Dont drive and watch a movie at the same time.
A watch is a timepiece, typically worn either around the wrist or attached on a chain and carried in a pocket. Wristwatches are the most common type of watch used today. Watches evolved in the 17th century from spring powered clocks, which appeared in the 15th century. The first watches were strictly mechanical. As technology progressed, the mechanisms used to measure time have, in some cases, been replaced by use of quartz vibrations or electronic pulses. The first digital electronic watch was developed in 1970.
Before wristwatches became popular in the 1920s, most watches were pocket watches, which often had covers and were carried in a pocket and attached to a watch chain or watch fob. In the early 1900s, the wristwatch, originally called a Wristlet, was reserved for women and considered more of a passing fad than a serious timepiece. Men, who carried pocket watches, were quoted as saying they would "sooner wear a skirt as wear a wristwatch". This changed in World War I, when soldiers on the battlefield found pocket watches to be impractical and attached their watches to their wrist by a cupped leather strap. It is also believed that Girard-Perregaux equipped the German Imperial Navy with wristwatches in a similar fashion as early as the 1880s, to be used while synchronizing naval attacks and firing artillery.
Most inexpensive and medium-priced watches used mainly for timekeeping are electronic watches with quartz movements. Expensive collectible watches, valued more for their workmanship and aesthetic appeal than for simple timekeeping, often have purely mechanical movements and are powered by springs, even though mechanical movements are less accurate than more affordable quartz movements. In addition to the time, modern watches often display the day, date, month and year, and electronic watches may have many other functions. Watches that provide additional time-related features such as timers, chronographs and alarm functions are not uncommon. Some modern designs even go as far as using GPS technology or heart-rate monitoring capabilities.
The study of timekeeping is known as horology.
Watches evolved from portable spring-driven clocks, which first appeared in 15th century Europe. Watches weren't widely worn in pockets until the 17th century. One account says that the word "watch" came from the Old English word woecce which meant "watchman", because it was used by town watchmen to keep track of their shifts. Another says that the term came from 17th century sailors, who used the new mechanisms to time the length of their shipboard watches (duty shifts).
A movement in watchmaking is the mechanism that measures the passage of time and displays the current time (and possibly other information including date, month and day). Movements may be entirely mechanical, entirely electronic (potentially with no moving parts), or they might be a blend of the two. Most watches intended mainly for timekeeping today have electronic movements, with mechanical hands on the watch face indicating the time.
Compared to electronic movements, mechanical watches are less accurate, often with errors of seconds per day, and they are sensitive to position, temperature and magnetism. They are also costly to produce, require regular maintenance and adjustment, and are more prone to failure. Nevertheless, the craftsmanship of mechanical watches still attracts interest from part of the watch-buying public. Skeleton watches are designed to leave the mechanism visible for aesthetic purposes.
Mechanical movements use an escapement mechanism to control and limit the unwinding and winding parts of a spring, converting what would otherwise be a simple unwinding into a controlled and periodic energy release. Mechanical movements also use a balance wheel together with the balance spring (also known as a hairspring) to control motion of the gear system of the watch in a manner analogous to the pendulum of a pendulum clock. The tourbillon, an optional part for mechanical movements, is a rotating frame for the escapement, which is used to cancel out or reduce the effects of gravitational bias to the timekeeping. Due to the complexity of designing a tourbillon, they are very expensive, and only found in "prestige" watches.
The pin-lever escapement (called the Roskopf movement after its inventor, Georges Frederic Roskopf), which is a cheaper version of the fully levered movement, was manufactured in huge quantities by many Swiss manufacturers as well as by Timex, until it was replaced by quartz movements.
Tuning-fork watches use a type of electromechanical movement. Introduced by Bulova in 1960, they use a tuning fork with a precise frequency (most often 360 hertz) to drive a mechanical watch. The task of converting electronically pulsed fork vibration into rotary movement is done via two tiny jeweled fingers, called pawls. Tuning-fork watches were rendered obsolete when electronic quartz watches were developed. Quartz watches were cheaper to produce and even more accurate.
Traditional mechanical watch movements use a spiral spring called a mainspring as a power source. In manual watches the spring must be rewound periodically by the user by turning the watch crown. Antique pocketwatches were wound by inserting a separate key into a hole in the back of the watch and turning it. Most modern watches are designed to run 40 hours on a winding and thus must be wound daily, but some run for several days and a few have 192-hour mainsprings and are wound weekly.
A self-winding or automatic watch is one that rewinds the mainspring of a mechanical movement by the natural motions of the wearer's body. The first self-winding mechanism was invented for pocket watches in 1770 by Abraham-Louis Perrelet, but the first "self-winding", or "automatic", wristwatch was the invention of a British watch repairer named John Harwood in 1923. This type of watch allows for constant winding without special action from the wearer; it works by an eccentric weight, called a winding rotor, which rotates with the movement of the wearer's wrist. The back-and-forth motion of the winding rotor couples to a ratchet to automatically wind the mainspring. Self-winding watches usually can also be wound manually so they can be kept running when not worn or if the wearer's wrist motions are inadequate to keep the watch wound.
Electronic movements have few or no moving parts, as they use the piezoelectric effect in a tiny quartz crystal to provide a stable time base for a mostly electronic movement. The crystal forms a quartz oscillator which resonates at a specific and highly stable frequency, and which can be used to accurately pace a timekeeping mechanism. For this reason, electronic watches are often called quartz watches. Most quartz movements are primarily electronic but are geared to drive mechanical hands on the face of the watch in order to provide a traditional analog display of the time, which is still preferred by most consumers.
In 1959 Seiko gave an order to Epson (a daughter company of Seiko and the actual brain behind the quartz revolution) to start developing a quartz wristwatch. The project was codenamed 59A and by the 1964 Tokyo Summer Olympics, Seiko had a working prototype of a portable quartz watch which took part in time measurements throughout the event.
The first prototypes of an electronic quartz wristwatch (not just portable quartz watches as the Seiko timekeeping devices at the Tokyo Olympics in 1964) were made by the CEH research laboratory in Neuchâtel, Switzerland. From 1965 through 1967 pioneering development work was done on a miniaturized 8192 Hz quartz oscillator, a thermo-compensation module and an inhouse-made, dedicated integrated circuit (unlike the hybrid circuits used in the later Seiko Astron wristwatch). As a result, the BETA 1 prototype set new timekeeping performance records at the International Chronometric Competition held at the Observatory of Neuchâtel in 1967.
The first quartz watch to enter production was the Seiko 35 SQ Astron, which hit the shelves on December 25, 1969. One particularly interesting decision made by Seiko at that time was to not patent the whole movement of the quartz wristwatch, thus allowing other manufacturers to benefit from the Seiko technology. This played a major role in the popularity and quick development of the quartz watch, which in less than a decade was dominant in the watch market, nearly ending an almost 100 years of mechanical wristwatch heritage. The modern quartz movements are produced in very large quantities, and even the cheapest wristwatches typically have quartz movements. Whereas mechanical movements can typically be off by several seconds a day, an inexpensive quartz movement in a child's wristwatch may still be accurate to within half a second per day—ten times better than a mechanical movement.
