Transcript Document

J
ob Chaula
Niels Bohr’s World View
Niel Bohr
1885 -1962
Bohr's family fled to Sweden
in a fishing boat when German army occupied Denmark
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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Introduction

Niel Bohr was a Danish Physist (1885-1962).

His contributions

Significance of Quantum Theory

His ways of Treatment of Puzzles, History and
refutations
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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Bohr’s Contribution

Bohr made numerous contributions to our
understanding of atomic structure

Bohr is considered to be one of the founders of
quantum mechanics.
Added new idea of quanta to the model put forth by
Max Planck. That electrons existed at set levels of
energy, that is, at fixed distances from the nucleus.
His model made the theory fit the experimental
evidence .
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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Bohr’s Contribution
 Complementarity
Principal
That things may have a dual nature
(as the electron is both particle and wave)
But we can only experience one aspect at
a time.
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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Bohr’s Contribution

correspondence principle
A new, more general theory should dovetail with an
older, more restricted theory.
The two should generate the same results, under the
‘normal’ circumstances where
The older theory remains a good approximation.
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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Bohr’s Contribution

In 1920 founded the Institute for Theoretical
Physics at the University of Copenhagen

Offered a place for many escaping Jewish
scientists to live and work during II WW

He later donated his gold Nobel medal to the
Finnish war effort.

He contributed to CERN, Europe's great particle
accelerator and research station.
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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Significance of Quantum Theory

New fields in physics emerged:condensed matter
physics, superconductivity, nuclear physics, and
elementary particle physics—that all found a
consistent basis in quantum mechanics

Enhanced the understanding of the structure of
matter

The understanding of chemical bonding
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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Bohr’s Treatment of Puzzles

Should not only be assimilated to old
paradigm but

Should be turned into fundamental
difficulties by looking at them from a new
direction and

By testing their background
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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Bohr’s Considerations of History
His papers are heavily seasoned with historical
material
 Are characterized as preliminary summaries
surveying the past
 giving account of present state of knowledge
and making general suggestions, in the spirit of
correspondence principal on the possible
course of research
 Early Einstein papers lack this important
component of history.

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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Bohr’s View of Refutation

He generalized Einstein’s considerations and
published a purely statistical particle theory with
waves acting as probability field only. …..This
theory was refuted…..

He considered “Refutation” and “Success” to be
part of progress

Realized the need to retain the sense of
perspective even in surprising successes and
failures!
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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Never
Express
Yourself more clearly
Than you can think
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Realism, Rationalism & Scientific Method By P.K. Feyerabend
Questions
?
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Realism, Rationalism & Scientific Method By P.K. Feyerabend