Heinrich Rudolf Hertz (1857-1894)

Heinrich Rudolf Hertz (1857-1894)

Γεννήθηκε στο Αμβούργο στις 22 Φεβρουαρίου 1857.

Πρώτα σπούδασε μηχανικός στο Μόναχο, αργότερα ασχολήθηκε με τη Φυσική. Έγινε βοηθός πανεπιστημίου (Assistent) δίπλα στον Helmholtz, ο οποίος και υπέδειξε στον Hertz να ασχοληθεί με την ηλεκτρομαγνητική θεωρία του Maxwell.

Το αρχικό πρόβλημα προς διευκρίνιση ήταν, αν «η ηλεκτρική δύναμη οδεύει με απεριόριστη ταχύτητα», όπως υπεστήριζε ο Weber, ή συμπεριφερόταν «ως κύμα», όπως έλεγε ο Maxwell. Αποτέλεσμα αυτής της έρευνας ήταν να επιβεβαιωθεί πειραματικά η ηλεκτρομαγνητική θεωρία και η ύπαρξη ηλεκτρομαγνητικών κυμάτων.

Για την ολοκλήρωση των ερευνών του παρήγαγε ο Hertz με τα πρωτόγονα μέσα της εποχής ηλεκτρομαγνητικά κύματα με συχνότητες μέχρι 1 GHz!

Οι σχετικές δημοσιεύσεις έγιναν το 1888. Στο πλαίσιο των ίδιων ερευνών διαπιστώθηκε ότι τα ηλεκτρομαγνητικά κύματα ανακλώνται σε μεταλλικές επιφάνειες, αλλά «διαπερνούν ξύλινες πόρτες», όπως γράφτηκε τότε εντυπωσιακά. Πολλά από τα ερευνητικά θέματα των πρωτοπόρων αποτελούν βέβαια για τον 21ο αιώνα γραφικότητες, πρέπει όμως να σκεφτούμε ότι θεμέλιο των δορυφορικών επικοινωνιών, της κινητής τηλεφωνίας, των δικτύων Η.Υ., της εγγραφής/ αναγνώσεως με ακτίνες Laser και ό,τι άλλο σχετικό προκύψει μελλοντικά, είναι οι εργασίες ιδιοφυών ανθρώπων του 19ου αιώνα.

Ο Hertz είχε εντυπωσιακή ικανότητα να συνδυάζει τη θεωρία με το πείραμα.

Δημοσίευσε δε σημαντικές εργασίες για πολλά θέματα Ηλεκτρομαγνητισμού, καθώς επίσης για θέματα Θερμότητας και Μηχανικής.

Δίδαξε για μικρό χρονικό διάστημα στο Κίελο και μετά έγινε καθηγητής στην Καρλσρούη.

To 1889 έγινε καθηγητής στη Βόννη, όπου και δημοσίευσε το βιβλίο «Αρχές Μηχανικής». Πέθανε την πρωτοχρονιά του 1894 σε ηλικία μόλις 37 ετών!

Αναδημοσίευση από το Συλλεκτικό Παζάρι

Σχετικά Ο Γουλιέλμος από τη Μπολόνια

Δεκαοκτώ (37-54) από 54 διάσημους Φυσικούς, αλφαβητικά.

37) Lise Meitner (1878-1968) Birthplace: Vienna, Austria
Throughout the 1920s and early 1930s, Meitner worked in Berlin doing experimental research in nuclear physics, but went into exile in 1938 to escape the Nazis. In Sweden, she received information about work done by her former colleague Otto Hahn, who was continuing their research with what they considered to the transuranic elements. Meitner realized that the explanation instead was nuclear fission. The atomic age had began.

38) Albert Michelson (1852-1931) Birthplace: Strelno, Poland
(Nobel Prize: 1907)
The interferometer that this superb experimentalist invented has been a basic tool in many different investigations. Michelson used it to measure the standard meter in terms of the wavelengths of light, and to see if the speed of light depends on the motion of the Earth through the ether. Although the Michelson – Morley experiment is now considered one of the proofs of Einstein’s relativity theory, Michelson himself was never satisfied with its null result.

