Occam’s razor

Taken From Wikipedia, the free encyclopedia on September 1, 2016

Andreas Cellarius’s illustration of the Copernican system, from the Harmonia Macrocosmica (1660). The motions of the sun, moon and other solar system planets can be calculated using a geocentric model (the earth is at the centre) or using a heliocentric model (the sun is at the centre). Both work, but the geocentric system requires many more assumptions than the heliocentric system, which has only seven. This was pointed out in a preface to Copernicus’ first edition of De revolutionibus orbium coelestium.

Occam’s razor (also written as Ockham’s razor, and lex parsimoniae in Latin, which means law of parsimony) is a problem-solving principle attributed to William of Ockham (c. 1287–1347), who was an English Franciscan friar, scholastic philosopher and theologian. The principle can be interpreted as stating Among competing hypotheses, the one with the fewest assumptions should be selected.

In science, Occam’s razor is used as a heuristic technique (discovery tool) to guide scientists in the development of theoretical models, rather than as an arbiter between published models. In the scientific method, Occam’s razor is not considered an irrefutable principle of logic or a scientific result; the preference for simplicity in the scientific method is based on the falsifiability criterion. For each accepted explanation of a phenomenon, there may be an extremely large, perhaps even incomprehensible, number of possible and more complex alternatives, because one can always burden failing explanations with ad hoc hypotheses to prevent them from being falsified; therefore, simpler theories are preferable to more complex ones because they are more testable.

Testing the razor

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Some cardiac arrest victims ignore warning symptoms

Associated Press
By LAURAN NEERGAARD  Dec. 21, 2015

Cedars-Sinai Medical Center in Los Angeles

Cedars-Sinai Medical Center in Los Angeles

WASHINGTON (AP) — Sudden cardiac arrest may not always be so sudden: New research suggests a lot of people may ignore potentially life-saving warning signs hours, days, even a few weeks before they collapse.

Cardiac arrest claims about 350,000 U.S. lives a year. It’s not a heart attack, but worse: The heart abruptly stops beating, its electrical activity knocked out of rhythm. CPR can buy critical time, but so few patients survive that it’s been hard to tell if the longtime medical belief is correct that it’s a strike with little or no advance warning.

An unusual study that has closely tracked sudden cardiac arrest in Portland, Oregon, for over a decade got around that roadblock, using interviews with witnesses, family and friends after patients collapse and tracking down their medical records.

 About half of middle-aged patients for whom symptom information could be found had experienced warning signs, mostly chest pain or shortness of breath, in the month before suffering a cardiac arrest, researchers reported Monday. The research offers the possibility of one day preventing some cardiac arrests if doctors could figure out how to find and treat the people most at risk.

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