Paul Ehrenfest. Worstelingen Met De Moderne Wetenschap, 1912-1933
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Memorial Tablets*
Memorial Tablets* Gregori Aminoff 1883-1947 Born 8 Feb. 1883 in Stockholm; died 11 Feb. 1947 in Stockholm. 1905 First academic degree, U. of Uppsala, after studying science in Stockholm. 1905 to about 19 13 studied painting in Florence and Italy. 1913 Returned to science. 1918 Ph.D. ; appointed Lecturer in Mineralogy and Crystallo- graphy U. of Stockholm. Thesis: Calcite and Barytes from Mzgsbanshiitten (Sweden). 1923-47 Professor and Head of the Department of Mineralogy of the Museum of Natural History in Stockholm. 1930 Married Birgit Broome, herself a crystallographer. see Nature (London) 1947, 159, 597 (G. Hagg). Dirk Coster 1889-1950 Born 5 Oct. 1889 in Amsterdam; died 12 Feb. 1950 in Groningen. Studied in Leiden, Delft, Lund (with Siegbahn) and Copenhagen (with Bohr). 1922 Dr.-ing. Tech. University of Delft. Thesis: X-ray Spectra and the Atomic Theory of Bohr. 1923 Assistant of H. A. Lorentz, Teyler Stichting in Haarlem. 1924-50 Prof. of Physics and Meteorology, U. of Groningen. Bergen Davis 1869-1951 Born 31 March 1869 in White House, New Jersey; died 1951 in New York. 1896 B.Sc. Rutgers University. 1900 A.M. Columbia University (New York). 1901 Ph.D. Columbia University. 1901-02 Postgraduate work in GMtingen. 1902-03 Postgraduate work in Cambridge. * The author (P.P.E.) is particularly aware of the incompleteness of this section and would be gratefid for being sent additional data. MEMORIAL TABLETS 369 1903 Instructor 1 1910 Assistant Professor Columbia University, New York. 1914 Associate Professor I 1918 Professor of Physics ] Work on ionization, radiation, electron impact, physics of X-rays, X-ray spectroscopy with first two-crystal spectrometer. -
Zirconium and Hafnium in 1998
ZIRCONIUM AND HAFNIUM By James B. Hedrick Domestic survey data and tables were prepared by Imogene P. Bynum, statistical officer, and the world production table was prepared by Regina R. Coleman, international data coordinator. The principal economic source of zirconium is the zirconium withheld to avoid disclosing company proprietary data. silicate mineral, zircon (ZrSiO4). The mineral baddeleyite, a Domestic production of zircon increased as a new mine in natural form of zirconia (ZrO2), is secondary to zircon in its Virginia came online. Production of milled zircon was economic significance. Zircon is the primary source of all essentially unchanged from that of 1997. According to U.S. hafnium. Zirconium and hafnium are contained in zircon at a Customs trade statistics, the United States was a net importer of ratio of about 50 to 1. Zircon is a coproduct or byproduct of the zirconium ore and concentrates. In 1998, however, the United mining and processing of heavy-mineral sands for the titanium States was more import reliant than in 1997. Imports of minerals, ilmenite and rutile, or tin minerals. The major end zirconium ore and concentrates increased significantly as U.S. uses of zircon are refractories, foundry sands (including exports of zirconium ore and concentrates declined by 7%. investment casting), and ceramic opacification. Zircon is also With the exception of prices, all data in this report have been marketed as a natural gemstone, and its oxide processed to rounded to three significant digits. Totals and percentages produce the diamond simulant, cubic zirconia. Zirconium is were calculated from unrounded numbers. used in nuclear fuel cladding, chemical piping in corrosive environments, heat exchangers, and various specialty alloys. -
5Th World Congress on Physics July 17-18, 2018 Prague, Czech Republic