39) Robert Millikan (1836-1953) Birthplace: Morisson, IL
(Nobel Prize: 1923)
Robert Millican was an outstanding teacher and textbook author (the AAPT award for notable contributions to physics teaching is named for him). However, he is the best known for his series of experiments on charged oil drops by which he determined the electron charge. His other contributions to physics include the experimental verification of Einstein’s photoelectric equation and the determination of Planck’s constant. His studies of Brownian motion in gases put an end to all opposition to the atomic and kinetic theories of matter.

40) Isaac Newton (1642-1727) Birthplace: Lincolnshire, England
Inventor of the calculus, creator of laws of dynamics, framer of the law of universal gravitation, discoverer of many optical phenomena. And yet he said, “I do not Know what I may appear to the world, but to myself, I seen to have been only like a boy playing on the seashore and diverting myself in now and then finding a smoother pebble ar a prettier shell than ordinary, why the great Ocean of Truth lay all undiscovered before me.”

41) H. Kamerlingh Onnes (1853-1926) Birthplace: Groningen, The Netherlands
(Nobel Prize: 1913)
Kamerlingh Onnes was the first to liquify helium. He conducted extensive studies of the properties of materials at temperatures of 4K and lower. Among his discoveries was that at sufficiently low temperatures the electrical resistance of certain metals vanishes. In 1901, Albert Einstein attempted unsuccessfully to obtain a position at Kamerlingh Onnes’ laboratory.

42) Wolfgang Pauli (1900-1958) Birthplace: Vienna, Austria
(Nobel Prize: 1945)
Pauli was of the inventors and refiners of the quantum theory. His exclusion principle was the key to understanding the periodic table of elements. Typical of his acerbic but valuable style was his comment when he was 20 years old and attending a colloquium where Einstein was the speaker. Said Pauli, “What Professor Einstein has said is not all that stupid.” He was in a position to know; he had just written a definitive survey of Einstein’s special theory of relativity for an encyclopedia of mathematics.

43) Jean Baptiste Perrin (1870-1942) Birthplace: Lille, France
(Nobel Prize :1926)
In 1895 Perrin demonstrated that cathode rays of negatively charged particles. He later measured the vertical distribution of colloidal particles undergoing Brownian motion. His results were consistent with the theoretical results of Einstein and Smoluchowski on Brownian motion and provided proof of the existence of atoms.

44) Max Planck (1858-1947) Birthplace: Kiel, Germany
(Nobel Prize: 1918)
Max Planck developed a rather simple relationship of blackbody radiation over all wavelengths. The equation was based on the assumption that energy can only be emitted or absorbed in discrete amounts, which he called “quanta”. The energy of a quantum of electromagnetic radiation is proportional to the radiation frequency, and the proportionality constant later became known as Planck’s constant.

45) Jules Henri Poincare (1854-1912) Birthplace: Nancy, France
Poincare was equally at home in mathematics and physics. He invented the qualitative theory of differential equations, which is the foundation for today’s approach to nonlinear mechanics and “chaos”. In retrospect, some of his work seems to have anticipated Einstein’s special theory of relativity, though lacking the powerful simplicity of Einstein’s formulation.

46) Isidor I. Radi (1898-1988) Birthplace: Raymanov, Austria
(Nobel Prize: 1944)
From a childhood spent in the immigrant tenements of New York, Radi rose to be one of the dominant figures in American physics during the mid-20th century. He invented and exploited atomic beam techniques to measure fundamentals constants of nuclei, atoms, and molecules. His work is the foundation for such allpications as atomic clocks and nuclear magnetic resonance.

47) Lord Rayleigh (1842-1919) Birthplace: Essex, England
(Nobel Prize: 1904)
“Tell me why the sky’s so blue.” It’s Rayleigh scattering. John William Strutt, third Baron Rayleigh, skilled experiment and discovered of argon, explained a vast number of sound and light. Indded, many of his mathematical techniques apply to problems in quantum mechanics.

