Science Projects And Inventions

"A Worker may be the hammer's master, but the hammer still prevails...." Milan Kundera, writer Hammers—tools for striking or pounding—have been around for millions of years in the form of specially shaped stones used to break or shape other stones, bones, or wood. They are most commonly associated with woodworking. But after the invention of the nail, someone realized it would be very useful to be able to insert and remove nails with the same tool. Nails were valuable, and a carpenter who hammered one at the wrong angle would have rescued and reused it. Thus, the claw hammer was born. A claw hammer has a two-sided head attached to a handle and can be said to be roughly T-shaped. One side of the head is the striking surface and is usually flat. The other side is a rounded or angled wedge and is used for removing nails. Archeologists found more...

"Clothes make the man. Naked people have little or no influence in society." Mark Twain, More Maxims of Mark (1927) Around 400,000 years ago, Homo sapiens devised a solution to protect the vulnerable naked human body from the environment—clothes. Anthropologists believe the earliest clothing was made from the fur of hunted animals or leaves creatively wrapped around the body to keep out the cold, wind, and rain. Determining the date of this invention is difficult, although sewing needles made from animal bone dating from about 30,000 B.C.E. have been found by archeologists. However, genetic analysis of human body lice reveals that they evolved at the same time as clothing. Scientists originally thought the lice evolved 107,000 years ago, but further investigations placed their evolution a few hundred thousand years earlier. Clothing has changed dramatically over the centuries, although its ancient role as an outward indication of the status, wealth, and more...

“... people like to stare at: a flowing stream, a crackling fire, and a Zamboni clearing the ice." Charlie Brown, Peanuts character The Zamboni name is synonymous with ice rink resurfacing in the United States, although few people outside of ice-skating would recognize it. Frank Zamboni (1901-1988) was born just after the turn of the twentieth century to Italian immigrant parents. As a young man he worked on the family farm and as a mechanic in a local garage. Frank opened an ice-making plant, with his younger brother Lawrence, producing blocks of ice for refrigeration. When electrical refrigerators were invented in the mid 1930s, making the production of ice blocks redundant, the Zambonis transformed their ice-making equipment and expertise into an ice rink. "Iceland" proved a popular local attraction, with 150,000 visitors a year. Cleaning, or resurfacing, of the rink was a time-consuming business, requiring three men and taking an more...

Since Viagra® (sildenafil citrate)—the first oral drug to treat erectile dysfunction—went on sale ten years ago, more than 27 million men in 120 countries have been prescribed it for impotence. Initially the drug was designed to treat high blood pressure, but in clinical trials this use proved disappointing. One side effect, shyly reported by the healthy volunteers, was that the drug produced super-charged erections. It was known that sexual arousal messages from the brain spark the production of cyclic guanosine monophosphate (cyclic GMP), a chemical that relaxes the pelvic muscles and allows the penis to become engorged with eight times its normal supply of blood. Sildenafil suppresses an enzyme (phosphodiesterase type 5), whose normal role is to break down cyclic GMP and cause the erection to subside. Pharmaceutical company Pfizer conducted twenty-one randomized, placebo-controlled clinical trials involving more than 3,700 participants aged from nineteen to eighty-seven suffering from varying degrees more...

"The development involved more than $30,000 In experimentation and marketing." Lloyd E. Griscom, The Historic County of Burlington For almost a millennium the farming practices of the Saxons remained unchanged. To plow the ground, farmers used the primitive scratch plow developed in Mesopotamia in 5500 B.C.E. The work was laborious. In 1797 Charles New bold (1764-1835), a blacksmith from New Jersey, patented a practical plow in which the three main parts were made as one solid piece of cast iron. These were the moldboard (a curved iron plate), the share (the cutting edge of the plow attached to the moldboard), and the landslide (the stabilizing mechanism that counteracts the sideways motion of turning over the soil). Newbold also integrated a runner that allowed directional control and therefore straighter furrows. Farmers were initially wary of Newbold's plow, believing that the cast iron would poison their fields and ruin their crops. Eventually more...