Štefan Zajac, J Laser Opt Photonics 2018, Volume:5 DOI: 10.4172/2469-410X-C2-025 5th World Congress on Physics July 17-18, 2018 Prague, Czech Republic Štefan Zajac Czech Technical University, Czech Republic Physics and Prague hysics has been cultivated in Prague since at least 1348, when a University was founded here by Emperor Charles IV. At Pthe beginning the main emphasis was on Astronomy. First astronomers Křišťan from Prachatice (1360 – 1439) and Jan Ondřejov Šindel (1375 – 1456) in co-operation with clockmaker Mikuláš of Kadaň around 1410 had designed and installed the astronomical clock placed on the Old Town Hall tower in Prague. Astronomer and Chief Physician Tadeuš Hájek of Hájek (1525-1600) had inluenced Emperor Rudolph II to invite Tycho Brahe (1546 – 1601) and Johannes Kepler (1571 – 1630) to come to Prague where the first two of his laws of planetary motion have been formulated. Jan Marcus Marci of Kronland (1595 – 1667), a physicist, physician and rector of Prague University made original research in mechanics (impact of bodies) and optics (diffraction of light, explanation of rainbow). In the middle of the 18th century at the Clementinum, the Jesuit College, physicist Josef Stepling (1716 -1778) and his successors at the Prague Faculty of Philosophy promoted Newtonian Physics . Christian Doppler (1803 – 1853) as professor at Prague Polytechnic in 1842 published important phenomenon of the frequency shift due to the velocity of the source of waves relative to the observer. His younger colleague Bohumil Kučera (1874 – 1921) had started pioneering research in radioactivity and had inspired professor Jaroslav Heyrovský (1890 – 1967) to develop polarography for which he in 1959 earned Nobel Prize for chemistry. -
Cesta Ke Hvězdám I Do Nitra Molekul
Matematický ústav Akademie věd Èeské republiky Cesta ke hvězdám i do nitra molekul Osudy Vladim´ıra Vanda, konstruktéra počítačů Alena Solcovˇ ´a, Michal Kˇr´ıˇzek Praha 2011 Recenzenti RNDr. Pavla Pavlíková, Ph. D. RNDr. Václav Vopravil Vydal Matematický ústav AV ÈR, Praha Sazbu programem TEX pøipravil Michal Křížek c Alena ©olcová, Michal Křížek Obálka Pavel Křížek Vydání 1., Praha 2011 ISBN 978-80-85823-56-1 Věnováno prof. Vladimíru Vandovi ke 100. výročí jeho narození. 4 A. ©olcová, M. Křížek: Cesta ke hvězdám i do nitra molekul Obsah Pøedmluva : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 7 1. Úvod : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :9 2. Období dospívání : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 11 2.1. ®ivot na Ukrajině : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 11 2.2. Rodina a dětství : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 11 2.3. Studium na Univerzitě Karlově : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 12 2.4. Vzpomínka Zdeňka Kopala : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 21 3. Vladimír Vand v Říši hvězd : : : : : : : : : : : : : : : : : : : : : : : : : : -
Alpha-Decay Half-Life of Hafnium Isotopes Reinvestigated by a Semi-Empirical Approach∗
Alpha-decay half-life of Hafnium isotopes reinvestigated by a semi-empirical approach∗ O.A.P. Tavares a, E.L. Medeiros a,y, and M.L. Terranova b aCentro Brasileiro de Pesquisas F´ısicas- CBPF/MCTIC Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro-RJ, Brazil bDipartimento di Science e Tecnologie Chimiche Universit`adegli Studi di Roma \TorVergata" via dela Ricerca Scientifica s/n, 00133 Roma, Italy 156{162;174;176 Abstract - New estimates of partial α-decay half-life, T1=2, for Hf isotopes by a semi- empirical, one-parameter model are given. The used model is based on the quantum mechanical tunneling mechanism through a potential barrier, where the Coulomb, centrifugal and overlapping components to the barrier have been considered within the spherical nucleus approximation. This approach enables to reproduce, within a factor 2, the measured T1=2 of ground-state to ground- state (gs{gs) α-transitions for the artificially produced 156{162Hf isotopes. Half-life predictions for α-transitions from the ground-state of 159;161Hf isotopes to the first