How much did the first microwave oven cost?
Microwave oven
Japan's Sharp Corporation began manufacturing microwave ovens in 1961. Between 1964 and 1966, Sharp introduced the first microwave oven with a turntable, a feature that promotes convenient even heating of food. In 1965, Raytheon acquired Amana. In 1967, they introduced the first popular home model, the countertop Radarange, at a price of US$495 ($ in dollars).
Pot-in-pot refrigerator
Abba, who hails from a family of potmakers, tapped into the large unemployed local workforce and hired skilled pot makers to mass-produce the first batch of 5,000 Pot-in-Pots. He received the Rolex Award for Enterprise in 2001 and used his $75,000 award to make the invention available throughout Nigeria. Abba devised an educational campaign tailored to village life and the illiterate population featuring a video-recorded play by local actors to dramatise the benefits of the desert refrigerator. The pots sell at 40 US cents a pair.
Mobile television
Early mobile television receivers were based on the old analog television signal system. They were the earliest televisions that could be placed in a coat pocket. The first was the Panasonic IC TV MODEL TR-001, introduced in 1970. The second was sold to the public by Clive Sinclair in January 1977. It was called the Microvision or the MTV-1. It had a two-inch (50 mm) CRT screen and was also the first television which could pick up signals in multiple countries. It measured 102×159×41 mm and was sold for less than £100 in the UK and for around $400 in the United States. The project took over ten years to develop and was funded by around £1.6 million in British government grants.
Microwave burn
In 1983, a 35-year-old male was heating a sandwich in a microwave oven at work. After opening the door, the magnetron did not shut off and his right hand was exposed to microwave radiation as he retrieved the sandwich. After exposure, his hand was pale and cold; 30 minutes later the man presented himself to a doctor, with paresthesia in all fingers and the hand still pale and cold. An Allen's test showed a return to normal color after 60 seconds (normal is 5 seconds). By 60 minutes after exposure the hand was normal again, and the patient was discharged without treatment. A week later there was no paresthesia, motor weakness nor sensory deficit.
WTTV
In its early years, instead of buying most of the expensive items needed to run a television station, Tarzian had his own engineers and technicians design and build the items needed. For example, an overhead microphone boom cost approximately $300. Tarzian employees built one for less than $30. When Tarzian decided to start broadcasting network programs, establishing a coaxial cable link from Cincinnati would prove impractical, so Tarzian built his own microwave relay system from Cincinnati to Bloomington.
Grabit (cookware)
Grab-Its are microwave-safe cookware easily identifiable by their tab handle. They were introduced by Corning Glass Works in 1977, under the Corning Ware brand and are now sold in a slightly different form by Corelle Brands. Grab-Its are notable as being among the first cookware specifically designed for microwave use - their design was recognized by the Smithsonian's Cooper-Hewitt, National Design Museum. Grab-Its strongly resemble porringers.
Neff GmbH
In 1957, it introduced the first microwave oven. In 1957, it introduced the first induction cooker (hob) in Europe, marketing it under the revolutionary slogan of "Kochen auf der kalten Platte" (cook on a cold surface). In 1961 it introduced the first integrated cooker units in Europe, built into other kitchen units - the built-in oven. Also in the same year they began selling larger microwave cookers for commercial (catering) uses. By 1970 it was branching out into providing for the full range of units to make up a fitted kitchen. By the early 1970s the cookers were among the first to be controlled with a digital clock.
Microwave oven
Uneven heating in microwaved food can be partly due to the uneven distribution of microwave energy inside the oven, and partly due to the different rates of energy absorption in different parts of the food. The first problem is reduced by a stirrer, a type of fan that reflects microwave energy to different parts of the oven as it rotates, or by a turntable or carousel that turns the food; turntables, however, may still leave spots, such as the center of the oven, which receive uneven energy distribution. The location of dead spots and hot spots in a microwave can be mapped out by placing a damp piece of thermal paper in the oven. When the water saturated paper is subjected to the microwave radiation it becomes hot enough to cause the dye to be released which will provide a visual representation of the microwaves. If multiple layers of paper are constructed in the oven with a sufficient distance between them a three-dimensional map can be created. Many store receipts are printed on thermal paper which allows this to be easily done at home.
Microwave oven
Any metal or conductive object placed into the microwave will act as an antenna to some degree, resulting in an electric current. This causes the object to act as a heating element. This effect varies with the object's shape and composition, and is sometimes utilized for cooking.
Microwave
Microwaves were first generated in the 1880s and 1890s in some of the earliest radio experiments by physicists who thought of them as a form of "invisible light". James Clerk Maxwell in his 1873 theory of electromagnetism, now called Maxwell's equations, had predicted the existence of electromagnetic waves and proposed that light was composed of these waves. In 1888, German physicist Heinrich Hertz was the first to demonstrate the existence of radio waves using a primitive spark gap radio transmitter. Hertz and the other early radio researchers were interested in exploring the similarities between radio waves and light waves, to test Maxwell's theory. They concentrated on producing short wavelength radio waves in the UHF and microwave ranges, with which they could duplicate classic optics experiments, using quasioptical components such as prisms and lenses made of paraffin, sulfur and pitch and wire diffraction gratings, to refract and diffract radio waves like light rays. Hertz produced waves up to 450 MHz; his directional 450 MHz transmitter consisted of a 26 cm brass rod dipole antenna with a spark gap between the ends suspended at the focal line of a parabolic antenna made of a curved zinc sheet, powered by high voltage pulses from an induction coil. His historic experiments demonstrated that radio waves like light exhibited refraction, diffraction, polarization, interference and standing waves, proving that radio waves and light waves were both forms of Maxwell's electromagnetic waves.
Speed of light
A household demonstration of this technique is possible, using a microwave oven and food such as marshmallows or margarine: if the turntable is removed so that the food does not move, it will cook the fastest at the antinodes (the points at which the wave amplitude is the greatest), where it will begin to melt. The distance between two such spots is half the wavelength of the microwaves; by measuring this distance and multiplying the wavelength by the microwave frequency (usually displayed on the back of the oven, typically 2450 MHz), the value of "c" can be calculated, "often with less than 5% error".
Microwave oven
Microwaves generated in microwave ovens cease to exist once the electrical power is turned off. They do not remain in the food when the power is turned off, any more than light from an electric lamp remains in the walls and furnishings of a room when the lamp is turned off. They do not make the food or the oven radioactive. Compared to conventional cooking, the nutritional content of some foods may be altered differently, but generally in a positive way by preserving more micronutrients - see above. There is no indication of detrimental health issues associated with microwaved food.
Induction cooking
Modern implementation in the USA dates from the early 1970s, with work done at the Research & Development Center of Westinghouse Electric Corporation at Churchill Borough, near Pittsburgh, That work was first put on public display at the 1971 National Association of Home Builders convention in Houston, Texas, as part of the Westinghouse Consumer Products Division display. The stand-alone single-burner range was named the Cool Top Induction Range. It used paralleled Delco Electronics transistors developed for automotive electronic ignition systems to drive the 25 kHz current.
