The Top 50 Inventions of the Past 50 Years

The Top 50 Inventions of the Past 50 Years

In the past half-century, scientific and technological advances have transformed our world। PM convened a panel of 25 experts to identify innovations that have made the biggest impact, from the hospital to outer space to the kitchen। Here, then, are the breakthroughs of our time.

1955—TV REMOTE CONTROL
It marks the official end of humanity's struggle for survival and the beginning of its quest for a really relaxing afternoon. The first wireless remote, designed by Zenith's Eugene Polley, is essentially a flashlight. When Zenith discovers that direct sunlight also can change channels on the remote-receptive TVs, the company comes out with a model that uses ultrasound; it lasts into the 1980s, to the chagrin of many a family dog. The industry then switches to infrared.

1955—MICROWAVE OVEN
In 1945 Raytheon's Percy Spencer stands in front of a magnetron (the power tube of radar) and feels a candy bar start to melt in his pocket: He is intrigued. When he places popcorn kernels in front of the magnetron, the kernels explode all over the lab. Ten years later Spencer patents a "radar range" that cooks with high-frequency radio waves; that same year, the Tappan Stove Co. introduces the first home microwave model.

1957—BIRTH-CONTROL PILL
Enovid, a drug approves for menstrual disorders, comes with a warning: The mixture of synthetic progesterone and estrogen also prevents ovulation। Two years later, more than half a million American women are taking Enovid—and not all of them have cramps। In 1960 the FDA approves Enovid for use as the first oral contraceptive.

1958—JET AIRLINER
The Boeing 707-120 debuts as the world's first successful commercial jet airliner, ushering in the era of accessible mass air travel. The four-engine plane carries 181 passengers and cruises at 600 mph for up to 5280 miles on a full tank. The first commercial jet flight takes off from New York and lands in Paris; domestic service soon connects New York and Los Angeles.

1959—FLOAT GLASS
There's a reason old windowpanes distort everything: They were made by rapidly squeezing a sheet of red-hot glass between two hot rollers, which produced a cheap but uneven pane. British engineer Alastair Pilkington revolutionizes the process by floating molten glass on a bath of molten tin—by nature, completely flat. The first factory to produce usable float glass opens in 1959; an estimated 90 percent of plate glass is still produced this way.


1961—CORDLESS TOOLS
Black and Decker releases its first cordless drill, but designers can't coax more than 20 watts from its NiCd batteries. Instead, they strive for efficiency, modifying gear ratios and using better materials. The revolutionary result puts new power in the hands of DIYers and—thanks to a NASA contract—the gloves of astronauts.

1961—INDUSTRIAL ROBOT
The Unimate, the first programmable industrial robot, is installed on a General Motors assembly line in New Jersey. Conceived by George C. Devol Jr. to move and fetch things, the invention gets a lukewarm reception in the United States. Japanese manufacturers love it and, after licensing the design in 1968, go on to dominate the global market for industrial robots.

1962—COMMUNICATIONS SATELLITE
Telstar is launched as the first "active" communications satellite—active as in amplifying and retransmitting incoming signals, rather than passively bouncing them back to Earth. Telstar makes real a 1945 concept by science fiction author Arthur C. Clarke, who envisioned a global communications network based on geosynchronous satellites. Two weeks after Telstar's debut, President Kennedy holds a press conference in Washington, D.C., that is broadcast live across the Atlantic.

1962—LED
Working as a consultant for General Electric, Nick Holonyak develops the light-emitting diode (LED), which provides a simple and inexpensive way for computers to convey information. From their humble beginnings in portable calculators, LEDs spread from the red light that indicates coffee is brewing to the 290-ft.-tall Reuters billboard in Times Square.

1964—UNMANNED AERIAL VEHICLES
Widespread use of remotely piloted aircraft begins during the Vietnam War with deployment of 1000 AQM-34 Ryan Firebees. The first model of these 29-ft.-long planes was developed in just 90 days in 1962. AQM-34s go on to fly more than 34,000 surveillance missions. Their success leads to the eventual development of the Unmanned Aerial Vehicles widely used today.

STATS



1962/VIDEO GAMES MIT programmers write Spacewar; 43 years later 89 percent of school-age kids own video games

1955/POLIO VACCINE The year Jonas Salk finds a way to prevent polio, there are 28,985 global cases; by 2005, the number drops to 1200।

1957/THREE-POINT SEATBELT According to the U.S. Department of Transportation, more than 15,000 American lives are saved in 2005 by Nils Bohlin's device.

