Transcript Noble Prize In Physics

Nobel prize in physics
The Nobel Prize in Physics has been awarded to 180 individuals
since 1901. (John Bardeen was awarded the prize in both 1956 and 1972 (.
Noble Prize In Physics- Ashraf Gouda
Presented by: Ashraf Gouda
What Is physics?
(and why should you care?)
• Physics is the study of the basic physical
world
– It addresses “How” and “Why” questions
– It explains and predicts how the universe works.
• Physics is key to scientific literacy
– Understanding physics is useful in every day life
– Leaving physical problem to other is expensive
– Modern technological society depend on physics.
The Nobel Prize in Physics 1901
"in recognition of the extraordinary services he has
rendered by the discovery of the remarkable rays
subsequently named after him“
Wilhelm Conrad Röntgen
Germany
X-rays
How Are X-rays Made?
The penetrating rays discovered by Röntgen in 1895.
X-rays, What Are They?
electromagnetic waves of shorter wavelength and higher energy than normal
light
But the debates over the nature of the rays – waves or particles?
continued until the wave-particle duality was generally accepted in the
1920s. Photons can be described both as waves and particles.
X-rays in Use
The Nobel Prize in Physics 1902
"in recognition of the extraordinary service they rendered
by their researches into the influence of magnetism
upon radiation phenomena“
Hendrik Antoon Lorentz
the Netherlands
Pieter Zeeman
the Netherlands
Zeeman effect
Is the splitting of a spectral line into several components in the
presence of a static magnetic field
Since the distance between the Zeeman sub-levels is proportional to
the magnetic field, this effect is used by astronomers to measure the
magnetic field of the Sun and other stars.
Lorentz transformation
converts between two different observers' measurements of space and
time, where one observer is in constant motion with respect to the
other
Time is different from frame to another
You can’t transfer energy with a v
greater than c
The Nobel Prize in Physics 1903
"in recognition of the extraordinary services he has rendered by his
discovery of spontaneous radioactivity"
"in recognition of the extraordinary services they have rendered by their
joint researches on the radiation phenomena discovered by
Professor Henri Becquerel“
Antoine Henri Becquerel 1/2
Pierre Curie 1/4
Marie Curie 1/4
France
Radioactive decay
Radioactive decay is the process in which an unstable atomic nucleus
loses energy by emitting radiation in the form of particles or
electromagnetic waves
The Nobel Prize in Physics 1906
"in recognition of the great merits of his theoretical and
experimental investigations on the conduction of
electricity by gases“
Joseph John Thomson
United Kingdom
Work on cathode rays
In his first experiment, he investigated whether or not the negative
charge could be separated from the cathode rays by means of
magnetism
In his second experiment, he investigated whether or not the rays could
be deflected by an electric field
In his third experiment, Thomson measured the charge-to-mass ratio
of the cathode rays by measuring how much they were deflected by a
magnetic field and how much energy they carried
Application:
Cathode Rays Tube (CRT)
The Nobel Prize in Physics 1909
"in recognition of their contributions to the development
of wireless telegraphy“
Guglielmo Marconi
Italy
Karl Ferdinand Braun
Germany
Invention of radio
Marconi began to conduct experiments, building much of his own
equipment in the attic of his home at the Villa Griffone in Pistachio, Italy.
His goal was to use radio waves to create a practical system of "wireless
telegraphy”.
Marconi's system had the following components
1.A relatively simple oscillator.
2.A wire or capacity area placed at a height above the ground;
3.A coherer receiver
4.A telegraph key to operate the transmitter to send short and long pulses,
corresponding to the dots-and-dashes of Morse code
5.A telegraph register, activated by the coherer, which recorded the
transmitted Morse code dots-and-dashes onto a roll of paper tape.
The Nobel Prize in Physics 1915
"for their services in the analysis of crystal structure by
means of X-rays“
Sir William Henry Bragg
United Kingdom
William Lawrence Bragg
United Kingdom
X-ray crystallography
Diffraction from a three dimensional periodic structure such as atoms in
a crystal is called Bragg diffraction.
