Henry Ross Perot is an American business magnate and former politician. As the founder of the successful Electronic Data Systems corporation, he became a billionaire, he ran an independent presidential campaign in 1992 and a third party campaign in 1996, establishing the Reform Party in the latter election. Both campaigns were among the strongest presidential showings by a third party or independent candidate in U. S. history. Born in Texarkana, Texas, he became a salesman for IBM after serving in the United States Navy. In 1962, he founded a data processing service company. In 1984, General Motors bought a controlling interest in the company for $2.4 billion. Perot established Perot Systems in 1988 and was an angel investor for NeXT, a computer company founded by Steve Jobs after he left Apple. Perot became involved in the Vietnam War POW/MIA issue, arguing that hundreds of American servicemen were left behind in Southeast Asia after the Vietnam War. During President George H. W. Bush's tenure, Perot became active in politics and opposed the Gulf War and ratification of the North American Free Trade Agreement.
In 1992, Perot announced his intention to run for president and advocated a balanced budget, an end to the outsourcing of jobs, the enactment of electronic direct democracy. A June 1992 Gallup poll showed Perot leading a three-way race against President Bush and presumptive Democratic nominee Bill Clinton. Perot withdrew from the race in July, but re-entered the race in early October after he qualified for all 50 state ballots, he chose Admiral James Stockdale as his running mate and appeared in the 1992 CPD debates with Bush and Clinton. In the election, Perot did not win any electoral votes, he won support from across the ideological and partisan spectrum, but performed best among self-described moderates. Perot ran for president again in 1996, he won 8.4 % of the popular vote against Republican nominee Bob Dole. Perot did not seek public office again after 1996 and did not enter the 2000 Reform Party presidential primaries, he endorsed Republican George W. Bush over Reform nominee Pat Buchanan in the 2000 election and supported Republican Mitt Romney in 2008 and 2012.
In 2009, Dell acquired Perot Systems for $3.9 billion. According to Forbes, Perot was the 167th richest person in the United States in 2016. Perot was born in Texarkana, the son of Lula May Perot and Gabriel Ross Perot, a commodity broker specializing in cotton contracts, his patrilineal line traces back to an immigrant to French Louisiana in the 1740s. He attended, he graduated from Texas High School in Texarkana in 1947. One of Perot's childhood friends was Hayes McClerkin, who became the Speaker of the Arkansas House of Representatives and a prominent lawyer in Texarkana, Arkansas. Perot made Eagle Scout in 1942, after 13 months in the program, he is a recipient of the Distinguished Eagle Scout Award. From 1947 to 1949, he attended Texarkana Junior College entered the U. S. Naval helped establish its honor system. Perot said his appointment notice to the academy—sent by telegram—was sent by W. Lee "Pappy" O'Daniel, Texas's 34th governor and former senator. Perot married Margot Birmingham of Greensburg, Pennsylvania, in 1956.
After he left the Navy in 1957, Perot became a salesman for IBM. He became a top employee and tried to pitch his ideas to supervisors, who ignored him, he left IBM in 1962 to found Electronic Data Systems in Dallas and courted large corporations for his data processing services. Perot was refused. EDS received lucrative contracts from the U. S. government in the 1960s, computerizing Medicare records. EDS went public in 1968 and the stock price rose from $16 a share to $160 within days. Fortune called Perot the "richest Texan" in a 1968 cover story. In 1984 General Motors bought controlling interest in EDS for $2.4 billion. In 1974, Perot gained some press attention for being "the biggest individual loser on the New York Stock Exchange" when his EDS shares dropped $450 million in value in a single day in April 1970. Just prior to the 1979 Iranian Revolution, the government of Iran imprisoned two EDS employees in a contract dispute. Perot sponsored their rescue; the rescue team was led by retired U.
S. Army Special Forces Colonel Arthur D. "Bull" Simons. When the team was unable to find a way to extract the two prisoners, they decided to wait for a mob of pro-Ayatollah revolutionaries to storm the jail and free all 10,000 inmates, many of whom were political prisoners; the two prisoners connected with the rescue team, the team spirited them out of Iran via a risky border crossing into Turkey. The exploit was recounted in On Wings of Eagles by Ken Follett, which became a best-seller. In the 1986 mini-series, Perot was portrayed by Richard Crenna. In 1984, Perot bought a early copy of Magna Carta, one of only a few to leave the United Kingdom, it was lent to the National Archives in Washington, D. C. where it was displayed alongside the Declaration of Independence and the United States Constitution. In 2007, it was sold by the Perot Foundation "for medical research, for improving public education and for assisting wounded soldiers and their families." The document sold for US$21.3 million on Dec. 18, 2007, to David Rubenstein, managing director of the Carlyle Group, is kept on display at the National Archives.
