Bez tytulu slajdu

1
O n t h e T r a c k o f M o d e r n
P h y s i c s
All is trembling
Harmonize glass
Napoleon made in Egypt two invaluable
discoveries the basalt plate, known as la
Rosette" and the professor of analysis of
Polytechnic Ècole Jean-Baptist-Joseph Fourier.
It is not easy to obtain a simple monochromatic
sound. Only one good wine glass can produce it.
If wine is added, the song changes.
Wine glass (125cm3) f1290 Hz
1290 Hz
J.-B.-J. Fourier (1768-1830).
The first, containing one of the decrees of
Ptolemeus V(196 D.C.) registered in hieroglyphes,
demotic and Greek allowed in 1822 J.F.
Champollion to decode the Egyptian writing.
Big cognac glass (4000 cm3) f290Hz
290 Hz
La Pierre de Rosette, British Museum
Narrow and isolated peak is called delta of
Dirac. Paul Adrien Maurice was English and owes
his beautiful name to the mother, who was
Suisse. Other that its "delta", it formulated a
quantum equation, from which in 1930 the
existence deduced from a positive electron. The
positron was discovered in the cosmic rays in
1932.
The analysis of Fourier makes it possible to
decode the components of an unspecified periodic
function.
Transormé de Fourier et transformé inverse
Transformation of Fourier "seeks" if in the
periodic function (as a vibration) are specific
frequencies the periodic function of period 2p
is developed in series
Magic flute
A simple flute produces a very complex sound,
with various harmonic components, according to
whether the flute remains closed or open. The its
characteristic is called "stamp".
The black curve has two components sin2x and
sin(3x0.2) it is superimposed with the pink
sinusoid the two periods, with the orange
sinusoid the three periods.
During the same time Pierre-Simon de Laplace
lived. Recommended by Alembert became in 1773
member of the French Academy of Science, and in
1796 professor of LÉcole Normale in Paris.
An oscillation which is propagated in space (e.g.
along x axis), becomes "a wave". ? (x,t)A sin
(?t kx), where the period is T2p/? and the
wavelength is ?2p/k. The sound is a simple
example of wave. The human ear is able to
recognize the sound of a particular individual
musical instrument in the symphony in full
orchestratration. Ear makes it by that an
analysis of Fourier. There is 100 years since
the analysis of Fourier was done via complicated
mechanical devices masses oscillating or sphere
vacuums, for the sound. Today one analyzes the
sound with a simple computer and the virtual
oscilloscope (http//polly.phys.msu.su/zeld/oscil
l.html)
P.-S. de Laplace (1749-1827)
First he made assumptions on the formation of the
solar system starting from a nebula. The
existence of stable particular points between
Jupiter and the Sun were confirmed from the
astronomical observations only recently (1996).
Sound analyzer of König (Charles University,
Prague)
Harmonic analyzer of de Sir. W. Thomson
Virtual oscilloscope
Laplaces transformation is generalized approach
of Fourier each function, not necessarily
periodic can be substituted. For transformed of
Laplace are delighted the electric theorists of
circuits, considering which it makes it possible
to solve complicated differential equations.
 These small African artisanal animals make the
same operation as the complicated analyzer of Sir
Thomson and H. Helmholtz they raise the
vibrations, each one at its particular own
frequency!
The oscillating towers are in front of the
Faculty of Chemistry of the University of Berlin
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