From nuclear disaster to transistor

2000/06/01 Kortabarria Olabarria, Beñardo - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Historia

Researchers at Bell Willian Shockely, Walter Brattain and Jon Bardeen presented the transistor on 23 December 1947. The three inventors immediately realized the importance of discovery, but in those years no one felt the influence of transistor development. Electronic Business magazine last December described the discovery as: "... was presented as a vacuum pipe replacement device, currently comparable to the invention of the wheel." The transistor was formed by thin sheets of semiconductor germanium. Being small in size and stronger, it had a great advantage over valves and pipes. Nobel Prize in Physics. 20 years later, electronic machines with a transistor at the base became ordinary machines.

However, before the invention of the transistor, in the 1940s there were important advances in the field of Electronics: The first programmable calculator was capable of adding 3/4 per second and multiplication took about 3 seconds (1941). The Harvard Mk I calculator, a five-ton calculator, was built. IBM director Thomas Watson said: "I think there can be a market for 5 computers in the world" (1943). They finished the ENIAC computer, 30 tons, with 18,000 electronic valves and 5,000 operations per second. Although by then the transistor was already invented, the University of Manchester presented the computer Mark I, the first computer capable of using the programs it had stored in memory (1948). EDVAC, the first computer to use magnetic tape. It was a revolutionary system, since to reprogram all computers until then it was necessary to change the cables (1949). In view of this, that same year the magazine Popular Mechanics made a brave announcement for the time: "Future computers can weigh less than 1.5 tons." They succeeded.

It is observed that the smallness of the atom is mentioned in the period 30-39. And it is true, but being small it has enormous power to destroy atoms. In 1945 a demonstration of the misuse of this power was made. But it's not that simple. In 1941, in the middle of World War II, Ernest Lawrence arrived at the Manhattan project, which aimed to build atomic explosives in the United States. This man was the designer of the cyclotron, the nuclear accelerator. Since he learned of the fission, Lawrence tried to figure out how the uranium fission in the cyclotron occurred and put his research team into it. In the following years, the work done in laboratories with cyclotrons resulted in numerous results, due to the appearance of new elements derived from the fission of uranium: the first neptune and the later plutonium. The plutonium with advantage over the neptune was capable of fission with slow neutrons. This allowed to optimize the use of uranium. In fact, only the U-235 isotope could cause a chain reaction, being this isotope very poor, while the U-238 isotope was not able to cause a chain reaction, but could produce plutonium.

Therefore, the bases of the atomic explosives were established, it was already a real choice. In November 1942, the Los Alamos laboratory was opened in New Mexico, with the aim of conducting nuclear explosion tests. On July 16, 1945, the first atomic bomb exploded in the desert of New Mexico. On August 6 of the same year an atomic uranium bomb destroyed Hiroshima; three days later, a plutonium destroyed Nagasaki. The war ended and the nuclear era began.

The most important facts and discoveries of the decade can be mentioned, but in other areas too much progress was made. In medicine, for example, they began to perform the first safe blood transfusions, found the way to produce pure and concentrated penicillin, and removed antibiotic streptomycin to fight tubercolosis. New materials also increased: velcro, polyester, silicones, etc. Also, as far as the media is concerned, the tube of the shadow mask was invented, the basis of color television. Edwin Herbert Land invented the Polaroid system and launched the Polaroid camera. In another field, Willard Frank Libby launched the 14 carbon dating system. Among the appliances, after checking that microwaves are able to heat food, they brought the microwave to the market. The development of the field of means of transport was also important: they launched the world's largest water plane, the 200-tonne Mars aircraft, the first supersonic flight in history with the Bell X-1 aircraft, flew to the world and took the first nonstop lap... and took the first steps of the era of space launchers.