks delivered by catfish and torpedo rays, and knew that such shocks could travel along conducting objects.Patients suffering from ailments such as gout or headache were directed to touch electric fish in the hope that the powerful jolt might cure them.[4] Possibly the earliest and nearest approach to the discovery of the identity of lightning, and electricity from any other source, is to be attributed to the Arabs, who before the 15th century had the Arabic word for lightning (raad) applied to the electric ray.
That certain objects such as rods of amber could be rubbed with cat's fur and attract light objects like feathers was known to ancient cultures around the Mediterranean. Thales of Miletos made a series of observations on static electricity around 600 BC, from which he believed that friction rendered amber magnetic, in contrast to minerals such as magnetite, which needed no rubbing. Thales was incorrect in believing the attraction was due to a magnetic effect, but later science would prove a link between magnetism and electricity. According to a controversial theory, the Parthians may have had knowledge of electroplating, based on the 1936 discovery of the Baghdad Battery, which resembles a galvanic cell, though it is uncertain whether the artifact was electrical in nature.

Benjamin Franklin conducted extensive research on electricity in the 18th century
Electricity would remain little more than an intellectual curiosity for millennia until 1600, when the English physician William Gilbert made a careful study of electricity and magnetism, distinguishing the lodestone effect from static electricity produced by rubbing amber. He coined the New Latin word electricus ("of amber" or "like amber", from ήλεκτρον [elektron], the Greek word for "amber") to refer to the property of attracting small objects after being rubbed. This association gave rise to the English words "electric" and "electricity", which made their first appearance in print in Thomas Browne's Pseudodoxia Epidemica of 1646.
Further work was conducted by Otto von Guericke, Robert Boyle, Stephen Gray and C. F. du Fay. In the 18th century, Benjamin Franklin conducted extensive research in electricity, selling his possessions to fund his work. In June 1752 he is reputed to have attached a metal key to the bottom of a dampened kite string and flown the kite in a storm-threatened sky.He observed a succession of sparks jumping from the key to the back of his hand, showing that lightning was indeed electrical in nature.
In 1791 Luigi Galvani published his discovery of bioelectricity, demonstrating that electricity was the medium by which nerve cells passed signals to the muscles.Volta's battery, or voltaic pile, of 1800, made from alternating layers of zinc and copper, provided scientists with a more reliable source of electrical energy than the electrostatic machines previously used. The recognition of electromagnetism, the unity of electric and magnetic phenomena, is due to Hans Christian Ørsted and André-Marie Ampère in 1819-1820; Michael Faraday invented the electric motor in 1821, and Georg Ohm mathematically analysed the electrical circuit in 1827
While it had been the early 19th century that had seen rapid progress in electrical science, the late 19th century would see the greatest progress in electrical engineering. Through such people as Nikola Tesla, Thomas Edison, Ottó Bláthy, George Westinghouse, Ernst Werner von Siemens, Alexander Graham Bell and Lord Kelvin, electricity was turned from a scientific curiosity into an essential tool for modern life, becoming a driving force for the Second Industrial Revolution.

Electricity

Electricity : is a general term that encompasses a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena such as lightning and static electricity, but in addition, less familiar concepts such as the electromagnetic field and electromagnetic induction.
In general usage, the word 'electricity' is adequate to refer to a number of physical effects. However, in scientific usage, the term is vague, and these related, but distinct, concepts are better identified by more precise terms:
Electric charge – a property of some subatomic particles, which determines their electromagnetic interactions. Electrically charged matter is influenced by, and produces, electromagnetic fields.
Electric current – a movement or flow of electrically charged particles, typically measured in amperes.
Electric field – an influence produced by an electric charge on other charges in its vicinity.
Electric potential – the capacity of an electric field to do work, typically measured in volts.
Electromagnetism – a fundamental interaction between the magnetic field and the presence and motion of an electric charge.
Electrical phenomena have been studied since antiquity, though advances in the science were not made until the seventeenth and eighteenth centuries. Practical applications for electricity however remained few, and it would not be until the late nineteenth century that engineers were able to put it to industrial and residential use. The rapid expansion in electrical technology at this time transformed industry and society. Electricity's extraordinary versatility as a source of energy means it can be put to an almost limitless set of applications which include transport, heating, lighting, communications, and computation. The backbone of modern industrial society is, and for the foreseeable future can be expected to remain, the use of electrical power.