The first general-purpose computer, the nearly 30-ton ENIAC (1947), contains 18,000 vacuum tubes, 70,000 resistors and 10,000 capacitors. In 1959, the INTEGRATED CIRCUIT puts those innards on one tiny chip. Before the entire world is networked, there is the ARPANET—four computers linked in 1969. It introduces the concept of "packet switching," which simultaneously delivers messages as short units and reassembles them at their destination. The Apple II, Commodore Pet and Radio Shack's TRS-80 are introduced in 1977—four years before IBM, soon to become synonymous with the term "PC," unveils its PERSONAL COMPUTER. In 1989, Sir Tim Berners-Lee creates "hypertext markup language" (HTML) to make Web pages and the "Uniform Resource Locator" (URL) to identify where information is stored. These breakthroughs form the foundation of the WORLD WIDE WEB.

1964—MUSIC SYNTHESIZER
Robert Moog develops the first electronic synthesizer to make the leap from machine to musical instrument. Moog's device not only generates better sounds than other synthesizers, it can be controlled by a keyboard rather than by punch cards. The subsequent acceptance of electronic music is a crucial step in developing audio technology for computers, cellphones and stereos.

1966—HIGH-YIELD RICE
The International Rice Research Institute in the Philippines releases a semi-dwarf, high-yield Indica variety that, in conjunction with high-yield wheat, ushers in the Green Revolution. Indica rice thrives in tropical regions of Asia and South America, raising worldwide production more than 20 percent by 1970.

1969—SMOKE DETECTOR
Randolph Smith and Kenneth House patent a battery-powered smoke detector for home use. Later models rely on perhaps the cheapest nuclear technology you can own: a chunk of americium-241. The element's radioactive particles generate a small electric current. If smoke enters the chamber it disrupts the current, triggering an alarm.

1969—CHARGE-COUPLED DEVICE
Bell Labs' George Smith and Willard Boyle invent a charge-coupled device (CCD) that can measure light arriving at a rate of just one photon per minute. Smith and Boyle's apparatus allows extremely faint images to be recorded, which is very useful in astronomy. Today, its most noticeable impact is in digital cameras, which rely on CCD arrays containing millions of pixels.

1970—DIGITAL MUSIC
James Russell, a scientist with the Pacific Northwest National Laboratory, invents the first digital-to-optical recording and playback system, in which sounds are represented by a string of 0s and 1s and a laser reads the binary patterns etched on a photosensitive platter. Russell isn't able to convince the music industry to adopt his invention, but 20 years later, Time Warner and other CD manufacturers pay a $30 million patent infringement settlement to Russell's former employer, the Optical Recording Co.

1971—WAFFLE-SOLE RUNNING SHOES
Bill Bowerman, the track coach at the University of Oregon, sacrifices breakfast for peak performance when he pours rubber into his wife's waffle iron, forming lightweight soles for his athletes' running shoes. Three years later, Bowerman's company, Nike, introduces the Waffle Trainer, which is an instant hit.

N THEIR WORDS
1962 Computer Mouse
"I don't know why we call it a mouse. It started that way, and we never changed it." —Doug Engelbart, engineer, Stanford Research Institute, 1968

1969 Automated Teller Machine
"On Sept. 2, our bank will open at 9:00 and never close again!" —Long Island branch of Chemical Bank, advertisement from 1969

1973 Cellphone
"Joel, I'm calling you from a real cellular phone." —Martin Cooper, leader of Motorola's cellphone team, to Joel Engel, research head of rival AT&T's Bell Labs, April 3, 1973

1978 In-Vitro Fertilization
"We'd love to have children of our own one day. That would be such a dream come true." —Louise Brown Mullinder, the first test-tube baby, on her wedding day, in 2003

1979 Sony Walkman
"This is the product that will satisfy those young people who want to listen to music all day." —Akio Morita, Sony Chairman, February 1979

RADICAL FIBERS

From easy-on shoes to lighter tennis rackets and stronger planes, revolutionary materials have changed our lives.

