On historical development of Chemistry/Science
Historical development of Science/Chemistry [4], [5]
The reasons for the initial rise of modern Science/Chemistry in W. Europe are
discussed at some length. The analysis is based on the scheme below and is
exemplified by the development of China and W. Europe from 15th
century onwards. The scheme favors physical/geographical explanations instead
of often utilized cultural explanations.
Physical/geographical environment
Nature of Society/Civilization
Character of Science in a particular Society
Scientific achievements
Case studies in the development of Chemistry
Case 1: Combustion theories
Theories of combustion were the first, scientific, general theories in Chemistry. They originated from the combination of theoretical and experimental considerations as indicated on the diagram below.
Principles of Phlogiston theory of combustion/oxidation:
Substance =>
residue + phlogiston
Metal =>
rust + phlogiston
Iron ore + phlogiston(carbon) =>
iron (metal)
Principles of Modern theory of combustion/oxidation:
Substance + oxygen (air) => oxide
The discussion of combustion theories provides crucial insights for the students about how Science/Chemistry evolves and operates. It also gives example of when theories may be considered to be scientific.
The two important take-away lessons are:
- Scientific theories need not be correct to be scientific
- Combustion theories illustrate paradigm shift on going from phlogiston theory to oxygen theory (dynamics of scientific theories: T. Kuhn). Such paradigm shifts often happen in Chemistry and are necessary for progress.
The dynamics of theories is summarized in the diagram below
Case 2: Periodic Table ; "Grand Unified Theory (GUT) of Chemistry"
Like all the most important theories in Chemistry, it is the product of many separate developments as indicated below. It also lead to the new developments in Chemistry.
The discussion again provides crucial insights for students.
- Scientific theories must have predictive capabilities in addition to explanatory properties (reference to K. Popper and falsificationism)
Mendeleev was not the first to suggest periodicity in the properties of elements, but his approach was the most insightful and fruitful because it lead to the discovery of new elements.
- It is sometimes claimed that the Periodic Table can be deduced from quantum mechanics as in Dirac's famous statement:
"The underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known and the difficulty is only that the exact application of these laws leads to equations much too complicated to be soluble" [6], [7].
The corollary of such a statement is that Chemistry can be reduced to Physics.
Via this example the students are introduced to the notion of “Theories of Everything” (TOE) and the concept of "Reductionism" in Science.
Case 3: Life and work of Fritz Haber (1868-1934)
(on the relationship between Chemistry and Society)
Haber obtained a PhD in organic chemistry, but could not find academic position for some time so he took industrial jobs. When he finally obtained an academic position he switched from organic to physical chemistry. He worked on a wide range of pure & applied chemistry problems (fuel cells, glass electrodes, electrochemistry, thermodynamics). His life’s work is highlighted below and so is the dual nature of many scientific/chemical applications.
Topics for discussion in this case study:
- Outstanding chemical careers are possible either in academia or in industry
- Applied research is important and can win Nobel prizes for it's initators (compare with Nobel prizes awarded in year 2000)
- Chemistry maintains a delicate and complex relationship with social institutions & social values (Haber was in charge of the first chemical weapons programme: "Manhattan project of Chemistry" )
- The influence of Politics on
Science can be immense as exemplified by political purges of scientists during
Nazi regime in Germany. Such political interference in Science affairs was one
of the prime factors which lead to relative decline of Science in Europe at the
expense of USA.