In our efforts to understand natural phenomena, science divides the world of experience into specific domains which are then studied little by little; or else, we will be confronted with a staggering immensity far beyond any individual’s grasp. Once a field of study is chosen, every phenomenon related to it is carefully observed. If we wish to understand something, we must first get well acquainted with its various facets.
We become aware of the physical world through our channels of perception, through our various senses. Neurophysiologist Walter Freeman explained how “the brain transforms sensory messages into conscious perceptions almost instantly. Chaotic, collective activity involving millions of neurons seems essential for such rapid recognition.”
The awareness of the external world can occur in two different ways: It could be an unconscious registering of external stimuli, or it could be associated with a deliberate act of will. When a conscious effort is combined with the process of sense perception we say that we are observing. In other words, the mind also takes part in an observation. Hence the importance of observation in science.
Our sense perceptions include sight, hearing, smell, taste, and touch, made possible through our eyes, ears, nose, tongue, and sensitive finger tips and skin. These are undoubtedly among the most remarkable systems that have evolved in the universe. But they are not perfect. We recognize their imperfection at least three different levels.
To begin with, the sensitivity of our senses is limited. For example, the normal ear cannot hear very faint sound vibrations that may be present in its vicinity. The eye is unable to detect stars that are present in the day sky. A tiny thread landing on our head may go unrecognized. Science overcomes these limitations by devising instruments that amplify the effects on the senses. Thus, a combination of lenses in a telescope enables us to detect very faint or distant objects. Another such combination is the microscope through which very minute entities are rendered visible. In like manner, there are sound magnifying instruments also.
Secondly, the range of perception of the senses is also limited. Thus the eye is sensitive to only one small region of the electromagnetic spectrum. Electromagnetic waves whose wavelengths lie beyond this interval of the visible spectrum are undetected by the human eye. The place where you are reading these lines at this moment is, like any other spot in the world, bathed with radio waves of all wavelengths coming from the most distant regions and beyond. Your own physiological mechanisms are inadequate to register these effectively. We need special instruments, such as a short wave radio set, which can respond in some detectable way to aspects of the universe to which the human body is totally insensitive.
Finally, the revelations of the senses can sometimes be misleading. Perfectly parallel lines may be made to appear to converge or to diverge by appropriately inserting sets of slanting lines between them. Another example of the misleading trait of our senses is the rising and setting of the sun and the stars. To all appearances these celestial objects seem to be moving across the sky, but we know that this is not quite so. Similarly, if one were to taste sweetened coffee after eating a candy, the coffee will not taste sweet. There are a number of other instances where our mislead us.
The way to handle this problem is by careful analysis. It is not enough to observe and record. It is equally important to probe into the relationships between the data of observation and weigh them against other items experienced.