Crick on Coding
“The nucleic acids are made by joining up four kinds of nucleotide to form a polynucleotide chain. The chain provides a backbone from which four kinds of side group, known as bases, jut at regular intervals. The order of the bases, however, is not regular, and it is their precise sequence that is believed to carry the genetic message. The coding problem can thus be stated more explicitly as the problem of how the sequence of the four bases in the nucleic acid determines the sequence of the 20 amino acids in the protein. —F.H.C. Crick”
Crick shared the 1962 Nobel Prize in medicine for work he had done in 1953.
“Two items of information that psychologically do not fit together are said to be in a dissonant relation to each other. The items of information may be about behavior, feelings, opinions, things in the environment and so on. The word ‘cognitive’ simply emphasizes that the theory deals with relations among items of information. Such items can of course be changed. A person can change his opinion; he can change his behavior, thereby changing the information he has about it; he can even distort his perception and his information about the world around him. Changes in items of information that produce or restore consistency are referred to as dissonance-reducing changes. Cognitive dissonance is a motivating state of affairs. Just as hunger impels a person to eat, so does dissonance impel a person to change his opinions or his behavior. —Leon Festinger”
Bacteria vs. Locusts
“A bacterial epidemic has within two years freed Yucatan of the locust swarms which periodically invaded the country. The malady lasts 12 to 46 hours and is characterized by a violent diarrhea, the contents of the bowels of the insects yielding a nearly pure microbe culture. The microbe has been isolated by M. Félix d'Hérelle, who in a memoir presented to the French Academy of Sciences examines its specific pathological effects. Now, M. d'Hérelle, having been asked by the Argentine government to test the effects of the same microbe on another locust species which every year devastates large portions of the Parana district, has reached surprisingly favorable results.”
D'Hérelle's continued work on bacteria eventually led to his discovery of bacteriophages (viruses that infect bacteria) in 1917.
The Despised Horse “The London Daily Mirror published a trenchant editorial on the foolishness of taxing automobiles for the use of city streets: ‘The horse is a danger and a nuisance in the streets of a large city. We hear a lot of motor-car street taxes, but it is the horse which should be taxed, not the motor car. The horse is unhygienic, erratic and occupies too much space. Tax the horse as you would dogs, and leave the motor cars alone!’”
“The gearing of vessels by which the anchors are hoisted and let go, constitutes a very important mechanism for the safety and working of every ship that goes upon the ‘mighty waters.’ The accompanying engraving [see opposite page] represents this gearing in different and improved forms.”
Inventions Helping Farmers
“The report of the Superintendent of the Census for 1860 says: ‘The greatest triumphs of mechanical skill, in its applications to agriculture, are witnessed in the instruments adapted to the tillage, harvesting and subsequent handling of the immense grain crops of the country, and particularly upon the Western prairies. Without the improvements in plows and other implements of tillage, which have been multiplied to an incredible extent, and are now apparently about to culminate in the steam plow, the wheat and corn crops of those fertile plains could not probably be raised. The reaping machine, the harvester and machines for thrashing, winnowing and cleaning wheat for the market, have become quite indispensable to every large grain grower.’”
View a slide show of agricultural technology from 1862 at www.ScientificAmerican.com/oct2012/agriculture
This article was originally published with the title 50, 100 & 150 Years Ago.