The Truth in Science
(Last update : March 17th, 2001.)
In this page I will try to develop my own point of view respecting the Truth of Scientific Theories. At first sight this is a fully demonstrable " type " of truth . Nevertheless I want to analyze some points that are not as simple as they pretend to be.
At first, it is highly convenient to analyze how the truth is reached by means of scientific methodology.
The experimentation (reintroduced by Galileo) is one of the fundamental pillars of scientific demonstrations. In order a scientific theory be accepted, it must be able to justify the available experimental results. And in addition it must do it in simpler form, or greater completeness, that other available theories .
However it is not usually taken under consideration is that successful experimental results not necessarily demonstrate " the truth " of a particular scientific theory. Behind each experimental measurement reside a series of suppositions conditioning the analysis of the results.
If it were accepted, as it were postulated during an extended period in the past, that the movement of planets (with a stationary Earth) was due to the work of the angels who gave them their capricious displacements respect to the fixed stars, each experimental data only demonstrates the efficiency of the angels to make their task. But if the Newton's law of gravitation is accepted, ( or the curvature of space-Time owed to Einstein), the experimental data verify the capacity of these theories to describe the physical world. As observed, the selection of a model put conditions to the analysis of experimental data. And this always happens.
Almost certainly the reason above mentioned is the fundamental for the existence of lines of thought developing models of the reality independent from experimental data. From my own point of view, the misconception of these schools of thought resides in the fact that all our mental processes are originated from the interaction with the physical world. And our interaction with the reality (by means of our senses) is a continuous experiment.
Another very illustrative example (and also very amused) is the one of the scientist who, when not discovering ears in the spiders, decided to study the relation between the eight appendices of the arachnids and the reception of sonorous signals. With this objective in mind, he trained a spider so that, at a whistle signal, the spider raised by an incline. And next, the "scientific" were cutting, one to one, the legs of the poor tiny beast and after cutting the eighth leg "was demonstrated" that THE SPIDER WITHOUT LEGS IS DEAF, since it never more answered to the whistle signal (it is not recommended to detail the efforts the poor spider made to climb with a single leg). This story may be graceful (although cruel) because "we know" where the "failure" of the scientist resides. Nevertheless almost all old theories (phlogisto, transmutation , etc, etc) look like similar to this history, now that "we know" the truths of the atomic theory.
The mentioned example serves also to illustrate another important point of the "scientific truths". It is normally accepted that whatever more experiments are made "more proven" is the theory on which they are based. This way, if the scientist of the story, makes his experiment repeated times and in addition he convinces other scientists so that they make the same experience, we will "advance" in the consolidation of the theory. And still more: we will be able to make valid predictions such as: "all insect without movable appendices (wings including) also are deaf ".
And we can follow with the same example in order to show the habitual destiny of all the scientific theories: With time they will appear detractors that will mention things such as that the snakes hear perfectly although they do not have legs. And the defenders of the theory will say (for example) that it is only applied to animals without internal skeleton. And finally, after long debates, "we will accept" that the theory was an erroneous one.
Once this process for searching the truth by means of scientific method is understood, one may
Be fully disappointed because we never will be sure to have reached the truth,
or
Accept that by means of this way, although very slowly, we will be obtaining a most satisfactory image of what we call reality.
And this last one is the flame that feeds the passion by science and its methods. As an example, It is possible to mention that at the present time the behavior of the stars is far better understood that was during XIX century. And this knowledge derived in numerous technological applications that we enjoy at the present time.
The example of the spider is particularly apt to demonstrate that without a suitable model, the experiments alone do not lead to reach the "truth". During very many time it was accepted that the fact that the stones fell on the foot of the towers from which they were dropped, was a irrefutable test that the Earth was immovable. In this model it was accepted that, once the stone was dropped, it loose the impulse of the hand and, therefore it had to remain stationary, undergoing a displacement with respect to the moving Earth. Until it was not postulated (and accepted) the inertial law (in its present formulation) was not possible to refute this "demonstration".
Consequently the interpretative model is as important as the experiment. And, in fact, when experiments are designed to prove the validity of a theory, it is because we have a different model, that uses different explanations to justify the behavior of the "reality". Without an alternative model, the deficiencies of the model in use are "patched" or accepted like exceptions.
The scientific method employs two alternative processes to build the concepts (theories) that allow us to approach to the understanding of the reality: The inductive method and the deductive method.
The inductive method is based on the accumulation of data whose tendency allows us to extrapolate or to generalize the behavior of the systems under study. The veracity of their conclusions is reaffirmed with the generation of more and more data than point to the same direction.
The deductive method is basically an intellectual process. In this case a creative mind imagines a reasonable explanation for a data set and elaborates a theory to join all the available information. The image of the detective who manages to solve the puzzle of a crime is perfectly valid to illustrate this method.
Neither methods are guarantee of success in the search of the truth. Only the continued effort and the permanent critic allow us to aspire to obtain a better image of the reality.
The universal gravitation theory of Newton is an excellent example of the application of both methods. By means of the inductive method it was generated the theory that all the bodies are attracted by the Earth. This Theory that now seems trivial and self-evident to us presented, at its time, serious difficulties. How does this theory explained that flames were in opposite direction to the the fall of other bodies?. This is now very simple to explain (the atomic theory and the thermodynamics are tools of recent development). In the ancient time the fire was considered an independent element with special behavior.
