Experimental science is science based on experimental research that plays the role of testing hypothesis, typically in controlled laboratory settings. The hypothesis investigated in classical experimental science postulate regularities among event-types. These regularities may be statistical, as in quantum mechanics, and they may or may not be causal. Experimental scientist are interested in testing functional regularities (e.g. the Boyle-Charles's law for ideal gases), as well as causal regularities. A test condition C is inferred from the hypothesis and a prediction is made about what should happen if C is realized. This forms the basis for a series of controlled experiments.
According to Jean Antoine Nollet (1770), experimental physics cannot do without instruments.
- In the second half of the 19.century Louis Pasteur was engaged in a dispute with evolutionists of his day over the speculations on spontaneous generation of living organisms. Georges-Louis Leclerc, count de Buffon, held to the doctrine of spontaneous generation and in his theory of organic molecules declared that after the death of biological organism and consequent body's decomposition, the organic molecules survive and reunite themselves thus spontaneously form a multitude of small organized bodies. M. Michelet affirmed that drop of sea-water, which contains a bit of "inanimate nitritic matter" evolves bit by bit gradually reaching the level of insects, and then, after a hundred of thousand years, the level of apes, and finally of Man himself. He further remarked that Harvey dared not dispute this ancient belief that the life comes from "the dissolute elements of previous life". Michelet also called it a theory which "has been revived with rigor by experiments of M. Pouchet". Pouchet, the Director of Rouen Museum of Natural History told Academy of Sciences as its active member that he had succeeded in producing experiments which demonstrated, "beyond the shadow of doubt", the evolution of microscopic organized beings that entered the world without germs, and thus without parents resembling to themselves.[note 1] All these naturalist scientists were publicly celebrated while Pasteur was grossly vilified both by contemporary scientific establishment and media for his support of the germ theory of disease claiming i.a. that dust in atmospheric gases can be bearer of the germs for primitive organisms. La presse wrote in 1860 that "the experiments you quote, M. Pasteur, will turn against you ... The world into which you wish to take us is really too fantastic." Yet it was Pasteur, who in his historical lecture at the Sorbonne university in Paris on April 7, 1864 experimentally demonstrated that the belief of his opponents was "a mere chimera" and that they were deluded by their poorly conducted experiments when error in their experiment was introduced by using the mercury contaminated by everywhere-present dust which brought the germs into the flask. He showed that when experiment repeated with flask that has the curved neck and surrounding air is not extremely turbulent, the hay alias infusion in the flask remains completely unchanged, i.e. without any mold (living micro-organisms) developed even when left so for arbitrarily long time. Pasteur declared that it remained thus because he had deprived it "of the one thing not given to Man to produce, ... of life itself" and that the doctrine of spontaneous generation suffered the mortal blow inflicted by this experiment.
- The experiment itself consisted in having a liter-flask, filled with boiling water, hermetically sealed and inverted over a vat of mercury; once the water was completely cooled, the flask was uncorked below the metal's surface and a half-liter of pure oxygen (extracted from chemical compound) was introduced as the vital component of air necessary to the lives of microscopic beings. At the end a bit of hay, previously heated beyond 100°C for 30 minutes (environment unsuited to the appearance of microscopic beings), was placed into the flask as infusion of organic material (nourishment) below the surface of the mercury. A fully developed mold appearing at the infusion after 8 days was then declared as proof that the atmosphere didn't serve as the vehicle for these germs but that they have evolved by spontaneous generation from organic molecules of non-living hay.
- Cleland, C.E. (September 2002). "Methodological and Epistemic Differences between Historical Science and Experimental Science" (PDF). Philosophy of Science 69: 474–496. http://spot.colorado.edu/~cleland/articles/Cleland.PS.Pdf. Retrieved 25.1.2012.
- (2002) The art of teaching Physics, The Eighteenth-Century Demonstration Apparatus of Jean Antoine Nollet. Les éditions du Septentrion, 220. ISBN 2-89448-320-1. “Experimental physics, Nollet insisted, cannot do without instruments”
- Louis Pasteur. History Learning Site. Retrieved on 02-03-2013. “"I am afraid that the experiments you quote, M.Pasteur, will turn against you. The world into which you wish to take us is really too fantastic." La Presse, 1860”
- On Spontaneous Generation; An address delivered by Louis Pasteur at the "Sorbonne Scientific Soirée" of April 7, 1864. Pasteur Brewing. Retrieved on 03.February 2013.