Honors | Theory of the Earth
H205 | 6674 | Abhijit Basu


Examination of how progressively increasing knowledge about the
interior of the earth and planetary bodies is shaping the
understanding of mechanisms of earth processes. Inferring earth
processes from properties of materials. Designed for non-science
majors.

The course aims to reason why and how the Theory of the Earth would
evolve in the current century. Wisdom distilled from the knowledge
gained from information from space research is moving the theory from
being earth-centric to one based on the evolution of the solar
system.

The foundation of the modern Theory of the Earth (Hutton, 1788-95)
came into being in the late 18th century. Qualitative observation of
the earth's surface and an explanation (~theory) in terms of its
interaction with the atmosphere and the hydrosphere, and motion in
the upper few km of the solid earth formed the basis of the theory.
Acceptance of the theory of Continental Drift (Wegener, 1912; tr.
1966) depended on new knowledge of the global pattern of continents
and the first 10s of km below the earth's surface. Quantitative data
on the earth's deep interior (1000s of km), sea floor, and global
satellite images led to the Theory of Plate Tectonics (e.g., Dewey,
1972). Only Anderson (1989) considered properties of other planetary
bodies in expanding the theory but a general theory of terrestrial
planets is yet to come.

Since Darwin (1859) a flexible consensus exists on theories of the
origin, evolution and extinction of life. Distribution of fossils in
space and time provides some evidence for the theories of continental
drift and plate tectonics. Meteoritic impacts, causing mass
extinction and spawning subsequent biodiversity, have established an
extraterrestrial connection. Interesting as that may be, it is the
theory of the earth that has influenced the theory of origin,
evolution and extinction of life, and, is now poised to interject a
solar system perspective.

The course will debate this contemporary movement in reshaping the
theory of the earth and its influence.

OVERLAP: The course content overlaps with parts of G103, G104, G111,
G112, and G121, which is understandable. However, the underlying
theme of this course, evolution of scientific thought, is
fundamentally different from any of the above.