Westinghouse decided to make a few hundred production units to develop the market. Those were named Cool Top 2 (CT2) Induction ranges. The development work was done at the same R&D location by a team led by Bill Moreland and Terry Malarkey. The ranges were priced at $1,500 ($8,260 in 2017 dollars), including a set of high quality cookware made of Quadraply, a new laminate of stainless steel, carbon steel, aluminum and another layer of stainless steel (outside to inside).
Big Boy Restaurants
The novel hamburger started as a joke. In February 1937, members of an area big band, who were regular customers, visited Bob's Pantry, one asking, "How about something different, something "special"?" [emphasis added]. Bob Wian improvised, creating the first (then unnamed) Big Boy, intending the thing "look ridiculous, like a leaning tower". Demand for "the special" soared but Wian sought a "snappy" name, which became Big Boy. In 1938, the Big Boy hamburger cost 15¢ ($2.65 in 2018). The Big Boy costs $6.49 in Michigan, in 2018.
Wesley A. Clark
Each Linc had a tiny screen and keyboard and comprised four metal modules, which together were about as big as two television sets, set side by side and tilted back slightly. The machine, a 12-bit computer, included a one-half megahertz processor. Lincs sold for about $43,000—a bargain at the time—and were ultimately made commercially by Digital Equipment, the first minicomputer company. Fifty Lincs of the original design were built.
MicroConsignment
The MCM first emerged in 2003 when Greg donated money to a wood-burning stove project from the profits of tourism businesses he created in the town of Nebaj, where he was working during the Peace Corps. This donation supplied a handful of stoves to an equal number of families in a local village. Like millions of Guatemalans, these families had always cooked campfire-style on their dirt floors, which had long been recognized as extremely energy inefficient and harmful to the health of family members, particularly women and children. Relief agencies had determined that the construction of inexpensive, locally manufactured, concrete stoves could immediately and dramatically reduce energy costs and improve the health and safety of family members.
Greg realized, however, that merely donating stoves severely limited the capacity for distribution. Once the relief money was expended, nobody else could get a stove. Greg concluded that many more people could obtain these stoves if their distribution was built on a sustainable economy. As a response to this challenge, Greg developed what would become the MCM. Stoves would be locally manufactured, materials provided to local entrepreneurs on consignment and marketed and sold to low income families in villages on an interest-free basis. The money saved in energy costs allowed the stoves to essentially pay for themselves as families made payments over six months. The health, economic and environmental benefits would go on for years. This model would not only provide an essential, high-quality product at an affordable cost to villagers but would provide new income generating opportunities to local individuals as entrepreneurs. Soon after this initial iteration of the model was launched, George joined Greg to further develop and expand this initiative.
Raytheon
Raytheon's research on the magnetron tube revealed the potential of microwaves to cook food. In 1945, Raytheon's Percy Spencer invented the microwave oven by discovering that the magnetron could rapidly heat food. In 1947, the company demonstrated the Radarange microwave oven for commercial use.
Microwave oven
Direct microwave exposure is not generally possible, as microwaves emitted by the source in a microwave oven are confined in the oven by the material out of which the oven is constructed. Furthermore, ovens are equipped with redundant safety interlocks, which remove power from the magnetron if the door is opened. This safety mechanism is required by United States federal regulations. Tests have shown confinement of the microwaves in commercially available ovens to be so nearly universal as to make routine testing unnecessary. According to the United States Food and Drug Administration's Center for Devices and Radiological Health, a U.S. Federal Standard limits the amount of microwaves that can leak from an oven throughout its lifetime to 5 milliwatts of microwave radiation per square centimeter at approximately (2 in) from the surface of the oven. This is far below the exposure level currently considered to be harmful to human health.
Caloric
The Janesville Caloric Company factory existed from 1908 to 1924. It manufactured the Caloric Cooker, a “fireless cook stove” and precursor to modern day slow cookers. The company operated out of an old furniture factory. The Caloric Cooker consisted of an insulated cabinet with one or more deep wells fitted with soapstones on the top and on the bottom. After the stones were heated and the food was put into the wells; one stone was placed at the top and the bottom of the stove. You could close the lid and the meal would be cooked without danger of its burning. About 150 men were employed by this company when it was in full production. The cookers sold for $8.50 – $15, depending on the number of wells, and came with a 160-page book on how to use it. The company moved operations to Pennsylvania in 1924. In the 1960s, the Caloric Company launched the iconic ad slogan “Now you’re cooking with gas.”
Microwave oven
A variant of the conventional microwave is the convection microwave. A convection microwave oven is a combination of a standard microwave and a convection oven. It allows food to be cooked quickly, yet come out browned or crisped, as from a convection oven. Convection microwaves are more expensive than conventional microwave ovens. Some convection microwaves—those with exposed heating elements—can produce smoke and burning odors as food spatter from earlier microwave-only use is burned off the heating elements.
Crowbar (circuit)
Microwave ovens often use a microswitch that acts as a crowbar circuit in the door latch assembly. This will absolutely prevent the magnetron from being energized with the door open. Activation will blow the main fuse and ruin the microswitch.
Mills Novelty Company
In November 1955, Mills Industries, Inc. announced a coin-operated vending machine, developed jointly with H. J. Heinz Company, that would dispense a tin can of hot food (one of a selection of six soups or dinners), a can opener, and a spoon. The cans were maintained a constant temperature of 150 degrees Fahrenheit (65 °C). The machine was intended for use in factories or large offices, and the company claimed that it was a first of a kind in the United States.
Thermador
In 2001, Julia Child's kitchen was inducted into the Smithsonian Institution, National Museum of American History at the Kenneth E. Behring Center featuring a Thermador oven. Thermador produced the first domestic Jet Impingement Oven in 2002. This technology improved Speedcooking by using 60 MPH variable directed jets of air along with microwave radiation to reduce cooking time by 75 percent. In 2006, Thermador announced the Freedom Collection refrigerators, a new modular concept of built-in food, freezer and wine preservation column refrigerators. 2006 also marks the first introduction of the convection warming drawer. In 2008 and 2009, Thermador added Sensor Dome technology to its electric and induction cooktops. Sensor Dome uses infrared light to automatically measure the temperature of the cookware, and uses the information to adjust cooking temperature and time. In 2009, Thermador unveiled the Sapphire Dishwasher that offers the largest wine glass capacity on the market. 2010 saw the launch of the award-winning Freedom Induction Cooktop
Electrical engineering
In 1920, Albert Hull developed the magnetron which would eventually lead to the development of the microwave oven in 1946 by Percy Spencer. In 1934, the British military began to make strides toward radar (which also uses the magnetron) under the direction of Dr Wimperis, culminating in the operation of the first radar station at Bawdsey in August 1936.
Waltham, Massachusetts
Another first in Waltham industrial history involves the method to mass-produce the magnetron tube, invented by Percy Spencer at Raytheon. During World War II, the magnetron tube technology was applied to radar. Later, magnetron tubes were used as components in microwave ovens.