Yea, Nay, Or Eh: Britney Spears In Concert

Say what you will about the troubled starlet, but we have to hand it to Britney Spears for hitting the stage at New York’s Nassau Coliseum looking surprisingly on trend. There’s the showstopping bandleader jacket, not unlike versions spotted on the Spring runways at Balmain and 3.1 Phillip Lim. And while Sienna Miller and Daisy Lowe drew ire for their hot-pants experiments, we think Spears actually pulls off these sequin briefs. What do you think: Is a Courtney Love-style fashion comeback in the works, or will the former Mouseketeer be back in trucker hats and flip-flops before she can lip-synch “Oops! I did it again?”

Blasblog: Only The Essentials At A La Perla Party

Back in January, during the haute couture shows, Liz Goldwyn told me that in these times of economic strife she’s only investing in the thing that means the most to her: designer lingerie. And then she added that she was working on a top secret jewelry line for a “very important fashion house,” which she would announce later this year. That led me to the somewhat obvious conclusion that the modern lady is only looking for two things in her life: good intimates and fun bling-bling. On Tuesday night, both were on offer at La Perla’s Meatpacking District outpost, where girl-about-town-turned-jewelry designer Genevieve Jones hosted a preview of her fall line. “If I could, that’s all I would wear—fancy jewelry and fancy panties,” Jones sighed. Joining her were the likes of designers Zac Posen and Elise Øverland and fellow fashion friends Sophia Hesketh, Bonnie Morrison, and Julia Restoin-Roitfeld. “I didn’t expect it to be such hard work,” Jones said of her design forays. (She also does accessories; Kate Moss has been carrying a black leather tassel bag of hers for months now.) “But it’s so rewarding, and something I have a genuine passion for.” Passion was a theme: Restoin-Roitfeld said that she was returning to the scene of her own crime just by entering the store. “I was just in here before I went to Europe and spent so much money on sexy things,” she smiled.

Deconstructing The Street Fashion At South By Southwest

pageant of counterculture fashion on display at this year’s South by Southwest music festival (SXSW for those fluent in indie-speak) was, as always, a study in undifferentiated differentiation. Bopping along to the Psych Folk, Proto Punk, and No Wave beats that permeated downtown Austin last week was a sea of under-thirtysomethings who, despite their best efforts, all looked vaguely alike. Today’s faction of iconoclastic youth enjoy a very limited sartorial vocabulary consisting of American Apparel T-shirts, thrift store flannels, and a pair of Wayfarer shades, which admittedly do come in a dizzying array of colors these days. Of course, that’s not to say there weren’t some risk takers, especially among the actual performers. They come to SXSW to get noticed, after all, and an eye-popping outfit is a surefire plan of attack. Shown above are four prime examples of festival participants who proudly flew their freak flag at full mast. Clockwise from top left: soul/blues singer Andre Williams, Black Lips guitarist Cole Alexander, Peelander-Z drummer Akihiko Naruse, and Alela Diane’s Alina Hardin and Benjamin Oak Goodman, who describes his personal style as “Jewish Bruce Springsteen.”

Love At First Sight: A.P.C. X Liberty Shift

Why: The easy little dress got no love on the Spring runways, but when the temperature starts creeping up, there’s really nothing a girl would rather throw on for a run around town. A.P.C. has long been the source nonpareil for these no-brainer pieces, and now brand founder Jean Touitou is throwing a bone to his trend-minded fans by introducing a few styles made from Liberty prints. The Liberty archives are having a moment—Cacharel tapped Liberty for a special Spring ‘09 collection celebrating its 50th anniversary, for example, and brands ranging from Lover to Opening Ceremony have used the company’s microflorals this season—but the pictured A.P.C. x Liberty shift seems to sum up the print’s enduring boho appeal. The unfussy silhouette is the perfect canvas for Liberty’s psychedelic paisley, and the crocheted neckline is hippie without being dippy. Now we just need the weather to get with the program.

