How Science Works–Some Case Studies*

“Man is not born to solve the problem of the universe, but to find out where the problem begins and then restrain himself within the limits of the comprehensible.”
—J.W. von Goethe, as quoted in The Homiletic Review”

Many leftists complain that conservatives/Republicans/Trump followers are “anti-science.”  I am puzzled by this, since most of the complainants are scientific illiterates and innumerates (e.g. Al Gore, Hillary Clinton, and-alas-some in the Catholic hierarchy).   In a spirit of “educate your enemies,” I thought to proffer an article on how science does work, so that these advocates might then give more constructive criticisms.

The Lakatos “Research Programme” for Science

If you were to do a man-in-the-street survey, asking “How does science work?” you’ll get many different answers.  Here are some from an adult education class I taught on “Science and the Church” (actually, I supplied the last two answers):

  • Finding theories to explain everything;
  • Formulating a hypothesis, testing the hypothesis by experiment;
  • Finding an unusual experimental result, formulating a theory to explain the result;
  • Finding a theory that will explain a body of experimental knowledge;
  • Finding theories that could be proved false by suitable experiments;
  • Finding which theories are the most elegant and are also consistent with experimental results;
  • Depends on a scientist’s presuppositions and assumptions;
  • Is “reductionist”, i.e. attempts to reduce phenomena and the objects comprising these phenomena to the smallest components and the scientific laws governing the action of these components: for example, intelligence can be reduced to biochemical and electrical events on the molecular level;
  • Establishes a research program consisting of a network of hypotheses and experimental data: core theory, based on inner core principles, linked to secondary theories and results (Lakatos’ scientific research programme—see below).

The correct answer is “all the above,” depending on the scientist and his/her research focus.  However, I believe the last answer, the Lakatos Scientific Research Program,, illustrated in the feature image, gives the best, the most complete description of how science is carried out.  This  “Scientific Research Programme” can be thought of as a sphere:

  •  An inner core of fundamental principles--not theories, but principles to which theories have to adhere; these principles are assumed, because they seem obvious and confirmed generally by our experience:  for example, The First and Second Laws of Thermodynamics. But, as we’ll see below, there are  occasions when these fundamental principles are modified or violated.
  • A shell of primary or fundamental theoriessurrounds this core of fundamental principles (e.g. thermodynamics, general relativity, quantum mechanics).
  • Other shells representing auxiliary theoriessurround this shell of fundamental theories; such auxiliary theories are derived from the primary theories and other auxiliary theories; MRI, chemical bonding, heat transfer are examples of  such auxiliary theories.
  • Finally  there is an outermost shell of experimental facts or data.   The interplay between the shells and core that shows how science works is described in the diagram below and illustrated  below by several examples.

In this diagram the inner core principles are linked to fundamental and auxiliary theories, as shown by the black arrows.   There is feedback from data to theories,  as shown by the red arrows.   There is even feedback from data and fundamental theories to inner core principles, as shown by the red arrows.

Examples of how the Lakatos scheme works are given below.


History of  Thermodynamics: Count Rumford: Cannon Boring —> Heat Not Conserved.

Count Rumford’s Cannon-Boring Experiment–Making Water Boil

In 1798 Benjamin Thompson, Count Rumford, submitted a  paper to the Royal Society about his experiments in which boring a cannon could make water boil, and boring with a blunt instrument produced more heat than with a sharp one (more friction with the blunt).     The experiments showed that  repeated boring on the same cannon continued to produce heat, so clearly heat was not conserved and therefore could not be a material substance.

This experiment disproved the then prevalent theory of heat, that it was a fluid transmitted from one thing to another, “the caloric.”  The results validated another theory of heat, the kinetic theory,in which heat was due to the motion of atoms and molecules. However the kinetic theory, despite Rumford’s groundbreaking experiment, still did not hold sway until years later, after James Joule showed in 1845 that work could be quantitatively converted into heat.

