Floppy disk(1971) Noble and IBM develop flexible data storage.

In 1967, IBM was looking for a better way of sending software to its customers. Their popular system/370 mainframe computers "booted up" from big, heavy magnetic tapes, which were slow and expensive to ship. Engineer David L. Noble(b.1981) tried all sorts of improvement schemes, from better tape systems to vinyl records, just like those used for music.

None of them were right for the job, so Noble proposed a new system based on a flexible disk of magnetic material. Developed by IBM over the next few years and finally released commercially in 1971, IBM's 8-inch (20 cm) "floppy" disk was made from flexible plastic. After a hunt for a package for mailing the new disks, the engineers had the idea of making a protective envelope part of the design of the disk itself. The disk was sandwiched into a square jacket that included a fabric liner--a built-in cleaning cloth--and the final design of all final design of all future floppy disks was born.

These cheap, light disks really caught on and over the years they shrank from 8 inches (20 cm) to 5.25 inch (13.3 cm), then to the 3.5-in (8.89 cm) standard that you may still see occasionally today. Untold billions of floppy disks were manufactured over the next thirty years.

The floppy disk is now almost obsolete, replaced by networks, flash memory, or optical media such as DVDs. These innovations can store much more information than their predecessors--to match the storage capacity of a single Blu-ray DVD, you would need 600,000 of IBM's original 80 kilobyte, 8-inch (20 cm) floppies.

Map (c. 6500 B.C.E.)

Charting of the world begins with the Babylonians.

Some of the earliest known examples of maps-in the land form of Babylonian tablets-are Egyptian land drawings and paintings discovered in early tombs. However, in 1961 a town plan of Catalhoyuk in Turkey was unearthed, painted on wall. Featuring houses and the peak of a volcano,it is around 8,500 years old.

The sixth-century tablet known as Imago Mundi shows Babylon on the Euphrates, with cities on a circular land mass, surrounded by a river. Some maps are known as T and O maps. In one illustrating the inhabited world in Roman times, T represents the Mediterranean, dividing the continents. Asia, Europe, and Africa, and O is the surrounding ocean. The T and the O Hereford Mappa Mundi of 1300, drawn on a single sheet of vellum, includes writing in black ink and water painted green, with the Red
Sea colored red.

Greek scholars developed a spherical Earth theory using astronomical observations, and in 350 B.C.E. Aristotle produced arguments to justify this practice. In the first century C.E., Ptolemy, an astronomer and mathematician, developed a reference-line principle. His Guide to Geography lists 8,000 locations with their approximate latitudes and longitudes. However, Ptolemy underestimated the size of the Earth. His suggestion that India could be reached by traveling westward resulted in Columbus underestimating the distance centuries later. Cartography greatly benefited from wealth of corrective information brought to Europe by Marco Polo in the thirteenth century.

The 1981 International Geographical Congress established specifications for a scale map of the world, and World Wars I and II brought more progress.

Invention of photography (1826)

Niepce uses light-sensitive chemicals to take the first photograph.

Ever since the invention by Alhazen (965-1040) of the pinhole camera, which projected an image onto a surface, people sought a way of "fixing," and thus recording, that image. By accident, in 1727, the German chemist Johann Schulze discovered that a mixture of chalk, nitric acid, and silver darkened when exposed to sunlight, and the rate of darkening increased if more silver was added. By 1777 the Swedish chemist Carl Scheele had been able to fix, or make permanent, the results of this change using ammonia.

Joseph Nicephore Niepce (1765-1833) produced the first permanent photographic image in 1826. he first used a flat pewter plate covered with bitumen, but then quickly moved on to silver compounds. Louis Daguerre produced silvered images that were very delicate and could not be copied. although the exposure time was about ten minutes, he managed to produce daguerreotypes of famous people such as Abraham Lincoln (1846) and Edgar Allen Poe (1848). Around this time William Henry Fox Talbot produced the calotype, in which an intermediate stage of the process resulted in a paper "negative" that could be used to make a multitude of final "positive" prints. Unfortunately, the paper and glass plates were wet.

By 1884 George Eastman invented a dry process. Cameras became simple to use and all the complex chemistry could be left for later processing.

1907 heralded the commercial color photographic plate, and 1925 saw the introduction of 35-millimeter film. In the kate 1980s, the manufacture of relatively inexpensive megapixel charge-coupled devices threatened the demise of film-based technology.

Lunar Calendar (c. 15,000 B.C.E.)

Early humans record the passing of time.

The earliest known lunar calendar is in the caves at Lascaux, southwest France, and dates from around 15,000 B.C.E. Various series of spots represent half of the moon's near-monthly cycle, followed by a large empty square, which perhaps indicated a clear sky.

   A  lunar calendar counts months ( a period of 29.530588 days) and is based on the phrases of the moon. Months have twenty-nine and thirty days alternately, and additional days are added every now and then to keep step with the actual moon phase.

   The lunar calendar was widely used in parts of the ancient world for religious observation. Agriculturally the lunar calendar is confusing as it takes no account of annual seasonal variations in temperature, daylight lenght, plant growth, animal migration, and mating. .the lunar month divides into the solar year twelve times but with 10.88 days remaining.

  Meton of Athens (circa 440 B.C.E.) noticed that nineteen-year Metonic cycle where years three, five, eight, thirteen, sixteen, and nineteen had thirteen lunar months each, and all the other years had twelve months.

"DAY ARE PUSHED BY THE DAY, AND EACH NEW MOON HASTENS TO ITS DEATH.."

                                                                                                                      -Horace, Odes, Book II

Random Access Memory (RAM) (1968)

Dennard combines a transistor with a capacitor in a revolutionary memory cell.

   
RAM, or Random Access Memory, the short term, high speed "working" memory of a computer, has existed sine the invention of magnetic core memory in 1949. Modern RAM, though, owes its invention to Texan Robert Dennard (b. 1932).

     In 1966 Dennard was working at IBM's Thomas J. Watson Research Center. IBM knew that magnetic core memory was too bulky, power-hungry, and slow, and that transistors would be the answer to replacing it. They had reduced the problem of storing a single bit of memory to a cell that used only six transistors. Added to a silicon chip, this cell was already tiny compared to a magnetic core. Dennard, though, simplified the memory cell even more, to a single transistor and capacitor, a component that an hold an electric charge. The memory was stored as charge on the capacitor, and the transistor was used to read and write it. Capacitors "leak" charge, though, so the memory had to be continuously refreshed, many times a second. Because of this constant forgetting and refreshing, Dennard's system is called "dynamic" RAM, or DRAM.

    Despite its need to be refreshed, DRAM had a world-beating advantage. With only two components, which could be placed side by side in the thousands on a single silicon chip, it was the smallest memory ever made. The computer industry quickly took advantage of Dennard's invention, and fledgling company Intel released the first commercial DRAM chip in 1970. Magnetic core memory became the technology of yesteryear almost as soon as Intel began to ship its new chip.