After Steve Jobs lost the original power struggle at Apple an
A space suit is a garment worn to keep a human alive in the harsh environment of outer space and temperature extremes. Space suits are worn inside spacecraft as a safety precaution in case of loss of cabin pressure, are necessary for extravehicular activity, work done outside spacecraft. Space suits have been worn for such work in Earth orbit, on the surface of the Moon, en route back to Earth from the Moon. Modern space suits augment the basic pressure garment with a complex system of equipment and environmental systems designed to keep the wearer comfortable, to minimize the effort required to bend the limbs, resisting a soft pressure garment's natural tendency to stiffen against the vacuum. A self-contained oxygen supply and environmental control system is employed to allow complete freedom of movement, independent of the spacecraft. Three types of space suits exist for different purposes: IVA, EVA, IEVA. IVA suits are meant to be worn inside a pressurized spacecraft, are therefore lighter and more comfortable.
IEVA suits are meant for use such as the Gemini G4C suit. They include more protection from the harsh conditions of space, such as protection from micrometeorites and extreme temperature change. EVA suits, such as the EMU, are used outside spacecraft, for either planetary exploration or spacewalks, they must protect the wearer against all conditions of space, as well as provide mobility and functionality. Some of these requirements apply to pressure suits worn for other specialized tasks, such as high-altitude reconnaissance flight. At altitudes above the Armstrong limit, around 19,000 m, water boils at body temperature and pressurized suits are needed; the first full-pressure suits for use at extreme altitudes were designed by individual inventors as early as the 1930s. The first space suit worn by a human in space was the Soviet SK-1 suit worn by Yuri Gagarin in 1961. A space suit must perform several functions to allow its occupant to work safely and comfortably, inside or outside a spacecraft.
It must provide: A stable internal pressure. This can be less than earth's atmosphere, as there is no need for the space suit to carry nitrogen. Lower pressure allows for greater mobility, but requires the suit occupant to breathe pure oxygen for a time before going into this lower pressure, to avoid decompression sickness. Mobility. Movement is opposed by the pressure of the suit. See the Theories of space suit design section. Supply of breathable oxygen and elimination of carbon dioxide. Unlike on Earth, where heat can be transferred by convection to the atmosphere, in space, heat can be lost only by thermal radiation or by conduction to objects in physical contact with the exterior of the suit. Since the temperature on the outside of the suit varies between sunlight and shadow, the suit is insulated, air temperature is maintained at a comfortable level. A communication system, with external electrical connection to the spacecraft or PLSS Means of collecting and containing solid and liquid bodily waste Advanced suits better regulate the astronaut's temperature with a Liquid Cooling and Ventilation Garment in contact with the astronaut's skin, from which the heat is dumped into space through an external radiator in the PLSS.
Additional requirements for EVA include: Shielding against ultraviolet radiation Limited shielding against particle radiation Means to maneuver, release, and/or tether onto a spacecraft Protection against small micrometeoroids, some traveling at up to 27,000 kilometers per hour, provided by a puncture-resistant Thermal Micrometeoroid Garment, the outermost layer of the suit. Experience has shown the greatest chance of exposure occurs near the gravitational field of a moon or planet, so these were first employed on the Apollo lunar EVA suits; as part of astronautical hygiene control, a space suit is essential for extravehicular activity. The Apollo/Skylab A7L suit included eleven layers in all: an inner liner, a LCVG, a pressure bladder, a restraint layer, another liner, a Thermal Micrometeoroid Garment consisting of five aluminized insulation layers and an external layer of white Ortho-Fabric; this space suit is capable of protecting the astronaut from temperatures ranging from −156 °C to 121 °C.