After a consolidation of the mechanical watch industry in Switzerland during the 1970s, mass production of quartz wristwatches took off under the leadership of the Swatch Group of companies, a Swiss conglomerate with vertical control of the production of Swiss watches and related products. For quartz wristwatches, subsidiaries of Swatch manufactured watch batteries (Renata), oscillators (Oscilloquartz) and integrated circuits (Ebauches Electronic SA). The launch of the new SWATCH brand in 1983, was marked by bold new styling, design and marketing. Today, the Swatch Group is the world's largest watch company.
Seiko's efforts to combine the quartz and mechanical movements bore fruit after 20 years of research, leading to the introduction of the Seiko Spring Drive, first in a limited domestic market production in 1999 and to the world in September 2005. The Spring Drive manages to keep time within quartz standards without the use of a battery, using a traditional mechanical gear train powered by a spring, while at the same time doesn't have the need of a balance wheel either.
Radio time signal watches are a type of electronic quartz watch which synchronizes (time transfer) its time with an external time source such as in atomic clocks, time signals from GPS navigation satellites, the German DCF77 signal in Europe, WWVB in the US, and others. Movements of this type may -among others- synchronize not only the time of day but also the date, the leap-year status of the current year, and the current state of daylight saving time (on or off). However, other than the radio receiver these watches are normal quartz watches in all other aspects.
Electronic watches require electricity as a power source, and some mechanical movements and hybrid electronic-mechanical movements also require electricity. Usually the electricity is provided by a replaceable battery. The first use of electrical power in watches was as a substitute for the mainspring, in order to remove the need for winding. The first electrically powered watch, the Hamilton Electric 500, was released in 1957 by the Hamilton Watch Company of Lancaster, Pennsylvania.
Watch batteries (strictly speaking cells, as a battery is composed of multiple cells) are specially designed for their purpose. They are very small and provide tiny amounts of power continuously for very long periods (several years or more). In most cases, replacing the battery requires a trip to a watch-repair shop or watch dealer; this is especially true for watches that are designed to be water-resistant, as special tools and procedures are required to ensure that the watch remains water-resistant after battery replacement. Silver-oxide and lithium batteries are popular today; mercury batteries, formerly quite common, are no longer used, for environmental reasons. Cheap batteries may be alkaline, of the same size as silver-oxide cells but providing shorter life. Rechargeable batteries are used in some solar powered watches.
Some electronic watches are also powered by the movement of the wearer of the watch. For instance, Seiko's Kinetic powered quartz watches make use of the motion of the wearer's arm turning a rotating weight which causes a tiny generator to supply power to charge a rechargeable battery that runs the watch. The concept is similar to that of self-winding spring movements, except that electrical power is generated instead of mechanical spring tension.
Solar powered watches are powered by light. A photovoltaic cell on the face (dial) of the watch converts light to electricity, which in turn is used to charge a rechargeable battery or capacitor. The movement of the watch draws its power from the rechargeable battery or capacitor. As long as the watch is regularly exposed to fairly strong light (such as sunlight), it never needs battery replacement, and some models need only a few minutes of sunlight to provide weeks of energy (as in the Citizen Eco-Drive). Some of the early solar watches of the 1970s had innovative and unique designs to accommodate the array of solar cells needed to power them (Synchronar, Nepro, Sicura and some models by Cristalonic, Alba, Seiko and Citizen). As the decades progressed and the efficiency of the solar cells increased while the power requirements of the movement and display decreased, solar watches began to be designed to look like other conventional watches.
A rarely used power source is the temperature difference between the wearer's arm and the surrounding environment (as applied in the Citizen Eco-Drive Thermo).
Traditionally, watches have displayed the time in analog form, with a numbered dial upon which are mounted at least a rotating hour hand and a longer, rotating minute hand. Many watches also incorporate a third hand that shows the current second of the current minute. Watches powered by quartz usually have a second hand that snaps every second to the next marker. Watches powered by a mechanical movement appears to have a gliding second hand, although it is actually not gliding; the hand merely moves in smaller steps, typically 1/5 of a second, corresponding to the beat (half period) of the balance wheel. In some escapements (for example the duplex escapement), the hand advances every two beats (full period) of the balance wheel, typically 1/2 second in those watches, or even every four beats (two periods, 1 second), in the double duplex escapement. A truly gliding second hand is achieved with the tri-synchro regulator of Spring Drive watches. All of the hands are normally mechanical, physically rotating on the dial, although a few watches have been produced with "hands" that are simulated by a liquid-crystal display.
Analog display of the time is nearly universal in watches sold as jewelry or collectibles, and in these watches, the range of different styles of hands, numbers, and other aspects of the analog dial is very broad. In watches sold for timekeeping, analog display remains very popular, as many people find it easier to read than digital display; but in timekeeping watches the emphasis is on clarity and accurate reading of the time under all conditions (clearly marked digits, easily visible hands, large watch faces, etc.). They are specifically designed for the left wrist with the stem (the knob used for changing the time) on the right side of the watch; this makes it easy to change the time without removing the watch from the wrist. This is the case if one is right-handed and the watch is worn on the left wrist (as is traditionally done). If one is left-handed and wears the watch on the right wrist, one has to remove the watch from the wrist to reset the time or to wind the watch.
Analog watches as well as clocks are often marketed showing a display time of approximately 1:50 or 10:10. This creates a visually pleasing smile-like face on upper half of the watch, in addition to enclosing the manufacturer's name. Digital displays often show a time of 12:08, where the increase in the number of active segments or pixels gives a positive feeling.
Eone Timepieces, a company owned by Hyungsoo Kim that is based in Washington D.C., United States (U.S.), launched its first tactile analog wristwatch on July 11, 2013 on the Kickstarter website. The device is primarily designed for sight-impaired users, who can use the watch's two ball bearings to determine the time, but it is also suitable for general use. The timepiece is named the "Bradley", after Paralympic swimmer Bradley Snyder, a former U.S. Navy member who lost his sight in Afghanistan. Snyder, who was introduced to Kim through a mutual friend, responded positively to the watch, stating: "... the first time I put it on, I was blown away." As of July 14, 2013, the Kickstarter had raised over US$149,000 and the first batch of 350 watches is scheduled to ship during November 2013.
A digital display simply shows the time as a number, e.g., 12:08 instead of a short hand pointing towards the number 12 and a long hand 8/60 of the way round the dial. The digits are usually shown as a seven-segment display.
The first digital mechanical pocket watches appeared in late 19th century. In the 1920s, the first digital mechanical wristwatches appeared.
The first digital electronic watch, a Pulsar LED prototype in 1970, was developed jointly by Hamilton Watch Company and Electro-Data, founded by George H. Thiess. John Bergey, the head of Hamilton's Pulsar division, said that he was inspired to make a digital timepiece by the then-futuristic digital clock that Hamilton themselves made for the 1968 science fiction film 2001: A Space Odyssey. On April 4, 1972, the Pulsar was finally ready, made in 18-carat gold and sold for $2,100. It had a red light-emitting diode (LED) display.
