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Particle Physics Timeline• 2500 years of

particle progress in under 60 slides…guaranteed!

Democritus(late 5th Century B.C.)

• Supposed that the cosmos consisted of “atoms and the void” , i.e. very small indivisible particle and empty space.

Aristotle(384 – 322 B.C.)

• Opposed atomism. Supposed the cosmos consisted of a plenum of infinitely divisible particles: Earth, Water, Air, Fire on Earth and Aether in the heavens.

R. Boscovic

  

Rudjer Bošković (1711-1787) Croatia 5000 dinara note (1992).A mathematician and astronomer, Bošković imagined atoms as point sources of force that repel each other at small separations (making liquids and solids difficult to compress) and attract at larger separations (making solids difficult to pull apart).

Rene Descartes(1596 - 1650)

• Followed Aristotle in believing the Cosmos is full of invisible particles. Supposed those particles whirling in vortices are responsible for gravity of Earth and planetary motion.

Daniel Bernoulli

• Daniel Bernoulli in Hydrodynamica (1738) proposed that a gas is a collection of very many very small particles (molecules) in constant motion that exert pressure by collisions – the first kinetic theory of gasses.

John Dalton(1766 - 1844)

Proposed the idea of the “chemical atom” in New System of Chemical Philosophy (1808-1827) and gave first set of relative atomic weights based on combining proportions of elements in compounds.

James Clerk Maxwell

• James Clerk Maxwell in 1866 developed a statistical kinetic theory of gases that related molecular motion to gas temperature.

Wilhelm Roentgen• Wilhelm Röntgen in

1895 discovered x-rays, a previously unknown radiation that traveled in straight lines and gave shadow pictures of bones within the skin. Röntgen received the first Nobel Prize in Physics in 1901.

Early Particle Physics

J.J. Thomson at work on his electron discovery.

Ernest Rutherford(1871 – 1937)

• Named a and b radiation based on absorption of rays, explored radioactive decay series, proposed atomic transmutation in radioactive elements (1902), showed aparticles are He nuclei, developed nuclear model of atom (1910) based on a particle scattering, demonstrated artificial transmutation (proton ejected when a collided with N nucleus, measured nuclear size.

Rutherford’s Experiment

Henri Becquerel

• Henri Becquerel discovered natural radioactivity in1896 while searching for x-rays produced from phosphorescent uranium salts. He received the Nobel Prize in Physics in 1903.

Albert Einstein(1879 – 1955)

• His 1905 paper on the photoelectric effect proposed that light energy comes in “quantum” units (later called photons). The energy of a photon is E = hf, where f = frequency of the light and h = Planck’s constant.

Robert Millikan

• Robert Millikan demonstrated the quantization of electric charge (qe = 1.6 x 10-19 C) in 1910 and in 1915 verified Einstein’s photoelectric theory based on energy carrying photons. He received the Nobel Prize in Physics in 1923.

Victor Hess

• Victor Hess discovered the existence of cosmic rays, high energy particles from space, as a result of measurements in balloon flights 1911-1913. He received the Nobel Prize in 1936.

C.T.R. Wilson

• Charles Thomson Rees Wilson invented the cloud chamber in 1896 to examine the formation of clouds. In 1911 he made the first photographs of tracks of particles, particles, and electrons. He received the Nobel Prize in 1927.

Niels Bohr

Niels Henrik David Bohr (1885-1962) Denmark 500 kroner note (1999). Bohr established the first quantum theory of atomic structure in 1912 to explain atomic spectral lines and the periodic table. He received the 1922 Nobel Prize for Physics for that work. His liquid drop model later explained nuclear fission.

Henry Moseley

• Henry Moseley in 1913 found a pattern of characteristic x-rays from cathodes of different materials that reflected the number of proton positive charges (atomic number) in the cathode materials. He was killed at Gallipoli in 1915 during WW I.

James Chadwick

• James Chadwick studied with Ernest Rutherford at Cambridge, investigated decay, and in 1932 demonstrated the existence of the neutron. He received the Nobel Prize in 1935.

Arthur Compton

• Arthur Compton studied the scattering of x-rays from electrons in metals and in 1922 developed evidence for the existence of photons proposed by Einstein to explain the photoelectric effect. He received the Nobel Prize in 1927.

Louis de Broglie

• Louis de Broglie proposed that particles were characterized by wave properties in his doctoral thesis of 1924, an idea subsequently verified by the electron diffraction results of Davisson and Germer and by G. P. Thomson. He received the Nobel Prize in 1929.

Werner Heisenberg

• German physicist and one of the founders of quantum mechanics. He is most well-known for discovering one of the central principles of modern physics, the Heisenberg uncertainty principle. He received the Nobel Prize in Physics in 1932.

Max Born

• German physicist and mathematician. He won the 1954 Nobel Prize in Physics for the formulation of the now-standard interpretation of the probability density function for ψ*ψ in the Schrödinger equation of quantum mechanics.

Erwin Schroedinger

• An Austrian - Irish physicist who achieved fame for his contributions to quantum mechanics, especially the Schrödinger equation, for which he received the Nobel Prize in 1933.

Enrico Fermi

Italian physicist most noted for his work on the development of the first nuclear reactor, and for his contributions to the development of quantum theory and particle physics.He won the 1938 Nobel Prize in Physics

P.A.M. Dirac

• British theoretical physicist and a founder of the field of quantum mechanics. Dirac shared the Nobel Prize in physics for 1933 with Erwin Schrödinger.

Clinton Davisson

• American physicist who confirmed the De Broglie hypothesis that all matter has a wave-like nature through the discovery of electron diffraction. He shared the Nobel Prize in Physics in 1937 with George Paget Thomson.

