Modern refrigeration was invented by Jacob Perkins, a Massachusetts native residing in London. Perkins's patented machine closely resembles today's refrigerator: a compressed fluid - ether for Perkins, Freon for us - evaporates to cool goods, then re-condenses. Today, fewer than one percent of American homes lack this cool convenience.
Elisha Graves Otis demonstrated the world's first safe elevator at an 1854 New York City fair. Like other elevators, Otis's invention ran up and down on a rope coiled around a power-driven drum. However, when Otis had his assistant cut the supporting rope, the public saw Otis's real innovation: a spring that set iron teeth into secure notches when tension in the rope slackened.
In 1498, the Chinese invented the toothbrush, a row of bristles mounted at right angles to a straight handle. Society has enjoyed cleaner teeth and brighter smiles ever since.
In 1582, Pope Gregory XIII boldly changed the course of history and of timekeeping when he instituted the present-day Christian calendar. The Gregorian calendar chopped ten days off the previously-used Julian calendar, which had been the standard since 46 BC, and switched New Year's Day from March to the first of January. The still-active Gregorian calendar is not quite accurate: it runs twenty-six seconds fast per year.
Daniel Fahrenheit, a German physicist working in Holland, invented the mercury thermometer. This invention was a more accurate temperature gauge than the alcohol-filled thermometer which was popular at the time. Fahrenheit's thermometer had three fixed points: water's freezing point, its boiling point, and the temperature of human blood. This temperature scale is still in use today.
John Pemberton, an Atlanta druggist, invented the famous carbonated blend of coca leaf and kola nut in 1886. Pemberton originally marketed his drink as "French wine of Coca - an ideal Nerve Tonic and Stimulant," but today 606 million people choose Coke "just for the taste of it" every day.
The twin robot geologists, the Mars Exploration Rovers, has successfully launched on the surface of Mars this year. The rovers have started their mission of looking for signs of past water, which would be helpful for further determination whether life ever arose on Mars.
when the government plans to build a dam, experts from different disciplines may be aggregated to discuss about the plan. In the discussion, it is quite possible that those experts may have contrasting points of view. The hydrologist claims that the dam would be significant in combating drought and flood; the geologist concludes that the project may be infeasible as earthquakes are frequent in this region; the economist infers that the project must be quite helpful to solve the problems of electric power deficit, and the local economics would benefit much; and the ecologist and archaeologist may disagree with the project, because building such a dam may be perilous to some species and historic relics in the ambient regions.
Perhaps the region chosen by the hydraulician is the habitat of many rare species, and thus the project would probably cause species extinction; or in the ambient region there are many priceless historic relics, which may be damaged by the project.
With the help of the Hubble space telescope, we can get more close to the universe and observe the stars, planets, nebulas, galaxies much more conveniently.
A researcher working for 3M, a materials company, had planned to make the world greatest glue. However, in the research he found the world’s worst glue, a sticky substance that never sticks. This glue is one of the best things 3M ever invented.