48) Ernest Rutherford (1871-1937) Birthplace: Nelson, New Zeland
(Nobel Prize: 1908, Chemistry)
Master of research with natural radioactivity. Discovered of atomic nucleus. “Lucky fellow,” a friend once said to him. “Always riding the crest of the wave.” “Yes,” answered Rutherford, “but I made the wave.”

49) Erwin Schrodinger (1887-1961) Birthplace: Vienna, Austria
(Nobel Prize: 1933)
The Schrodinger wave equation is the starting point of the most calculations in quantum mechanics. The “waves” are not the “particles,” nor do they describe the motion of the particles. Instead the solutions to the equation are probability functions that (properly combined) give the probability of the particle being in certain positions or having certain properties.

50) Leo Szillard (1898-1995) Birthplace: Budapest, Hungry
Soon after discovery of nuclear fission, Leo Szillard conducted experiments to determine if neutrons are released in the process. The positive result indicated that a nuclear fission chain reaction was possible. He and Fermi developed the first nuclear reactor and they were jointly awarded a patent for the design. It was Szilard who drafted Einstein’s famous letter to President F.D. Roosevelt that ultimately led to the initiation of the Manhattan Project.

51) Charles H. Townes (1915- ) Birthplace: Greenville, SC
(Nobel Prize: 1964)
Townes received the Nobel Prize in physics for his work in quantum electronics. He expanded the uses of atomic and molecular beams to produce masers, the forerunners of lasers and atomic clocks. As a pioneer in infrared astronomy, he discovered that there are many complex molecules in space.

52) Hermann Weyl (1885-1955) Birthplace: Elmshorn, Germany
Mathematician, physicist, philosopher, and teacher, Weyl wrote the books that introduced many physicists to quantum theory and relatively. His most famous work concerned symmetry in physics. He saw the relevance of gauge theory, which was later shown by others to underlie all present physical theory.

53) Eugene Winger (1902-1995) Birthplace: Budapest, Hungary
(Nobel Prize: 1963)
Winger was awarded the Nobel Prize “for his contributions to the theory of the atomic nucleus and the elementary particles, particularly though the discovery and application of fundamental symmetry principles.” He determined that the force that binds nucleons together is short – range and independent of the particles’ electric charge. He also developed the theory of neutron absorption, which was invaluable in the design of nuclear reactors.

54) Chien – Shiung Wu (1912-1997) Birthplace: Shanghai, China
Wu was a skilled experimenter in atomic and nuclear physics. Her specially concerned processes involving beta decay. When Yang and Lee proposed that parity is not conserved in weak interactions, Wu led a team to test the proposal. With a clever and delicate experiment involving low temperatures and nuclear detectors, she showed that parity was not conserved.

54 Φημισμένοι Φυσικοί σε κάρτες (19-36)

Το 2005 (έτος εορτασμού Φυσικής) το περιοδικό Physics Teacher έστελνε μαζί με τα τεύχη, μία σειρά 54 φημισμένων Φυσικών σε κάρτες με το πορτραίτο και ένα συντομότατο βιογραφικό των ελαχίστων λέξεων.

(θα θυμάστε ίσως ανάλογες κάρτες ποδοσφαιριστών από σοκολάτες και μπισκότα)
Τα βιογραφικά στο πρωτότυπο (19-37) για αποφυγή μεταφραστικών λαθών...εξάλλου υπάρχει και η αυτόματη μηχανή μετάφρασης της Google.

19) Hans Bethe (1906-2005) Birthplace: Strassburg, Germany
(Nobel Prize: 1967)
Hans Bethe discovered why stars shine. In 1938 he proposed (and calculated) a sequence of nuclear reaction in stars that would turn hydrogen into helium, thus providing the needed energy. Two generations of physics students learned nuclear physics from Bethe’s monumental articles in The Reviews of Modern Physics. He headed the theoretical physics section at Los Alamos.

