Science Projects And Inventions

"When the tide of misfortune moves over you, even jelly will break your teeth." Persian proverb Gels arejellylike colloidal substances that have a liquid body containing a network of interconnecting 2-5 nanometer nanoparticles surrounding 100-nanometer pores. If the liquid is carefully removed and replaced by a gas, you have an aerogel. These are light, low-density solid foams, sometimes called "frozen smoke." Steven S. Kistler (1900-1975), a chemical engineer at the College of the Pacific in California, was investigating the gels produced by the acidic condensation of aqueous sodium silicate. He noticed that gels shrank and cracked as they dried, due to the high surface tension of the water they contained. Kistler managed to stop the volume reduction by replacing the water with low-surface-tension alcohol. The end-product, aerogel, was simply the unshrunk, microporous, solid component of the original gel. In the late 1970s French rocket engineers considered aerogels—whose 99 percent air more...

The history of dentures stretches back fat" before 1791, when a dentist, Nicholas Dubois de Chemant (1753- 1824), obtained the patent for them. There are records from around 700 B.C.E. of Etruscans using dentures made from human and animal teeth. By the fifteenth century, ivory or bone dentures were in use in Europe, attached in the mouth by wire to surviving teeth. All these early forms of dentures would have been highly uncomfortable to wear, deteriorated rapidly, and contributed to the malodor of the mouth, In 1774 Alexis Duchateau (1714-1792), a French chemist who was dissatisfied with his own set of dentures, produced a new design that used porcelain teeth. He was helped in this endeavor by de Chemant. However, Duchateau was unable to promote his new dentures properly and his idea stalled. De Chemant continued the experimentation and by 1787 had perfected new dentures. He applied for the patent more...

Fiberglass consists of extremely fine glass fibers, made from molten glass extruded at a specified diameter. Glassmakers have experimented with glass fibers throughout history, but mass manufacturing had to wait for the refinement of machine tooling before a practical product could be made possible. The product commonly referred to as "fiberglass" was invented as a form of insulation by Russell Games Slayter (1896-1964)—he dropped the Russell early in life—and John Thomas of the Owens-Illinois Glass Company in-the 1930s. In 1938 Owens-Illinois and Corning Glass formed Owens-Corning to make fiberglass using Slayter and Thomas's method. Fiberglass was discovered—like many other scientific discoveries—by accident. While Thomas's assistant, Dale Kleist, was spraying molten glass for a project, tiny fibers formed. Thomas realized the process could be used to improve the production of fiberglass. Thomas and Slayter refined the process, leading to what is known as the steam-blowing method. As the molten glass is more...

"Count your blessings; in the old days, they had to send a sketch-artist up there." Two and a Half Men (2003) on colonoscopy The first eridoscope was the Lichtleiter (light-guiding instrument) developed by Philipp Bozzini (1773-1809) of Vienna, Austria, and demonstrated in 1805. Using the reflected light of a candle in a series of lenses, he was able to see inside the urinary tract, rectum, and throat. Suspicion within the medical community and his early death brought endoscopy to a halt. In 1853, Antoine Jean Desormeaux, a French surgeon, modified the Lichtleiter. He used a system of mirrors and lenses, a lamp flame for illumination that burned alcohol and turpentine, and the occasional patient. He was also the first to use the term endoscope. Dr. Adolph Kussmaul of Germany was the first to look inside the stomach of a living human with an endoscope in 1868. He did this with more...

"My whole body was shaken as though by a thunderbolt." Pieter Van Musschenbroek,physicist In 1745 the Dutch physicist Pietervan Musschenbroek (1692-1791) took a sealed glass vial partially filled with water, passed a conducting wire through a cork at one end and attached it to a nearby Wimshurst friction machine, which generated a static charge. The glass jar, called a Leyden Jar in honor of the inventor's home town  and  university,  absorbed  the  charge, demonstrating for the first time that electricity could be produced and stored successfully and then discharged through the exposed wire to any grounded object. Musschenbroek tested the device by holding the jar in one hand and touching the charged, exposed wire with the other. He received such a shock that he swore not even a promise of the entire French nation could persuade him to do so again. The Leyden jar created a sensation within the worldwide more...

