Experiment in Science

Experiment in Science

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We noted that observation is a step beyond merely seeing or responding to our senses.  It is a conscious and sustained mode of recording our sense impressions of the external world. In a scientific observation one tries to relate what is observed to its several parts or to other observed phenomena: In other words, one tries to discern patterns and discover relationships.

Two conditions are necessary for this.  First, it is essential to have a framework of concepts and terminology in terms of which the observations may be properly recorded.  Only then can we even attempt to find relationships between the observed features of the world. Secondly, the observation must be on a specific phenomenon or part of a phenomenon for detailed study. An observation with these two characteristics may be called an experiment in science.

One of the earliest recorded experiment is reported in the Ch‚ndogya Upanishad, dating back to the 6th century or earlier. The work treats of ritual chants, of the primordial significance of the sun, breath, and food, of the genesis of Vedic hymns and much more. In the midst of all this, we encounter a personage by the name of Udd‚laka ¬runi. He instructs his son on the ultimate essence of things. He refers to water as essential for physical life and food for the mind. More importantly, he demonstrates this by asking his son to live only on water for fifteen days. The son obeys, but though he is still alive, is unable to recall whatever he had learned. Then he is instructed to feed himself well and return after fifteen days. The son obeys and is now able to recite the verses. In this way Udd‚laka ¬runi experimentally demonstrates to his son what he had stated. Here the concept is the essentials of life. The phenomenon relates to the effect of water on our life processes.

This is a very significant episode, but as it is buried in metaphysical musings, its unusual empirical undertone had escaped the scrutiny of scholars. Debiprasad Chattopdhyaya, a modern historian of science, has argued that it entitles Udd‚laka, rather than Thales of Miletus, to be regarded as the first scientific thinker in history. In his words, “From the viewpoint of our understanding of science in Indian history, by far the greatest calamity …. is overlooking the real contribution of … Udd‚laka ¬runi… (who) did in fact boldly knock at the gates of natural science to be opened. This made him the first rational natural scientist in the history of the Indian subcontinent, if not in global history.”

Arab alchemists did experiments with acids and alkalis, using a variety of instruments. Consider, for example, the ninth century scholar Al-R‚zÓ (9th century), who authored a famous work entitled Book of the Secrets of Secrets. Contrary to the impression created by the title, the book is essentially an introduction to simple experiments in chemistry. According to E. J. Holmyard, the alchemical laboratory of al-R‚zÓ contained “beakers, flasks, phials, glass crystallizing dishes, jugs, casseroles, candle-lamps, naphta-lamps, basins,  braziers, furnaces, …., smelting furnaces, files, spatulas, hammers, ladles, shears, tongs, sand-baths, filters of hair-cloth and linen, alembics, aludels, funnels, cucurbits, pestles, and mortars….” His stone-cupboard contained not only specimens of all metals then known, but pyrites, malachite, turquoise, galena, stibnite, alum, green vitriol, matron, borax, common salt, lime, potash, cinnabar, white lead, red lead, litharge, ferric oxide, cupric oxide, verdigris, and vinegar.” It is generally agreed that the work done in some of these centers was the predecessor of the experimental method of later centuries. J. D. Bernal stated that: “The crucial extension of Islamic science was to be in chemistry or alchemy, where they transformed old theories and added new experiment to create a new discipline and tradition of science.”

It may be noted that direct sense experiences were referred to as experimenta by the scholastics. However, though Thomas of Aquinas “spoke of the resulting knowledge as scientia experimentalis, these expressions should not be taken to connote systematic and controlled experimentation in the modern sense.”

In the modern scientific laboratory, aside from a jumble of logs and notes, experiments also give numbers which may lead to graphs. No matter what the experiment, there is always a presumption when a scientist launches an experiment that when the data are carefully analyzed, patterns will emerge which will lead to valuable information about whatever is studied.  Without such a presumption one will not do the experiment.  The importance of experiments was clearly recognized by most of the seventeenth century founders of modern science. Their recognition of the importance of experiments was expressed strongly by Descartes when he spoke of rationalist philosophers as people “who neglect experiments and expect truth to rise from their own heads like Minerva from Jupiter’s.”

When the scientific investigator is interested in a very specific aspect of a phenomenon she tries to separate it out from other concurrent events in the real world.  For example, sunlight heats the air, winds blow, birds fly in the atmosphere, leaves rustle in it, and a hundred other things happen in air.  Let us suppose that we are interested in finding out about the effect of heat on air.  For this we may fill up a jar with a quantity of air and study its behavior when heated.  When we do this, we are performing an experiment.

In order to do this experiment we need to have a conceptual framework.  For, when we say we wish to determine the effect of heat on air, there must be ways of stating what kinds of effects we have in mind, and how we will measure that heat.  Thus, concepts of volume, pressure, and density, may be useful here, as also that of temperature.  There cannot be an experiment without a conceptual or theoretical framework.

In such a framework, an experiment may be looked upon as a personal interview that the investigator conducts with a particular aspect of nature.  She is posing specific questions to nature regarding its behavior under well defined conditions.  The results of the interview constitute the data of the experiment.  These consist of verbal descriptions, columns of numbers, graphs, etc.