In 1955, Patent No. 2,717,437 is issued to George de Mestral for VELCRO, a fabric inspired by burrs that stick to his dog's fur. In 1961 researchers in Japan develop high-quality CARBON-FIBER COMPOSITES, capping a decade of experimentation with plastics reinforced by carbon fibers. Thanks to DuPont's Stephanie Kwolek and Herbert Blades, who in 1965 invent a high-strength polymer called KEVLAR, the body armor of 2920 police and correctional officers has protected them from fatal attacks. The term "FIBEROPTIC" is coined in 1956, but it isn't until 1970 that scientists at Corning produce a fiber of ultrapure glass that transmits light well enough to be used for telecommunications.

1972—ELECTRONIC IGNITION
Chrysler paves the way for the era of electronic—rather than mechanical—advances in automobiles with the electronic ignition. It leads to electronic control of ignition timing and fuel metering, harbingers of more sophisticated systems to come. Today, these include electronic control transmission shift points, antilock brakes, traction control systems, steering and airbag deployment.

1973—MRI
Everyone agrees that magnetic resonance imaging (MRI) is a brilliant invention—but no one agrees on who invented it. The physical effect that MRIs rely on—nuclear magnetic resonance—earns various scientists Nobel Prizes for physics in 1944 and 1952. Many believe that Raymond Damadian establishes the machine's medical merit in 1973, when he first uses magnetic resonance to discern healthy tissue from cancer. Yet, in 2003, the Nobel Prize for medicine goes to Peter Lauterbur and Peter Mansfield for their "seminal discoveries." The topic of who is the worthiest candidate remains hotly debated.

1978—GPS
The first satellite in the modern Navstar Global Positioning System (GPS) is launched. (The GPS's precursor, TRANSIT, was developed in the early 1960s to guide nuclear subs.) It is not until the year 2000, though, that President Clinton grants nonmilitary users access to an unscrambled GPS signal. Now, cheap, handheld GPS units can determine a person's location to within 3 yards.

1981—SCANNING TUNNELING MICROSCOPE
By moving the needle of the scanning tunneling microscope (STM) across a surface and monitoring the electric current that flows through it, scientists can map a surface to the level of single atoms. The STM is so precise that it not only looks at atoms—it also can manipulate them into structures. The microscope's development earns IBM researchers Gerd Binnig and Heinrich Rohrer a Nobel Prize and helps launch the emerging era of nanotechnology.

1984—DNA FINGERPRINTING
Molecular biologist Alec Jeffreys devises a way to make the analysis of more than 3 billion units in the human DNA sequence much more manageable by comparing only the parts of the sequence that show the greatest variation among people. His method quickly finds its way into the courts, where it is used to exonerate people wrongly accused of crimes and to finger the true culprits.

USES
1958/LASER BEAM Whitens teeth, removes tattoos, corrects vision, scans groceries, tracks missiles. 1978/GENETIC ENGINEERING Produces insulin, creates vaccines, clones sheep, increases shelf life of tomatoes, manipulates human cells to prevent disease. 1958/SUPER GLUE Repairs a broken taillight, reassembles a vase, strengthens knots on a hammock, closes wounds, lifts fingerprints.

LIFESAVERS

Over the past 50 years, a few pivotal medical discoveries have helped to boost adult life expectancy dramatically.

In 1956, Wilson Greatbatch grabs the wrong resistor and connects it to a device he is building to record heartbeats. When the circuit emits a pulse, he realizes the device can be used to control the beat; in 1960 the first PACEMAKER is successfully implanted in a human. Rene Favaloro performs the first CORONARY BYPASS SURGERY in 1967, taking a length of vein from a leg and grafting it onto the coronary artery. This allows blood to flow around the blocked section. Thanks in part to these advances, the number of deaths from heart disease declines in the U.S. by almost 50 percent. The outlook for people infected by HIV also dramatically changes. The FDA approves Invirase, the first of a class of drugs called HIV PROTEASE INHIBITORS, in 1995. By blocking the function of enzymes used in the virus's replication, the inhibitors can reduce HIV to undetectable levels for sustained periods in up to 90 percent of patients.


1985—POLYMERASE CHAIN REACTION
Biochemist Kary Mullis invents a technique that exploits enzymes in order to make millions of copies of a tiny scrap of DNA quickly and cheaply. No matter how small or dried-out a bloodstain is, forensic scientists can now gather enough genetic material to do DNA fingerprinting. With PCR, doctors also can search for trace amounts of HIV genetic code to diagnose infection much sooner than by conventional methods.

