What is science?






Scientists and philosophers often refer to the “laws of nature”, which are regarded as basic properties of the universe.  The use of these terms is misleading and leads to important misunderstandings.  These “laws” are a human endeavor, not a property of the universe.   In a similar vein, science is often viewed as a quest to discover these laws of the universe.  This view makes two completely unwarranted assumptions: that the universe follows “laws” as we know them, and that we are capable of understanding them.

Our ancestors found that living in an unpredictable, ever-changing world was very difficult.  So they sought to observe regularities in the world about them that enabled them to predict some portion of the future with sufficient accuracy to make their lives more comfortable and comforting.  Yes, it is predictability that we crave, not conservation laws or symmetries or any other universal property.  We need to reduce the unpredictability of life to make it possible for us to survive and then to do more than just survive.

Thus we seek ways of predicting some part of the future.  The all-important sun sets in the evening and we do not panic since we have observed on many occasions that it will rise the next morning.  In the same way we look for other types of prediction that will make our life easier by reducing the uncertainties of the future.  We may need to predict the behavior of a particle in a field, or the strength of a structural material.  If, along the way, we find apparent conservation laws or other universalities, so much the better, but these are helpful tools along the way to our real goal which is, always, predictability.

The universe is what it is.  It can do any damn thing that it wants to without regard to our “laws” or “principles”.  It has repeatedly shown humankind that it has the capability and the inclination to do things that seem simply irrational in our eyes.  The properties of atoms, which at first appeared to be small versions of the solar system, are dramatically different from what was expected based on our experience with the solar system in astronomy.  A whole new branch of science, quantum physics, another human (and uncomfortable) representation of reality, had to be created to give orderliness to our view of the atomic world.  There are many such examples.

So we observe and then describe what we have observed, in the language of our experiences and, often, in mathematics.  But we have not deduced a “law of nature”.  We have, instead, proposed a law of humankind that is a useful approximation to what the universe is doing over the range of the set of observations from which the law was derived.  Often this “law” is regarded as a Law of Nature, extending to regions far beyond that which was observed, but this is a mistake.  The law is humankind’s law, not a law of the universe, and nature is not bound to obey it in any way.  If the law is well founded on observation and describes reality over some significant range, it can be highly useful.  But, again, it is not a law of the universe, and we should not be surprised at all when it is incorrect outside of the range over which it was originally validated.  Sometimes, extending our deduced laws far beyond their confirmed range is the best we can do, having no other alternative, but we need to remember that the universe itself is not obliged to respect our extrapolation.

Sometimes we find that we need to have more than one human law to describe adequately a full range of experience and/or experiment.  This range can be over an extent of physical parameters, or of circumstances, or of any other variable(s) bearing on our observations.  Quantum field theory and gravity each successfully describe the behavior of nature over large but non-overlapping ranges.  While we strive to find some “theory of everything” that will correctly predict behavior over the entire range, we should have no a priori expectation that such a theory exists and should not be surprised when the attempts at unification fail.

But it is not just a range of parameters (for example, dimensions in the case of gravity and quantum theory) that can delimit the effectiveness of our scientific theories.  Our laws can also be limited by the situation in which our observations of nature are conducted.  Both electromagnetic waves and matter show properties which we associate with both waves and particles, depending on the type of observation we make.  In each case, waves or particles, we have developed a set of predictive laws based on our experience with waves or particles in other realms of observation, and we find it helpful to apply these laws to our new observations, choosing whichever one seems to fit the case at hand.  But it seems likely that electromagnetic waves and particles are neither waves nor particles, but something more profound and complex which is not represented in our human experience and which does not show directly in our measurements.  It is a perfect case of the blind men and the elephant – some feel “waves”, some feel “particles”, but no one feels “elephant”.

The Uncertainty Principle, which stands up well to experimental experience, may be another example of the imperfectness of the fit of our “laws” to reality.  We may have been approximating nature with the wrong variables – perhaps we have been trying to characterize the behavior of “foot” when it actually “trunk”.  Perhaps this principle is an expression of the inaccuracy of our laws at the extremes of range at which it matters.

Science is about prediction.  Science is our human attempt to find predictability in nature by fitting to it various experiential (and often mathematical) tools to give us the ability to predict in some realm of our activities.  It is not some mystical quest to find something that we believe is out there.  It is a bald, human attempt to make order out of a universe that may well be far messier than we can comprehend.



John W. Weil