Savannah College Of Art And Design’s Starry Night

My best purpose is to allow creative expression to flourish,” said Russell Simmons as he accepted his SCAD Étoile Award, alongside Robin Givhan, Cornelia Guest, costume designer William Ivey Long, and NYC planning director Amanda Burden last night at Manhattan’s James Cohan Gallery. The evening was the New York kickoff for SCAD Style, two months of events at the Savannah College of Art and Design in Georgia—including exhibitions and lectures by Rita Konig, Lela Rose, Simon Doonan, and Badgley Mischka, among others—which culminates with a student fashion show and the bestowing of the André Leon Talley Lifetime Achievement Award. This year’s award will go to Ruben and Isabel Toledo. (John Galliano was last year’s recipient.) In the crowd last night were Yigal Azrouël and Lars Nilsson, both SCAD mentors. The former, a self-taught designer, is getting a kick out of the gig as well as appreciating the irony of teaching at a fashion school, as he never attended one. “You learn something about yourself,” he said of the experience. What lessons is Nilsson imparting to his students? “To stay focused and never give up,” said the Swede, who is working on a furniture line in Paris and keeping mum on future fashion plans. If the sparkle in his eye is any indication, there might soon be news to report on that front.

shaved catfish anyone ?

When Billy Reid was a kid, his family made the drive to New Orleans with some regularity. And every time the Reid clan piled in the car for that trip, they marked its midway point with a stop at the legendary seafood restaurant Mittendorf’s. “I guess you could say I was raised on shaved catfish,” noted Reid of Mittendorf’s signature dish. “It’s a treat.” Thanks to Reid, New Yorkers can now attest to that fact: To fête his Fall collection, the designer opened the doors to his Bond Street shop last night and flew up a Mittendorf’s chef and many pounds of fresh catfish for the occasion. The fish was shaved wafer thin and fried on site and served with a selection of special rémoulades and tartar sauces, and as if that weren’t distracting enough, Reid had also set up a beer ‘n’ bourbon bar in the basement and invited local alt-country band Railbird to play live. “I’m really not worried if people aren’t checking out the clothes,” he noted. “I mean, that stuff will take care of itself, so why not have some fun?” Adding to the southern-fried flavor of the evening: Reid’s mother, father, and sister had made the trip up north as well. “My dad was like, I can’t believe I had to fly all the way to New York City just to eat some Mittendorf’s catfish,” joked Reid. “I told him, hey, at least the bourbon’s free.”
—Maya Singer

John Galliano

With his muscle-bound physique and runway swagger (no reticent post-show wave from backstage for this designer), John Galliano almost upstages the sensational creations he dreams up for the House of Dior and his own line. Almost. A provocateur since his French Revolution-themed graduation collection at Central Saint Martins, Galliano excels at excess. Opera divas, Masai tribesmen, medieval warrior women, Austro-Hungarian royalty, and even the homeless have stomped down the catwalk at his theatrically themed shows (often inspired by his world travels). One of the most avant-garde couturiers, Galliano has stayed true to the spirit of Dior while pushing the house well into the modern age. Cate Blanchett, Charlize Theron, and Nicole Kidman have worn his showstopping creations on some of the biggest nights of their lives.Born in Gibraltar in 1960, Galliano began his career in London. After launching his label there in 1984 and being named Britain's Designer of the Year in 1988, he decamped for Paris in 1991. It wasn't easy to make it in fashion's mightiest capital: He bunked on friends' floors as he struggled to get his business off the ground. But—with a little help from Anna Wintour, the Vogue editor—his breakthrough came with an all-black show staged at the artfully decaying Left Bank mansion of the socialite São Schlumberger.In 1995, LVMH placed Galliano in charge of Givenchy's haute couture and ready-to-wear lines, an unheard-of coup for a British designer at a French house. Two years later, Galliano took another lofty step up the LVMH ladder, being crowned design director at Christian Dior. In addition to his obsessive work at Dior—where he oversees ad campaigns and even window displays—Galliano continues to design his own line, producing a dozen shows all told each year and, as ever, romancing his audiences with his knock-down-drag-out showmanship and soaring imagination.