Module 4 Unit 1 Abacus

This may sound surprising but most of the discoveries and inventions on which modern societies have been constructed were made in prehistoric times.

It is a good idea to think about the history of arithmetic, mathematics, writing and recording information. Man's invention of the computer resulted from man's need to quantify, to count and to do mathematic calculations.

The earliest counting devices known to man were his own hands and fingers. Primitive people needed a way to calculate and store information for future use. To keep track of the number of animals killed, they collected small rocks and pebbles in a pile. Each stone stood for one animal. In other words, early man counted by means of matching one set of objects with another set (stones and sheep). The operations of addition and subtraction were simply the operations of adding or subtracting groups of objects to the sack of counting stones or pebbles. Early counting tables, named abaci, not only formalized this counting method but also introduced the concept of positional notation that we use today.

The next logical step was to produce the first "personal calculator"—the abacus—which used the same concepts of one set of objects standing for objects in another set, but also the concept of a single object standing for a collection of objects, that is positional notation.

The Chinese abacus was developed about 5000 years ago and it was man’s first attempt to automate the counting process. It was built out of wood and beads. It could be held and carried around easily. The abacus was so successful that its use spread from China to many other countries. And it is still in use in some countries today.

The abacus does not actually do the computing, as today's calculators do. It helps people to keep track of numbers as they do the computing. People who are good at using an abacus can often do calculations as quickly as a person who is using a calculator.

All in all, only when the process of counting and arithmetic became a more abstract process and different sizes of groups were given a symbolic representation so that the results could be written on a "storage medium" such as papyrus or clay the process of calculation became a process of symbol manipulation.

(Adapted from: http://www.ideafinder.com/history/inventions/abacus.htm)

Module 4 Unit 2

“My name is Anthony Willbourn and I am a chemist.

I was really fortunate to be able to meet and talk to the discoverers of polythene because many plastics, as they were developed, didn't have individuals you could point to and say, he or she was a discoverer. The discovery was made in 1933 by two men - Gibson and the other one was Eric Forsett, and he was trained as an organic chemist, and they were working in the field of the study of phenomena at high pressures.

They had no idea what they were going to find. And certainly didn't plan to make a plastic. In fact, they were trying to react, at that very moment, ethylene with benzaldehyde, to make a very ordinary sort of compound, ethyl phenyl ketone. But they didn't make it. They made by accident a white, waxy solid, and the other problem was that, when they tried to repeat these experiments, they didn't produce anything at all. They had explosions, because the gases decomposed explosively. And all this was being done in an open laboratory, which today would be unthinkable, because the pressures were up at about two thousand atmospheres. And they reacted at about 180 degrees centigrade.

And finally they had produced a few grams of this white waxy solid, because it was interesting of course, they had to stop the work because it was too dangerous, and they had to wait until a special building had been completed, into which they could put this equipment and work safely.

What was basically remarkable was that they made something they didn't expect to make. Nobody knew that you could join together these atomic components and produce molecules of such enormous lengths, which gave it not only good solid state properties, but a sort of toughness that made it possible to make cable covering, and to make films and so on.

The first plant which had a capacity of only making pounds per day came into operation in September 1939, the day the war broke out. And that was very significant, because within several months it became clear that polythene was the ideal material for making radar and using it from aircraft, which had been impossible before polythene became available. The RAF, which was of course heavily outnumbered by the Luftwaffe, couldn't stay in the air long enough to find the enemy and engage them without some help. And radar provided that essential help that made it possible for the RAF to contain the attacks of the enemy.

So of course polythene had a tremendous practical effect on the war effort."

(Abriged and dapted from http://www.bbc.co.uk/worldservice/people/features/mycentury/transcript/wk37d2.shtml)