Wednesday, January 18, 2012

The 5 Best Graphing Calculators

!±8± The 5 Best Graphing Calculators

Graphing calculator is a kind of handheld calculator that is able to plot graphs, perform a variety of tasks with variables and even perform simultaneous equations. Some of these calculators are programmable and are used for educational, engineering and even scientific purposes. These calculators have large screens for plotting graphs. Some of these calculators can even be attached to other gadgets like Ph gauges, decibel meters, light meters, electronic thermometers and other sensors. When attached to these gadgets, the calculator will act as a data logger. Other graphing calculators have 3D graphing and contour displays. If you want to have a graphing calculator, here are 5 of the best calculators in the market today.

Texas Instruments TI-84 Plus Graphing Calculator: This calculator handles calculus, engineering, trigonometric and financial functions. It has a USB port for file sharing with other calculators or connecting to a PC. It displays graphs and tables on split screen to trace graph while scrolling on the value table. It also has 11 apps preloaded. HP 50g Graphing Calculator: This one has a powerful SD card slot which enables you to format in your calculator and expand your memory. It also has a massive 2.5Mb of total memory, 512 kb RAM, and 2 MB flash ROM for future upgrades. Texas Instruments TI-89 Titanium Graphing Calculator: This one handles calculus, algebra, matrices, and statistical functions. It has 188 KB RAM and 2.7 MB flash memory for speed. It has plenty of storage for functions, programs and data. Texas Instruments TI-84 Plus Silver Edition Graphing Calculator: This one displays tables and graphs on a split screen so you can trace the graphs while you are scrolling through table values. It also has the USB on-the-go technology so you can share files with other calculators or connect with a PC. Casio fx-9860G Slim Graphing Calculator: This calculator has a RAM of 64KB and a flash ROM of 1.5MB. Its screen size is 64x128 pixels and it has an interface icon menu.

So if you want a graphing calculator that can be trusted, choose from these choices.


The 5 Best Graphing Calculators

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Sunday, January 1, 2012

From Dynasty to Destiny: Ten Celebrated Inventions of Ancient China

!±8± From Dynasty to Destiny: Ten Celebrated Inventions of Ancient China

In the last two centuries, new cultural discoveries have nearly rewritten history. It's been an exciting time, full of adventure and surprises. Around every corner there are new responses to questions we had already imagined answered. And of these breakthroughs, none shines as brightly as the impact of ancient Chinese inventions on modern life. As we explore ten of the greatest inventions and innovations of Ancient China, you may be surprised at their influence on recent technology.

1. Paper. Paper, as we know it, was invented in China around the year 105. After seeing earlier attempts made from silk, bamboo sticks and animal skins, Cai Lun came up with his own idea. After mixing mulberry bark, rags, wheat stalks and other stuff, a pulp formed. This pulp was pressed into sheets and dried, becoming a crude form of paper. Paper was such an important invention that the process of making it was a jealously guarded secret. The secret was safe until the seventh century when the art spread to India.

2. The Printing Press. Before Johann Gutenberg "invented" the printing press in the 1440's, China created a type of printing press between 206 B.C. and A.D. 45. It was made using stone tablets to create a "rubbing" of famous Buddhist and Confucian texts. Next came block printing in the Sui Dynasty. In block printing, images and words were engraved on wooden boards, smeared with ink and pressed onto sheets of paper. Later, moveable type printing presses were introduced. According to the authors of Ancient Inventions, "By A.D. 1000, paged books in the modern style had replaced scrolls - a good 450 years ahead of Gutenberg."

3. The First Book. Due to the early advent of the printing press, China also claims the first book. In 868, almost six hundred years before the Gutenberg Bible, the earliest known book was printed. By the end of the Tang dynasty, China had bookstores in almost every city.

4. Paper Money. While today you'd rather carry a lot of cash instead of coin, that hasn't always been the case. The idea of paper currency was first attempted under Emperor Han Wu-Ti (140-87 B.C.) after war had drained the treasury. He issued treasury notes, worth and in exchange for 400,000 copper coins. Instead of paper, the Emperor used the skin of the white stag. But the creature was so rare that the idea soon lost appeal. In the early 800's, the idea revived to deter highway robbers. In 812, the government was again printing money. By the year 1023, money had an expiration date and was already plagued by inflation and counterfeiting. Nearly six hundred years later paper money headed west, first printed in Sweden in 1601.