Digital LED watches were very expensive and out of reach to the common consumer until 1975, when Texas Instruments started to mass-produce LED watches inside a plastic case. These watches, which first retailed for only $20, reduced to $10 in 1976, saw Pulsar lose $6 million and the Pulsar brand sold to Seiko.
An early LED watch that was rather problematic was The Black Watch made and sold by British company Sinclair Research in 1975. This was only sold for a few years, as production problems and returned (faulty) product forced the company to cease production.
Most watches with LED displays required that the user press a button to see the time displayed for a few seconds, because LEDs used so much power that they could not be kept operating continuously. Usually the LED display color would be red. Watches with LED displays were popular for a few years, but soon the LED displays were superseded by liquid crystal displays (LCDs), which used less battery power and were much more convenient in use, with the display always visible and no need to push a button before seeing the time. Only in darkness you had to press a button to light the display with a tiny light bulb, later illuminating LEDs. The first LCD watch with a six-digit LCD was the 1973 Seiko 06LC, although various forms of early LCD watches with a four-digit display were marketed as early as 1972 including the 1972 Gruen Teletime LCD Watch, and the Cox Electronic Systems Quarza. In Switzerland, Ebauches Electronic SA presented a prototype eight-digit LCD wristwatch showing time and date at the MUBA Fair, Basle, in March 1973, using a Twisted Nematic LCD manufactured by Brown, Boveri & Cie, Switzerland, which became the supplier of LCDs to Casio for the CASIOTRON watch in 1974.
From the 1980s onward, digital watch technology vastly improved. In 1982 Seiko produced a watch with a small television screen built in, and Casio produced a digital watch with a thermometer as well as another that could translate 1,500 Japanese words into English. In 1985, Casio produced the CFX-400 scientific calculator watch. In 1987 Casio produced a watch that could dial your telephone number and Citizen revealed one that would react to your voice. In 1995 Timex released a watch which allowed the wearer to download and store data from a computer to their wrist. Some watches, such as the Timex Datalink USB, feature dot matrix displays. Since their apex during the late 1980s to mid-1990s high technology fad, digital watches have mostly become simpler, less expensive time pieces with little variety between models.
Despite these many advances, almost all watches with digital displays are used as timekeeping watches. Expensive watches for collectors rarely have digital displays since there is little demand for them. Less craftsmanship is required to make a digital watch face and most collectors find that analog dials (especially with complications) vary in quality more than digital dials due to the details and finishing of the parts that make up the dial (thus making the differences between a cheap and expensive watch more evident).
Many watches have displays that are illuminated, so they can be used in darkness. Various methods have been used to achieve this.
Mechanical watches often have luminous paint on their hands and hour marks. In the mid-20th Century, radioactive material was often incorporated in the paint, so it would continue to glow without any exposure to light. Radium was often used, but produced small amounts of radiation outside the watch which might have been hazardous. Tritium was used as a replacemant, since the radiation it produces has such low energy that it cannot penetrate a watch glass. However, tritium has a half-life of only about 12 years, so the paint did not remain luminous for more than a few years. Nowadays, luminous paint is still sometimes used on analog displays, but no radioactive material is contained in it. This means that the display glows soon after being exposed to light, but quickly fades.
Watches that incorporate batteries often have electric illumination of their displays. However, lights consume far more power than electronic watch movements. In order to conserve the battery, the light is activated only when the user presses a button. Usually, the light remains lit for a few seconds after the button is released, which allows the user to move his hand out of the way.
In some early digital watches, LED displays were used, which could be read as easily in darkness as in daylight. However, the user had to press a button to light up the LEDs, which meant that the watch could not be read at all without the button being pressed, even in full daylight.
Some cheaper watches have small incandescent lamps to illuminate the display. However, these tend to produce very non-uniform illumination, and are very wasteful of electricity. Other watches use electroluminescent material to produce uniform illumination of the background of the display, against which the hands or digits can be seen.
All watches provide the time of day, giving at least the hour and minute, and usually the second. Most also provide the current date, and often the day of the week as well. However, many watches also provide a great deal of information beyond the basics of time and date. Some watches include alarms. Other elaborate and more expensive watches, both pocket and wrist models, also incorporate striking mechanisms or repeater functions, so that the wearer could learn the time by the sound emanating from the watch. This announcement or striking feature is an essential characteristic of true clocks and distinguishes such watches from ordinary timepieces. This feature is available on most digital watches.
A complicated watch has one or more functions beyond the basic function of displaying the time and the date; such a functionality is called a complication. Two popular complications are the chronograph complication, which is the ability of the watch movement to function as a stopwatch, and the moonphase complication, which is a display of the lunar phase. Other more expensive complications include Tourbillon, Perpetual calendar, Minute repeater, and Equation of time. A truly complicated watch has many of these complications at once (see Calibre 89 from Patek Philippe for instance). Some watches can both indicate the direction of Mecca and have alarms that can be set for all daily prayer requirements. Among watch enthusiasts, complicated watches are especially collectible. Some watches include a second 12-hour or 24-hour display for UTC or GMT.
The similar-sounding terms chronograph and chronometer are often confused, although they mean altogether different things. A chronograph has a stopwatch complication, as explained above, while a chronometer watch has a high quality mechanical or a thermo-compensated movement that has been tested and certified to operate within a certain standard of accuracy by the COSC (Contrôle Officiel Suisse des Chronomètres). The concepts are different but not mutually exclusive; so a watch can be a chronograph, a chronometer, both, or neither.
Many computerized wristwatches have been developed, but none have had long-term sales success, because they have awkward user interfaces due to the tiny screens and buttons, and a short battery life. As miniaturized electronics became cheaper, watches have been developed containing calculators, tonometers, barometers, altimeters, a compass using both hands to show the N/S direction, video games, digital cameras, keydrives, GPS receivers and cellular phones. A few astronomical watches show phase of the Moon and other celestial phenomena. In the early 1980s Seiko marketed a watch with a television in it. Such watches have also had the reputation as unsightly and thus mainly geek toys. Several companies have however attempted to develop a computer contained in a wristwatch (see also wearable computer).
Braille watches have analog displays with raised bumps around the face to allow blind users to tell the time. Their digital equivalents use synthesised speech to speak the time on command.
Wristwatches and antique pocket watches are often appreciated as jewelry or as collectible works of art rather than just as timepieces. This has created several different markets for wristwatches, ranging from very inexpensive but accurate watches (intended for no other purpose than telling the correct time) to extremely expensive watches that serve mainly as personal adornment (featuring jewel bearings to hold gemstones) or as examples of high achievement in miniaturization and precision mechanical engineering.
Traditionally, men's dress watches appropriate for informal (business), semi-formal, and formal attire are gold, thin, simple, and plain, but increasingly rugged, complicated, or sports watches are considered acceptable for such attire. Some dress watches have a cabochon on the crown and many women's dress watches have faceted gemstones on the face, bezel, or bracelet. Some are made entirely of facetted sapphire (corundum).