When pioneer automobile makers, searching for an effective braking system, looked back to the horse- powered carriages on which their vehicles were based, they realized, unfortunately, that no one had ever actually managed to design one. So for several years, brake technology dragged along behind that of engines and transmissions. Carriage brake evolution had peaked in 1838 with the spoon brake—in essence, a crude lever and shoe system that forced a block of wood directly against the tire. Henry Ford avoided the dilemma of which braking system to fit to his Quadricycle in 1896 by not installing any. Instead, a lever released a drive belt and the vehicle (eventually) coasted to a stop. Drivers could assist the process by pressing their feet against the front wheels.                         The introduction of pneumatic tires rendered a block-on-tire system impracticable. A leap more...

 “I have now made an engine that shall not waste a particle of steam. It shall be boiling hot" James Watt to his friend John Robison Scottish engineer James Watt (1736-1819) was responsible for some of the most important advances in steam-engine technology. Steam engines had been in use since the 1710s, mainly to pump water from mines. These machines depended upon steam condensing inside a large cylinder after the cylinder was cooled with cold water. As the steam condensed, it took up less space, allowing atmospheric pressure to push down on a movable piston inside the cylinder. In 1765 Watt made the first working model of his most important contribution to the development of steam power; he patented it in 1769. His innovation was an engine in which steam condensed outside the main cylinder in a separate condenser; the cylinder remained at working temperature at all times. Watt made more...

"After a complex laparoscopic operation, the 65-year-old patient was home in time for dinner." Elisa Birnbaum, surgeon The laparoscope is the James Bond-like gadget of the surgeon's repertoire of instruments. Only a small incision through the patient's abdominal wall is made into which the surgeon puffs carbon dioxide to open up the passage. Using a laparoscope, a visual assessment and diagnosis, and even surgery can then be performed using tiny tools. This surgery causes less physiological damage, reduces patients' pain and speeds their recovery leading to shorter hospital stays. In the early 1900s, Germany's Georg Kelling (1866-1945) developed a surgical technique in which he injected air into the abdominal cavity and inserted a cytoscope—a tubelike viewing scope—to assess the patient's innards. In late 1901, he began experimenting and successfully peered into a dog's abdominal cavity using the technique. Without cameras, laparoscopy's use was limited to diagnostic procedures carried out by more...

Before the early 1990s, the Internet was primarily a text-based medium as bitmap (binary data) images were too large to easily download or distribute. This all changed with the introduction in 1992 of the JPEG—a new standard for compressing the size of images. These days the term JPEG is well known, but surprisingly it was not meant to be the name of a picture format. The term comes from the Joint Photographic Experts Group, the international organization set up in 1986 that came up with the standard compression algorithm responsible for reducing the amount of memory JPEG pictures take up. Technically, the JPEG format is called JFIF, for JPEG Pile Interchange Format, but the name never stuck. JPEG works by converting the pixels of a color image into blocks of pixels, and then taking an average of the values of the brightness and color of these blocks so that less more...

Today the deadly and debilitating poliomyelitis virus is only endemic in four countries—Afghanistan, India, Nigeria, and Pakistan. This is- thanks to the groundbreaking research undertaken by U.S. medic and biologist Jonas Salk (1914-1995). In 1947, at the University of Pittsburgh, SaIk combined his work on the influenza vaccine with searching for a vaccine to protect against polio. The virus was deadly in 5 to 10 percent of cases where patients became paralyzed, and thus were unable to breathe. Medical opinion at the time held that only a live virus could prompt complete immunity, but Salk disproved this. In 1952 he used formaldehyde to inactivate the polio virus and developed a vaccine still capable of triggering an immune response in a host. Initially tested on monkeys, then patients at the D. T. Watson Home for Crippled Children, Salk's success convinced him to test it on himself, his family, his staff, and more...