sade030

  The earliest microscope was no more than a single small lens that magnified between 6 and 10 times.   Sacharias Jensen and his father, Hans, a lens maker, experimented with combinations of lenses and realized that greater magnification could be obtained by an inversion of the telecope.   Their compound microscope combined a magnifying objective lens (the one closest to the object being investigated) with an eye lens at the opposite end of a tube.   A focusing device was added by the Italian Gallileo Galilei. The circulation of blood through capillaries was observed by the Italian physiologist Marcello Malpighi (1624-1694).   The popularity of microscopes was greatly enhanced by the publication of Micrographia (1655) by English scientist Robert Hooke.   The Dutchman Anthoni van Leeuwenhoek (1632-1723) used a microscope to count the number of threads in woven cloth, and his refined instrument could magnify 270 times.   Van Leeuwenhoek’s microscope on...

Dennard combines a transistor with a capacitor in a revolutionary memory cell.  RAM, a random Access Memory, the short-term, high-speed ‘working’ memory of a computer, has existed since 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 Watson Research Centre.   IBM knew that magnetic core memory was too blocky, 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 to only six transistors.   Added to a silicon chip, this cell was already tine compared to a magnetic core.   Dennard, though simplified the memory cell even more to a single transistor and a capacitor, a component that can hold an electric charge.   The memory was used to read and write it.   Capacitors “leak” charge through so the memory had to be continuou...

There is a story that when French scientist and inventor Deins Papin (1647-1712) first demonstrated his wonderfully named ‘digester’ to London’s Royal   Society in 1679, the device exploded.   So another invention swiftly came into being: “Papin’s Safety Valve”, which went on to have other applications. By 1682, a refined version of the steam digester proved excellent at cooking food and making nutritious bones soft and tasty.   After a demonstration dinner at the Royal Society in that year, one guest, leading horticulturalist John Evelyn noted in his diary that food served from the digester was among the most delicious that I have ever seen or tasted. Papin was an interesting character of diverse scientific interest.   Trained in medicine as a young man, he had long been interested in food preservation.   His tightly sealed digester vessel showed how atmospheric pressure affected boiling points.   Under high pressure water in the vessel produced steam th...

 Russian doctor Osip Krichevsky first produced powdered milk in 1802.   It is made by drying or dehydrating milk until it forms a fine white powder.   This can be achieved either by spraying a fine mist of milk into a heated chamber or by adding the milk in a thin layer to a heated surface, from which the dried milk solids can be scraped off.   Freeze-drying is now used because it conserves more nutrition and the milk cane be fortified to improve its nutritional value.   The resulting powder can then be stored for a long periods, because the dry environment means it is less prone to bacterial contamination that   would spoil fresh milk. As well as its potential for long term storage, powdered milk has several practical advantages over fresh milk.   In the developing world, its relative light weight and the fact that is does not need refrigerating mean that it is easy to transport over long distances, without the need for expensive refrigerated trucks...

Not everyone has their own award named after them.   The Oskar Barnack award, given annually to photo journalists, was initiated in 1979 to mark the hundredth anniversary of the birth of the man who invented the 35-mm still camera.   Barnack (1879-1936) had the idea for it back in 1905, but it was not until 1913-1914, while he was working as head of development at the German Camera company Leitz, in Wetzlar, Hesse, that he was able to transform his idea into reality. Traditional heavy plate cameras were cumbersome to use and required significant preparation before each shot.   It was impossible to take a quick snap of anything.   Barnack’s camera was a tough metal box that could fit in a jacket pocket and used a new kind of film, adapted from Thomas Edison’s 35-mm cine film.   In 1914 Barnack took a picture of a soldier who had just put up the Imperial order for mobilization.   This was a new kind of picture-spontaneous and capturing a moment in history....