The Nobel Prize in Physics 1918
"in recognition of the services he rendered to the
advancement of Physics by his discovery of energy
quanta“
Max Karl Ernst Ludwig Planck
Germany
Quantum Mechanics:
The word “quantum” (Latin, “how much”( in quantum mechanics refers
to a discrete unit that quantum theory assigns to certain physical
quantities,
such as the energy of an atom at rest .The discovery that waves have
discrete energy packets (called quanta) that behave in a manner
similar to particles .
E=hv
The Nobel Prize in Physics 1921
"for his services to Theoretical Physics, and especially
for his discovery of the law of the photoelectric effect“
Albert Einstein
Germany and Switzerland
Photoelectric effect
The photoelectric effect is a quantum electronic phenomenon in
which electrons are emitted from matter after the absorption of
energy from electromagnetic radiation such as x-rays or visible light.
The emitted electrons can be referred to as photoelectrons in this
context.
Study of the photoelectric effect led to important steps in understanding
the quantum nature of light and electrons and influenced the
formation of the concept of wave–particle duality.
Applications:??
Special theory of relativity
First postulate:
The laws of physics are the same in all inertial frames of reference.
Second postulate:
The speed of light in a vacuum is a universal constant, c, which is
independent of the motion of the light source. c (299792458 m/s)
1.Time dilation (twin paradox)
2.Lorentz contraction
3.Equivalence of mass and energy, E = mc^2
The Nobel Prize in Physics 1922
"for his services in the investigation of the structure of
atoms and of the radiation emanating from them“
Niels Henrik David Bohr
Denmark
Bohr model
In atomic physics, the Bohr model depicts the atom as a small,
positively charged nucleus surrounded by electrons that travel in
circular orbits around the nucleus — similar in structure to the solar
system, but with electrostatic forces providing attraction, rather than
gravity.
The electrons travel in orbits that have discrete quantized speeds, and
therefore quantized energies. That is, not every orbit is possible but
only certain specific ones, at certain specific distances from the
nucleus.
The electrons do not continuously lose energy
as they travel. They can only gain and lose
energy by jumping from one allowed orbit to
another.
The Nobel Prize in Physics 1927
"for his discovery of the effect named after him"
"for his method of making the paths of electrically
charged particles visible by condensation of vapor”
Arthur Holly Compton
USA
Charles Thomson Rees Wilson
United Kingdom
Compton scattering
In physics, Compton scattering or the Compton effect is the
decrease in energy (increase in wavelength) of an X-ray or gamma
ray photon, when it interacts with matter
The Nobel Prize in Physics 1929
"for his discovery of the wave nature of electrons“
Prince Louis-Victor Pierre Raymond de Broglie
France
De Broglie hypothesis
all matter (any object) has a wave-like nature (wave-particle duality).
He suggested that the wave-particle dualism that applies to EM
radiation also applies to particles of matter. He proposed that every
kind of particle has both wave and particle properties. Hence,
electrons can be thought of as either particles or waves.
The Nobel Prize in Physics 1932
"for the creation of quantum mechanics, the application
of which has, inter alia, led to the discovery of the
allotropic forms of hydrogen“
Werner Karl Heisenberg
Germany
Uncertainty principle
which lays it down that the determination of the position and
momentum of a mobile particle necessarily contains errors the
product of which cannot be less than the quantum constant h and
that, although these errors are negligible on the human scale, they
cannot be ignored in studies of the atom.
The Nobel Prize in Physics 1933
"for the discovery of new productive forms of
atomic theory“
Erwin Schrödinger
Austria
Paul Adrien Maurice Dirac
United Kingdom
Atomic theory
In chemistry and physics, atomic theory is a theory of the nature of
matter, which states that matter is composed of discrete units called
atoms, as opposed to obsolete beliefs that matter could be divided
into any arbitrarily small quantity. Or, in a nutshell, the idea that all
things are made of atoms.
The chemists of the era believed the basic units of the elements were
also the fundamental particles of nature and named them atoms
(derived from the Greek word atomos, meaning "indivisible").
However, around the turn of the 20th century, through various
experiments with electromagnetism and radioactivity, physicists
discovered that the so-called "indivisible atom" was actually a
conglomerate of various subatomic particles (chiefly, electrons,
protons and neutrons) which can exist separately from each other.