Many fashion and department stores offer a variety of less-expensive, trendy, "costume" watches (usually for women), many of which are similar in quality to basic quartz timepieces but which feature bolder designs. In the 1980s, the Swiss Swatch company hired graphic designers to redesign a new annual collection of non-repairable watches.
Trade in counterfeit watches, which mimic expensive brand-name watches, constitutes an estimated market per year.
Zero gravity environment and other extreme conditions encountered by astronauts in space requires the use of specially tested watches. On April 12, 1961, Yuri Gagarin wore a Shturmanskie (a transliteration of Штурманские which actually means “navigator’s”) wristwatch during his historic first flight into space. The Shturmanskie was manufactured at the First Moscow Factory. Since 1964, the watches of the First Moscow Factory have been marked by the trademark “Полёт”, transliterated as “POLJOT”, which means “flight” in Russian and is a tribute to the many space trips its watches have accomplished. In the late 1970s, Poljot launched a new chrono movement, the 3133. With a 23 jewel movement and manual winding (43 hours), it was a modified Russian version of the Swiss Valjoux 7734 of the early 1970s. Poljot 3133 were taken into space by astronauts from Russia, France, Germany and Ukraine. On the arm of Valeriy Polyakov, a Poljot 3133 chronograph movement-based watch set a space record for the longest space flight in history.
Through the 1960s, a large range of watches were tested for durability and precision under extreme temperature changes and vibrations. The Omega Speedmaster Professional was selected by NASA, the U.S. space agency. Heuer became the first Swiss watch in space thanks to a Heuer Stopwatch, worn by John Glenn in 1962 when he piloted the Friendship 7 on the first manned U.S. orbital mission. The Breitling Navitimer Cosmonaute was designed with a 24-hour analog dial to avoid confusion between AM and PM, which are meaningless in space. It was first worn in space by U.S. astronaut Scott Carpenter on May 24, 1962 in the Aurora 7 mercury capsule. Since 1994 Fortis is the exclusive supplier for manned space missions authorized by the Russian Federal Space Agency. China National Space Administration (CNSA) astronauts wear the Fiyta spacewatches. At BaselWorld, 2008, Seiko announced the creation of the first watch ever designed specifically for a space walk, Spring Drive Spacewalk. Timex Datalink is flight certified by NASA for space missions and is one of the watches qualified by NASA for space travel. The Casio G-Shock DW-5600C and 5600E, DW 6900, and DW 5900 are Flight-Qualified for NASA space travel. The various Datalink models were used both by cosmonauts and astronauts.
Watches may be crafted to become water resistant. These watches are sometimes called diving watches when they are suitable for scuba diving or saturation diving. The International Organization for Standardization issued a standard for water resistant watches which also prohibits the term "waterproof" to be used with watches, which many countries have adopted.
Water resistance is achieved by the gaskets which forms a watertight seal, used in conjunction with a sealant applied on the case to help keep water out. The material of the case must also be tested in order to pass as water resistant.
None of the tests defined by ISO 2281 for the Water Resistant mark are suitable to qualify a watch for scuba diving. Such watches are designed for everyday life and must be water resistant during exercises such as swimming. They can be worn in different temperature and pressure conditions but are under no circumstances designed for scuba diving.
The standards for diving watches are regulated by the ISO 6425 international standard. The watches are tested in static or still water under 125% of the rated (water)pressure, thus a watch with a 200 metre rating will be water resistant if it is stationary and under 250 metres of static water. The testing of the water resistance is fundamentally different from non-dive watches, because every watch has to be fully tested. Besides water resistance standards to a minimum of 100 metre depth rating ISO 6425 also provides eight minimum requirements for mechanical diver's watches for scuba diving (quartz and digital watches have slightly differing readability requirements). For diver's watches for mixed-gas saturation diving two additional requirements have to be met.
Watches are classified by their degree of water resistance, which roughly translates to the following (1 metre = 3.281 feet):
Some watches use bar instead of meters, which may then be multiplied by 10, and then subtracted by 10. This is because 1 bar is equal to one atmosphere or 10 metres of water (therefore 1 bar at the surface and one more each 10 metres). to be approximately equal to the rating based on metres. Therefore, a 5 bar watch is equivalent to a 40 metre watch. Some watches are rated in atmospheres (atm), which are roughly equivalent to bar.
An analog watch can be used to locate north and south. The Sun appears to move in the sky over a 24 hour period while the hour hand of a 12-hour clock face takes twelve hours to complete one rotation. In the northern hemisphere, if the watch is rotated so that the hour hand points toward the Sun, the point halfway between the hour hand and 12 o'clock will indicate south. For this method to work in the southern hemisphere, the 12 is pointed toward the Sun and the point halfway between the hour hand and 12 o'clock will indicate north. During daylight saving time, the same method can be employed using 1 o'clock instead of 12.
The method depends on the assumption that the azimuth of the Sun changes at a constant rate during a day. Strictly, this is true only when the observer is at one of the Earth's poles. Seen from moderately high latitudes, say more than 50 degrees North or South, the Sun's azimuth changes at a rate that is sufficiently constant to allow this method to be useful. Seen from lower latitudes, the Sun's azimuth changes much more rapidly around noon than at other times of day. In an extreme case, when the Sun passes directly overhead at noon, its azimuth abruptly changes by 180 degrees, from due East to due West. Obviously, this completely invalidates the use of a watch as a compass. There are also relatively minor inaccuracies due to the difference between local time and zone time, and due to the equation of time.
DVD-R is a DVD recordable format. A DVD-R typically has a storage capacity of 4.7 GB. Pioneer has also developed an 8.5 GB dual layer version, DVD-R DL, which appeared on the market in 2005.
Data on a DVD-R cannot be changed, whereas a DVD-RW (rewritable DVD) can be rewritten multiple (1000+) times. DVD-R(W) is one of three competing industry standard DVD recordable formats; the others are DVD+R(W) and DVD-RAM.
The DVD-R format was developed by Pioneer in 1997. It is supported by most normal DVD players, and is approved by the DVD Forum.
The larger storage capacity of a DVD-R compared to a CD-R is achieved through smaller pit size and smaller track pitch of the groove spiral which guides the laser beam. Consequently, more pits can be written on the same physical sized disc. In order to write smaller pits onto the recording dye layer, a red laser beam with a wavelength of 640 nm (for general use recordable DVD, versus a wavelength of 780 nm for CD-R) is used in conjunction with a higher numerical aperture lens. Because of this shorter wavelength, DVD-R and DVD+R use different dyes from CD-R to properly absorb this wavelength.
DVD-R discs are composed of two 0.6 mm acrylic discs, bonded with an adhesive to each other. One contains the laser guiding groove and is coated with the recording dye and a silver alloy or gold reflector. The other one (for single-sided discs) is an ungrooved 'dummy' disc to assure mechanical stability of the sandwich structure, and compatibility with the compact disc standard geometry which requires a total disc thickness of about 1.2 mm. The sandwich structure also helps protect the data containing layer from scratches with a thick "dummy" disc, a problem with CDs, which lack that structure. Double-sided discs have two grooved, recordable disc sides, and require the user to flip the disc to access the other side. Compared to a CD's 1.2 mm thickness, a DVD's laser beam only has to penetrate 0.6 mm of plastic in order to reach the dye recording layer, which allows the lens to focus the beam to a smaller spot size to write smaller pits.