20) Niels Bohr (1885-1962) Birthplace: Copenhagen, Denmark
(Nobel Prize: 1922)
He was the guru of quantum mechanics. By requiring quantized angular momentum, Bohr developed the first successful theory of the hydrogen atom and its spectra. Throughout the late 1920s and 1930s, his institute in Copenhagen became the focal point for the small band of theoretical physicists who developed the quantum theories. His philosophical theme was “complimentarity”, dual nature of reality.

21) Ludwig Boltzmann (1844-1906) Birthlpace: Vienna, Austria
Boltzmann established the statistical interpretation of entropy and the second law of thermodynamics. He calculated the number of arrangements of momentum and energy possible for a group of molecules with a fixed total energy. From his theory of a microworld of interacting particles, Boltzmann successfully predicted macroscopic features of thermodynamics, and thus demonstrated the likelihood of atomicity.

22) Max Born (1882-1970) Birthplace: Breslau, Germany
(Nobel Prize: 1954)
Max Born was a pioneer in the development of quantum theory. He was awarded the Nobel Prize “for his fundamental research in quantum mechanics, especially for his statistical interpretation of the square of Schrodinger’s wave function as the particle’s probability distribution function”. Born was a close friend of Albert Einstein’s; they agreed to disagree about “God plays dice with the universe”.

23) Louis de Broglie (1892-1987) Birthplace: Dieppe, France
(Nobel Prize: 1929)
De Broglie used Einstein’s E=mc2 along with Plank’s equation E=hf to show that any particle there should be an associated wave, the wavelength of which depends on the particle’s momentum. The revolutionary nature of the de Broglie’s theory was not well appreciated until Einstein called it to the attention of the physics community. Ultimately, de Broglie’s work served as the foundation for the development of wave mechanics by Erwin Shrodinger and others.

24) A.H. Compton (1892-1962) Birthplace: Wooster, OH
(Nobel Prize: 1927)
In his experiments on the scattering of x-rays, Compton found that some of the scattered radiation suffered an increase in wavelength. He accounted for this by presuming that radiation has a particle nature. (he coined the name photon) and that in collisions with electrons the photons lose energy. This work gave support to Einstein’s theory of the particle nature of light.

25) Nicolaus Copernicus (1473-1543) Birthplace: Torun, Poland
In his book On the Revolutions, Copernicus moved our Earth from the center of the universe to an orbit around the Sun, and a position as a minor planet. The book is not only a remarkable analysis of astronomical observations, but is also a courageous denial of the religious – philosophical dogma of his age.

26) Marie Curie (1867-1934) Birthplace: Warsaw, Poland
(Nobel Prizes: 1903, Physics; 1911, Chemistry)
Marie (Maria Sklodowska) Curie received her early scientific training from her father in Warsaw, then went to Cracow, and finally to the Sorbonne in Parris. After the death of her husband, Pierre Curie, she succeeded to his professorship and developed a major institute for the study of radioactivity.

27) Paul Dirac (1902-1984) Birthplace: Bristol, England
(Nobel Prize: 1933)
Dirac merged quantum mechanics and relativity. His equations predicted the existence of a whole other world of antiparticles. Dirac was a shy man who usually worked alone. His guide to research and criterion for validity was the beauty of the equations.

28) Albert Einstein (1879-1955) Birthplace: Ulm, Germany
(Nobel Prize: 1921)
The most revolutionary mind of the 20th century. In 1905 he published three papers in the same journal: one on Brownian motion clinched the case for the existence of atoms; one explained the photoelectric effect; and the third presented the special theory of relativity. Ten years later his general theory of relativity supplanted Newton’s gravitation with a vastly different view of space – time and the universe.

29) Michel Faraday (1791-1867) Birthplace: London, England
Son of a blacksmith, apprenticed to a bookbinder, self-educated, Faraday was a laboratory assistant to Sir Humphry Davy, the great chemist. Yet Davy later said, “My greater discovery was Faraday”. Faraday originated our ideas of electromagnetic fields, discovered the induction of electric fields, and created the first generator. He worked out and demonstrated the laws of electrolysis, and found fundamental relationships between light and electromagnetism in matter.

