Scientific hypotheses

Gold, T. and Soter, S. (1980). The deep-earth-gas hypothesis. Scientific American 242,154-161. 

The scientific method, as mentioned, involves observation and experimentation (research) to discover or establish facts. These are followed by deduction or hypothesis, establishing theories or principles. This sequence, however, may be reversed. The noted twentieth-century philosopher Karl Popper, who also dealt with science, expressed the view that the scientist s work starts not with collection of data (observation) but with selection of a suitable problem (theory). In fact, both of these paths can be involved. vSignificant and sometimes accidental observations can be made without any preconceived idea of a problem or theory and vice versa. The scientist, however, must have a well-prepared, open mind to be able to recognize the significance of such observations and must be able to follow them through. Science always demands rigorous standards of procedure, reproducibility, and open discussion that set reason over irrational belief. 

The scientific method is taught starting in elementary school. The first step in the scientific method is to form a hypothesis. A hypothesis is just an educated guess or logical conclusion from known facts. It is then compared against all available data and its details developed. If the hypothesis is found to be consistent with known facts, it is called a theory and usually published. The characteristics most theories have in common are that they explain observed phenomena, predict the results of future experiments, and can be presented in mathematical form. When a theory is found to be always correct for many years, it is eventually referred to as a scientific law. However useful this process is, we often use constructs that do not fit in the scientific method scheme as it is typically described. 

Adherence to the scientific method is what de fines science The scientific method has four major el ements observation law theory and hypothesis... 

It IS worth remembering that a theory can never be proven correct It can only be proven incor rect incomplete or inadequate Thus theories are always being tested and refined As important as anything else in the scientific method is the testable hypothesis Once a theory is proposed experiments are designed to test its validity If the results are con sistent with the theory our belief in its soundness is strengthened If the results conflict with it the theory IS flawed and must be modified Section 6 7 describes some observations that support the theory that car bocations are intermediates in the addition of hydro gen halides to alkenes... 

When Mitchell first described his chemiosmotic hypothesis in 1961, little evidence existed to support it, and it was met with considerable skepticism by the scientific community. Eventually, however, considerable evidence accumulated to support this model. It is now clear that the electron transport chain generates a proton gradient, and careful measurements have shown that ATP is synthesized when a pH gradient is applied to mitochondria that cannot carry out electron transport. Even more relevant is a simple but crucial experiment reported in 1974 by Efraim Racker and Walther Stoeckenius, which provided specific confirmation of the Mitchell hypothesis. In this experiment, the bovine mitochondrial ATP synthasereconstituted in simple lipid vesicles with bac-teriorhodopsin, a light-driven proton pump from Halobaeterium halobium. As shown in Eigure 21.28, upon illumination, bacteriorhodopsin pumped protons... 

As this hypothesis is an interesting example of the influence of logical and psychological factors in the development of scientific discoveries, it will be discussed briefly in a short interlude on factors that are the basis for many scientific discoveries in general (Ch. 9). 

In Section 8.3 the mechanism of heterolytic dediazoniation of arenediazonium ions was discussed, and it was shown that the hypothesis of Crossley et al. (1940) that the aryl cation is the characteristic metastable intermediate in those reactions was not consistent with some experimental facts found in 1952 by Lewis and Hinds. Nevertheless, these facts did not have significant influence on the scientific community, which continued to accept the original and apparently convincing hypothesis of the rate-limiting formation of an aryl cation as an intermediate as correct . The incom-patabilities of various mechanistic hypotheses with experimental facts were, however, discussed in some detail only two decades later (Zollinger, 1973 a). Another year passed before I performed a crucial experiment that refuted a number of hypotheses (Bergstrom et al., 1974, 1976). ... 

Popper s theory has been criticized by Thomas Kuhn (1962, 1969), who asserts that the development of science proceeds in revolutions hypotheses and theories are not refuted and replaced by new ones instead the scientific community will accept a new, more convincing, or better presented hypothesis without the old one having been disproved. 