1987—PROZAC
Prozac becomes the first in a new class of FDA-approved antidepressants called "selective serotonin re-uptake inhibitors," which block the reabsorption of the mood-elevating neurotransmitter serotonin, thereby prolonging its effects. Though at times controversial, Prozac helps patients cope with clinical depression, reshaping our understanding of how personality and emotion can be chemically controlled. Within five years, 4.5 million Americans are taking Prozac—making it the most widely accepted psychiatric drug ever.

1998—GENETIC SEQUENCING
Scientist Craig Venter announces that his company will sequence the entire human genome in just three years and for only $300 million—12 years and $2 billion less than a federally funded project established to do the same thing. Venter uses a method called "shotgun sequencing" to make automated gene sequencers, instead of relying on the laborious approach used by the government program. The result is an acrimonious race to the finish, which ends in a tie. Both groups announce the completion of the human genome sequence in papers published in 2001.

1998—MP3 PLAYER
Depending on who you ask, the MP3 is either the end of civilization (record companies) or the dawn of a new world (everyone else). The Korean company Saehan introduces its MPMan in 1998, long before Apple asks, "Which iPod are you?" When the Diamond Rio hits the shelves a few months later, the Recording Industry Association of America sues—providing massive publicity and a boost to digital technology.

2002—IEEE 802.16
The geniuses at the Institute of Electrical and Electronics Engineers publish a wireless metropolitan area network standard that functions like Wi-Fi on steroids. An 802.16 antenna can transmit Internet access up to a 30-mile radius at speeds comparable to DSL and cable broadband. When it all shakes out, 802.16 could end up launching developing nations into the digital age by eliminating the need for wired telecommunications infrastructure.

FORWARD DRIVE

With 196 million licensed drivers in the U.S., a little automotive innovation can conserve a whole lot of oil.

The fuel cell goes back more than 150 years, and the first FUEL CELL VEHICLE—a 20-hp tractor—is built in 1959. But it isn't until 1993 that a Canadian company, Ballard Power Systems, demonstrates the first zero-emissions fuel cell bus. Since then, progress toward an economically viable fuel cell car has remained slow but steady. Likewise, Ferdinand Porsche wins his class at the 1902 Exelberg Hill-Climb in Austria in a front-wheel-drive HYBRID-ELECTRIC CAR. But it is almost a century later, in 1997, that Toyota surprises its rivals by unveiling the hybrid Prius to Japanese consumers. It takes nearly three years for the Prius to reach North America.

Synthetics

Synthetics

Most of the products and materials we use today are of synthetic origin; from the garments we wear to the rubber used in the production of various tools। This article briefly discusses some examples of synthetics.

Synthetic Fibres

Synthetic fibres are "man-made textile fibres produced entirely from chemical substances, unlike those man-made fibres derived from such natural substances as cellulose or protein." The polymers of synthetic fibres do not occur in nature, instead, they are produced from scratch in chemical plants or laboratories, "almost always from by-products of petroleum and natural gas." Of these polymers are nylon, polyethylene terephthalate, as well as other compounds such as the acrylics, the polyurethanes and polypropylene. Synthetic fibres are "spun and woven into huge consumer and industrial products", from garments such as shirts and scarves, home furnishings such as carpets ad drapes, to industrial parts such as flame-proof linings and drive belts.

Stages in the wet spinning of polymeric fibres

Stages in the melt spinning of polymeric fibres

Examples of textured yarns

Table 1: Properties & Applications of Prominent Synthetic Fibres

Synthetic Abrasives

"Abrasives are sharp, hard materials used to wear away the surface of softer, less resistant materials." Examples of abrasives range from the soft particles used in household cleansers and jeweler's polish to the hardest known material, the diamond. The forms in which abrasives are used include grinding wheels, sandpapers, honing stones, polishes, cutoff wheels, tumbling and vibratory mass-finishing media, sandblasting, pulpstones, ball mills, and other tools and products. "Only through the use of abrasives is industry able to produce the highly precise components and ultrasmooth surfaces required for the manufacture of automobiles, airplanes and space vehicles, mechanical and electrical appliances, and machine tools." The most important characteristics that should exist in an abrasive are hardness and toughness or strength. It was proved that a certain degree of control over the characteristics of synthetic abrasives could be achieved by various methods, to develop abrasives that would "meet the operating conditions found in a variety of applications."

