Transcript Schrodinger’s Cat - Trinity College, Dublin

Erwin
Schrödinger
(1887 – 1961)
“The task is not so much to see what no-one has yet seen, but to think
what nobody has yet thought, about that which everybody sees.”
Early life
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Erwin Rudolf Josef Alexander Schrödinger was
born in 1887 in Erdberg, Vienna to Rudolf
Schrödinger, a linoleum factory owner &
botanist, and Georgine Emilia Brenda,
daughter of Alexander Bauer (a Professor of
Chemistry).
Vienna
Early life
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Erwin Rudolf Josef Alexander Schrödinger was
born in 1887 in Erdberg, Vienna to Rudolf
Schrödinger, a linoleum factory owner &
botanist, and Georgine Emilia Brenda, daughter
of Alexander Bauer (a Professor of Chemistry).
The young Schrödinger received private
lessons from a tutor at home until the age of
ten.
He then attended Akademisches Gymnasium
until his graduation in 1906.
From 1906 to 1910 he was a student at the
University of Vienna, during which time he
came under the strong influence of Fritz
Hasenöhrl, who was Boltzmann's successor.
On 20 May 1910, Schrödinger was awarded his
doctorate for the dissertation On the conduction
of electricity on the surface of insulators in
moist air. He then became assistant to Franz
Exner- an important pioneer of modern physics
in Austria at the time.
Academic Life
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In 1914, Schrodinger participated in the war effort as part of the
Austrian Fortress Artillery. In 1920, he took up an academic position
as assistant to Max Wien, followed by positions at Stuttgart
(extraordinary professor), Breslau (ordinary professor), and at the
University of Zurich (replacing von Laue) where he settled for six
years. Schrödinger, in his autobiography “Meine Leben, Meine
Weltansicht,” described Wien as “moderately anti-semetic.”
His papers at this time dealt with specific heats of solids, with
problems of thermodynamics (he was greatly interested in
Boltzmann's probability theory) and of atomic spectra; in addition, he
indulged in physiological studies of colour (as a result of his contacts
with Kohlrausch and Exner, and of Helmholtz's lectures).
It was during his stay at the University of Vienna that he became
interested in eigenvalue problems and especially in their application
to the new ‘quantum theory’.
Academic life
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His great discovery, Schrödinger's wave
equation, was made in the first half of
1926. It came as a result of his
dissatisfaction with the quantum
condition in Bohr's orbit theory and his
belief that atomic spectra should really
be determined by some kind of
eigenvalue problem.
He became convinced that the energies
of a confined particle could be
determined as eigenvalue solutions to a
particular eigenfunction, a probabilistic
wave function.
He published his work in Annalen der
Physik (the same publication that
Einstein used to publish his theories of
relativity) under the very imaginative
title, ‘Quantisation as an eigenvalue
problem’.
For this work he shared the Nobel Prize
in 1933 with Paul Dirac for “the
discovery of new productive forms of
atomic theory”.
Academic life
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His great discovery, Schrödinger's wave equation, is below. H-bar is
Planck’s constant, m is the mass of the particle, Psi is the wave
function, V(x) is the potential energy and E is the particle’s energy.
This formulation of quantum mechanics has the form of an eigenvalue
problem.
The solution of the Schrodinger Equation (the eigenvalues) gives the
allowed energy levels (or orbitals surrounding a nucleus).
 d


V
(
x
)


E

2
2m dx
2
2
Schrodinger’S cat
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After consultation with Einstein, Schrodinger proposed a thought
experiment in which he highlighted the apparent inconsistencies
between the so-called Copenhagen interpretation of Quantum
Mechanics and the reality of macroscopic measurements.
He proposed that a cat be placed in a sealed box. The release of a
poison is then subject to the probabilistic decay of a radioactive
isotope. If the isotope decays, the poison is released. If no decay
occurs, the poison is not released.
The result is that the cat is in a superposition of states between
being dead, and being alive. This is very unintuitive.
His Dublin life
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In 1940, Schrodinger was asked by
Eamonn deValera (who had been a
Mathematics teacher at Blackrock College)
to help establish the Dublin Institute for
Advanced Studies, on Merrion Square.
He became Director of the School of
Theoretical Physics and remained in
Ireland for 17 years until his retirement in
1955. During this time he became a
naturalised Irish citizen.
During his time at the Institute he wrote
about fifty further publications on various
topics including his attempt at formulating
a unified field theory.
After retiring at the ripe old age of 68, he
returned to Vienna
What is life?
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In 1944, Schrodinger wrote a book that was to change the course of
scientific endeavour in the biological sciences.
He published his book, What is life?, with a view to explaining the
characteristics of life and speculating on the mechanism for the
storage of biological information.
Both James Watson and Francis Crick, who discovered the structure
of DNA in 1953, later cited Schrodinger’s book as their inspiration in
searching for the information transfer mechanism.
Schrodinger also delivered a series of lectures with the same title in
what is now the Schrodinger Lecture Theatre in Trinity College a
year before the book was published.
It was from this platform that he introduced the idea of negative
entropy or negentropy, which means that life may be associated with
a local decrease in entropy (organisation of the organism) which is
offset by borrowing entropy from the surroundings (food).
Schrodinger’S
Other equation
+
=
Personal life
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Despite being one of the greatest thinkers of the 20th Century,
Schrodinger had a more unusual approach to his personal life.
Schrodinger had married Annemarie Bertel in 1920.
It has been widely reported (mostly by Cormac McGuinness) that
Schrodinger had a eureka moment when he was holidaying in the
Alps with one of his mistresses in which he saw his famous
Schrodinger Equation flash before his eyes.
Schrodinger requested that Arthur March become his assistant while
he was working in Oxford because Schrodinger was in love with
March’s wife, Hilde.
Schrodinger was offered a teaching position at Princeton but after
extensive negotiations he declined the position. It is thought that
Princeton would not house him with his wife and his mistress.
Instead, he went to DUBLIN, to the Dublin Institute for Advanced
Studies, who obligingly provided said housing arrangement.
While in Ireland, Schrodinger also fathered two children, by two
different women.
Schrodinger’S legacy
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Schrodinger died on January 4th, 1961, of
tuberculosis at the age of 73, in his native
Austria.
He was survived by his widow, Anny (his
original wife), his various misstresses and
numerous children.
The huge Schrodinger Crater, on the far
side of the moon, was named after him by
the IAU (International Astronomical
Union).
The Erwin Schrodinger International
Institute for Mathematical Physics was
established in Vienna in 1993.
That’s a psi, by the way!
Applause
+ ANY QUESTIONS
By Catherine McGinty and Simon Hall
stop
Applause