Once they have detected patterns, scientists develop hypotheses, possible explanations of the laws—or the observations—in terms of more fundamental concepts. Observation requires careful attention to detail, but the development of a hypothesis requires insight, imagination, and creativity. In 1807, John Dalton interpreted experimental results to propose the hypothesis that matter consists of atoms. Although Dalton could not see individual atoms, he was able to imagine them and formulate his atomic hypothesis. Dalton s hypothesis was a monumental insight that helped others understand the world in a new way. The process of scientific discovery never stops. With luck and application, you may acquire that kind of insight as you read through this text, and one day you may make your own extraordinary hypotheses. 

If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generations of creatures, what statement would contain the most information in the fewest words I believe it is the atomic hypothesis (or the atomic/act, or whatever you wish to call it) that all things are made of atoms—little particles that move around in perpetual... 

All compounds, from the simple ones such as water and ammonia to the most complex, are held together by chemical bonds. All chemical bonds—from purely covalent to strongly ionic—act the way they do because of the nature of the atoms that form the bonds. Our knowledge of those atoms is at the heart of the science of chemistry. Understanding Richard Feynmans little particles has enabled mankind to manage the natural world to suit its needs. Feynman was undoubtedly correct when he said that the atomic hypothesis (or the atomic fact, or whatever you wish to call it) is the most concise and important summary of scientific knowledge produced by mankind. And it is crucial that every generation passes it on to the next. 

In the last decade, an intense and successful investigation of this phenomenon has focused on its mechanism. The experimental facts discovered and the debate of their interpretation form large portions of these volumes. The views expressed come both from experimentalists, who have devised clever tests of each new hypothesis, and from theorists, who have applied these findings and refined the powerful theories of electron transfer reactions. Indeed, from a purely scientific view, the cooperative marriage of theory and experiment in this pursuit is a powerful outcome likely to oudast the recent intense interest in this field. 

Based on this hypothesis, from the year 1990 onward, lutein and zeaxanthin have received increasing attention in the scientific literature as possible contributors to risk reduction of AMD, an attention that continues as indicated by the still increasing number of hits in PubMed for the keywords eye and lutein or zeaxanthin (Figure 13.3) and by a steady flux of review articles on the subject (some of the more recent reviews are O Connell et al. [2006], Trumbo and Ellwood [2006], Whitehead et al. [2006], Bhosale and Bernstein [2007], Coleman and Chew [2007], Loughman et al. [2007], Renzi and Johnson [2007], Afzal and Afzal [2008], and Loane et al. [2008]). 

Day by day, the number of scientific works and techniques based on in vitro tools has increased their relevancy, supporting the hypothesis of the use of in vitro models as refinement technique due to their ability to provide information on central events involved in toxicant mode of action. 

The standard of testability (vulnerability to negation in the framework of a working hypothesis in the hypothetico-deductive mode or of simultaneous adjustment in the framework of Bayesian modeling) is probably the toughest standard demanded in science. Ideas as old as the monad are not necessarily tested and validated by repeated corroboration. Indeed, they may be untested and powered by inertia. Ideas which are testable are those for which there are alternatives otherwise ideas are either unnecessary or untestable. Since Dennett has already asserted that reductionism permits no alternative, monophyly as such would have to be untestable, but, before condemning it to the rank of scientific dogma, let me cite two cases in which monophyly was tested as the alternative to a different (polyphylic) hypothesis. 

Not all scientific statements are testable hypotheses, laws or theories. For example, scientific paradigms, by one definition (Masterman, 1970 Horgan, 1996), are organizing principles which encompass much of the work of ordinary science, in the language of Thomas Kuhn (1970) but are not necessarily testable. Ordinary science is not the source of revolutionary science (except, possibly when it breaks down) and is not hypothesis driven so much as driven by the requirement to fill in the holes opened in a field by the scientific paradigm. 

The deciding impulse which introduced biogenesis into scientific discussion came from Russia. After the upheavals of the civil war, that country was the subject of worried observation by the rest of the world. It was assumed that no great scientific achievements would be possible there. Then, in 1924, a book on the material basis of the origin of life on Earth appeared in Red Russia . Its author was Alexandr Ivanovich Oparin (1894-1980) from the Bakh Institute of Biochemistry in Moscow (Oparin, 1924). Basically, the Oparin hypothesis makes the following assumptions ... 

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