Table 2: Hardness of Prominent Synthetic Abrasive Materials

The Verneuil Process

The Verneuil process -also referred to as the Flame-Fusion Process, is a method by which synthetic rubies and sapphires are produced. It was originally developed in 1902 by a French chemist, Auguste Verneuil. By applying slight modifications to this method, spinel, rutile and strontium titanate can be produced. Star rubies and sapphires were first developed in 1947 in the United States. "The synthetic gems have sharper and more distinctly developed stars than the natural crystals", which is why they are superior to natural gemstones.

Synthetic Food Additives

Food additives are produced for the purpose of enhancing sensory characteristics of foods, that are subject to degradation or loss during food processing. Food additives include colouring agents, flavourings and sweeteners.

Synthetic Colorants: "Synthetic colorants are primarily petroleum-based chemical compounds", unlike natural colorants that are derived from plants, animals and mineral sources. Synthetic colorants exist in the forms of powders, pastes, granules or solutions. The fact that synthetic colorants can be modified gives them superiority to natural colorants that are associated with certain problems, including "the lack of consistent colour intensities", instability under special conditions and "reactivity with other food components".

Flavourings: The flavour of foods is influenced by their taste and smell (odour). Flavour additives form the largest group among food additives. Those of synthetic origin are mixtures of synthetic compounds, whereas natural flavourings are extracted from plants, animals, spices and herbs.

Sweeteners: Since the discovery of saccharin -the first synthetic sweetener- in the late 1800s, efforts have been carried out to develop other synthetic sweeteners that provide few or no calories or nutrients. These are thus referred to as "nonnutritive sweeteners", unlike the natural sweeteners such as sucrose, glucose, fructose....etc. that are known as "nutritive sweeteners" for the energy they provide in the form of carbohydrates. Synthetic sweeteners are used in the manufacture of low-calorie products. They also serve persons with diabetes as a carbohydrate replacement.

Synthetic Chemical Agents

Synthetic chemical agents are used to treat bacterial diseases. Examples of them include the sulfonamides; used for treating urinary tract infections, preventing infection of burns as well as certain forms of malaria, isoniazid, ethabutol, pyrazinamide and ethionamide; useful in treating tuberculosis.

Synthetic Rubber

Rubber is made of elastic polymers, which are "materials composed of long, chainlike molecules that are capable of recovering their original shape after being stretched to great extents." The molecules of rubber stretch in the direction in which they are pulled and upon release, they return to their state that existed before the application of force. Rubber is used in the manufacture of automobile tyres, mountings, gaskets, belts, hoses and consumer products such as shoes, clothing, furniture and toys. Natural rubber nowadays competes with synthetic rubber such as styrene-butadiene rubber and polybutadiene, which are extracted from the by-products of petroleum and natural gas.

Nuclear Energy

Nuclear Energy

"Nuclear Energy is the safest, cleanest, cheapest, and most efficient type of energy." It supplies about 17% of the world's electricity. Nowadays, it has become an issue in a major debate as to whether such type of energy ought to be disposed of, or continued to be used and developed while disregarding its disadvantages.

What is Nuclear Energy?

The structure of the nucleus of an atom can undergo changes. Such changes are called "nuclear reactions". The form of energy produced in a nuclear reaction is referred to as "nuclear energy" or "atomic energy". Nuclear energy is either produced by "nuclear fission" (in which large nuclei are split to release energy) or by "nuclear fusion" (in which small nuclei are combined to release energy). The atomic bomb and nuclear reactors in nuclear plants work on the principle of nuclear fission, where the element uranium (isotope U-235) is used to undergo fission. Stars produce their heat and light through nuclear fusion. The hydrogen bomb operates by nuclear fusion as well.

Advantages

• Speaking in terms of limited supplies of energy, nuclear energy is the most efficient alternative to coal, oil and natural gas, which are on their way of becoming scarce.

• Nuclear energy has environmental benefits. It is a pure form of energy, the production of which doesn't involve the burning of fossil fuel in no way whatsoever.

• Uranium fuel -upon which nuclear power plants run- contains much more concentrated energy than any other fuel. It is estimated that one pound of uranium can produce as much electricity as 12,000 pounds of coal and 1,200 gallons of oil. Therefore, nuclear power plants consume less amounts of fuel than needed by those which burn other fuels, and at the same time they produce additional amounts of electricity, making countries' economies grow.

• Nuclear fuel is less costly than other fuels.

• For countries that rely on foreign oil suppliers, nuclear energy is good news, for it cuts their demands for imported oil.

