Science Projects And Inventions

They are so commonplace today that many people even have them in their cell phones; some companies have even added them to digital watches. Digital cameras are now taken for granted, but it was only in 1975 that the first prototype was produced. Steve Sasson (b. 1950) had recently graduated in electrical engineering before taking a job with Kodak. His assignment was a broad one: Was it possible to make a camera using solid-state electronics? Starting from Scratch, he gathered together various pieces of electronic equipment including a movie camera lens, an analog-to-digital converter, and, most importantly, charge-coupled devices (CCDs). By December 1975 Sasson's rough prototype was ready for initial testing. Weighing in at 8 pounds (3.6 kg) and the size of a toaster, the camera was hardly portable, but Sasson convinced a lab assistant to pose for a test shot. It took twenty-three seconds for the image to be more...

"Computers offer the possibility of truly individualized instruction." Donald Bitzer Today computers can be used to teach young children how to add up, government employees how to speak a foreign language, and even medical students how to dissect a human body. The idea of using a computer as an educational tool, or e-learning, is often seen as a recent innovation, whereas it has existed, at least in concept, for quite some time. By the end of the 1950s, computers were being used educationally by such early innovators as IBM and the University of Illinois. In 1960, Donald Bitzer was concerned about the number of illiterate students coming out of schools. When a professor posed a simple question in class one day about the use of computers for teaching, Bitzer took up the task. He designed one of the first learning systems specifically for computers, which used graphics and touch-sensitive screens. more...

"The scythe was faster... to use than the ancient, short handled,curved, serrated blade sickle." The Countryside Museum The scythe is often ranked among the world's most significant advances in agricultural implements of the past thousand years. Its appearance on the farms of Europe in the latter half of the thirteenth century was to profoundly revolutionize agricultural production. Initially used as a grass cutter to gather hay, it was later used to harvest grain. Consisting of a curved blade, sharpened on the inside of the curve, and a long wooden handle (called a snath), the scythe allowed the reaper to stand upright while cutting grass—a vast improvement over the short-bladed sickle, which required the user to stoop uncomfortably as he cut. A worker using a sickle, which was essentially unaltered in design since its emergence in around 5000 B.C.E., could harvest at best only three-quarters of an acre. (0.3 ha) per more...

“... the comparison of the rotary movements... will show no discrepancy or contradiction...." Su Song, The Rotation of an Armillary Sphere (1092) The world's first water-driven astronomical clock tower was by far the most advanced astronomical instrument of its day. Its designer was Su Song (1020- 1101), who oversaw the project with the aid of mathematician Han Gong-lian. The elaborate, 40-foot (12 m), water-powered, mechanically driven clock had bronze castings, precision gears, gear rings, and pinions. A bronze armillary sphere with a celestial globe mounted below allowed the sun, moon, and selected stars to be seen through a sighting tube. The tower was a three-level, pagoda-like structure powered by thirty-six buckets attached to a central wheel, each of which would trip a lever and tilt forward at a predetermined point to engage the clock's complex system of gears and counterweights. Song's greatest achievement, however, was an ingenious escapement mechanism that more...

Since its tentative beginnings, the diagnostic imaging technique of ultrasound—which uses sound waves to visualize the body's internal organs—has found its way into most areas of medicine. Early experiments were made by Dr. George Ludwig at the Naval Medical Research Institute in Bethesda, Maryland, in the late 1940s. Ludwig successfully.-used. ultrasonics to detect human gallstones implanted in a dog. Inge Edier (1911-2001), a Swedish cardiologist, took the idea further. He was frustrated with the inadequacies of techniques then available to examine the heart. While making decisions on heart disease prior to surgery at University Hospital Lund, he found that cardiac catheterization and contrast X-rays did not tell clinicians enough about the heart's mitral valve. He asked Carl Hertz (1920-1990), who was working in nuclear physics at Lund University, if radar might be the answer. Hertz said it was not, but he suggested ultrasonography might work instead. After borrowing an ultrasonic more...

