TOPIC 5
DEVELOPMENT OF THEORIES AND PARADIGMS

 

Introduction

In discussing how we do science, we delineated a framework for science that includes four elements.

UNIVERSE

IMPERFECT MODEL OF UNIVERSE

DOING SCIENCE

IMPERFECT SCIENTISTS

The first element, that the universe exists separate from our perception of it, is an untestable assumption. The second element constitutes Lund's view of what is science, namely a working model of the universe that explains the universe and makes predictions. Paterson argues that the third element, doing science is the key to science and that the imperfect model is only one part of science.

The key concepts that we use in building the model and in doing science are hypotheses, theories, and paradigms. We might try to define these as follows:

Hypothesis: an idea or explanation for some part of science. It may be a simple hypothesis or one quite complicated.

Theory: a more formalized explanation for some part of science. It may be a simple theory or one quite complicated. A theory is a hypothesis that has been repeatedly tested and is accepted by a group of scientists as valid.

Theories should:
(1) explain kinds of events/data and not single events,
(2) be supported by large amounts of data, and
(3) show functional relationships to other theories.
Example: Newton's law of gravity.

Paradigm: Here are two definitions.

A group of theories that explain some larger component of science.
The total complex of a science. That is the language, conceptual framework, theories, methods, and limits of a science.

Examples of paradigms:
geo- and heliocentric views of the universe,
Newtonian physics,
relativity,
quantum mechanics,
plate tectonics.

One can imagine the imperfect model of the universe as being composed of a group of paradigms. In the course of doing science, one starts with hypotheses, develops theories, and puts groups of theories together into paradigms.

Origin of Scientific Theories

The development of hypotheses and theories originated in Greece together with the development of logic. A logical induction can be viewed as a theory in that the theory generalizes some component of science and is based on facts/observations. A logical deduction is a predictive inference based on some theory that can be tested. Obviously, inductive and deductive logic both apply to all human thought and transcend science. Never the less, logic and scientific hypotheses/theories were tightly interwoven in their development and still are today.

It is certain that implicitly stated hyptheses were the ideas of the first Greek scientific thinkers. But, the formal use of hypotheses and assumptions to develop theories was not formalized until it had first been developed in mathematics.

Explicit hypotheses were formally used by mathematicians to help codify mathematics into fields like geometry. The hypotheses had associated with them explicit assumptions that limited the use of the hypotheses to particular cases. Thus, Euclid's Elements was a group of hypotheses (actually theories by that time, since they had been tested and fit into a framework with other theories) and underlying assumptions. Altogether, them form the paradigm for geometry that still works today.

The explicit statement in science 'let me hypothesize based on the following assumptions' did not get written down until after the death of Aristotle.

 

Paradigm Shifts (Scientific Revolutions)

Thomas Kuhn, a specialist in history of science, defined paradigm shifts in 1962. He saw scientific development as abandonment of one theoretical structure and replacement by another, incompatible one. He saw scientific advance as the following general sequence:

Pre-Science--Normal Science--Crisis/Revolution--New Normal Science--New Crisis

Examples of paradigms include:
Newton's Laws - Newtonian Physics
Maxwell's Equations - Electromagnetic Theory

A tricky question is why do paradigm-shifts occur?

One view is that paradigm-shifts are totally irrational and dependent on the social interactions of scientists because there is no true way to evaluate which paradigm is better.

Another view is that the current paradigm is constantly being tested and eventually is strained beyond usefulness by its inability to explain new observations and ideas. In this view, paradigms and those they replace are not necessarily incommensurate; the shift occurs when the old paradigm is less effective than the new paradigm at describing the world (or some aspect of it).

During a revolution, there is a sense in which the proponents of rival theories are seen as 'living in different worlds'.

This leads to a critical idea in science, that there will always be unstated criteria for choosing one theory over another.

- a new theory must be as broad as possible and encompass a wide range of phenomena.

- it should be able to predict new relationships and offer scope for further development.

- it should be as simple as possible, with a minimum number of hypotheses.

- it should be testable by confirmation by independent observers.

- it should be self-consistent

- it should be capable of being linked with other branches of science.

- it should be quantifiable and expressible by mathematics.

Rival paradigms will regard different kinds of questions as legitimate or meaningful.

- Questions about the mass of planets were fundamental for Newtonians but heretical to Aristotelians.

- Uncaused motion was nonsense to Aristotle but axiomatic to Newton.

 

Some Paradigms of the Ancient Greeks

Paradigm on the Nature of Matter:
- Water, earth, fire (despite Theophrastus) , and air are fundamental materials.
- Materials are composed of pieces (atoms).
- A void exists.
- Materials can be 'transmuted' from one material to another.

Paradigm on the Nature of Motion:
1) Motion on Earth is natural, violent(unnatural), or animated.
2) Natural motion is not uniform in speed, but has acceleration toward the Earth.
3) Natural motion not linearly dependent on weight of objects.
4) Unnatural motion is due to transfer of motive force to object in motion.
5) Motion of astronomical objects is circular and constant uniform speed.

Paradigm on the Nature of the Universe:
1) Earth at rest at the center of the Universe.
2) Sun, Moon, five planets, and all stars together revolve around Earth on 8 concentric spheres in uniform circular motion.
3) Each sphere (deferent) rotates on an axis embedded in the next outer sphere.
4) Astronomical objects also revolve around smaller epicycle spheres embedded in the deferent spheres.

 

Statements about Science: True or False?



Accumulation of facts is goal of science.

Science is exact.

Science is deficient since it is inexact.

Science is primarily concerned with societal needs.

'There is some kind of inference procedure that enables us to derive scientific theories to be proven true or probably true.'

'Scientific knowledge is proven knowledge.'

How do we distinguish between science and non-science?

"Part of the problem may lie in the observation that some aspects of science can only be treated properly with sufficient background information. It is likely that social science and psychoanalysis are sciences in an embryonic form. But they both have so many complexities and unknown factors that it is hard to even imagine quantifying them in a manner as we normally due in the natural sciences. 'Science is the art of the soluble'." (Peter Medawar)

Beliefs of Science vs Nonscience

Mysticism = belief that knowledge can be
gained by nonsensory means
Tentative versus Dogmatic
Believe in evidence not authority
Beliefs not influenced by faith, power,
monetary rewards, self-protection.

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