In a DVD-R, the addressing (the determination of location of the laser beam on the disc) is done with additional pits and lands (called land pre-pits) in the areas between the grooves. The groove on a DVD-R disc has a constant wobble frequency used for motor control, etc.
In 2011, JVC announced an archival DVD recording media manufactured with quality control and inspection frequencies techniques greater than is traditionally used in media manufacturing, and using specially developed silver alloy as a reflective layer and organic dye with in-house developed additives to secure long-term data retention.
A DVD recordable format called DVD-RAM (DVD random access memory) predates DVD-R. Developed in 1996, DVD-RAM is a rewritable optical disc usually encased in a cartridge. Currently available in standard 4.7 GB (and sometimes in other sizes), it is useful in applications that require quick revisions and rewriting. In 2002, a new format was developed called DVD+R (or "plus" R). Created by a coalition called the DVD+RW Alliance, this format uses a number of improved technologies that, while generally unnoticeable to the end user, make a more reliable technology. One example is the ADIP (ADdress In Pregroove) system of tracking and speed control used by DVD+R being less susceptible to interference and error than the LPP (Land Pre Pit) system used by DVD-R, which makes the ADIP system more accurate at higher speeds. In addition, DVD+R(W) has a more robust error management system than DVD-R(W), allowing for more accurate writing to media independent of the quality of the media. Additional session linking methods are more accurate with DVD+R(W) versus DVD-R(W), resulting in fewer damaged or unusable discs due to buffer under-run and multi-session discs with fewer PI/PO errors.
This new format, among other things, resulted in DVD-R being unofficially referred to as DVD "minus" R (though in countries where British English is dominant, the term "minus R" was already common; not just in contrast to "plus R"). DVD-R and DVD+R technologies are not directly compatible, which created a format war in the DVD technology industry. To reconcile the two competing formats, manufacturers created hybrid drives that could read both — most hybrid drives that handle both formats are labeled DVD±R and Super Multi (which includes DVD-RAM support) and are very popular.
As of 2006, the market for recordable DVD technology shows little sign of settling down in favour of either the plus or dash formats, which is mostly the result of the increasing numbers of dual-format devices that can record to both formats. It has become very difficult to find new computer drives that can only record to one of the formats. By contrast, DVD Video recorders still favour one format over the other, often providing restrictions on what the unfavoured format will do. However, because the DVD-R format has been in use since 1997, it has had a five-year lead on DVD+R. As such, older or cheaper DVD players (up to 2004 vintage) are more likely to favour the DVD-R standard exclusively.
For comparison, the table below shows storage capacities of the four most common DVD recordable media, excluding DVD-RAM. SL stands for standard single-layer discs, while DL denotes the double-layer variants. See articles on the formats in question for information on compatibility issues.
The following table describes the maximal speed of DVD-R and the relative typical write time for a full disc according to the reviews from cdrinfo.com and cdfreaks.com. Many reviews of multiple brand names on varying conditions of hardware and DVD give much lower and wider measurements than the optimal numbers below.
The write time may vary (± 30 s) between writer and media used. For high speed, the write strategy changes from constant linear velocity (CLV) to constant angular velocity (CAV), or zoned constant linear velocity (ZCLV). The table below largely assumes CAV.
Eco-Drive is the series name of a line of mainly solar powered watches (marketed as "light powered") manufactured by the Citizen Watch Co., Ltd. In 1995 Citizen introduced the Eco-Drive line to Asia, Latin America and Europe. In the United States the first Eco-Drive watches were sold in April 1996.
The Eco-Drive concept introduced several major technical refinements over previous solar powered watches. The combination of these refinements for the first time gave watch designers the opportunity to design light powered watches without the need to incorporate conspicuous solar cells on the watch dial.
The technical platform that made the Eco-Drive concept possible was the Eco-Drive caliber 7878 movement. This movement was the first light powered movement where the solar panel could be mounted under the round dial. Previous light powered watches from Citizen and other manufacturers had the solar cell(s) mounted directly on the dial. This innovation was possible due to the introduction of the amorphous silicon solar cell in a watch movement. These thin film solar cells had just prior to the mid-1990s become more efficient compared to their 1980s performance. As long as the dial material was sufficiently translucent, enough light would get through to the cell to generate sufficient energy. This opened up the design possibility to make a light powered watch look like a primary battery powered watch. Besides that, the first Eco-Drive watches used a lithium-ion rechargeable or secondary battery. The Eco-Drive 7878 caliber movement was able to run for 180 days on its secondary power cell before it needed light exposure for recharging. This was a significant increase in the ability to store energy compared to previous light powered watches. Further the movement had an insufficient recharging warning feature.
Besides the first 3 Eco-Drive models Citizen introduced in 1995 the company produced dozens other Eco-Drive models during the 1990s. Amongst these models was the 6.05 mm (0.238 in) thick Eco-Drive Slim of 1996. The first fairly uncomplicated (hours, minutes, seconds and date only) analog Eco-Drive movements technically evolved to more complex analog and digital/analog Eco-Drive movements featuring complications that Citizen applied in various specialized Promaster Eco-Drive watches like chronographs, flyback chronographs and diving watches.
In the early 2000s the sale of wristwatches declined due to the ubiquity of items like cell phones with built in clocks. Demand for Citizen watches in North America, however, remained robust as the Eco-Drive models were particularly well received and were generating ⅓ of Citizens North American revenues by 2000. During the mid-2000s wristwatch sales improved for Citizen thanks to further developing the Eco-Drive line and integrating radio-controlled timing in 2002 into the Eco-Drive line.
Since 2009 Citizen also develops Eco-Drive Concept Models as technology demonstration and marketing projects. These Eco-Drive Concept Models are generally shown at exhibitions and produced in limited editions. The Concept Model 2011 was the Eco-Drive SATELLITE WAVE that has a movement that can receive time synchronization signals from GPS satellites. This makes radio-controlled timing possible in remote areas that are not serviced by land based radio time signal stations. In 2012 Citizen announced the Eco-Drive RING Concept Model. This watch features a ring-shaped solar cell surrounding the watch case sidewall.
According to Citizen in 2011 80% of their wristwatches were equipped with Eco-Drive and the company sees Eco-Drive type watches as the heart of new generations of watches.
In 2012 Citizen offered over 320 Eco-Drive watch models in various types, styles and price ranges.
Most Eco-Drive type watches are equipped with a special titanium lithium ion secondary battery that is charged by an amorphous silicon solar cell located behind the dial. Light passes through the covering crystal and dial before it reaches the solar cell.
Depending on the electronic movement model, a fully charged secondary power cell could run with no further charging anywhere from 30 days to 3,175 days (8.7 years), though most Eco-Drive men's watch models offer a six-month power reserve. If kept in the dark for too long, some Eco-Drive movement models engage a hibernate mode, where the hands of the watch stop running but the internal quartz movement still keeps track of time. If an ample supply of light is given, the hands move to the proper positions and resume regular timekeeping.
