Proved that a physical system described by a Lagrangian
invariant with respect to the symmetry transformations of a Lie group has,
in the case of a group with a
finite (or countably infinite) number of independent, infinitesimal generators,
a conservation law
for each such generator, and certain `dependencies' in the case
of a larger infinite number of generators.
The latter case applies, for example, to
the general theory of relativity and gives the Bianchi identities.
These `dependencies'
lead to understanding of energymomentum conservation in the general theory.
Her paper
proves both the theorems described above and
their converses.These are collectively referred to by physicists as
Noether's Theorem.
The key to the relation of symmetry laws to conservation laws is Emmy Noether's celebrated Theorem. ... Before
Noether's Theorem the principle of conservation
of energy was shrouded in mystery, leading to the obscure physical systems of
Mach and Ostwald. Noether's simple and profound mathematical formulation did
much to demystify physics.
 Feza Gursey [encp1983nj]
An historical account of how she came to make this discovery is given in
E. Noether's Discovery of the Deep Connection Between Symmetries and
Conservation Laws.
The main body of her work was in the creation of modern abstract
algebra. As the topologist P. S. Alexandrov wrote
It was she who taught us to think in terms of simple and general
algebraic concepts  homomorphic mappings, groups and rings with operators,
ideals ...theorems such as the `homomorphism and isomorphism theorems',
concepts such as the ascending and descending chain conditions for subgroups and ideals,
or the notion of groups with operators were first introduced by Emmy Noether and have
entered into the daily practice of a wide range of mathematical disciplines.
... glance at Pontryagin's work on ..continuous groups, Kolmogorov on
... combinatorial topology ..., ... Hopf on continuous mappings, ...
van der Waerden on algebraic geometry, ... to sense the influence of
Emmy Noether's ideas. This influence is also keenly felt in H. Weyl'
book Gruppentheories und Quantenmechanik. [en1981ad]
Specifically, Nathan Jacobson writes
Abstract algebra can be dated from the publication of
two papers by Noether, the first a joint paper
with Schmeidler and .. a truly monumental work
Idealtheorie in Ringbereichen [which] belongs to one of the
mainstreams of abstract algebra, commutative ring theory, and
may be regarded as the first paper in this vast subject ...
[encp1983nj]
And Hermann Weyl writes of her
important later work
The theory of noncommutative algebras and their representations wa
built up by Emmy Noether in a new unified, purely conceptual manner
by making use of all the results that has been accumulated by the
ingenious labors of decades by Frobenius, Dickson, Wedderburn and
others. [sm1935hw]
Some Important Publications
"Invariante Variationsprobleme," Nachr. v. d. Ges. d. Wiss. zu
Göttingen
1918, pp 235257 _{ }
English translation by M. A. Tavel.
"Moduln in nichtkommutativen bereichen, insobesondere aus
Differential und Differenzenausdrucken," Math. Zs. 8:1 (1920)
with W. Schmeidler.
"Idealtheories in Ringbereichen," Math. Ann. 83:24 (1921).
"Hyperkomplexe Grossen und Darstellungstheorie,"
Math. Zs. 30:641 (1929).
"Beweis eines Hauptsatzes in der Theorie de Algebren,"
Journal f. d. reine u. amgew. Math. 167:399 (1932)
with R. Brauer and H. Hasse.
"Nichtkommutative Algebren," Math. Zs. 37:514 (1933).
1907 Doctorate summa cum laude University
of Erlangen
1908 member of the Circolo mathematico di Palermo [en1981ad]
1909 member Deutsche
Mathematiker Vereinigung (DMV) [en1981ad]
1932 Cowinner, Alfred AckermannTeubner Memorial Prize for the
Advancement of Mathematical Knowledge
1958 A conference at the University of Erlangen was held to
commemorate the 50th anniversary of Noether's doctorate.
1982 Emmy Noether Gymnasium, a coeducational school emphasizing
mathematics, natural sciences and language, opened in Erlangen,
Germany on the 100th anniversary of Noether's birth.
1992 Emmy Noether Institute for Mathematical Research established in
Bar Ilan University, Tel Aviv, Israel.
19081915 unpaid lecturer and supervisor of doctoral student
in University of Erlangen.
19161922 unpaid lecturer and member of Hilbert's research team
in the University of Göttingen.
19221933 nichtbeamteter ausserordentlicher
Professor (adjunct, notordinary Professor  untenured),
University of Göttingen.
19221933 Lehrauftrag
for algebra  which brought her a small stipend; "the first and only salary she was ever
paid in Göttingen." [h1970cr]
19331935 Visiting Professor, Bryn Mawr College.
Education
1903 Reifeprüfung, Königliches Realgymnasium, Nuremburg
1907 Doctorate in Mathematics, University of Erlangen
1919 habilitation, University of Göttingen
Emmy Noether's name is used to designate many concepts specific to abstract
algebra
; for example,
 a ring is called Noetherian if each ideal has a finite basis;
 a group is called Noetherian if each subgroup can be generated by a finite basis;
 and mathematicians speak of Noetherian equations, Noetherian modules, Noetherian factor systems, etc..
[en1981ad]
She was never elected to the Königl. Gesellschaft
der Wissenschaften zu Göttingen
. [h1970cr]
Her great 1918 paper on symmetries and conservation
laws was communicated to the Gesellschaft by Felix Klein.
Auguste Dick raises interesting questions regarding the fact that Noether wa
never appointed to a paid position in the faculty of the University of
Göttingen:
How was it then that in her academic career
she did not go beyond the [unpaid] level of nichtbeamteter ausserordentlicher
Professor? ... Was it because she was Jewish? There were several Jewish
Ordinarii in Göttingen. Was it because she was a member of the social
democratic party? ... Or was it her firm stance as a pacifist that was frowned
upon? ..."  [en1981ad]
As a Jewish woman, in 1933 Emmy Noether was fired from her position as a privat docent in
Göttingen. By decree no Jew was allowed to teach
after Hitler came to power. (In 1934
women were dismissed from University
posts.)
Hermann Weyl wrote about her in this period
" A stormy time of struggle like this one we spent in Göttingen in the
summer of 1933 draws people closely together; thus I have a vivid recollection
of these months. Emmy Noether  her courage, her frankness, her unconcern about
her own fate, her conciliatory spirit  was in the midst of all the hatred and
meaness, despair and sorrow surrounding us, a moral solace."
[sm1935hw]
Part of a Letter to the Editor of the New York Times that Albert Einstein
wrote on the occasion of her untimely death:
``The efforts of most human beings are consumed in the struggle for
their daily bread, but most of those who are, either through fortune
or some special gift, relieved of this struggle are largely absorbed in
further improving their worldly lot. ... There is, fortunately, a minority composed of those
who recognize early in their lives that the most beautiful and satisfying
experiences open to humankind are not derived from the outside, but are
bound up with the development of the individual's own feeling,
thinking and acting. The genuine artists, investigators and thinker
have always been persons of this kind. However inconspicuously the life of
these individuals runs its course, none the less the fruits of their
endeavors are the most valuable contributions which one generation can
make to its successors.''[NYT1935ae]
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Recommended further reading on Emmy Noether's contributions to mathematics:
There are two papers by Nina Byers on her contributions to physics:
Field Editor: Nina Byers
<nbyers@physics.ucla.edu >