During exploration of the moon or Mars, there will be the potential for lunar/Martian dust to be retained on the space suit. When the space suit is removed on return to the spacecraft, there will be the potential for the dust to contaminate surfaces and increase the risks of inhalation and skin exposure. Astronautical hygienists are testing materials with reduced dust retention times and the potential to control the dust exposure risks during planetary exploration. Novel ingress/egress approaches, such as suitports, are being explored as well. In NASA space suits, communications are provided via a cap worn over the head, which includes earphones and a microphone. Due to the coloration of the version used for Apollo and Skylab, which resembled the coloration of the comic strip character Snoopy, these caps became known as "Snoopy caps." To supply enough oxygen for respiration, a space suit using pure oxygen must have a pressure of about 32.4 kPa, equal to the 20.7 kPa partial pres
The Vostok was a type of spacecraft built by the Soviet Union. The first human spaceflight was accomplished with Vostok 1 on April 12, 1961, by Soviet cosmonaut Yuri Gagarin; the spacecraft was part of the Vostok programme, in which six manned spaceflights were made, from 1961–63. Two further manned space flights were made in 1964 and 1965 by Voskhod spacecraft, which were modified Vostok spacecraft. By the late 1960s both were superseded by the Soyuz spacecraft, which are still used as of 2019; the Vostok spacecraft was designed for use both as a camera platform and as a manned spacecraft. This dual-use design was crucial in gaining Communist Party support for the program; the basic Vostok design has remained in use for some 40 years adapted for a range of other unmanned satellites. The descent module design was reused, in modified form, by the Voskhod program; the craft consisted of a spherical descent module, which housed the cosmonaut and escape system, a conical instrument module, which contained propellant and the engine system.
On reentry, the cosmonaut would eject from the craft at about 7,000 m and descend via parachute, while the capsule would land separately. The reason for this was that the Vostok descent module made an rough landing that could have left a cosmonaut injured; the ejector seat served as an escape mechanism in the event of a launch vehicle failure, which at this early phase of the space program was a common occurrence. If an accident occurred in the first 40 seconds after liftoff, the cosmonaut would eject from the spacecraft and parachute to Earth. From 40 to 150 seconds into launch, ground controllers could issue a manual shutdown command to the booster; when the launch vehicle fell to a low enough altitude, the cosmonaut would eject. Higher altitude failures after shroud jettison would involve detaching the entire spacecraft from the booster. One problem, never adequately resolved was the event of a launch vehicle malfunction in the first 20 seconds, when the ejector seat would not have enough time to deploy its parachute.
LC-1 at the Baikonour Cosmodrome had netting placed around it to catch the descent module should the cosmonaut eject while still on the pad, but it was of doubtful value since he would end up landing too close to the exploding booster. An accident in the initial seconds of launch likely would have not put the cosmonaut in a position where he could make a survivable ejection and in all probability, this situation would have resulted in his death. A 2001 recollection by V. V. Molodsov stated that Chief Designer Sergei Korolev felt "absolutely terrible" about the inadequate provisions for crew escape on the Vostok during the opening seconds of launch. There were several models of the Vostok leading up to the manned version: Prototype spacecraft. Photo-reconnaissance and signals intelligence spacecraft. Named Zenit spy satellite; the Vostok 3KA was the spacecraft used for the first human spaceflights. They were launched from Baikonur Cosmodrome using Vostok 8K72K launch vehicles; the first flight of a Vostok 3KA occurred on March 9, 1961.
The first flight with a crew—Vostok 1 carrying Yuri Gagarin—took place on April 12, 1961. The last flight—Vostok 6 carrying the first woman in space, Valentina Tereshkova—took place on June 16, 1963. A total of 8 Vostok, 6 of them with a human crew. Specifications for this version are: Reentry Module: Vostok SA. SA stands for Spuskaemiy apparat - descent system, it was nicknamed "Sharik". Crew Size: 1 Diameter: 2.3 m sphere Mass: 2,460 kg Heat Shield Mass: 837 kg Recovery equipment: 151 kg Parachute deploys at 2.5 km altitude Crew seat and provisions: 336 kg Crew ejects at 7 km altitude Ballistic reentry acceleration: 8 g Equipment Module: Vostok PA. PA stands. Length: 2.25 m Diameter: 2.43 m Mass: 2,270 kg Equipment in pressurized compartment RCS Thrusters: 16 x 5 N RCS Thrusters pressure: 59 PSI RCS Propellants: Cold gas at 2200 PSI RCS Propellants: 20 kg stored in 12 pressure bottles Main Engine: 397 kg Main Engine Thrust: 15.83 kN Main Engine Propellants: RFNA/amine Main Engine Propellants: 275 kg Main Engine Isp: 266 s Main Engine Burn Time: 1 minute Spacecraft delta v: 155 m/s Electrical System: Batteries Electric System: 0.20 average kW Electric System: 24.0 kW·h Total Mass:4,730 kg Endurance: Supplies for 10 days in orbit Launch Vehicle: Vostok 8K72K Typical orbit: 177 km x 471 km, 64.9 inclinaton The Vostok capsule had limited thruster capability.