George P. Thomson

A Nobel-Prize-winning, (1937)English physicist who discovered the wave properties of the electron by electron diffraction.He was the son of Nobel Prize winning physicist J.

J. Thomson and Rose Elisabeth Paget, the daughter of the Professor of Medicine at Cambridge

Wolfgang Pauli

An Austrian theoretical physicist noted for his work on the theory of spin, and in particular the discovery of the exclusion principle, He received the Nobel

Prize in Physics in 1945. He had been nominated for the prize by Enstein.

E.O. Lawrence

• An American physicist best known for his invention, utilization, and improvement of the cyclotron. He was awarded the Nobel Prize in Physics in 1939.

Robert Van de Graaff

• American physicist and designer of the Van de Graaff generator. In 1929, he developed his first generator (80,000 volts); by 1933, he had constructed a much larger generator, capable of generating 7 million volts.

John Cockroft & E. Walton

• Winners of the 1951 Nobel Prize in Physics for the development of the accelerator that bears their name.

Carl Anderson• Carl Anderson discovered

the positron in 1932 by examining tracks of cosmic ray particles in a cloud chamber. Continuing cosmic ray research with his cloud chamber, he and his first graduate student, Seth Neddermeyer, discovered the muon in 1936, the year that Anderson received the Nobel Prize

P. Cherenkov

• Pavel Čerenkov in 1934 observed the blue glow produced in a bottle of water bombarded by fast-moving particles from a radioactive source. This Čerenkov effect results from light emitted when particles travel through a medium faster than light travels in the medium, analogous to a sonic boom shock wave produced when an object travels through air faster than sound travels in air. Čerenkov received the Nobel Prize in 1958.

H. Yukawa

• Hideki Yukawa in 1935 published a field theory of nuclear forces in which he predicted the existence of a new particle, later identified with the pion that was first observed by Cecil Powell in 1947. Yukawa received the Nobel Prize in 1949.

Seth Neddermeyer• Seth Neddermeyer, while

a graduate student with Cark Anderson, participated in the discovery of cloud chamber tracks that led to the discovery of the muon in 1936. Neddermeyer later championed the development of the implosion mechanism for exploding plutonium nuclear bombs in the Manhattan Project during WW II.

Cecil Powell

• Cecil Powell pioneered methods of tracking particles with fine grained “nuclear” photographic emulsions. With this method he and his colleagues discovered the pion predicted by Hideki Yukawa in 1935. Powell received the Nobel Prize in 1950.

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G. Rochester & C. Butler• George Rochester, working

with Clifford Butler in 1947 on cosmic rays, discovered a pair of tracks indicating oppositely charged particles emanating from blank spot in a cloud chamber. Rochester and Butler inferred the existence of a heavy neutral particle later identified as a kaon, the first known strange particle.

F. Reines & C. Cowan

• Frederick Reines, working with Clyde Cowan in 1956, observed the first direct evidence for the existence of a neutrino (electron antineutrino) in observations at the Savannah River nuclear reactor. After a long career in physics teaching and research, Reines received the Nobel Prize in 1995.

Donald Glaser

• Donald Glaser developed the bubble chamber to view tracks of charged particles in 1952. For over twenty years analysis of bubble chamber tracks led to a variety of important discoveries including the - particle and the existence of weak neutral currents. Glaser received the Nobel Prize in 1960.

Owen Chamberlain & Emilio Segre

• Owen Chamberlain and Emilio Segrè, working with Wiegand and Ypsilantis in 1955, produced and discovered the antiproton with the “Bevatron” accelerator at Berkeley, California. They received the Nobel Prize in 1959.

L. Lederman, J. Steinberger, M. Schwartz

• Leon Lederman, Melvin Schwartz, and Jack Steinberger developed the spark chamber experiment at Brookhaven in 1962 that led to the realization that muon neutrinos () are distinct from electron neutrinos (e). They received the Nobel Prize in 1988.

Murray Gell-Mann• Murray Gell-Mann

developed the Eight-Fold Way theory relating particle properties in patterns of multiplet symmetry groups. This led to his prediction of the existence of the - particle in 1962 (confirmed in 1964) and the proposal that hadrons are composed of quarks with electric charges of + ⅔ qe and -⅓ qe. Gell-Mann received the Nobel Prize in 1969.

A. Salam, S. Glashow, S. Weinberg

• Salam, Glashow and Weinberg arrived at the Electro-Weak theory independently and shared the Nobel Prize in Physics in 1979.

Richard Feynman

• American physicist known for expanding the theory of quantum electrodynamics and particle theory. He was a joint recipient of the Nobel Prize in Physics in 1965

G. ‘t Hooft & M. Veltman• Shared the

1999 Nobel Prize in Physics "for elucidating the quantum structure of electroweak interactions".

D. Gross, F. Wilczek, H.D. Politzer

They were awarded the 2004 Nobel Prize in Physics for their discovery of asymptotic freedom

S. Ting & B. Richter

• 1976 winners of the Nobel Prize in Physics for the discovery of the J particle

Martin Perl

• American physicist, who won the Nobel Prize in Physics in 1995 for his discovery of the tau lepton

Leon Lederman

• American experimental physicist who was awarded the Nobel Prize in Physics in 1988 for his work on neutrinos. He is Director Emeritus of the Fermilab.

C. Rubbia & S. Van der Meer

• Winners of the Nobel Prize in Physics in 1984 for their decisive contributions which led to the discovery of the field particles W and Z, the communicators of weak interaction"

CDF Collaboration - 1995

• Two words…

DZero Collaboration - 1995

…TOP QUARK!!!

DONUT Collaboration

• Discovered Tau Neutrino in 2000 at Fermilab

CERN• The

next chapter in the ongoing particle physics progress sstory…

Compact Muon Solenoid

…where the story will be told!