“I don't know whether I prefer AstroTurf to grass. I never smoked AstroTurf." Joe Namath, American football quarterback James Faria and Robert Wright were researchers' at Monsanto, Inc., in the United States when they invented AstroTurf. Originally called Chemgrass, this artificial grass for sports and playing fields was first installed in 1964 at Moses Brown School in Providence, Rhode Island. Monsanto adopted the name AstroTurf after the product was installed at Houston Astrodome stadium in 1966. It was patented in 1967. The first AstroTurf, a short-pile carpet of nylon, was harder than real-grass and caused serious injuries to players. Several English League soccer teams adopted AstroTurf in the 1980s, but the clubs quickly returned to natural grass. Recent developments have largely overcome these problems. The addition of sand or rubber infill, superior backing, and nylon yarn fibers have made it as safe as normal grass. The newest version of AstroTurf, more...

"[The customers] had a tendency to stop shopping when the basket became too full or too heavy." Sylvan N. Goldman, businessman The origins of the cart are inextricably linked to the invention of the wheel. In fact, one theory of how the wheel was invented suggests that the cart and the wheel were developed simultaneously, inspired by earlier bladed sledges that were dragged across logs. The earliest sources of evidence for wheeled vehicles are Mesopotamian tablets. Although the dating methods used for these artifacts are not exact, the tablets are known to be from the middle of the fourth millennium B.C.E. Around the same time there is also evidence for wheeled vehicles in Europe, including wheel tracks at a long barrow near Kiel, Germany, and wagon pictographs found on a beaker at Bronocice, Poland. This has led archeologists to debate whether wheeled vehicles were developed in multiple places simultaneously or more...

The saw evolved from Neolithic tools. Archeologists have found metal-toothed Egyptian saws dating back to 2000 B.C.E., but China claims that the saw was invented by Lu Ban in the fifth century B.C.E. Early blades were of copper; the Romans then used iron and reinforced the blade at the top, holding it in a wooden frame. In the nineteenth century in Europe a rigid blade of steel with a pistol-grip handle was introduced to produce a more accurate cut. The cutting edge of a saw blade may be either serrated or abrasive. A handsaw with a stiff serrated blade can cut on both the push and pull strokes, but flexible blades allow cutting on the pull stroke only. Each tooth is bent to a precise angle, called the "set," which is determined by the saw's intended use Some teeth are usually splayed to each side, s-6.' that the blade does more...

"Bankers were at first reluctant to adopt a lock that barred friend as well as foe."        John Erroll and David Erroll, writers It is thought that the first time-lock safe was patented by Scotsman Williams Rutherford in 1831. His work was part of a race between banks wanting to keep their vaults secure and robbers trying to break into them. The Romans were the first to invent locks made out of metal, and these had special notches and grooves that made them more difficult to pick. In 1784 Joseph Bramah invented the first "unpickable" lock, although one locksmith did succeed, albeit after more than fifty-one hours—more time than robbers normally have at their disposal. However, during the 1800s the incidence of bank robberies was fast increasing. The solution to the problem was the time-lock, a clockwork device that prevented the bolt of a lock from being opened more...

An ink consists of a liquid base and a pigment, or dye. The pigment provides a colored residue that sticks to a surface when the liquid dries. The first inks were invented by the Chinese some 4,500 years ago, made from a mixture of soot, lamp oil, gelatin (from animal skins), and musk (to counteract the smell of the oil). The ink was used to blacken the raised surfaces of stone carvings to emphasize shapes and letters. Later, in China and elsewhere, more reliable inks were developed using powdered minerals, plant extracts, and berry juices as pigments. With the advent of writing, and of papyrus and then paper, new types and colors of ink were required for use with writing implements designed for detailed and permanent texts. Some 2,500 years ago, the Chinese developed a solid ink to be stored as a stick; such inks are still in use today. more...