explosionchemical reaction

• ballistics ballistics

  ...shot are released. The shot is briefly overtaken by the rapid gas outflow and so may suffer severe yawing. The blast shock wave, traveling outward at a speed greater than that of sound, is heard as gunfire. Heat generated near the muzzle causes flash, which in large guns is accompanied by flames. Devices can be affixed to the muzzle to suppress blast and flash by dispersing shock waves, and...

• history of fusion bomb nuclear weapon

  Just prior to the conference, on May 8 at Enewetak atoll in the western Pacific, a test explosion named George had successfully used a fission bomb to ignite a small quantity of deuterium and tritium. The original purpose of George had been to confirm the burning of these thermonuclear fuels (about which there had never been any doubt), but with the new conceptual understanding contributed by...

• major reference technology, history of

  Assuming that the use of nuclear weapons can be averted, world civilization will have to come to grips with the population problem in the next few decades if life is to be tolerable on planet Earth in the 21st century. The problem can be tackled in two ways, both drawing on the resources of modern technology. In the first place, efforts may be made to limit the rate of population increase....

• deterioration of environment biology

  ...been the realization that man is as dependent upon the Earth’s natural resources as are other animals. The progressive destruction of the environment can be attributed, in part, to an increase in population pressure as well as to certain technological advances. Thus, though lifesaving advances in medicine have resulted in a dramatic drop in the death rate, they have also been a factor...

• modernization and industrialization

influence on

• birth control birth control

  In 1790 a Venetian monk, Gianmaria Ortis, concluded that human population growth could not continue indefinitely. Malthus’ work a few years later stimulated more discussion and also provided the intellectual clue that inspired Charles Darwin’s theory of biological evolution through the survival of the fittest. The debate about human numbers remained academic, however, until the 1950s, when a...

• urbanization urbanization

  One result of continued economic development and population growth could be the creation, in the next 100 years, of megalopolises—concentrations of urban centres that may extend for scores of miles. Evidence of this phenomenon has appeared on the east coast of the United States, where there may eventually be a single urban agglomeration stretching from Boston to Washington, D.C. Other...

• role in seismic survey seismic survey

  ...the time interval that elapses between the initiation of a seismic wave at a selected shop point and the arrival of reflected or refracted impulses at one or more seismic detectors. Though dynamite exploded underground is most commonly used to initiate the seismic waves, an electric vibrator or falling weight (thumper) may also be employed at sites where an underground explosion might cause...

• combustion reaction oxidation–reduction reaction

  It follows from the theory of branched-chain reactions that there is a limit to ignition, or to explosion, without a rise of temperature. In this case, what is called a chain explosion will occur when the probabilities of chain branching and of termination are equal. Usually, however, explosions are of a chain-thermal nature (i.e., both heat accumulation and chain auto-acceleration...