Schrödinger equation
Solutions of the analytical solutions of the time-independent
Schrödinger equation can be obtained for a variety of relatively
simple conditions.
These solutions provide insight into the nature of quantum phenomena
and sometimes provide a reasonable approximation of the behavior
of more complex systems (e.g., in statistical mechanics, molecular
vibrations are often approximated as harmonic oscillators).
The Nobel Prize in Physics 1935
"for the discovery of the neutron“
James Chadwick
United Kingdom
The Nobel Prize in Physics 1956
"for their researches on semiconductors and their
discovery of the transistor effect“
William Bradford Shockley
USA
John Bardeen
USA
Walter Houser Brattain
USA
Vacuum Tubes:
The vacuum tube that hundred years ago
only had a role in scientists' exploration of
the processes in matter, has, thanks to many
technical inventions, evolved into an
apparatus that is found in virtually every
home and office – the television tube and
the computer screen.
First transistor
Solid-state transistor
Since then semiconductor devices have evolved tremendously. Today
transistors are extremely small and come packed in millions onto tiny
Silicon chips called integrated circuits
This invention is essential for digital technologies like computers,
mobile phones, CDs, mp3s or DVDs. The list could be made almost
infinite. For instance, without semiconductor technology there would be
no Internet, so you would not be able to read this text.
Actions of transistor:
•Switches
•Amplifiers
How many transistors on the Pentium 4??
The Nobel Prize in Physics 1969
"for his contributions and discoveries concerning the
classification of elementary particles and their
interactions“
Murray Gell-Mann
USA
BibAlex
The Nobel Prize in Physics 1973
"for their experimental discoveries regarding tunneling phenomena in
semiconductors and superconductors, respectively"
"for his theoretical predictions of the properties of a supercurrent
through a tunnel barrier, in particular those phenomena which are
generally known as the Josephson effects“
Leo Esaki
Japan BibAlex
Ivar Giaever
USA
Brian David Josephson
United Kingdom
The Nobel Prize in Physics 1985
"for the discovery of the quantized Hall
effect“
Klaus von Klitzing
Federal Republic of Germany
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The Nobel Prize in Physics 1996
"for their discovery of superfluidity in helium-3“.
David M. Lee
USA
Douglas D. Osheroff
BibAlex
USA
Robert C. Richardson
USA
The Nobel Prize in Physics 1999
"for elucidating the quantum structure of electroweak
interactions in physics“
Gerardus 't Hooft
the Netherlands
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Martinus J.G. Veltman
the Netherlands
The Nobel Prize in Physics 2006
"for their discovery of the blackbody form and
anisotropy of the cosmic microwave
background radiation“
John C. Mather
USA
George F. Smoot
USA
The Nobel Prize in Physics 2007
"for the discovery of Giant Magnetoresistance“
Albert Fert
France
Peter Grünberg
Germany
Hard Disks:
Portable computers, music players, and powerful search engines, all require hard disks where
the information is very densely packed. Information on a hard disk is stored in the form of
differently magnetized areas
A certain direction of magnetization corresponds to the binary zero, and another
direction corresponds to the binary value of one.
In order to access the information, a read-out head scans the hard disk and
registers the different fields of magnetization.
When hard disks become smaller, each magnetic area must also shrink. This
means that the magnetic field of each bite becomes weaker and harder to read. A
more tightly packed hard disk thus requires a more sensitive read-out technique
Recently, the maximum storage capacity of hard disks for home use has soared to
a terabyte (a thousand billion bytes).
In a metal conductor, electricity is transported in the form of electrons
which can move freely through the material. The current is conducted
because of the movement of electrons in a specific direction, the
straighter the path of the electrons, the greater the conductance of the
material
In a magnetic material the scattering of electrons is influenced by the
direction of magnetization.
The very strong connection between magnetization and resistance that
one finds in giant magnetoresistance arises because of the intrinsic
rotation of the electron that induces a magnetic moment – the quantum
mechanical property called spin – which is directed in either one of two
opposite directions
In the following an example of the simplest type of system where giant
magnetoresistance can arise is described: It consists of a layer of nonmagnetic metal sandwiched between two layers of a magnetic metal
References
http://nobelprize.org/nobel_prizes/physics/la
ureates/
http://en.wikipedia.org