5. The Abacus. Well before Texas Instruments, the first calculator was in the works. The abacus dates from around the year 200 B.C. It is a very advanced tool with a simple design. Wood is crafted into a rectangular frame with rods running from base to top. About 2/3's from the base, a divider crosses the frame, known as the counting bar. On each of the rods are beads. All of the beads above the counting bar equal five. Those below equal one. The rows of rods are read from right to left. The furthest bar to the right holds the one's place, the next holds the ten's place, then the hundred's, and so on. While its design may sound complex, there are some Chinese today so skilled that they can solve difficult math problems faster than someone using a calculator!

6. The Decimal System. In the West, the decimal system appeared quite recently. Its first believed instance was in a Spanish manuscript dated around 976. But, the first true example goes back much further. In China, an inscription dated from the 13th century B.C., "547 days" was written as "five hundred plus four decades plus seven of days." The Chinese likely created the decimal system because their language depended on characters (like pictures) instead of an alphabet. Each number had its own unique character. Without the decimal system, the Chinese would have had a terrible time memorizing all of these new characters. By using units of ones, tens, hundreds, etc., the Chinese saved time and trouble.

7. The Mechanical Clock. In the year 732, a Buddhist monk and mathematician invented the first mechanical clock. He named it "Water-Driven Spherical Bird's-Eye-View Map of the Heavens." Like earlier clocks, water gave it power, but machinery cased the movement. But, after a few years, corrosion and freezing temperatures took their toll. It wasn't until 1090, when astronomer Su Sung designed his mechanical marvel "Cosmic Engine", that a more dependable timepiece was made. Created for Emperor Ying Zong, this clock had a tower over 30 feet tall. It housed machinery that, among other things, caused wooden puppets to pop from one of five doors at regular intervals throughout the day. (Much like the modern idea of a Cuckoo clock.) The entire machine was powered by a giant waterwheel. This clock ran until 1126, when it was dismantled by the conquering Tartars and moved to Peking for another several years. The first clock reference in Western history was in 1335, in the church of St. Gothard in Milan.

8. The Planetarium. A planetarium is a big enclosed space that shows the stars and constellations on the inside. Orbitoscope was the name of the first projection planetarium. It was built in Basil in 1912 by Professor E. Hinderman. But, once again, China is the mother of this invention. The first planetarium is attributed to the design of an early emperor. As one source states, an astronomer named Jamaluddin created a planetarium during the Yuan Dynasty (1271-1368), along with a perpetual calendar and other important astronomical devices.

9. The Earthquake Sensor. The earliest earthquake sensor was also an interesting piece of art. It was a bronze cylinder about 8 feet around, with 8 dragons perched above 8 open-mouthed frogs. In the mouth of each dragon rested a bronze ball. When an earthquake struck, a pendulum inside the cylinder would swing. It knocked the ball from the mouth of the dragon and down into the frog's mouth. That frog's back was then facing the direction of the center of the quake. Chang Heng invented it in A.D. 132 (during the Han Dynasty), almost 600 years before the first western sensor was made in France. Later, in 1939, Imamura Akitsune recreated the invention and actually proved it effective.

10. The Helicopter Rotor & Propeller. While the Ancient Chinese didn't actually invent the helicopter, they were involved in its creation. In the 4th century A.D., they invented a toy called the "Bamboo Dragonfly". You've probably seen them as prizes at local fairs or carnivals. It was a toy top, with a base like a pencil and a small helicopter-like blade at the end. The top was wrapped with a cord. When you pulled the cord, the blade would spin around and soar into the air. This toy was studied by Sir George Cayley in 1809 and played a role in the birth of modern aviation. It wasn't until the early 1900's that the first helicopter took flight.

It is sometimes a mind blowing thing to realize that what seemed to be modern ideas or inventions are much older than we'd imagined. And it's likely that there are more inventions to be discovered. More historical changes to be made. In the conclusion of The Greatest Inventions of the Past 2,000 Years, Jared Diamond summed it up well while referring to the changing view of history and its inventors, "So, forget those stories about genius inventors who perceived a need of society, solved it single-handedly, and thereby transformed the world. There has never been such a genius........If Gutenberg hadn't devised the better alloys and inks used in early printing, some other contemporary tinkerer with metals and oils would have done so......do give Gutenberg some of the credit---but not too much."

Questions:

1. Choose one of the inventions mentioned. Explain how different the world would be if it hadn't been invented.

2. Why do you think there was such a large space of time between the Eastern and Western dates of invention?

3. What are two other inventions that came from ancient China? Research and find out when the idea was introduced to Western culture.


From Dynasty to Destiny: Ten Celebrated Inventions of Ancient China

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