SCIENCE = INDUCTION + DEDUCTION

by James Craig Green
Edited 12/10/2012 and 8/21/2014

Science is not fact.

Science is not truth.

Science is not absolute.

Science can never be "settled."

SCIENCE is the creation of theories attempting to explain observations. According to philosopher of science KARL POPPER, any theory that cannot be falsified (proven wrong) by experimentation is not science. This important perspective illustrates why scientific theories and laws may have to be changed from time to time.

Science depends on INDUCTION  to create theories, and DEDUCTION to apply them. Each is dependent on the other, since deductions from applying existing theories may produce contradictions from future observations, dictating the revision of those theories. A scientific LAW is nothing more than a theory which has withstood many experiments that have corroborated it (failed to disprove it) over a period of time. This does NOT mean the theory has been "proven" for all time.

INDUCTION is extrapolation from the specific (observations, measurements and experiments) to the general (hypotheses, theories and laws). For example, Newton's Universal Law of Gravitation ("law of gravity") says that every mass in the universe exerts a force on every other mass in the universe proportional to the product of their mass and inversely proportional to the square of the distance between them. Measurement inaccuracies applied over large distances can be significant. This is why the Apollo missions to the moon required course corrections based on radar measurements of their actual, rather than predicted, location at times. This was demonstrated in the movie Apollo 13 when Jim Lovell (played by Tom Hanks) said after shutting down the spacecraft's guidance system, "We just put Sir Isaac Newton in the driver's seat." What he meant by that was, without the guidance system to constantly measure the error of Newton's laws (of motion and gravity), they would not know how to correct these errors until the system was turned back on.

The important thing to know about Newton's "law of gravity" is that no human has ever tested or measured this phenomenon except on earth, the moon, or by remote observations of distant celestial bodies. Since man has NEVER tested this "universal" law anywhere else, no one can be certain that it applies throughout the universe, under all possible conditions.

Once a HYPOTHESIS (educated guess) is tested by experiment without being falsified, it may be called a theory. A scientific "law" is nothing more than a theory with many successful experiments supporting it. It is important to realize that no experiment can PROVE a scientific theory, but can support or refute it.

One lesson to be learned from this is that every scientific theory (and law) is based on FAITH that it applies to conditions and places for which it has not been tested. This uncertainty - the possibility of future revision or rejection - is why scientific theories are not, and cannot be, absolute.

DEDUCTION in science is the application of a general theory to a specific case. For example, starting with Newton's law of gravity, one can calculate the gravitational force between the earth and moon, if one knows the mass of each and the distance between them. Once these input parameters are known, there is only one answer, within a chosen level of accuracy (number of decimal places). All experiments are limited by the accuracy of measurement.

Now, the bottom line, and the source of disagreement between some scientists and/or philosophers:


INDUCTION (the source of all scientific theories) is creative (non-rational) because it depends on creating something new that never before existed (a made-up hypothesis, theory or law). Several competing theories/hypotheses/laws might explain the same observations. (The Earth was once visualized as resting on the back of a giant turtle). An example of INDUCTION is Newton's law of gravity.

In his early 20th century work in physics, Albert Einstein concluded that Newton's law did not take into account how gravity bends light. Although it took many years (waiting for technology and observational conditions to catch up), Einstein's claim that Newton's law was not universally valid was finally confirmed by experiment in 1919, facilitated by the observation of a total solar eclipse of the sun by the moon. No one knows what future data, experiment or new theory will partially or wholly replace today's theories, none of which are absolute or proven for all time.

This is one reason why Dr. Richard Hammling, former Los Alamos and Bell Labs scientist, summarized the following in a 1986 Presentation at a Bell Communications Seminar:

Great scientists tolerate ambiguity very well. They believe the theory enough to go ahead; they doubt it enough to notice the errors and faults so they can step forward and create the new replacement theory. If you believe too much you'll never know the flaws. If you doubt too much you won't get started.


DEDUCTION is rational, because it rigidly applies the rules of logic without deviation. Logic is a human word/mind game that begins with arbitrary assumptions and rules, which dictate how the game is played. Like mathematics, it has nothing to do with REALITY, though it may be used to better understand reality.

When theories or laws change from INDUCTION based on new experiments - as with Einstein's modification of Newton's Law of Gravity - the very same rigid logic of DEDUCTION now has a changed result, due to the underlying change in the Scientific theory or law. The modified version now produces a different result for the changed theory or law, which was not so absolute after all.

See NEWTON'S LAW OF UNIVERSAL GRAVITATION

and  ALTERNATIVE EXPLANATION OF EINSTEIN