30) Enrico Fermi (1901-1954) Birthplace: Rome, Italy
(Nobel Prize: 1938)
Master of both experimental and theoretical techniques, Fermi helped explain beta decay in terms of Pauli’s neutrino. He realized the practical consequences of nuclear fission and created the first nuclear reactor in Chicago, which led to the construction of the first nuclear bomb. Fermi had a legendary ability to do mental calculations and obtain order of magnitude answers to problems of any kind.

31) Maria Goeppert – Mayer (1906-1972) Birthplace: Kattowitz, Germany
(Nobel Prize: 1963)
Goeppert – Mayer calculated the structure of atomic nuclei, relating the number of protons and neutrons to the stability and energy levels of the nuclei. She showed that the nucleus is not an amorhous soup of particles, but has a shell structure. She made many other important contributions to theoretical physics, but did so without academic position because of nepotism rules in force at the time.

32) Werner Heisenberg (1901-1976) Birthplace: Wurzurg, Germany
(Nobel Prize: 1932)
One of the founders of quantum mechanics, Heisenberg formulated the relationships between measurable quantities in terms of matrix algebra, equivalent to Shrodinger’s wave equations. One of the inescapable consequences of his theory is that certain linked quantities have linked uncertainties in their measured values.

33) Edwin Hubble (1889-1953) Birthplace: Marshfield, MO
Some people discover new worlds: Hubble discovered the universe. He proved that galaxies exist beyond our own, and that are all fleeing from each other. From his measurements of galastic redshifts, he determined the rate of expansion of the universe, and thus its age. When Einstein heard about Hubble’s results, he said that not realizing the expansion of the universe was his “greatest blunder”.

34) Elmer Samuel Imes (1883-1941) Birthplace: Memphis, TN
In 1918 Imes became the second African – American to earn a Ph.D. in physics. He worked under Harrison Randall at the University of Michigan on measuring high – resolution infrared spectra of diatomic molecules. Imes’ papers of 1919-1920 were the first research publications produced by an African – American physicist. They provided the accurate determination of interatomic distances in molecules and established that quantum theory is applicable to the study of molecular structure and behavior.

35) Max von Laue (1879-1960) Birthplace: Pfaffendorf, Germany
(Nobel Prize: 1914)
Von Laue showed that the layers of atoms forming a crystal could serve as a diffraction grating for x rays. This discovery, which Einstein called “one of the most beautiful in physics”, provide a method of determining the wavelength of the x-rays and of the structure of crystals. Von Laue was an early advocate of Albert Einstein’s theory of relativity.

36) Hendrik A. Lorentz (1853-1928) Birthplace: Arnhem, The Netherlands
(Nobel Prize: 1902)
Before the existence of electrons had been demonstrated, Lorentz proposed that oscillations of electric charge in the atom result in the emission of light waves. He shared the physics Nobel Prize with his student Piert Zeeman, who demonstrated the effect on the wavelength of such emitted light. Lorentz is also famous for his work to explain the null result of the Michelson – Morley experiment. The Lorentz transformations form the basis of Einstein’s special theory of relativity.

Οι δοξασμένοι Φυσικοί σε κάρτες αλφαβητικά (1-18)

Το 2005 (Έτος Φυσικής) το περιοδικό Physics Teacher μαζί με τα τεύχη έστειλε μια σειρά καρτών με 54 Φυσικούς που θεμέλιωσαν τη Φυσική ως τις μέρες μας. Πίσω από κάθε κάρτα είχε ένα βιογραφικό λίγων λέξεων.
Προτίμησα να αφήσω τα κείμενα στο πρωτότυπο, για την αποφυγή λαθών στη μετάφραση. Εξάλλου τα Αγγλικά που χρησιμοποιεί δείχνουν νάναι απλά, υπάρχει ακόμη και ο μεταφραστής Google.

1) Luis Alvarez (1911-1988) Birthplace: San Francisco, CA
(Nobel Prize: 1968)Alvarez was an ingenious and prolific experimenter. With Geiger counters he showed that incoming cosmic rays are mostly positive, with bubble chambers he discovered nucleon resonances, and with antenna arrays he refined the use of radar. He used cosmic – ray muons to probe for burial chambers in Egyptian pyramids, and radioactivity to detect a comet collision with the Earth that may have exterminated the dinosaurs.