As such, the reentry path and orientation could not be controlled after the capsule had separated from the engine system. This meant that the capsule had to be protected from reentry heat on all sides, thus explaining the spherical design; some control of the capsule reentry orientation was possible by way of positioning of the heavy equipment to offset the vehicle center of gravity, which maximized the chance of the cosmonaut surviving g-forces while in a horizontal position. The cosmonaut experienced 8 to 9g. If the retrorocket failed, the spacecraft would decay from orbit within ten days, the cosmonaut was provided with enough food and oxygen to survive until that time. Voskhod Zenit Foton (space program
In telecommunication, a communications system or communication system is a collection of individual communications networks, transmission systems, relay stations, tributary stations, data terminal equipment capable of interconnection and interoperation to form an integrated whole. The components of a communications system serve a common purpose, are technically compatible, use common procedures, respond to controls, operate in union. Telecommunications is a method of communication. Communication is the act of conveying intended meanings from one entity or group to another through the use of mutually understood signs and semiotic rules An optical communication system is any form of telecommunication that uses light as the transmission medium. Equipment consists of a transmitter, which encodes a message into an optical signal, a communication channel, which carries the signal to its destination, a receiver, which reproduces the message from the received optical signal. Fiber-optic communication systems transmit information from one place to another by sending light through an optical fiber.
The light forms a carrier signal, modulated to carry information. A radio communication system is composed of several communications subsystems that give exterior communications capabilities. A radio communication system comprises a transmitting conductor in which electrical oscillations or currents are produced and, arranged to cause such currents or oscillations to be propagated through the free space medium from one point to another remote therefrom and a receiving conductor at such distant point adapted to be excited by the oscillations or currents propagated from the transmitter. Power line communication systems operate by impressing a modulated carrier signal on power wires. Different types of powerline communications use different frequency bands, depending on the signal transmission characteristics of the power wiring used. Since the power wiring system was intended for transmission of AC power, the power wire circuits have only a limited ability to carry higher frequencies; the propagation problem is a limiting factor for each type of power line communications.
A duplex communication system is a system composed of two connected parties or devices which can communicate with one another in both directions. The term duplex is used when describing communication between devices. Duplex systems are employed in nearly all communications networks, either to allow for a communication "two-way street" between two connected parties or to provide a "reverse path" for the monitoring and remote adjustment of equipment in the field. An Antenna is a small length of a qwert conductor, used to radiate or receive electromagnetic waves, it acts as a conversion device. At the transmitting end it converts high frequency current into electromagnetic waves. At the receiving end it transforms electromagnetic waves into electrical signals, fed into the input of the receiver. Several types of antenna are used in communication. Examples of communications subsystems include the Defense Communications System. Telephone Mobile Telegraph Edison Telegraph T. V. Cable Computer A tactical communications system is a communications system, used within, or in direct support of tactical forces is designed to meet the requirements of changing tactical situations and varying environmental conditions, provides securable communications, such as voice and video, among mobile users to facilitate command and control within, in support of, tactical forces, requires short installation times on the order of hours, in order to meet the requirements of frequent relocation.
An Emergency communication system is any system, organized for the primary purpose of supporting the two way communication of emergency messages between both individuals and groups of individuals. These systems are designed to integrate the cross-communication of messages between are variety of communication technologies. An Automatic call distributor is a communication system that automatically queues and connects callers to handlers; this is used in customer service, ordering by telephone, or coordination services. A Voice Communication Control System is an ACD with characteristics that make it more adapted to use in critical situations Sources can be classified as electric or non-electric. Examples of sources include but are not limited to the following: Audio Files Graphic Image Files Email Messages Human Voice Television Picture Electromagnetic Radiation Sensors, like microphones and cameras, capture non-electric sources, like sound and light, convert them into electrical signals; these types of sensors are called input transducers in modern analog and digital communication systems.
