Top-rated
Wed, Jan 14, 2004
There would be no guns without gunpowder, the volatile mixture of saltpetre (potassium nitrate), charcoal and sulphur that came to Europe in the 14th century. Chinese chemists were experimenting with early forms of gunpowder by the 9th century or even earlier. Mixing gunpowder was a tricky procedure largely carried out by hand under the constant threat of accidental explosions. Gunpowder production was as dirty as it was dangerous. To make saltpetre, workers mixed rotting vegetable waste and animal (or human!) excreta together in large beds and waited for nitrates to form as a white powder, which was later refined.
Top-rated
Wed, Jan 21, 2004
In Victorian times 'computers' were people who added up rows of figures. Now they are mechanical wonders - without them we couldn't fly planes, drive cars or even run our dishwashers. We need them, but will they ever get smart enough to take over? Jeremy tells the remarkable story of the computer's evolution from man with pencil to android with sub-machine gun. It's an epic spanning three centuries, a tale of passion, espionage and suicide - and it's far from over. Jeremy discovers that the threat from computers lies not with Schwarzenegger's Terminator but from a much more devastating computer - Armageddon. The computer might yet change the world in a way that none of us are expecting.
Top-rated
Wed, Feb 11, 2004
Television would never have developed without the cathode ray tube (CRT). It was invented by a German, Karl Ferdinand Braun, in 1897. A CRT is a glass vacuum tube with a narrow neck that flares into a flat "screen" at one end. The inside surface of the screen is covered with a phosphorescent layer. Electrons are fired at high voltage along the tube, illuminating when they hit the phosphorescent layer. Refined versions of this basic tube were at the heart of millions of TVs, radars and computer monitors manufactured in the 20th century.