Citizen Eco-Drive Thermo watches were introduced in 1999 and use the temperature difference between the wearer's arm and the surrounding environment as a power source. The rare Eco-Drive Thermo watches use the Seebeck effect to generate thermo electricity that powers the electronic movement and charges the secondary power cell. In the sun or in the tropics the ambient temperature can come close to or exceed the temperature of the wearer's wrist causing the watch to stop generating thermo electricity. In case no power is generated, an Eco-Drive Thermo movement will save power by moving the second hand in ten second increments until the production of thermo electricity is resumed. Citizen has stopped making Eco-Drive Thermo watches.
Citizen also built an automatic quartz powered watch, the Citizen Promaster Eco-Duo Drive (released in December 1998). Novel to this watch was the use of both mechanical power as well as a solar cell to power the electronic movement and charge the secondary power cell. This model was an attempt to enter higher-priced markets (at a cost of around $1,000 USD). The Eco-Duo Drive technology failed to attract consumer interest and Citizen has since stopped making use of the unique movement.
According to Citizen, experimental data showed the solar cell and secondary battery will last for more than 10 years. According to Citizen Europe, laboratory tests showed that after 20 years the secondary battery retains a power storage capacity of 80% of its initial capacity.
For water resistant and diving Eco-Drive watches Citizen recommends a watch gasket exchange every 2 or 3 years to preserve their water resistance because watch gaskets which form a watertight seal degrade as they age. Further Citizen recommends maintenance for Eco-Drive watch movements in regular intervals in order to extend the life of the watch movement, since the gears used in running watch movements are subject to slow wear. Citizen states that their lubricants for Long-Lasting Precision Equipment when used in watches, timepiece movements remain smooth for a long time as the oil does not harden even after 20 years.
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A DVD recorder (also known as a DVDR, mainly outside of the UK and Ireland), is an optical disc recorder that uses Optical disc recording technologies to digitally record analog signal or digital signals onto blank writable DVD media. Such devices are available as either installable drives for computers or as standalone components for use in television studios or home theater systems.
As of March 1, 2007 all new tuner-equipped television devices manufactured or imported in the United States must include ATSC tuner. The US Federal Communications Commission (FCC) has interpreted this rule broadly so as to include apparatus such as computer with TV tuner cards with video capture ability, videocassette recorders and standalone DVD recorders. NTSC DVD recorders are therefore undergoing a transformation, either adding a digital ATSC tuner or removing over-the-air broadcast television tuner capability entirely. However these DVD recorders can still record analog audio and analog video.
Originally, DVD recorders supported one of three standards: DVD-RAM, DVD-RW (using DVD-VR), and DVD+RW (using DVD+VR), none of which are directly compatible. As a general rule, however, most current DVD drives support both the + and - standards, while few support the DVD-RAM standard, which is not directly compatible with standard DVD drives.
Recording speed is generally denoted in values of X (similar to CD-ROM usage), where 1X in DVD usage is equal to 1.321 MB/s, roughly equivalent to a 9X CD-ROM. In practice, this is largely confined to computer-based DVD recorders, since standalone units generally record in real time, that is, 1X speed.
Recorders use a laser (usually 650 nm red) to read and write DVDs. The reading laser is usually not stronger than 5 mW, while the writing laser is considerably more powerful. The faster the writing speed is rated, the stronger the laser is. DVD burner lasers often peak at about 100-400 mW in continuous wave (some are pulsed). Some laser hobbyists have discovered ways to extract the laser diode from DVD burners and modify them to create laser apparatus that can cause burning.
DVD recorder drives have become standard equipment in many, though not all, computer systems currently on the market, after being initially popularized by the Pioneer/Apple SuperDrive; aftermarket drives as of early 2007 can cost as little as $23. DVD recorder drives can be used in conjunction with DVD authoring software to create DVDs near or equal to commercial quality, and are also widely used for data backup and exchange. As a general rule, computer-based DVD recorders can also handle CD-R and CD-RW media; in fact, a number of standalone DVD recorders actually use drives designed for computers.
Most internal drives are designed with parallel ATA interfaces, with serial ATA becoming more readily available. External drives almost always use USB 2.0 or IEEE 1394, with eSATA becoming an option as well.
DVD recorder drives manufactured since January 2000 are required by the DVD consortium to respect DVD region codes when reading a disc, but are incapable of assigning region codes when writing a disc (as this is stored on a part of the disc to which regular PC based and stand alone video recorders do not have write access.
DVD duplication systems are generally built out of stacks of these drives, connected through a computer-based backplane.
When the standalone DVD recorder first appeared on the Japanese consumer market in 1999, these early units were very expensive, costing between $2500 and $4000 USD. However, as of early 2007, DVD recorders from notable brands are selling for US$200 or €150 and less, with even lower "street prices". Early units supported only DVD-RAM and DVD-R discs, but the more recent units can record to all major formats DVD-R, DVD-RW, DVD+R, DVD+RW, DVD-R DL and DVD+R DL. Some models now include mechanical hard disk drive-based digital video recorders (DVRs) to improve ease of use. Standalone DVD recorders generally have basic DVD authoring software built in; however, the appearance of the finished DVD is very basic and usually completely under the control of the unit.
Some believed that DVD recorders would supersede the VCR as the standard television-recording device; however as technology progresses, in 2009 Panasonic introduced the world's first Blu-ray Disc recorder which is capable of recording both DVDs and Blu-ray discs and features built in satellite HDTV tuners. A year later, Panasonic introduced further more Blu-ray disc recorders with terrestrial HDTV tuners.
DVD recorders have several technical advantages over VCRs, including:
Note: in addition Blu-ray disc recorders can record full high definition videos on BD-Rs and BD-REs.
It does have some disadvantages:][
However, an inconvenience exists in which DVDs recorded with DVD recorders must be finalized to view in other DVD players. (This disadvantage does not apply to DVD-RAM or DVD+RW discs, which require no finalization due to their 'random access' nature.) Also, the implementation of MPEG-2 compression used on most standalone DVD recorders is required to compress the picture data in real time, producing results that may not be up to the standard of professionally rendered DVD video, which can take days to compress.
The United States converted its over-the-air television broadcasts to digital "ATSC" in June 2009. However this will have very limited impact in ending the need for DVD recorders to perform realtime MPEG-2 encoding or transcoding. The only setup where ATSC could conceivably eliminate MPEG-2 encoding/transcoding in a DVD recorder would be where an antenna is hooked directly into a DVD recorder that has an integrated ATSC tuner. Even then however, the DVD recorder will have to transcode the ATSC MPEG-2 into DVD-Video-compliant MPEG-2 if the ATSC MPEG-2 stream isn't already DVD-Video-compatible. This would require transcoding for all high-definition broadcasts and some if not all standard-definition broadcasts. The same general situation applies to digital cable service; only DVD recorders with integrated digital cable ("QAM") tuners can possibly avoid transcoding, and then only if the digital cable system is already sending a DVD-Video-compatible MPEG-2 stream, which again requires transcoding of all HD content and some if not all SD content. All other setups (digital cable box's analog outputs to DVD recorder, satellite box's analog outputs to DVD recorder, DVD recorder tuning and recording analog cable channels which are still permitted after 2/2009, etc.) usually always involve an analog step with MPEG-2 encoding being necessary inside the DVD recorder.