White Sewing Machine
The White Sewing Machine was the first sewing machine from the White Sewing Machine Company. It used a vibrating shuttle bobbin driver design; for that reason, and to differentiate it from the later White models that used a rotary hook design instead, it came to be known as the "White Vibrating Shuttle" or "White VS". In 1879 it cost USD50 to USD125 (USD1097 to USD2744 adjusted) depending on which table or cabinet it was to be mounted in.
Microwave oven
Microwave ovens are frequently used for reheating leftover food, and bacterial contamination may not be repressed if the safe temperature is not reached, resulting in foodborne illness, as with all inadequate reheating methods. While microwaves can destroy bacteria as well as conventional ovens, they do not cook as evenly, leading to an increased risk that parts of the food will not reach recommended temperatures.
George Devol
Devol was part of the team that developed the first commercial use of microwave oven technology, the Speedy Weeny, which automatically cooked and dispensed hotdogs in places such as Grand Central Terminal.
Alexis Belonio
Belonio's first ovens cost $100 (or around ₱5,000) each, but due to further development and research, he was able to lower the price to $25 (or around ₱1,250) each. The only expected expense for the user of the oven would be 20 cents per day for running the built-in fan inside the stove. The invention is currently being produced by companies in the Philippines, Indonesia, and Cambodia, all cooperating with Belonio's works. According to Belonio his stove would be able to save a family of rice farmers $150 per year in fuel expenses. He also added that a ton of rice husk contains energy equal to 415 liters of petroleum (or 378 liters of kerosene). Belonio's stove lessens toxic fumes and smoke that affect the environment, and reduces greenhouse gases. The burnt remnants of the rice husks can later be used as soil fertilizers or in making small blocks of coal substitute.
Slow cooker
The Naxon Utilities Corporation of Chicago, under the leadership of Irving Naxon, developed the Naxon Beanery All-Purpose Cooker for the purposes of cooking a bean meal. Naxon was inspired by a story his grandmother told about how back in her native Lithuanian town, her mother made a stew called cholent, which took several hours to cook in an oven. A 1950 advertisement shows a slow cooker called the "Simmer Crock" made by the Industrial Radiant Heat Corp. of Gladstone, NJ. The Rival Company from Sedalia, Missouri, bought Naxon in 1970, and consequentially acquired Naxon’s patent for the bean simmer cooker. Rival asked inventor Robert Glen Martin, from Boonville, Missouri, to develop Naxon’s bean cooker into a large scale production model which could cook an entire family meal, going further than just cooking a bean meal. Martin also designed and produced the mass-making machines for Rival’s manufacturing line of the Crock-Pot. The cooker was then reintroduced under the name "Crock-Pot" in 1971. Slow cookers achieved popularity in the US during the 1970s, when many women began to work outside the home. They could start dinner cooking in the morning before going to work and finish preparing the meal in the evening when they came home. In 1974, Rival introduced removable stoneware inserts, making the appliance easier to clean. The brand now belongs to Sunbeam Products, a subsidiary of Jarden Corporation. Other brands of this appliance include Cuisinart, GE, Hamilton Beach, KitchenAid, Magic Chef, West Bend Housewares, and the now defunct American Electric Corporation.
Microwave oven
All microwaves use a timer for the cooking time, at the end of cooking time, the oven switches itself off.
Timeline of United States inventions (1890–1945)
A microwave oven cooks or heats food by dielectric heating. Cooking food with microwaves was discovered by Percy Spencer on October 8, 1945, while building magnetrons for radar sets at Raytheon. Spencer was working on an active radar set when he noticed a strange sensation, and saw that a peanut candy bar he had in his pocket started to melt. Although he was not the first to notice this phenomenon, as the holder of 120 patents, Spencer was no stranger to discovery and experiment, and realized what was happening. The radar had melted his candy bar with microwaves. The first food to be deliberately cooked with microwaves was popcorn, and the second was an egg. In 1947, Raytheon under Percy Spencer demonstrated the world's first microwave oven built at the company which was called the "Radarange".
Robert V. Decareau
After earning his Ph.D in 1955, Decareau worked for Raytheon in Allston on microwave technology that would lead to the development of the microwave oven. Decareau's wife, Rosa, commented that a lot of work on the microwave oven was done at their home. Then at Lipton, he was involved in freeze drying. In the 1960s, Decareau moved to Palo Alto, California to work with Litton Industries. While at Litton, he developed microwave ovens that would be the foundation of commercial versions. Decareau moved back to Natick, Massachusetts later in his career to work in research and development at the United States Army Soldier Systems Center to develop food processing techniques for military and space exploration applications. His work would earn him Fellowship of the Institute of Food Technologists in 1994. During his career, Decareau was one of the first people to refer to himself as a food scientist.
Microwave oven
Formerly found only in large industrial applications, microwave ovens increasingly became a standard fixture of residential kitchens in developed countries. By 1986, roughly 25% of households in the U.S. owned a microwave oven, up from only about 1% in 1971; the U.S. Bureau of Labor Statistics reported that over 90% of American households owned a microwave oven in 1997. In Australia, a 2008 market research study found that 95% of kitchens contained a microwave oven and that 83% of them were used daily. In Canada, fewer than 5% of households had a microwave oven in 1979, but more than 88% of households owned one by 1998. In France, 40% of households owned a microwave oven in 1994, but that number had increased to 65% by 2004.
American cuisine
The development of the microwave oven resulted in the creation of industrial food products and packaging that is intended take advantage of the unique opportunities and overcome the unique challenges of that technology. Microwave popcorn is an example of such a product.
WSAZ-TV
In 1950, WSAZ-TV received Federal Communications Commission (FCC) permission to build a private microwave link to Cincinnati allowing viewers to get NBC programming live. As the nation's first privately owned microwave system, it was a remarkable feat for one of the smallest cities in the country at the time to have a television station. The first live broadcast was scheduled for a Labor Day baseball game, but the system broke down for four hours and forced WSAZ to broadcast a fire at a nearby hotel. The Cincinnati link was replaced in favor of one from Columbus, Ohio in 1952.
Popcorn maker
In the middle of the 1970s, Pillsbury made microwave popcorn for sale in vending machines (and later to wide distribution in supermarkets, as microwave oven sales increased), thus reducing the need for a separate appliance in some homes. To improve flavour, texture and shelf life of pre-packaged microwave popcorn, companies started adding diacetyl, PFOA, and trans-fats into the packages which has led to some concern among health conscious snackers.
Mihi Creek heritage site
The first battery of beehive ovens, the "Mihi Ovens" built c.1884 by John Wright and Brydon and Jones & Coy, then owners of the Mihi Mine, is located on Lot 5 on AP3320 immediately north and west of the Klondyke Coke Ovens. The ovens were recorded by Whitmore (1983) and re-located by DERM (2010). In 1987 Whitmore noted a programme of tipping and re-contouring in this area which threatened to engulf the ovens. This fill event has been verified by Department of Environment and Resource Management test excavations. The entrances of three ovens from this original bank of ovens are now partly exposed on the slope situated between the upper and middle terraced areas to the immediate west of the Klondyke Coke Ovens. The full extent and dimensions of the ovens remains unclear, though this battery has been described as consisting of 12 ovens. Their orientation is most likely similar to other beehive ovens on the Ipswich - West Moreton field, being either back-to-back or in a stagger pattern. The space between each oven would be filled with earth or rubble for insulation, and evidence of compacted orange clay was recorded in DERM during test excavations in the area. Evidence of a stone retaining wall surrounding the ovens has not been re-located, but sections may still survive.