2) John Bardeen (1908-1991) Birthplace: Madison, WI
(Nobel Prizes: 1956, 1972)No one else has won two Nobel Prizes in physics. Bardeen was coinventor of the transistor, and the codeveloper of the BCS theory of superconductivity. Practical applications of his work have revolutionized our civilization, and his analytical methods have transformed theoretical research in condensed physics.

3) Herman R. Branson (1914-1995) Birthplace: Pocahontas, VA Branson’s primary research interests were mathematical biology and the structure of proteins. His collaboration with Robert B. Coney and Linus B. Pauling led to the identification of the alpha and gamma helical structure of proteins. His other efforts included experimental and theoretical investigations of the use of radioactive isotopes as tracers, and electron impact studies of small organic molecules. Following a research career of more than decades, Branson went on the serve as president of two historically black universities.

4) Subrahmanyan Chandrasekhar (1910-1995) Birthplace: Lahore, IndiaNobel Price: 1983. Chandrasekhar attacked several fields of theoretical physics, in each case producing a definitive analysis of the field. He was the first to propose the mechanism for the collapse of stars that degenerate to white dwarfs. In studying stellar dynamics, he made major advances in our understanding of hydrodynamics, hydromagnetics, and radiative energy transfer.

5) Richard P. Feyman (1918-1988) Birthplace: New York, NY
(Nobel Price: 1965)The all-American kid from Brooklyn. From his teaching to his popular books to his profound work on electromagnetism, all his contributions had a unique flair. We use the Feynman diagrams and gain new insights from the Feynman lectures derived from a freshman course. He loved physics with zest and, in his own words, was a “curious character”.

6) Benjamin Franklin (1706-1790) Birthplace: Boston, MA Publisher, bon vivant, patriot, and diplomat, Franklin’s role as a scientist was recognized more in Europe than in the United States. The article on electricity in the original Encyclopaedia Britannica (1775) is filled with references to the research of the inverse-square law to the problem of shielding. Eripuit coelo fulmen sceptrumque tyrannis.

7) Galileo Galilei (1564-1642) Birthplace: Pisa, ItalyGalileo devised and used a telescope to discover the moons of Jupiter, craters of the Moon, moving spots on the Sun, and the phases of Venus, all powerful evidence in favor of Copernican model of the solar system. His Dialogues laid the ground-work of kinematics, which led to Newton’s dynamics. Threatened by Inquisition in his old age, he publicly renounced his belief that the Earth moves around the Sun, but according to legend, whispered “Nevertheless, it moves”

8) George Gamow (1904-1968) Birthplace: Odessa, Russian Empire (now Ukraine) Gamow applied quantum mechanics to the problem of the alpha decay and showed that the alphas must tunnel through the nuclear potential barrier. He proposed the general scheme for the origin of the universe now known as the big bang theory, calculating (with R. Alpher) the production of the light elements during the explosion and predicting the existence of primordial electromagnetic radiation. Among his many books popularizing science is Mr. Tompkins in Wonderland

9) J. Willard Gibbs (1839-1903) Birthplace: New Haven, CT At age 32 Gibbs was appointed a full professor at Yale. He was without doubt he pre-eminent U.S. theoretical physicist in his era, yet very few Americans knew about him. He published fundamental but highly abstract papers on thermodynamics in an obscure journal, and was understood by only a few of his peers in Europe such as Maxwell. Now we realize that he laid the foundations for chemical thermodynamics and statistical mechanics.

10) Hermann von Helmholtz (1821-1894) Birthplace: Postdam, Germany.Helmholtz’s contributions to science cover a range of topics: optics, acoustic, mechanics, hydrodynamics, electromagnetism, mathematics, and medicine. Best known as a codisoverer (with Joule and Julius Mayer) of the law of conservation of energy, he expanded Young’s three color theory of vision, now known as the Young – Helmholtz theory. He formulated the resonance theory of hearing, implemented the use of resonators (now called Helmholtz resonators) in analyzing complex sounds, and made notable contributions to music theory. He constructed a generalized form of electromagnetic theory; the electromagnetic wave equation is named in his honor.