Without input transducers there would not be an effective way to transport non-electric sources or signals over great distances, i.e. humans would have to rely on our eyes and ears to see and hear things despite the distances. Not good! Other examples of input transducers include: Microphones Cameras Keyboards Mouse Force Sensors Accelerometers Once the source signal has been converted into an electric signal, the transmitter will modify this signal for efficient transmission. In order to do
An experiment is a procedure carried out to support, refute, or validate a hypothesis. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Experiments vary in goal and scale, but always rely on repeatable procedure and logical analysis of the results. There exists natural experimental studies. A child may carry out basic experiments to understand gravity, while teams of scientists may take years of systematic investigation to advance their understanding of a phenomenon. Experiments and other types of hands-on activities are important to student learning in the science classroom. Experiments can raise test scores and help a student become more engaged and interested in the material they are learning when used over time. Experiments can vary from personal and informal natural comparisons, to controlled. Uses of experiments vary between the natural and human sciences. Experiments include controls, which are designed to minimize the effects of variables other than the single independent variable.
This increases the reliability of the results through a comparison between control measurements and the other measurements. Scientific controls are a part of the scientific method. Ideally, all variables in an experiment are controlled and none are uncontrolled. In such an experiment, if all controls work as expected, it is possible to conclude that the experiment works as intended, that results are due to the effect of the tested variable. In the scientific method, an experiment is an empirical procedure that arbitrates competing models or hypotheses. Researchers use experimentation to test existing theories or new hypotheses to support or disprove them. An experiment tests a hypothesis, an expectation about how a particular process or phenomenon works. However, an experiment may aim to answer a "what-if" question, without a specific expectation about what the experiment reveals, or to confirm prior results. If an experiment is conducted, the results either support or disprove the hypothesis.
According to some philosophies of science, an experiment can never "prove" a hypothesis, it can only add support. On the other hand, an experiment that provides a counterexample can disprove a theory or hypothesis, but a theory can always be salvaged by appropriate ad hoc modifications at the expense of simplicity. An experiment must control the possible confounding factors—any factors that would mar the accuracy or repeatability of the experiment or the ability to interpret the results. Confounding is eliminated through scientific controls and/or, in randomized experiments, through random assignment. In engineering and the physical sciences, experiments are a primary component of the scientific method, they are used to test theories and hypotheses about how physical processes work under particular conditions. Experiments in these fields focus on replication of identical procedures in hopes of producing identical results in each replication. Random assignment is uncommon. In medicine and the social sciences, the prevalence of experimental research varies across disciplines.
When used, experiments follow the form of the clinical trial, where experimental units are randomly assigned to a treatment or control condition where one or more outcomes are assessed. In contrast to norms in the physical sciences, the focus is on the average treatment effect or another test statistic produced by the experiment. A single study does not involve replications of the experiment, but separate studies may be aggregated through systematic review and meta-analysis. There are various differences in experimental practice in each of the branches of science. For example, agricultural research uses randomized experiments, while experimental economics involves experimental tests of theorized human behaviors without relying on random assignment of individuals to treatment and control conditions. One of the first methodical approaches to experiments in the modern sense is visible in the works of the Arab mathematician and scholar Ibn al-Haytham, he conducted his experiments in the field of optics - going back to optical and mathematical problems in the works of Ptolemy - by controlling his experiments due to factors such as self-criticality, reliance on visible results of the experiments as well as a criticality in terms of earlier results.