History of Santa Clara County, California
In 1953, William Shockley left Bell Labs in a disagreement over the handling of the invention of the transistor. After returning to California Institute of Technology for a short while, in 1956 Shockley moved to Mountain View, California, and created Shockley Semiconductor Laboratory. Unlike many other researchers who used germanium as the semiconductor material, Shockley believed that silicon was the better material for making transistors. Shockley intended to replace the current transistor with a new three-element design (today known as the Shockley diode), but the design was considerably more difficult to build than the "simple" transistor. In 1957, Shockley decided to end research on the silicon transistor. As a result, the "traitorous eight" engineers left the company to form Fairchild Semiconductor. Two of the original employees of Fairchild Semiconductor, Robert Noyce and Gordon Moore, would go on to found Intel. In 1971, Intel created the first microprocessor, the Intel 4004. The next step in the Silicon Valley revolution occurred in March 1975, when the Homebrew Computer Club in Menlo Park was created by students with an interest in technology and a desire to experiment with building home computers. Steve Wozniak, a founding member, built a home computer from a cheap microprocessor, and showed it to his fellow club members, who included his friend Steve Jobs. Together, in Steve Job's garage in Cupertino, Wozniak and Jobs formed Apple Computer. By 1976 Apple's first personal computer, the Apple I, was being sold.
Trans Canada Microwave
Trans Canada Microwave or Trans-Canada Skyway was a microwave system built in the 1950s to carry telephone and TV from Canada's east coast to its west coast. Because microwaves travel in a straight line and do not follow the curvature of the Earth, towers were built every 48 kilometres. The towers ranged from nine metres high to over 100 metres high in northern Ontario. The system included 139 towers spanning over 6275 kilometres and cost $50 million ($336 million in 2003 dollars).
Microwave
A word was needed to distinguish these new shorter wavelengths, which had previously been lumped into the "short wave" band, which meant all waves shorter than 200 meters. The terms "quasi-optical waves" and "ultrashort waves" were used briefly, but didn't catch on. The first usage of the word "microwave" apparently occurred in 1931.
Brown Bobby
The Brown Bobby machine resembled and operated similar to a waffle iron. Its surfaces were made of aluminium and were prepared for baking by coating with paraffin, though users today would most often use cooking spray. The machine had a high (600 watt/surfaces connected in parallel) and a low (300 watt/surfaces connected in series) setting. Cooking was done on the high setting, the low setting was for allowing the machine to remain idle. Machines were available as either a single (aka Brown Bobby Junior) for US$52 or as two machines riveted together into a single unit for US$100. Since these machines are no longer manufactured they are prized by their owners and often handed down to subsequent generations to continue a tradition of Brown Bobby making, especially during the holidays.
The Terry and Gaby Show
One of the most memorable moments of the show's short history came when Baker placed a piece of soap in a microwave oven. Although an oven glove had been provided for protection, Baker failed to use it, resulting in him burning his hand when he took the plate out of the microwave to the great amusement of the audience, before removing the glass plate from the microwave which promptly shattered on the floor. The clip is a well-known out-take.
Cosmic microwave background
The cosmic microwave background was first predicted in 1948 by Ralph Alpher and Robert Herman. Alpher and Herman were able to estimate the temperature of the cosmic microwave background to be 5 K, though two years later they re-estimated it at 28 K. This high estimate was due to a mis-estimate of the Hubble constant by Alfred Behr, which could not be replicated and was later abandoned for the earlier estimate. Although there were several previous estimates of the temperature of space, these suffered from two flaws. First, they were measurements of the temperature of space and did not suggest that space was filled with a thermal Planck spectrum. Next, they depend on our being at a special spot at the edge of the Milky Way galaxy and they did not suggest the radiation is isotropic. The estimates would yield very different predictions if Earth happened to be located elsewhere in the universe.
The 1948 results of Alpher and Herman were discussed in many physics settings through about 1955, when both left the Applied Physics Laboratory at Johns Hopkins University. The mainstream astronomical community, however, was not intrigued at the time by cosmology. Alpher and Herman's prediction was rediscovered by Yakov Zel'dovich in the early 1960s, and independently predicted by Robert Dicke at the same time. The first published recognition of the CMB radiation as a detectable phenomenon appeared in a brief paper by Soviet astrophysicists A. G. Doroshkevich and Igor Novikov, in the spring of 1964. In 1964, David Todd Wilkinson and Peter Roll, Dicke's colleagues at Princeton University, began constructing a Dicke radiometer to measure the cosmic microwave background. In 1964, Arno Penzias and Robert Woodrow Wilson at the Crawford Hill location of Bell Telephone Laboratories in nearby Holmdel Township, New Jersey had built a Dicke radiometer that they intended to use for radio astronomy and satellite communication experiments. On 20 May 1964 they made their first measurement clearly showing the presence of the microwave background, with their instrument having an excess 4.2K antenna temperature which they could not account for. After receiving a telephone call from Crawford Hill, Dicke said "Boys, we've been scooped." A meeting between the Princeton and Crawford Hill groups determined that the antenna temperature was indeed due to the microwave background. Penzias and Wilson received the 1978 Nobel Prize in Physics for their discovery.
Trivection oven
The Trivection oven is a convection microwave created by General Electric, which combines radiant heat, convection, and microwaves for customized cooking. According to GE, it cooks food five times faster than a traditional oven. Alton Brown, host of "Good Eats", was involved in developing the oven.
Microwave burn
Microwave heating seems to cause more damage to bacteria than equivalent thermal-only heating. However food reheated in a microwave oven typically reaches lower temperature than classically reheated, therefore pathogens are more likely to survive.
Thelma Pressman
Pressman studied microwave technology at California Community Colleges in 1967. In 1969 she founded the first microwave cooking school in the United States in Encino, California. The Microwave Cooking Center became an industry test kitchen in which products were evaluated and cookware and recipes were developed for the nascent microwave industry.
G.I. pocket stove
During World War II, the U.S. government tasked Coleman to develop a compact stove for military use. The stove had to be lightweight, no larger than a quart-sized thermos bottle, burn any kind of fuel, and operate in weather from −60 to +125 °Fahrenheit. Within 60 days, Coleman came up with what became the G.I. Pocket Stove. Designated the Model 520 Coleman Military Burner, the stove first saw service in November 1942 when 5,000 of the stoves accompanied U.S. forces during the invasion of North Africa. Over 1 million of the stoves were produced for war use, where it won high praise in the field: Ernie Pyle ranked it "just behind the ” in its usefulness.