History of Thermodynamics: James Joule: Work—>Heat

Diagram of Joule’s Apparatus for Measuring the Mechanical Equivalent of Heat
from Wikimedia Commons

As the weight falls, the potential energy of the weight is converted into work done (a paddle stirs the water in the container against a frictional force due to water viscosity).   The temperature rise corresponding to a given fall of weights (work done) yields the amount of heat rise (in calories) of the known mass of water.   Since the temperature rise is very small, the measurements have to be very accurate.

It took 30 to 50 years after Joule’s definitive experiment (and subsequent refinements and repetitions) for the kinetic theory of heat—heat caused by random, irregular motion of atoms and molecules–to be fully accepted by the scientific community.   James Clerk Maxwell published in 1871 a paper,  “Theory of Heat”. This comprehensive treatise and advances in thermodynamics convinced scientists  finally to accept that heat was a form of energy related to the kinetic energy (the energy of motion) of the atoms and molecules in a substance.

Contemporary Science: Experimental Tests of Fundamental Theories

Links are given below to examples of modern experimental tests of  ground-breaking primary and secondary theories in various fields of science.  (Some are discussed below in more detail and in other Essays.)


Rumford and Joule’s  Experiments on Heat and Work

The core principle involved in the caloric theory of heat was the conservation of caloric (since it was a substance).  Count Rumford’s cannon-boring experiments showed that the more the cannon was bored, the more heat was produced;  therefore the supply of heat in the cannon was inexhaustible and clearly not conserved. A core principle involved in Joule’s experiment is the First Law of Thermodynamics:  conservation of energy, with heat and work as forms of energy.   Note that this conservation principle is linked to the fundamental theory of thermodynamics developed in the middle of the 19th century  and earlier, theories of classical mechanics developed in the 18th century and early 19th century.

Einstein’s Special Theory of Relativity and General Theory of Relativity

Einstein’s two theories of relativity are  striking examples of how theory influences  fundamental principle (the red arrow), or perhaps more accurately, how fundamental principles are proposed as a basis for general theories.  His theory, special relativity, introduced the following new general principles:

  • the laws of physics are the same for systems (“frames of reference”) moving at constant velocity (i.e. “inertial systems”);
  • the speed of light (in vacuum) is constant, regardless of the speed of source or receiver;
  • neither energy nor mass is conserved but only mass + energy (from E= mc²)

His general relativity theory introduced the “equivalence principle“, that inertial and gravitational mass are the same.   In every-day terms, this principle says that a person (mass m) in an elevator accelerating upward experiences a force holding him to the floor due to earth’s gravitation, mg, plus a force due to the acceleration of the elevator, ma. This is the same force that the person would experience on a planet where the gravitational acceleration would correspond  to g+a, or in a spaceship accelerating at a rate g+a.  (See Science Background—Physics of Motion,for more about force and acceleration.)

Recently Einstein’s Theory of general relativity has been confirmed again from LIGO measurements of gravity waves.  See “Peeling Back the Onion Layers—Gravitational Waves Detected”for a more detailed account.

Is Parity Conserved?  Right- and Left-handedness

Left- and right-handed molecules (chiral molecules). These amino acids are mirror images of each other. from Wikimedia Commons



Parity refers to mirror symmetry.  For example,  many organic molecules are either right- or left-handed  (see the illustration above of two amino acids, constituents of proteins:  COOH is the organic acid group, NH2 is an amino group, C is the central carbon, R represents a general group attached to the carbon). Now biological molecules can be chiral either as a whole, or with respect to the constituent parts.  For example, amino acids found in nature are left-handed;  sugars found in nature are right-handed;  DNA as a whole has a right-handed spiral (helix).    The question of why only one kind of handedness for biological molecules came about has fascinated chemists and biologists since the time of Pasteur 150 years ago.  There arerecent theoriesto explain this, but they are to some extent conjectural

Conservation of parity (handedness) had been a fundamental principle of physics  until the late 1950’s, when a proposal to test it for nuclear weak force interactions–e,g, beta decay of Co-60 nuclei–showed that it was violated.  (See here for an expanded story.)   Since that time a conservation principle, CPT symmetry, linking parity (P) with charge (C) and time reversal (T) has been found to hold.