Disadvantages

• Reactor meltdowns -where the nuclear fission reaction accidentally goes out of control- result in the occurrence of nuclear explosions. A famous reactor meltdown incident took place in Russia's Chernobyl nuclear power plant, where radiation escaped from the reactor to which many lives were exposed. Many died in the following days and others in the following years.

• Nuclear explosions cause the emission of massive amounts of harmful radiation. Living organisms exposed to nuclear radiation are subject to life-threatening diseases.

• Nuclear waste produced by nuclear reactors- is difficult to be disposed of. Nuclear waste emits harmful radiation that causes harm to living organisms.

Nuclear Weapons

Nuclear weapons, examples of which include the atomic bomb and the hydrogen bomb, are major threats in the field of nuclear physics. It is estimated that the amount of nuclear weapons that exist in the world today is sufficient enough to kill everyone. Those who argue in favour of nuclear weapons believe that they are essential for ensuring security and safety. Indeed, this is true. However, stricter methods should be adopted to control their use.If a nuclear war breaks out, the resultig damage would surely be devastating. We definitely don't want incidents like those which took place in Hiroshima and Nagasaki to occur again.

The Future of Nuclear Energy

Nuclear power plants will undergo major development, making them faster and less costly to build, better performing and safer to the environment and its inhabitants. A convenient solution to the problem of the disposal of nuclear waste will be found. More countries will sign the Nuclear Non-Proliferation Treaty and until then stricter methods will be applied to minimize the likelihood of the use of nuclear weapons. These aren't but a few attempts to make the world a safer place for all, and a better environment where Man is able to prosper and develop.

Ballistics Science

Ballistics Science

When a forensic investigation involves a shooting, ballistics becomes an important facet of the investigation. Ballistics is a term that refers to the science of the flight path of a bullet. The flight path includes the movement of the bullet down the barrel of the firearm following detonation and its path through both the air and the target.
Tracing the path of a bullet is important in a forensic examination. It can reveal from what direction the bullet was fired, which can be vital in corroborating the course of events in the crime or accident.

Once a bullet leaves the rifle or gun barrel, the aforementioned frictional and gravitational forces begin It is an obvious truism that the distance that a bullet can travel depends on its speed. A higher speed imparts more energy to the bullet. The frictional resistance of the air and the downward pull of gravity will take longer to slow the bullet's flight, as compared to a bullet moving at a lower initial velocity.

Generally, a bullet fired from a rifle will carry more energy than a bullet fired from a handgun. This is because the stronger firing chamber of a rifle is able to withstand the increased explosive power of a larger quantity of powder that would likely rupture the barrel of the handgun. Detonation of the powder in a rifle or handgun supplies the thrust to propel the bullet down the barrel.
Expansion of the exploding gunpowder generates pressure, which is measured as the force of the explosion that pushes on the area of the bullet's base. This area is essentially the diameter of the barrel of the firearm, which remains constant. Thus, the explosive energy that passes to the bullet depends on the mass of the bullet multiplied by the force of the explosion multiplied by the time that the force is applied (i.e., the time the bullet is in the barrel). A longer barrel will produce a faster moving bullet.

to slow its speed, producing a downward arc of flight. The frictional force is affected by the bullet's shape. A blunt shape will present more surface area to the air than will a very pointed bullet.

Another factor that affects the flight of a bullet is called yaw. As in an orbiting spacecraft or a football tossed through the air, yaw causes a bullet to turn sideways or tumble in flight. This behavior is decreased when the object spins as it moves forward (the spiraling motion of a football). The barrel of a rifle or gun contains grooves that cause the bullet to spin. More damage results from a bullet that is tumbling rather than moving in a tight spiral.
The shape of a typical bullet—much like a football with one end blunt instead of tapered—is a compromise that reduces air resistance while still retaining the explosive energy that allows the bullet to damage the target.

The composition of a bullet is also important. Lead is commonly used to form the core of bullets. However, because it tends to deform, the blending in of other metals (typically antimony and copper) produces a bullet that can withstand the pressure of flight and impart high energy to the target upon impact.

Copper is often used to jacket the inner lead core of a bullet. However, some bullets are deliberately made without this full metal jacket. Instead, the bullet has a tip made of lead or a tip that is hollow or very blunt. These bullets deform and break apart on impact, producing more damage to the target than is produced by a single piece of metal. This is because the bullet's energy is dissipated within a very short distance in the tissue.
Forensic and medical examiners are able to assess the nature of tissue damage in a victim and gain an understanding of the nature of the bullet used.