Marcel Audiffren
European-manufactured refrigerators based on his designs were first sold in the U.S. in 1903. He received U.S. Patents #551,107 (in 1895) and #898,400 (in 1908, with Albert Sigrun). These patents were purchased by C. A. Griscom for his American Audiffren Refrigerating Machine Company. Machines based on Audiffren's sulfur dioxide process were manufactured by General Electric in Fort Wayne, Indiana and marketed by the Johns-Manville company. The first unit was sold in 1911. Audiffren machines were expensive, selling for about $1,000—about twice as much as an automobile cost at the time.
Hot Pockets
Hot Pockets were developed by Paul Merage and his brother David, through their company Chef America Inc. Chef America invented a packaging sleeve and dough formula to keep its calzone-like sandwiches crispy when cooked in a microwave. In 1980, Chef America introduced its first stuffed sandwich, the Tastywich, the predecessor of the Hot Pocket. Hot Pockets supplanted Tastywiches in 1983, first sold to restaurants because they were easier to break into than retail stores. On May 22, 2002, Chef America was sold to Nestlé. Hot Pocket products were "a $2 billion category of frozen sandwiches and snacks". Breakfast style Hot Pockets were introduced in 2001.
Microwave oven
Microwave ovens, although shielded for safety purposes, still emit low levels of microwave radiation. This is not harmful to humans, but can sometimes cause interference to Wi-Fi and Bluetooth and other devices that communicate on the 2.45 GHz wavebands; particularly at close range.
Microwave oven
Microwave ovens are a common kitchen appliance and are popular for reheating previously cooked foods and cooking a variety of foods. They are also useful for rapid heating of otherwise slowly prepared foodstuffs, which can easily burn or turn lumpy when cooked in conventional pans, such as hot butter, fats, chocolate or porridge. Unlike conventional ovens, microwave ovens usually do not directly brown or caramelize food, since they rarely attain the necessary temperatures to produce Maillard reactions. Exceptions occur in rare cases where the oven is used to heat frying-oil and other very oily items (such as bacon), which attain far higher temperatures than that of boiling water.
Dielectric heating
Microwave heating, as distinct from RF heating, is a sub-category of dielectric heating at frequencies above 100 MHz, where an electromagnetic wave can be launched from a small dimension emitter and guided through space to the target. Modern microwave ovens make use of electromagnetic waves with electric fields of much higher frequency and shorter wavelength than RF heaters. Typical domestic microwave ovens operate at 2.45 GHz, but 915 MHz ovens also exist. This means that the wavelengths employed in microwave heating are 0.1 cm to 10 cm. This provides for highly efficient, but less penetrative, dielectric heating.
Raytheon
In 1965, it acquired Amana Refrigeration, Inc., a manufacturer of refrigerators and air conditioners. Using the Amana brand name and its distribution channels, Raytheon began selling the first countertop household microwave oven in 1967 and became a dominant manufacturer in the microwave oven business.
Microwave popcorn
EO technique also has some disadvantages, such as high cost and complexity of setting up and operating an electrochemical cell. Due to these disadvantages, EO has not yet been commercialized.
Some microwave ovens have a specific mode designed for cooking popcorn, which either uses factory-calibrated time and power level settings, or which uses humidity or sound sensors to detect when popping has finished.
Anova Culinary
In 2014, Anova introduced the first connected precision cooking device, the Anova Precision Cooker, following a successful campaign on the crowdfunding website Kickstarter. The device debuted on Kickstarter with a goal of $100,000 USD. It quickly became the most funded food campaign with 10,508 backers pledging $1,811,321 USD. The Precision Cooker was a wand-like sous vide immersion circulator that attaches to a pot or container, heats and maintains water at a precise temperature to cook food to a set time and temperature. It is Bluetooth-enabled and connects with the Anova Culinary App, allowing people to cook with temperature control. The product has now been discontinued.
Madison Symmetric Torus
There is a large electric current in the plasma inside this machine; it is responsible for creating the necessary magnetic fields to make the reversed field pinch configuration. It also heats the plasma very quickly — the same way wires inside your toaster get hot. Your toaster probably uses about 10 ampere of current, while the plasma in MST is heated by up to 600,000 amperes. But even though the plasma reaches over 10,000,000 degrees Fahrenheit, it is not hot enough for practical fusion energy and we need to find other ways to deposit energy into the plasma. The EBW is a way to inject microwave power to further heat the plasma. The standard microwave oven produces around 1 kW of power at a frequency of 2.45 GHz; the EBW experiment is currently producing 150 kW at 3.6 GHz, and it is a goal of the team to upgrade to over 2 MW. To generate this type of power (on a low budget), decommissioned military radar equipment and home-made voltage power supplies are used.
Microwave oven
Adoption has been slower in less-developed countries, as households with disposable income concentrate on more important household appliances like refrigerators and ovens. In India, for example, only about 5% of households owned a microwave in 2013, well behind refrigerators at 31% ownership. However, microwave ovens are gaining popularity. In Russia, for example, the number of households with a microwave grew from almost 24% in 2002 to almost 40% in 2008. Almost twice as many households in South Africa owned microwaves in 2008 (38.7%) as in 2002 (19.8%). Microwave ownership in Vietnam was at 16% of households in 2008—versus 30% ownership of refrigerators; this rate was up significantly from 6.7% microwave ownership in 2002, with 14% ownership for refrigerators that year.
Mohammed Bah Abba
Abba hails from a family of potmakers and tapped into the large underemployed local workforce for the project. Local pot-makers he hired produced the first batch of 5,000 pot-in-pot refrigerators. He received the Rolex Award for Enterprise in 2001 and used his $75,000 award to make the invention available throughout Nigeria. Abba devised an educational campaign tailored to village life and the illiterate population featuring a video-recorded play by local actors to dramatise the benefits of the desert refrigerator. The pots sell at 40 US cents a pair.
Microwave popcorn
An early susceptor popcorn bag design was patented by the American company General Mills in 1981 (US Patent #4,267,420).
Mini Rover ROV
The Mini Rover ROV was the world's first small, low cost remotely operated underwater vehicle (ROV) when it was introduced in early 1983. After a demonstration to industry professionals, in the Spring of 1984, it made a significant entry to the remotely operated vehicle market. It is a self-propelled, tethered, free swimming vehicle that was designed and built by Chris Nicholson of Deep Sea Systems International, Inc. (DSSI). The Mini Rover ROV entered the ROV market at a price of $26,850 when the next lowest cost ROV was $100,000. Nicholson built the first Mini Rover ROV in his garage in Falmouth, MA. It was 26 inches long and weighed 55 pounds. It could be carried on airplanes as luggage.
Science and invention in Birmingham
Birmingham becomes the major British manufacturer of the phenolic plastic Bakelite.
The magnetron, the core component in the development of radar, and the first microwave power oscillators are developed at the University of Birmingham during World War II (the microwave oven owes its existence to these developments).
Kitchen stove
The first practical design was patented by the Australian David Curle Smith in 1905. His device adopted (following the design of gas stoves) what later became the configuration for most electric stoves: an oven surmounted by a hotplate with a grill tray between them. Curle Smith's stove did not have a thermostat; heat was controlled by the number of the appliance’s nine elements that were switched on.