“... when... Ptolemy suppressed the export of paper, parchment was invented at Pergamum…” Pliny the Elder, Natural History, Book 13 According to Pliny the Elder, parchment was developed in the city of Pergamum (now Bergama, Turkey) because a king of Egypt, fearing that Pergamum's great library might overshadow that of Alexandria, stopped exporting papyrus to the city. It seems more likely that parchment already existed and was refined at Pergamum. Also, this was not the first time animal skin had been written on. Leather had been used occasionally, possibly dating back to circa 2000 B.C.E. However, previous attempts involved tanning the leather and produced documents that were slightly hairy, stiff, and one-sided. Parchment, on the other hand, was made from the skins of sheep, calves, and goats that were cleaned and, crucially, scraped thoroughly. Both sides of the smooth, flexible surface were ideal for writing and ultimately allowed sheets to more...

Although Raymond Vahan Damadian (b. 1936) is credited with the idea of turning to nuclear magnetic resonance to look inside the human body, it was Paul Lauterbur (1929-2007) and Peter Mansfield (b. 1933), who carried out the work most strongly linked to Magnetic Resonance Imaging (MRI) technology. The technique makes use of hydrogen atoms resonating when bombarded with' magnetic energy. MRI provides three-dimensional images without harmful radiation and offers more detail than older techniques. While training as a doctor in New York, Damadian started investigating living cells with a nuclear magnetic resonance machine. In 1971 he found that the signals carried on for longer with cells from tumors than from healthy ones. But the methods used at this time were neither effective nor practical, although Damadian received a patent for such a machine to be used by doctors to pick up cancer cells in 1974. The real shift came when more...

"...when I seek out the massed wheeling circle of the stars, my feet no longer touch the Earth..." Claudius Ptolemy, matematician and astronomer An astrolabe is a device with which astronomers solved problems relating to time and the position of the sun and stars in the sky. Its main element is a two-dimensional circular stereographic projection of the hemispherical sky. The projection was most probably formalized by the Greek astronomer Hipparchus (190-120 B.C.E.), who worked on the island of Rhodes. The astrolabe was suspended vertically and a cross-arm was used to measure the altitude above the horizon of the sun (in the day) and bright stars (at night). The rim of the astrolabe is marked off in months, days, and hours, and most astrolabes have a series of longitude-specific circular main plates each marked off with lines of constant altitudes, azimuths, declinations, and right ascensions. Fitting over the plate is more...

In 1954 George Devol created the first programmable industrial robot. It consisted of a multijointed manipulator arm and a magnetic storage device to hold and replay instructions. More advanced versions worked on assembly lines in the 1960s. In 1978 the PUMA (Programmable Universal  Machine for Assembly) was introduced by Victor Scheinman and quickly became the standard for commercial robots. Dr. Yik San Kwoh..(b. 1946) invented the robot- software interface that allowed the first robot-aided surgery in 1985. "Ole"' was a modified PUMA that could perform a type of neurosurgery. In the surgery, a small probe traveled into the skull, a linked CT scanner provided a 3D picture of the brain, and the robot plotted the best path to the lesion. "Ole" was used for biopsies of deeply located suspected tumors. Before his device could be used on humans, Kwoh needed to test it. Small metal objects were inserted into four more...

A dynamo is a device that converts mechanical energy into electrical energy. For example, power for bicycle lamps used to be provided by a type of dynamo in which a ribbed cylinder resting against the bike tire was made to rotate as the cyclist pedaled along. The two main components of a dynamo are a system for producing a magnetic field (a stator) and a coil of conducting wire (an armature) that rotates in such a way that the wires continually cut through the magnetic field lines. The end product is an alternating current flowing through the wires. A third component, a commutator (a set of contacts mounted around the machine's rotating shaft) is often used to convert the alternating current into a direct current. There is a close relationship between dynamos and electric motors. One converts movement into electric current; the other, electric current into movement. In fact, traction more...