A number of manufacturers have combined DVD recorders with mechanical hard disk drive-based digital video recorders, allowing for recording to large fixed disks, and the ability to view these recordings off the hard disk at a later date.
In Japan, AVCREC recorders, which are able to record MPEG-2 or AVC high definition video from ISDB broadcast with or without re-encoding, get increasingly popular. Initially, AVCREC recorders use DVD recordable discs, but newer models are able to record onto Blu-ray discs as well onto hard disk drives.
As a result of the North American digital switchover, tuner-equipped devices manufactured or imported into the United States are now required by the US Federal Communications Commission to include digital tuners.
This has caused most new VHS recorders to be implemented as DVD/VCR combo units, or to be manufactured without tuners. The US requirement of ATSC compatibility forces inclusion of MPEG-2 decoding hardware, which is already part of all DVD players but which otherwise would not have been needed in an analog-only VCR.
An ATSC-capable DVD unit can also serve as a more-powerful alternative to digital television adapters, which allow DTV reception with older NTSC analog televisions. The DVD recorders offer additional capabilities, such as automated VCR-style timeshifting of programming and a variety of output formats, that are deliberately not included in the most common mass-market US ATSC converters.
Unlike the more common digital television adapter boxes, newer DVD recorder units are able to tune both analog and digital signals - an advantage when receiving low-power television and foreign (analogue) signals. Some, however, do suffer from many of the same design limitations as the less costly converter boxes, including poorly designed signal strength meters, incomplete display of broadcast program information, incompatibility with antenna rotators or CEA-909 smart antennas and inability to add digital channels without wiping out all existing channels and rescanning the entire band.
A DVD recording of an over-the-air HDTV broadcast is at DVD resolution, which is inferior to the original broadcast with 720p or 1080i resolution. Some units also provide limited USB or flash memory interface capability, often only supporting viewing of digital camera still photos or playback of MP3s with no ability to write video to these media.
A small number of DVD recorders are also capable of recording to SVCD, VCD and even Audio CD formats. Recording to DVDs can be done at different speeds giving between 1 and 6 hours (even up to 8 hours on certain models) on a standard (single sided 12 cm) blank DVD. With some trade off between recording time and video quality.
8 cm miniDVDs are widely used on some digital camcorders, primarily those meant for a consumer market ("point and shoot"); such discs are usually playable on a full-sized DVD player, but may not record on a full-sized DVD recorder system. Though popular for their convenience (in the manner of VHS-C), DVD camcorders are not considered suitable for more than casual use due to the much higher level of compression used compared to MiniDV and the difficulty of editing MPEG-2 video.
Download To Own is a concept of legally downloading movies to your computer via a network such as the internet. Generally to obtain movies this way a user must have a broadband connection and an account from an internet distribution company. Download to Own movies are more convenient to watch, as opposed to having to find and insert a DVD into your computer because once it is saved on the hard drive it can be viewed instantly. Movies are saved on the hard drive, typically in AVI format, and are compressed using MPEG-4 or DivX compression formats. Disadvantages to "Download to Own" movies are that they have generally large file sizes, usually from 600MB to over 1GB. They may take a long time to download, and will fill up a hard drive quickly. The movie may be accidentally deleted or lost through a hard drive crash, but with proper back up procedures, and the continuing drop in prices for larger hard drives becoming commonplace, these problems can be minimized. Another disadvantage is that due to compression and other factors they rarely have the same image-quality as a regular DVD, much less than that of a high-definition format, and also often lack multi-channel audio. They may also be distributed in a DRM-protected format (such as through iTunes), which makes it difficult to play them on other portable devices, or to burn to a DVD to play on a television.
A drive-in theater is a form of cinema structure consisting of a large outdoor movie screen, a projection booth, a concession stand and a large parking area for automobiles. Within this enclosed area, customers can view movies from the privacy and comfort of their cars.
The screen can be as simple as a wall that is painted white, or it can be a steel truss structure with a complex finish. Originally, a movie's sound was provided by speakers on the screen and later by an individual speaker hung from the window of each car, which would be attached by a wire. This system was superseded by the more economical and less damage-prone method of broadcasting the soundtrack at a low output power on AM or FM radio to be picked up by a car radio. This method also allows the soundtrack to be picked up in stereo by the audience on an often high fidelity stereo installed in the car instead of through a simple speaker.
The drive-in theater was the creation of Camden, New Jersey, chemical company magnate Richard M. Hollingshead, Jr., whose family owned and operated the R.M. Hollingshead Corporation chemical plant in Camden. In 1932, Hollingshead conducted outdoor theater tests in his driveway at 212 Thomas Avenue in Riverton. After nailing a screen to trees in his backyard, he set a 1928 Kodak projector on the hood of his car and put a radio behind the screen, testing different sound levels with his car windows down and up. Blocks under vehicles in the driveway enabled him to determine the size and spacing of ramps so all automobiles could have a clear view of the screen. Following these experiments, he applied August 6, 1932, for a patent of his invention, and he was given on May 16, 1933.
Hollingshead's drive-in opened in New Jersey June 6, 1933, on Admiral Wilson Boulevard at the Airport Circle in Pennsauken, a short distance from Cooper River Park. It offered 400 slots and a 40 by 50 ft (12 by 15 m) screen. He advertised his drive-in theater with the slogan, "The whole family is welcome, regardless of how noisy the children are." The first film shown was the Adolphe Menjou film Wife Beware. The facility only operated three years, but during that time the concept caught on in other states. The April 15, 1934, opening of Shankweiler's Auto Park in Orefield, Pennsylvania, was followed by Galveston's Drive-In Short Reel Theater (July 5, 1934), the Pico Drive-In Theater at Pico and Westwood boulevards in Los Angeles (September 9, 1934) and the Weymouth Drive-In Theatre in Weymouth, Massachusetts (May 6, 1936). In 1937, three more opened in Ohio, Massachusetts and Rhode Island, with another 12 during 1938 and 1939 in California, Florida, Maine, Maryland, Massachusetts, Michigan, New York, Texas and Virginia. Early drive-in theaters had to deal with noise pollution issues. The original Hollingshead drive-in had speakers installed on the tower itself which caused a sound delay affecting patrons at the rear of the drive-in's field. In 1935, the Pico Drive-in Theater attempted to solve this problem by having a row of speakers in front of the cars. In 1941, RCA introduced in-car speakers with individual volume controls which solved the noise pollution issue and provided satisfactory sound to drive-in patrons.
The drive-in's peak popularity came in the late 1950s and early 1960s, particularly in rural areas, with some 4,000 drive-ins spread across the United States. Among its advantages was the fact that a family with a baby could take care of their child while watching a movie, while teenagers with access to autos found drive-ins ideal for dates. Revenue is more limited than regular theaters since showings can only begin at twilight. There were abortive attempts to create suitable conditions for daylight viewing such as large tent structures, but nothing viable was developed.