History of Ohio
In 1955 Joseph McVicker tested a wallpaper cleaner in Cincinnati schools, eventually becoming known as the product Play-Doh. The same year the Tappan Stove Company created the first microwave oven made for commercial, home use. James Spangler invented the first commercially successful portable vacuum cleaner, which he sold to The Hoover Company.
Microwave popcorn
Microwave popcorn is a convenience food consisting of unpopped popcorn in an enhanced, sealed paper bag intended to be heated in a microwave oven. In addition to the dried corn, the bags typically contain cooking oil with sufficient saturated fat to solidify at room temperature, one or more seasonings (often salt), and natural or artificial flavorings or both. With the many different flavors, there are many different providers.
Microwave oven
Any object containing pointed metal can create an electric arc (sparks) when microwaved. This includes cutlery, crumpled aluminium foil (though some foil used in microwaves are safe, see below), twist-ties containing metal wire, the metal wire carry-handles in paper Chinese take-out food containers, or almost any metal formed into a poorly conductive foil or thin wire; or into a pointed shape. Forks are a good example: the tines of the fork respond to the electric field by producing high concentrations of electric charge at the tips. This has the effect of exceeding the dielectric breakdown of air, about 3 megavolts per meter (3×10 V/m). The air forms a conductive plasma, which is visible as a spark. The plasma and the tines may then form a conductive loop, which may be a more effective antenna, resulting in a longer lived spark. When dielectric breakdown occurs in air, some ozone and nitrogen oxides are formed, both of which are unhealthy in large quantities.
Microwave oven
Microwave ovens produce heat directly within the food, but despite the common misconception that microwaved food cooks from the inside out, 2.45 GHz microwaves can only penetrate approximately into most foods. The inside portions of thicker foods are mainly heated by heat conducted from the outer .
Walter E. Hussman Sr.
Hussman extended Palmer's technological achievements. In 1963, he launched the first terrestrial microwave high-speed, high-definition facsimile network ito connect a group of newspapers. This allowed the company to purchase expensive cold type composition equipment, to handle all advertising production in one city and sharing those ads with the entire group of newspapers. Typesetting of news copy also was available from this shared facility. Hussman got the idea of microwave from having visited newspaper operations in Japan.
TrueCookPlus
TrueCookPlus is a microwave oven operating system developed and patented by Microwave Science JV LLC. TrueCookPlus is endorsed by the National Frozen & Refrigerated Foods Association on behalf of over 1300 US frozen food industry member companies.
Merage family
David and Paul Merage co-founded Chef America Inc. where they created the popular microwavable snack, Hot Pockets, in the early 1980s. The brothers later sold the Chef America Inc. company to Nestlé for $2.6 billion. Hot Pockets were manufactured in Englewood, Colorado, Chef America's former headquarters, until moving its business to the rest of Nestlé's frozen business in Solon, Ohio.
Microwave burn
An engineer replaced a woodpecker-damaged feed horn of a high-power microwave antenna, a 15-meter dish at an Earth station of a television network, using a cherry picker. After finishing, he sent his technician to power up the transmitter, and attempted to lower the cherry picker down. The engine failed and the engineer was stuck next to the antenna, outside of its main lobe but well within the first sidelobe. The technician, unaware that the engineer was still close to the antenna, powered it up. The engineer was exposed to an intense microwave field for about three minutes, until the error was realized. There were no immediate symptoms; the next morning the engineer detected blood and solid matter in his urine, and visited a doctor, who found blood in stool and massive bowel adhesions. The engineer's medical problems lasted for many years.
Microwave Massacre
Donald (Vernon) is a construction worker with a big problem: his shrew of a wife May (Claire Ginsberg) has started to only cook gourmet foods in a Hyacinth Bucket-style misguided effort to make themselves seem classier than they are. While his friends Roosevelt (Loren Schein) and Phillip (Al Troupe) dine on simple bologna-and-cheese sandwiches for lunch, Donald is saddled with crab sandwiches and other cooking atrocities. To his horror, he discovers his wife has bought an unusually large Major Electric microwave oven, which makes the meals worse in half the time.
Convection oven
The first convection oven in wide use was the Maxson Whirlwind Oven, invented in 1945.
Microwave
A microwave oven passes microwave radiation at a frequency near  through food, causing dielectric heating primarily by absorption of the energy in water. Microwave ovens became common kitchen appliances in Western countries in the late 1970s, following the development of less expensive cavity magnetrons. Water in the liquid state possesses many molecular interactions that broaden the absorption peak. In the vapor phase, isolated water molecules absorb at around 22 GHz, almost ten times the frequency of the microwave oven.
Chambers stove
The earliest Chambers ranges were small, but all were constructed of heavy gauge steel and porcelain enamel. All models were thickly insulated, which enabled their owners to use them like an ordinary range or cook using retained heat. To help owners of their products learn the proper use of the retained heat cooking feature of their ranges, Chambers developed a large home economics department in their Shelbyville, Indiana, factory. There, recipes and cooking times using the insulated properties of their products were carefully tested and perfected. These tests resulted in charts which indicated the amount of time - and at what temperature - the gas was to be burned in the oven and the Thermodome (which was succeeded by the Thermowell), before it was to be turned off completely while the food continued to cook on retained heat. By 1927, Chambers published a cookbook for the homemaker to not only help her learn how to care for and operate the appliance, but also to assist her in menu planning, proper table setting, etc. This publication was called The Idle Hour Cookbook. The Idle Hour Cookbook was replaced in the late 1960s by Rangaire with an actual operation manual. Chambers promoted the ranges using traveling cooking shows. John Chambers' daughter Alma Chambers, traveled coast-to-coast for over twenty years conducting large cooking shows to promote the Chambers Range.
Improvements over the original design were continuously developed over the years, but all were constructed around the concept of a heavily insulated oven, as originally designed by John Chambers. The most updated version of these was the C-series, which was produced from 1949–1963, succeeding the B-series (1939–1949). Chambers also built large, industrial-sized units, called the Imperial line, for use in hotels, restaurants, dormitory kitchens, tea rooms, road houses, large homes, etc.
Microwave oven
The lower temperature of cooking (the boiling point of water) is a significant safety benefit compared to baking in the oven or frying, because it eliminates the formation of tars and char, which are carcinogenic. Microwave radiation also penetrates deeper than direct heat, so that the food is heated by its own internal water content. In contrast, direct heat can burn the surface while the inside is still cold. Pre-heating the food in a microwave oven before putting it into the grill or pan reduces the time needed to heat up the food and reduces the formation of carcinogenic char. Unlike frying and baking, microwaving does not produce acrylamide in potatoes, however unlike deep-frying, it is of only limited effectiveness in reducing glycoalkaloid (i.e., solanine) levels. Acrylamide has been found in other microwaved products like popcorn.