A bullet produces tissue damage in three ways. First, a bullet can shred (lacerate) or crush tissue or bone. Bullets moving at relatively low velocity do most of their damage this way. Fragmentation of bone can cause further damage, as the bone shards themselves become missiles.

The second form of damage is known as cavitation. This damage is produced by the forward movement of air or tissue in the wake of the bullet. The wound that is produced by the bullet is destructively broadened by the force of the moving air or tissue. In a tissue, this produces even more structural damage.

Third, the air at the front and sides of a very fast moving bullet can become compressed. The explosive relaxation of the compression generates a damaging shock wave that can be several hundred atmospheres in pressure. Fluid-filled organs such as the bladder, heart, and bowel can be burst by the pressure.

Recovery of bullets can be a very useful part of forensic ballistics. A variety of bullet designs exist, some that are specific to the firearm. Furthermore, the scouring of a bullet's surface as it encounters the grooves of the firearm barrel can produce a distinctive pattern that enables a bullet to be matched with the firearm. A weapon recovered from a suspect can be test fired and the bullet pattern compared with a bullet recovered from the scene to either implicate or dismiss involvement of the firearm in the crime.
This aspect of ballistics was crucial in convicting John Allen Muhammad and John Lee Malvo of the 10 sniper murders and the wounding of three others in the Washington, D.C. area that occurred during three weeks in October of 2002.

Psychotherapy

Psychotherapy


Psychotherapy a set of techniques believed to cure or to help solve behavioraland other psychological problems in humans. The common part of these techniques is direct personal contact between therapist and patient, often in the form of talking.

Psychotherapy, or personal counselling with a psychotherapist, is an intentional interpersonal relationship used by trained psychotherapists to aid a client or patient in problems of living.

It aims to increase the individual's sense of their own well-being. Psychotherapists employ a range of techniques based on experiential relationship building, dialogue, communication and behavior change and that are designed to improve the mental health of a client or patient, or to improve group relationships (such as in a family).

Psychotherapy may also be performed by practitioners with a number of different qualifications, including psychiatry, clinical psychology, counseling psychology, mental health counseling, clinical social work, marriage and family therapy, rehabilitation counseling, music therapy, occupational therapy, psychiatric nursing, psychoanalysis and others.

Indeed, psychotherapy can increasingly be considered as a profession in its own right, and in Europe the European Association for Psychotherapy is promoting this view and has set professional training standards to this effect. However, some European countries have passed laws about psychotherapy that restrict its practice to the professions of psychology and psychiatry; Austria has a law that recognizes multi-disciplinary approaches; other European countries have not yet regulated psychotherapy. In the United Kingdom, psychotherapy is voluntarily regulated by the United Kingdom Council for Psychotherapy.

Einstein for scientist or a Bryan act ?

what do you think Einstein for scientist or a Bryan act ? think againhe was the advance physicist ,great noblest and he was the key maker tothe haven as you called it .how was he noblest not for the noble prizefor the great science noble which hold the key to heaven and make youto evolve faster to be your ultimate vi...sion god (your cravingpower).he is only not known for his book theory of relativity,or theformula E=mc2 (consider it square ) your advance tv,yourcellphone,gps,satellite all share his key not only that is was masterof abstracting microscopic DNA from a king size palace for solving mostdifficult cases and you computer is about to be changed to from 0 tohero with more GB more ram and faster processing 100 times better thanyou can even imagine,by the theory that proton can be at in twoplaces at once imagine you were the protons this all is derived fromhis great nobles and computer no longer need binary digits tofunction.He was some times mistaken this doesn't means that he was wrongthis means he opened new hints for making you understand thing better.next time Stephan Hawking child of Einstein.

Written by Khom Bhattarai

bio-desel

Bio-Disel(B20)

Its like disel but it is more Volitile(more than Water). We can call it B20. It can be easily created in our locality. The process involved are:-

• Oil or Fat + Sodium Hydroxide(NaoH)
• Grinding for 5-10 minutes
• Filtration through Cotton clothes. Then Pure biodisel is obtained.

It is volatile than water or any other Petrelium product. We need 20% pure disel to make Bio-Disel. i.e 80%biodisel + 20% pure disel.

Characterstic

• Efficient than Petrole Disel

i.e. Petrole disel= 68% , Bio-disel= 78%

• Less mobile needed to a disel enjeen.
• Longlivity of an enjeen.