He counts as one of the first scholars using an inductive-experimental method for achieving results. In his book "Optics" he describes the fundamentally new approach to knowledge and research in an experimental sense: "We should, that is, recommence the inquiry into its principles and premisses, beginning our investigation with an inspection of the things that exist and a survey of the conditions of visible objects. We should distinguish the properties of particulars, gather by induction what pertains to the eye when vision takes place and what is found in the manner of sensation to be uniform, unchanging and not subject to doubt. After which we should ascend in our inquiry and reasonings and orderly, criticizing premisses and exercising caution in regard to conclusions – our aim in all that we make subject to inspect
Soviet space dogs
During the 1950s and 1960s the Soviet space program used dogs for sub-orbital and orbital space flights to determine whether human spaceflight were feasible. In this period, the Soviet Union launched missions with passenger slots for at least 57 dogs; the number of dogs in space is smaller. Most survived. A notable exception is Laika, the first dog to be sent into orbit, whose death was expected from the outset. Dogs were the preferred animal for the experiments because scientists felt dogs were well suited to endure long periods of inactivity; as part of their training, they were confined in small boxes for 15–20 days at a time. Stray dogs, rather than animals accustomed to living in a house, were chosen because the scientists felt they would be able to tolerate the rigorous and extreme stresses of space flight better than other dogs. Female dogs were used because of their temperament and because the suit the dogs wore in order to collect urine and feces was equipped with a special device, designed to work only with females.
Their training included standing still for long periods of time, wearing space suits, being placed in simulators that acted like a rocket during launch, riding in centrifuges that simulated the high acceleration of a rocket launch and being kept in progressively smaller cages to prepare them for the confines of the space module. Dogs that flew in orbit were fed a nutritious jelly-like protein; this was high in fiber and assisted the dogs to eliminate during long periods of time while in their small space module. More than 60% of dogs to enter space were suffering from constipation and gallstones on arrival back to base. Dogs were flown to an altitude of 100 km on board 15 scientific flights on R-1 rockets from 1951 to 1956; the dogs wore pressure suits with acrylic glass bubble helmets. From 1957 to 1960, 11 flights with dogs were made on the R-2A series. Three flights were made to an altitude of about 450 km on R-5A rockets in 1958. In the R-2 and R-5 rockets, the dogs were contained in a pressured cabin.
Dezik and Tsygan were the first dogs to make a sub-orbital flight on 22 July 1951. Both dogs were recovered unharmed after travelling to a maximum altitude of 110 km. Dezik made another sub-orbital flight in July 29, 1951 with a dog named Lisa, although neither survived because the parachute failed to deploy. After the death of Dezik, Tsygan was adopted as a pet by Soviet physicist Anatoli Blagonravov. Lisa and Ryzhik flew to an altitude of 100 km on 2 June 1954. Smelaya ran away the day before the launch, she went on to make a successful flight with a dog named Malyshka. Bobik ran away just days before his flight in September 1951. A replacement named ZIB, an untrained street dog found running around the barracks, was located and made a successful flight. Otvazhnaya made a flight on 2 July 1959 along with a rabbit named Marfusha and another dog named Snezhinka, she went on to make 5 other flights between 1959 and 1960. Albina and Tsyganka were both ejected out of their capsule at an altitude of 85 km and landed safely.
Albina never flew in orbit. Damka and Krasavka were to make an orbital flight on 22 December 1960 as a part of the Vostok programme which included mice; however their mission was marked by a string of equipment failures. The upper-stage rocket failed and the craft re-entered the atmosphere after reaching a sub-orbital apogee of 214 km. In the event of unscheduled return to the surface, the craft was to eject the dogs and self-destruct, but the ejection seat failed and the primary destruct mechanism shorted out; the animals were thus still in the intact capsule. The backup self-destruct mechanism was set to a 60-hour timer, so a team was sent out to locate and recover the capsule. Although the capsule was reached in deep snow on the first day, there was insufficient remaining daylight to disarm the self-destruct mechanism and open the capsule; the team could only report that the window was frosted over in the −45 degree temperatures and no signs of life were detected. On the second day, the dogs were heard barking as the capsule was opened.
The dogs were wrapped in sheepskin coats and flown to Moscow alive, though all the mice aboard the capsule were found dead because of the cold. Damka was known as Shutka or Zhemchuzhnaya and Krasavka was known as Kometka or Zhulka. After this incident Krasavka was adopted by Oleg Gazenko, a leading soviet scientist working with animals used in space flights, she went on to have puppies and continued living with Gazenko and his family until her death 14 years later. After the incident Sergey Korolyov, the designer of the rocket, wanted to make the story public, but was prevented from doing so by state censorship. Bars and Lisichka were on a mission to orbit as a part of the Vostok programme, but died after their rocket exploded 28.5 seconds into the launch on 28 July 1960. Bars was known as Chayka (Чайка, "Se