Microwave oven
In 1945, the specific heating effect of a high-power microwave beam was accidentally discovered by Percy Spencer, an American self-taught engineer from Howland, Maine. Employed by Raytheon at the time, he noticed that microwaves from an active radar set he was working on started to melt a chocolate bar he had in his pocket. The first food deliberately cooked with Spencer's microwave was popcorn, and the second was an egg, which exploded in the face of one of the experimenters. To verify his finding, Spencer created a high density electromagnetic field by feeding microwave power from a magnetron into a metal box from which it had no way to escape. When food was placed in the box with the microwave energy, the temperature of the food rose rapidly. On 8 October 1945, Raytheon filed a United States patent application for Spencer's microwave cooking process, and an oven that heated food using microwave energy from a magnetron was soon placed in a Boston restaurant for testing.
Electric stove
Canadian inventor Thomas Ahearn filed patent number no. 39916 in 1892 for an "Electric Oven," a device he probably employed in preparing a meal for an Ottawa hotel that year. Ahearn and Warren Y. Soper were owners of Ottawa's Chaudiere Electric Light and Power Company. The electric stove was showcased at the Chicago World's Fair in 1893, where an electrified model kitchen was shown. Unlike the gas stove, the electrical stove was slow to catch on, partly due to the unfamiliar technology, and the need for cities and towns to be electrified. By the 1930s, the technology had matured and the electrical stove slowly began to replace the gas stove, especially in household kitchens.
Easy-Bake Oven
The Easy-Bake Oven was introduced in 1963 by Kenner Products, a Cincinnati, Ohio-based toy company. The original Kenner Easy-Bake Oven was heated by two 100-watt incandescent light bulbs, came in a pale yellow or turquoise, and was designed to resemble a conventional oven. The design changed many times over the years. An updated "Premier" model, available in avocado green or red, was released in 1969, followed by a "Mod" model in yellow or light green in 1971. A more recent model resembled a microwave oven.
Kitchen stove
Microwave ovens were developed in the 1940s, and use microwave radiation to directly heat the water held inside food.
Microwave oven
Sir Henry Tizard travelled to the U.S. in late September 1940 to offer the magnetron in exchange for their financial and industrial help (see Tizard Mission). An early 6 kW version, built in England by the General Electric Company Research Laboratories, Wembley, London, was given to the U.S. government in September 1940. The magnetron was later described by American historian James Phinney Baxter III as "[t]he most valuable cargo ever brought to our shores". Contracts were awarded to Raytheon and other companies for mass production of the magnetron.
Kitchen stove
The first half of the nineteenth century witnessed a steady improvement in stove design. Cast iron stoves replaced those made of masonry and their size shrank to allow them to be incorporated into the domestic kitchen. By the 1850s, the modern kitchen, equipped with a cooking range, was a fixture of middle-class homes. In 1850 Mary Evard invented the Reliance Cook Stove, which was divided in two with one half for dry baking and the other half for moist. Patents issued to Mary Evard are US76315 and US76314 on April 7, 1868. She demonstrated this stove with her husband at the St. Louis World's Fair.
In 1867 Elizabeth Hawks of New York invented and received a patent for a baking attachment for stoves, intended to spread heat thoroughly throughout loaves while keeping the top crust tender, which she called an "Auxiliary Air-chamber for Stoves." This was so successful that she sold two thousand within months of its release.
Anova Culinary
The Anova Precision Cooker Nano is the first lab-grade sous vide cooking device for under $100. The Bluetooth-enabled Nano supports multi-device communication through the Anova Culinary App, so users can coordinate cooking cycles with multiple dishes using the company's products. It has the same control over temperature as other expensive models, but has no Wi-Fi, and uses Bluetooth. to connect to the user's smartphone. Basic controls are on the device itself, for app-free control.
Wireless microphone
The first recorded patent for a wireless microphone was filed by Raymond A. Litke, an American electrical engineer with Educational Media Resources and San Jose State College, who invented a wireless microphone in 1957 to meet the multimedia needs for television, radio, and classroom instruction. His U.S. patent number 3134074 was granted in May 1964. Two microphone types were made available for purchase in 1959: hand-held and lavalier. The main transmitter module was a cigar-sized device which weighed . Vega Electronics Corporation manufactured the design in 1959, producing it as a product called the Vega-Mike. The device was first used by the broadcast media at the 1960 Democratic and Republican National Conventions. It allowed television reporters to roam the floor of the convention to interview participants, including presidential candidates John F. Kennedy and Richard Nixon.
Annie Fisher
Annie saved most of the money she made cooking to start her catering business which she operated out of her restaurant, the Wayside Inn, which was located at the sight of her childhood home behind Grindstone schoolhouse. She reportedly had over 1,000 place settings of china and handled many large catered events for the University of Missouri. One of her largest banquets at an Alumni dinner for the University of Missouri she was paid 1,200 dollars at a price of two dollars per plate. Annie's beaten biscuits became so popular that Missourians who had moved out of state would mail order her biscuits to be delivered to states as far away as New York and California. Annie cooked in what she referred to as, "old Missouri style," which meant she used local ingredients to give her food a distinct flavor and her cooking became so popular that she began endorsing local businesses such as the Boone County Mill's H-P flour which she used in her famous biscuits. In 1911, a Sedalia hostess who handled catering for the Missouri State fair made sure Fisher's biscuits were on the presidential table for William Howard Taft's visit. Fisher's ingenuity didn't end in the kitchen, she invented a specific cutter for her biscuits that would keep them from sticking to the surface of the cutter and after Fisher's mail order business had taken off, she incorporated a biscuit brake to meet the demand for her biscuits. In a news article, Fisher reported she usually makes around one million biscuits a year and around 50 dozen biscuits every hour with the help from her daughter. By 1919, Fisher was making 500 dollars a month on selling her biscuits alone, she sold them for 15 cents a dozen. Using the profits from her cooking and catering businesses, Fisher bought her first house in 1901 and paid it off in two years. After her first property purchase, Fisher went on to buy 18 rental properties in the downtown Columbia area, most of which were along what is now Ash street and fifth street. Later after Fisher's catering business had become quite successful, she purchased a 58 acre farm outside of Columbia where she raised livestock and crops to use in her cooking.
Easy-Bake Oven
The Easy-Bake Oven is a working toy oven which Kenner introduced in 1963, and which Hasbro still manufactured as of late April 2016. The original toy used an ordinary incandescent light bulb as a heat source; current versions use a true heating element. Kenner sold 500,000 Easy-Bake Ovens in the first year of production. By 1997, more than 16 million Easy-Bake Ovens (in 11 models) had been sold.
Partridge Wilson Engineering
In February 1937, they produced what they claimed was the first all-electric mobile fish-and-chips saloon. Beneath a serving counter was an oven, which was fitted with two sets of electric elements. One set could be plugged into a mains electrical socket, and was used to bring the oven up to temperature. Once it was hot, the second set were powered from the vehicle's battery, but the amount of current drawn was somewhat lower, as it only had to maintain the temperature. Two months later, they showcased a mobile milk bar, complete with egg-whisking machines, fountains and a refrigerator, again powered from the vehicle battery. A milk tank held of milk. Later in the year they held a competition for ideas to improve or develop their products. Prizes of 10, 5 and 3 guineas were offered.