In the 1950s, the greater privacy afforded to patrons gave drive-ins a reputation as immoral, and they were labeled "passion pits" in the media. During the 1970s, some drive-ins changed from family fare to exploitation films, as a way to offset declining patronage and revenue. Also, during the 1970s, some drive-ins began to show pornographic movies in less family-centered time slots to bring in extra income.][ This allowed censored materials to be viewed by a wide audience, some for whom viewing was illegal, and it was reliant upon the whims of local ordinances controlling such material. It also required a relatively remote location distant from populated areas such as towns and cities.
During their height, some drive-ins used attention-grabbing gimmicks to boost attendance. They ranged from small airplane runways, unusual attractions such as a small petting zoo or cage of monkeys, personal appearances by actors to open their movies, or musical groups to play before the show. Some drive-ins held Sunday religious services, or charged a flat price per car on slow nights like Wednesdays. On "buck" nights during the 1950s and 1960s, the admission price was one dollar per car.
One of the largest drive-in theaters was in Copiague, Long Island, New York. Covering over 29 acres, it could park 2,500 vehicles. It had a full-service restaurant with seating on the roof, and a trolley system to take children and adults to a playground and a large indoor theater for bad weather or for those who wanted to watch in air-conditioned comfort.
Over time, the economics of real estate made the large property areas increasingly expensive for drive-ins to operate successfully. Land became far too valuable for businesses such as drive-ins, which in most cases were summer-only. Widespread adoption of daylight saving time subtracted an hour from outdoor evening viewing time. These changes and the advent of color televisions, VCRs and video rentals led to a sharp decline in the drive-in popularity. Drive-ins were subject to the whim of nature as inclement weather often caused cancellations. They eventually lapsed into a quasi-novelty status with the remaining handful catering to a generally nostalgic audience, though many drive-ins continue to successfully operate in some areas.
By 2013, drive-ins comprised only 1.5 percent of movie screens in the United States. At the industry's height, 25 percent of the nation's movie screens had been in a drive-in.
Many drive-in movie sites remain, repurposed as storage or flea markets sites, often after residential housing or other higher value uses came to the lightly populated or unpopulated areas where the drive-ins were located. The largest drive-in theater in the world, the Fort Lauderdale Swap Shop, doubles as the world's largest daily flea market. Former drive-in properties in Michigan, for example, have become industrial parks, shopping centers, indoor theaters, and even churches (as with the Former Woodland Drive-In in Grand Rapids, MI). In Philadelphia, the South City Drive In became the location of the original Spectrum in the late 1960s, with a small portion of its old property line extending into what would become the (now demolished) Veterans Stadium complex. Another example of a drive in-turned-flea market is Spotlight 88 in North Sewickley Township, Beaver County, Pennsylvania, which ended business as a drive-in after an F3 tornado destroyed much of the property on May 31, 1985. As a joke after the tornado hit, the owners put up in the "now-showing" sign Gone with the Wind. It was most likely copied from a Taylor, Michigan Drive in called Ecorse Drive-In. On July 16, 1980, a freak derecho storm with 150 mph straight line winds swept the Drive-In away leaving only the "now-showing" sign with the letters "Now Playing Gone with the Wind". They rebuilt the screen and it never recovered, by 1989 it was sold and now is a Kroger Grocery store.
The ongoing conversion of the film distribution network to be exclusively digital distribution is also putting additional pressure on drive-in theaters. Most small drive-ins lack the finances (beginning at $70,000 per screen) needed to convert to digital projection. The lack of multiple screens with many daily showings means the low volume of ticket sales will make it hard for many drive-ins to justify the cost of installing digital projection.
Conversion of the projection booth to digital is more complex for drive-in theaters. The projector needs a more powerful bulb since the booth is usually the length of a football field away from the screen. In addition, digital projection equipment requires an Internet connection, and the booth must be retrofitted with special glass, more vents and stronger air conditioning.
The year 2001 marked the inception of the "Do-It-Yourself" Drive-In, which utilized contemporary tools such as LCD projectors and micro-radio transmitters. The first was the Liberation Drive-In in Oakland, California, which sought to reclaim under-utilized urban spaces such as vacant parking lots in the downtown area. The following years have seen the rise of the "guerrilla drive-in" movement, in which groups of dedicated individuals orchestrate similar outdoor film and video screenings. Showings are often organized online, and participants meet at specified locations to watch films projected on bridge pillars or warehouses. The content featured at these screenings has frequently been independent or experimental films, cult movies, or otherwise alternative programming. The best known guerilla drive-ins include the Santa Cruz Guerilla Drive-In in Santa Cruz, California, North Bay Mobile Drive-In in Novato, California, MobMov in San Francisco, California and Hollywood, and most recently Guerilla Drive-In Victoria in Victoria, British Columbia.
Faced with the closure of Hull's Drive In in Lexington, Virginia in 1999, the non-profit group Hull's Angels formed to raise funds, buy the property and operate the theater as a non-profit venture specializing in family-friendly films. Hull's continues to be the nation's only non-profit drive in.
As of 2012[update], a figure of 368 drive-ins has been published for the United States, though it is unclear how many of these are traditional versus non-traditional (e.g. guerilla).
Mobile Movie (aka "MobMov") is a worldwide network of guerrilla drive-ins using car-powered video projectors and FM transmitters. The MobMov represents over 150 independent guerrilla drive-ins, from United States to France, India, and Australia.
Shows are free and are announced via mailing list and SMS. Patrons drive to the listed location, tune their radios, and watch a movie drive-in style. The coordinator uses a car or small generator to power the projector and FM transmitter.
The MobMov was started by Bryan Kennedy in May, 2005. Kennedy's San Francisco-area MobMov has been defunct since late 2009 but other variations on the concept exist in the San Francisco Bay Area, and throughout the United States.
Information science (or information studies) is an interdisciplinary field primarily concerned with the analysis, collection, classification, manipulation, storage, retrieval, movement, and dissemination of information. Practitioners within the field study the application and usage of knowledge in organizations, along with the interaction between people, organizations and any existing information systems, with the aim of creating, replacing, improving, or understanding information systems. Information science is often (mistakenly) considered a branch of computer science. However, it is actually a broad, interdisciplinary field, incorporating not only aspects of computer science, but often diverse fields such as archival science, cognitive science, commerce, communications, law, library science, museology, management, mathematics, philosophy, public policy, and the social sciences.
Information science should not be confused with information theory or library science. Information theory is the study of a particular mathematical concept of information, while library science is a field related to libraries which uses some of the principles of information science.
car DVD player
In journalism, a human interest story is a feature story that discusses a person or people in an emotional way. It presents people and their problems, concerns, or achievements in a way that brings about interest, sympathy or motivation in the reader or viewer.
Human interest stories may be "the story behind the story" about an event, organization, or otherwise faceless historical happening, such as about the life of an individual soldier during wartime, an interview with a survivor of a natural disaster, a random act of kindness or profile of someone known for a career achievement.