11) William Thomson (Lord Kelvin) (1824-1907) Birthplace: Belfast, Ireland.Thomson made important contributions to several areas of physics, but was first and foremost a teacher, serving for 53 years as professor of natural philosophy at the Univ. of Glasgow. He published 660 papers on subjects including thermodynamics, optics, elasticity, electricity and magnetism, hydrodynamics, and navigation. In 1848 he proposed an absolute scale of temperature, and he later collaborated with Joule in working out the Joule-Thomson effect. He also invented an improved navigation compass, the mirror galvanometer, and an analog tide predictor.

12) Johannes Kepler (1571-1630) Birthplace: Weil der Stadt, Germany.Kepler discovered the arrangement of the solar system. By taking the astronomical data accumulated by Tyho Brade and fitting them to the Copernican model of planets orbiting the Sun, Kepler showed that the orbits were ellipses, and the periods and radial distances were related in a simple way. This set stage for Newton to derive the relationships from fundamentals laws of dynamics and the inverse-square law.

13) James Clerk Maxwell (1831-1879) Birthplace: Edinburg, Scotland.Maxwell is the best known for his formulation of electromagnetic theory. In the words of Einstein, “The special theory of relatively owes its origins to Maxwell equations of the electromagnetic field”. His other major contributions to the advancement of science included formulating, independently of Ludwig Boltzmann, the Maxwell-Boltzmann kinetic theory of gases.

14) Emmy Amalie Noether (1882-1935) Birthplace: Erlangen, GermanyNoether discovered and proved two theorems, and their converses, that have profoundly influenced modern physics. The theorems, known collectively as “Noethet’s theorem”, give a general relationship between symmetries in physics and conservation principles, and provide the formalism for understanding energy-momentum conversation in the theory of general relatively. But Noether’s theorem represents only a small fraction of her achievements. The bulk of her activity was in the development of modern abstract algebra.

15) Hans Christian Oersted (1777-1851) Birthplace: Rudkobing, DenmarkGreat physicist, chemist (first to prepare metallic aluminum), and admired teacher. While giving a lecture demonstration, Oersted discovered that an electric current influenced a compass needle. He had found the missing link between electricity and magnetism for which he and many others had been searching.

16) Sir Joseph John Thomson (1846-1940) Birthplace: Cheetham Hill, Great Britain.
J.J Thomson’s experiment on electrical discharge in gases showed that cathode rays are in fact negatively charged particles having a single charge-to-mass ratio. Thomson believed these “electrons” to be fundamental constituents of all matter and proposed a model of the atom in which electrons are embedded in a sphere of positive charge. He also investigated the effects of electric and magnetic fields on positives ions, providing the first experiment evidence for the existence of isotopes.

17) Rosalyn Sussan Yalow (1921-) Birthdate: New York, NY
(Nobel Prize: 1977 Physiology of Medicine)Yalow was a medical physicist who, in collaboration with S.A. Berson, developed methods of using radioactive isotopes to investigate physiological systems that allow detection of minute concentrations of biological or pharmacological substances in samples of body fluid. The methods are called radioimmunoassay (RIA). The RIA concept has led to innumerable innovations in research and practical applications. RIA may be used, for example, to screen blood in blood banks for hepatitis virus, determine dosage levels of drags and antibiotics, and treat and detect hormone-related health problems.

18) Chen Ning Yang (1922-) Birthplace: Hofei, Anhwei, China
(Nobel Prize: 1957)“Frank” Yang predicted that one of the most fundamental laws, parity conservation, would be violated in the Weak interactions. Experiment confirmation of this effect caused a complete rethinking of the nature of symmetry principles and conversation laws. The Yang-Mills gauge theories are now basic to our understanding of particle physics.

Μιά αυτόματη μετάφραση από τη μηχανή Google, και η πίσω όψη των καρτών πατήστε ΕΔΩ