Microwave oven
The exploitation of high-frequency radio waves for heating substances was made possible by the development of vacuum tube radio transmitters around 1920. By 1930 the application of short waves to heat human tissue had developed into the medical therapy of diathermy. At the 1933 Chicago World's Fair, Westinghouse demonstrated the cooking of foods between two metal plates attached to a 10 kW, 60 MHz shortwave transmitter. The Westinghouse team, led by I. F. Mouromtseff, found that foods like steaks and potatoes could be cooked in minutes.
Microwave oven
A microwave oven (also commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces polar molecules in the food to rotate and produce thermal energy in a process known as dielectric heating. Microwave ovens heat foods quickly and efficiently because excitation is fairly uniform in the outer of a homogeneous, high water content food item; food is more evenly heated throughout than generally occurs in other cooking techniques.
Mary Wiseman
During her first year on the bench, Wiseman presided over the high-profile trial of China Arnold, a mother found guilty of burning her month-old baby to death in a microwave oven. In a case that made headlines around the world, Wiseman sentenced Arnold to life in prison without the possibility of parole.
Microwave oven
Microwave ovens have limited roles in professional cooking, because the boiling-range temperatures of a microwave will not produce the flavorful chemical reactions that frying, browning, or baking at a higher temperature will. However, additional heat sources can be added to microwave ovens.
Microwave oven
A microwave oven heats food by passing microwave radiation through it. Microwaves are a form of non-ionizing electromagnetic radiation with a frequency higher than ordinary radio waves but lower than infrared light. Microwave ovens use frequencies in one of the ISM (industrial, scientific, medical) bands, which are reserved for this use, so they do not interfere with other vital radio services. Consumer ovens usually use 2.45 gigahertz (GHz)— It is a wavelength of —while large industrial/commercial ovens often use 915 megahertz (MHz)—. Water, fat, and other substances in the food absorb energy from the microwaves in a process called dielectric heating. Many molecules (such as those of water) are electric dipoles, meaning that they have a partial positive charge at one end and a partial negative charge at the other, and therefore rotate as they try to align themselves with the alternating electric field of the microwaves. Rotating molecules hit other molecules and put them into motion, thus dispersing energy. This energy, dispersed as molecular rotations, vibrations and/or translations in solids and liquids raises the temperature of the food, in a process similar to heat transfer by contact with a hotter body It is a common misconception that microwave ovens heat food by operating at a special resonance of water molecules in the food. As noted microwave ovens can operate at many frequencies.
Microwave burn
One such case involved a teenage babysitter who admitted to having placed a child in the microwave oven for approximately sixty seconds. The child developed a third degree burn to the back, measuring 5 inches x 6 inches. The babysitter later took the child to the emergency department, where multiple skin grafts were placed on the back. There were no signs of lasting emotional, cognitive or physical effects. CT scan of the head was normal, and there were no cataracts.
Microwave oven
By 1972, Litton (Litton Atherton Division, Minneapolis) introduced two new microwave ovens, priced at $349 and $399, to tap into the market estimated at $750 million by 1976, according to Robert I Bruder, president of the division.
From the late 1970s, Japanese companies such as Sharp Corporation manufactured low-cost microwave ovens that were affordable for residential use, leading to the rapid expansion of the microwave oven market in the 1980s. After Japanese dominance for much of the 1980s, with Sharp as market leader, South Korean manufacturers began entering the market in the late 1980s, with Samsung becoming a major microwave manufacturer.
Microwave
The ability of short waves to quickly heat materials and cook food had been investigated in the 1930s by I. F. Mouromtseff at Westinghouse, and at the 1933 Chicago World's Fair demonstrated cooking meals with a 60 MHz radio transmitter. In 1945 Percy Spencer, an engineer working on radar at Raytheon, noticed that microwave radiation from a magnetron oscillator melted a candy bar in his pocket. He investigated cooking with microwaves and invented the microwave oven, consisting of a magnetron feeding microwaves into a closed metal cavity containing food, which was patented by Raytheon on 8 October 1945. Due to their expense microwave ovens were initially used in institutional kitchens, but by 1986 roughly 25% of households in the U.S. owned one. Microwave heating became widely used as an industrial process in industries such as plastics fabrication, and as a medical therapy to kill cancer cells in microwave hyperthermy.
Oven
More recently, ovens have become slightly more high-tech in terms of cooking strategy. The microwave as a cooking tool was discovered by Percy Spencer in 1946, and with the help from engineers, the microwave oven was patented. The microwave oven uses microwave radiation to excite the molecules in food causing friction, thus producing heat.In cooking, the conventional oven is a kitchen appliance used for roasting and heating. Foods normally cooked in this manner include meat, casseroles and baked goods such as bread, cake and other desserts. In modern times, the oven is used to cook and heat food in many households across the globe.
List of 2.4 GHz radio use
The IEEE 802.11 committee that developed the Wi-Fi specification conducted an extensive investigation into the interference potential of microwave ovens. A typical microwave oven uses a self-oscillating vacuum power tube called a magnetron and a high voltage power supply with a half wave rectifier (often with voltage doubling) and no DC filtering. This produces an RF pulse train with a duty cycle below 50% as the tube is completely off for half of every AC mains cycle: 8.33 ms in 60 Hz countries and 10 ms in 50 Hz countries.
Microwave oven
The invention of the cavity magnetron made possible the production of electromagnetic waves of a small enough wavelength (microwaves). The magnetron was originally a crucial component in the development of short wavelength radar during World War II. In 1937–1940, a multi-cavity magnetron was built by the British physicist Sir John Turton Randall, FRSE, together with a team of British coworkers, for the British and American military radar installations in World War II. A more high-powered microwave generator that worked at shorter wavelengths was needed, and in 1940, at the University of Birmingham in England, Randall and Harry Boot produced a working prototype. They invented a valve that could spit out pulses of microwave radio energy on a wavelength of 10 cm, an unprecedented discovery.
Baked Alaska
In 1969, the recently invented microwave oven enabled Hungarian gastrophysicist Nicholas Kurti to produce a reverse baked Alaska (also called a "Frozen Florida")—a frozen shell of meringue filled with hot liquor.
Microwave oven
Food and cookware taken out of a microwave oven are rarely much hotter than . Cookware used in a microwave oven is often much cooler than the food because the cookware is transparent to microwaves; the microwaves heat the food directly and the cookware is indirectly heated by the food. Food and cookware from a conventional oven, on the other hand, are the same temperature as the rest of the oven; a typical cooking temperature is . That means that conventional stoves and ovens can cause more serious burns.
Northwestern Steel and Wire
In 1936 Washington Dillon's son, P.W. Dillon, installed two electric furnaces and rolling machines in the barbed wire factory in order to make low carbon steel. Two years later the company became known as Northwestern Steel and Wire. The systems and furnaces were successively upgraded in the ensuing years. During World War II, to keep up with escalating demand, two 50 ton electric furnaces were installed. By 1950 150 ton furnaces were in use. Throughout the years, as production increased, larger furnaces became the norm.