Thundering cannons herald the outbreak of wars and inflaming speeches herald political revolutions but scientific and technological revolutions usually come quietly without any fanfare. Something like that happened in Ohio State’s small town named Troy having barely 15,500 inhabitants on June 26, 1974. A small boy walked into a provision store to buy a packet of chewing-gum candies as soon as it opened for business. Who would take notice of a packet of candies bought by a small boy in a little-known town in a country which consumed fifty thousand tones chewing-gum every year? Even though this ordinary transaction had all the ingredients for a journalistic scoop, not even local newspaper considered the event newsworthy. A bar code label having twelve vertical black and white lines resembling teeth of a hair comb was printed on the packet of the chewing-gum. As the electronic bar code reader scanned that label the computer of the shop automatically carried out following tasks: It printed a cash memo containing details like brand name of chewing-gum, net weight of the packets contents, batch number, sale price etc. Simultaneously, the computer reduced one packet in the stock register to show the net stock of that variety and since the chewing-gum sold like a ‘hot cake’ added one packet to the order list while the small boy had satisfaction of seeing on a display meant for the customer, the sum of money he had to pay. This insignificant transaction was the harbinger of a great commercial revolution because for the first time in the human history a thing was sold on the basis of bar code alone. Yet no one foresaw that it was the beginning of the future revolution.
Within a period of thirty seven years since that eventful day, bar code is so widely used that instead of asking where else bar code is used besides the provision store and super markets, one has to ask whether there are any fields left wherein bar code system is not used. It is no wonder that grocery and provisions manufacturing and distributing sectors have already adopted the bar code system because mere scanning of the bar code labels enables the manufacturers and sellers to keep accurate computerized sales and inventory records of innumerable products irrespective of the size of the packages and quantities contained in them. What will come as a surprise to many readers is that bar code readers (scanners) are installed near suitable railway signal cabins in the USA and Europe. They read the bar code painted on the side of every wagon of the passing goods trains and convey information regarding those trains’ whereabouts and the expected time of arrival at their destinations to the railway companies which own them. Constant computerized tracking with the help of bar code system enables those railway companies to use their rolling stock efficiently. Some hospitals encode medical data of their patients in the bar code format and airlines attach bar code labels on the passengers’ baggage to keep track. Many libraries use bar code system for identification of the books as well as for checking the members’ ID cards. In its last war against Iraq the USA had kept inventory of the bombs by bar coding them.
Last but not least, bar code readers installed at various check points of cross-country races like the marathon race read bar code labels affixed on the vests of the passing competitors in order to record the order and time of their arrival at each check point.