Well, the genius of Newton consisted in accept also the Moon is falling towards the Earth and to assume the consequences of this assumption. In principle this is not more than the continuity of the inductive method. Nevertheless a deep revolution of ideas was necessary to develop the supposition that the orbit of the Moon is not more than the trajectory of a permanent fall towards the Earth. Newton "deducted" that the phenomenon that made stones (and the apples) fall, was the same one that maintained the Moon in its orbit, when the apparent evidence indicated that the Moon does not fall from its position.
And later the gravitational theory of Einstein was able to explain phenomena that were not possible to justify with the theory of Newton. It has no sense to ask about the possibility of Newton developing the theory that elaborated Einstein two centuries later. The theory of Einstein had no sense in the context where the theory of Newton was developed. In the same way the Quarks theory had sense only once it was solidly established the atomic theory and the first sketches of the sub-atomic world.
Very Important remark: The searching of the truth is not a linear way. With each step that we give we are not necessarily closer to the truth. Surely (and the examples are countless) many new theories move us us momentarily away from "the correct" way. The aim of science is to approach as closer as possible to the knowledge of the reality, and since the available tools are not perfect (really far from it), it is natural to make errors frequently. The underlying theory (the scientific theory, defined in its own terms) is that the knowledge (taken as understanding) of the reality is possible.
Of course, a great number of people (including a great number of scientists) accept that to try "to understand" the reality it is not a reasonable task and that the only thing that we can do is to describe it and to predict it. For personal reasons (in this point it cannot be other reasons) I prefer to enlist myself with people that believe about the possibility (at the very end of the way) to understand the "why?" and not only the "what?" or " how?" of the real world. And if this describes me as an arrogant people, I accept willingly, knowing that I can be in error but ready to make the effort. Also "I want" to have free will although I cannot demonstrate that I have it.
A great number of the habitual mistakes during the generation of "scientific truths" derives from accepting explicitly or implicitly that a very great number is something similar to infinite. Possibly the mental abstraction that lead us (as intelligent specie) to generate the concept of infinite and to operate mathematically with it, simultaneously generated innumerable ambiguities to us in our conception of the physical reality. Closely related to the concept of infinite is the concept of continuous, that lend to us to suppose that the physical properties (mass, volume, time, force...) are divisible until any size we want. And the physical world shows regularly to us the existence of limits for the increasing amounts as well as for decreasing ones. Some examples can be adequate at this point:
We can take decreasing amounts of water, without it stops being water. But only until we arrived at the size of molecules. Below this limit, without any doubt, any piece that we take no longer is water.
We can accumulate matter and continue applying the habitual physical laws until the gravitational collapse takes place leading to neutron stars or black holes.
We can accelerate a particle until approaching the speed of the light. But we cannot go further.
Generally speaking, when we advance in a certain direction (increasing or decreasing) we hit against a limit corresponding to a qualitative change. At some level things change and theories that worked perfectly stop doing it.
In the Big Bang theory (perhaps the best example of qualitative change) scientist are trying to describe the early universe 10-40 seg after the beginning of the explosion. And I am not sure that it was been "demonstrated" that Time is continuous until that value (I have already pointed that it is impossible to talk about 10-40 grams of water because we have no water 18 decimals before. Could we take 10-40 seg and be sure of having time?. I do not believe either that any people is very sure of which does it mean "Time" at that "time" of the universe in formation. I believe that this it is a typical example of application of the classic concepts to extreme situations. It is highly probable that the habitual tools do not work in the neighborhoods of the qualitative changes.
This theory constitutes an excellent example of the role of the model in the analysis of the experiments. When the existence of ether was postulated as obvious, all experiments were forced to admit justification through this theory (Null or partial ether drag according to the experiment). When ether was discarded explanations became to be different. Scientist looked for the way to eliminate the necessity of something like the ether to justify experimental results.
It may be worthy to comment that when the Ether theory was developed two well differentiated physical phenomena existed: Electromagnetic waves and solid particles (atoms or their components). Therefore, the theory must obtain certain compatibilization between and incredibly rigid medium able to transmit waves at the speed of light, with a soft consistency allowing solid particle displacement without apparent friction. This model is almost impossible to be solved and was discarded favoring the Special Relativity Theory that "demonstrated" that it was not necessary to have into account the ether hypotheses. It was demonstrated later (within the frame of the quantum theory) that waves and particles were not so different as initially considered. In fact both theories arose almost simultaneously and from the hand of the same creative genius (Einstein).
Nevertheless when it was possible to make an undulatory description of particles it was not reviewed the possibility of a consistent ether theory compatible with Relativity and Quantum Theories allowing the propagation of waves and particles. I believe that it will occur sometime resembling the re-discovery of the atomic and the heliocentric theory.
This examples show another typical characteristic of the scientific advance and the search of the scientific truth. When theories are developed scientist do not have all necessary data or judgment elements to fully validate or reject them. And when more data are collected, usually happens that old theories are reformulated becoming the new scientific truth. But theories are never re-discovered exactly like the original ones. During the way of rejection and reformulation they add consistency, they undergo debuggings and incorporate many improvements that were not possible in the first formulations.
I prefer a doubtful and perfectible truth and not a "revealed" truth by "illuminated" minds.
The way of searching the truth is much more attractive that the truth itself. It is like comparing between a solved puzzle and solve it. Both situations are attractive to me, but they are totally different things and I enjoy much more during solving than during contemplation.
I believe that the interest for the search of the truth (not the search but the interest for it) is a wonderful act of free will.
I believe that we will never get solved the problem. And what is the matter?. (and if you ask what problem?, I did not get to transmit the message in a suitable way).
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