gamma-excited level of 155;157Yb 16 isotopes are reported for the first time. The model also provides T1=2-values of (2:43 ± 0:28) × 10 a and (1:47 ± 0:19) × 1020 a for the naturally occurring 174Hf and 176Hf isotopes, respectively, in quite good agreement with a number of estimates by other authors. In addition, the present methodology indicates that 174;176Hf isotopes exhibit α-transition to the first gamma-excited level of their daughter Ytterbium isotopes which half-lives are found (0:9±0:1)×1018 a and (0:72±0:08)×1022 a, respectively, with a chance of being measured by improved α-detection and α-spectrometry methods available nowadays. -
A Selected Bibliography of Publications By, and About, Niels Bohr
A Selected Bibliography of Publications by, and about, Niels Bohr Nelson H. F. Beebe University of Utah Department of Mathematics, 110 LCB 155 S 1400 E RM 233 Salt Lake City, UT 84112-0090 USA Tel: +1 801 581 5254 FAX: +1 801 581 4148 E-mail: [email protected], [email protected], [email protected] (Internet) WWW URL: http://www.math.utah.edu/~beebe/ 09 June 2021 Version 1.308 Title word cross-reference + [VIR+08]. $1 [Duf46]. $1.00 [N.38, Bal39]. $105.95 [Dor79]. $11.95 [Bus20]. $12.00 [Kra07, Lan08]. $189 [Tan09]. $21.95 [Hub14]. $24.95 [RS07]. $29.95 [Gor17]. $32.00 [RS07]. $35.00 [Par06]. $47.50 [Kri91]. $6.95 [Sha67]. $61 [Kra16b]. $9 [Jam67]. − [VIR+08]. 238 [Tur46a, Tur46b]. ◦ [Fra55]. 2 [Som18]. β [Gau14]. c [Dar92d, Gam39]. G [Gam39]. h [Gam39]. q [Dar92d]. × [wB90]. -numbers [Dar92d]. /Hasse [KZN+88]. /Rath [GRE+01]. 0 [wB90, Hub14, Tur06]. 0-19-852049-2 [Ano93a, Red93, Seg93]. 0-19-853977-0 [Hub14]. 0-521-35366-1 [Kri91]. 0-674-01519-3 [Tur06]. 0-85224-458-4 [Hen86a]. 0-9672617-2-4 [Kra07, Lan08]. 1 2 1.5 [GRE+01]. 100-˚aret [BR+85]. 100th [BR+85, KRW05, Sch13, vM02]. 110th [Rub97a]. 121 [Boh87a]. 153 [MP97]. 16 [SE13]. 17 [Boh55a, KRBR62]. 175 [Bad83]. 18.11.1962 [Hei63a]. 1911 [Meh75]. 1915 [SE13]. 1915/16 [SE13, SE13]. 1918 [Boh21a]. 1920s [PP16]. 1922 [Boh22a]. 1923 [Ros18]. 1925 [Cla13, Bor13, Jan17, Sho13]. 1927 [Ano28]. 1929 [HEB+80, HvMW79, Pye81]. 1930 [Lin81, Whe81]. 1930/41 [Fer68, Fer71]. 1930s [Aas85b, Stu79]. 1933 [CCJ+34]. -
Planck's Quantum Theory of Ideal
Pursuing an Idea: Planck’s Quantum Theory of Ideal Gas ∗ Massimiliano Badino† 1 Prelude: One Hundred Years of ‘Quantitude’ Many years later, as he faced the firing squad, Erwin Planck was to remember that distant afternoon when his father took him to discover the quantum. It was indeed in a day at the beginning of the last century, during a walk in the Grunewald Forest, that Max Planck in- formed his youngest son that his recent discovery was the greatest since the time of Newton. After that day, physics was never the same again. From the mysterious realm of the interac- tion between matter and radiation, the quantum spread out both in the theory of radiation and in the theory of matter and eventually changed our picture of the physical world. Planck played a foremost role in this revolution till the mid-1920 and especially his work on the ap- plication of quantum hypothesis to the ideal gas was instrumental in setting the stage for quantum mechanics. In this paper I will give a cursory outline of this work and, centering on the argumen- tative structure, I will argue that Planck’s theory of gas was framed according to a theoretical strategy he had already adopted in his previous work on radiation theory. The thrust of this strategy consists in focussing on the general features of the system and leaving aside spe- cific assumptions on the micro-processes. Throughout the years Planck reconfigured and reorganized his arguments and the great flexibility of his theoretical strategy allowed him to maintain a consistent outlook on the problem. -
How Fluids Unmix. Discoveries by the School of Van Der Waals and Kamerlingh Onnes, , ---
4671 Sengers Voorwerkb 23-09-2002 09:17 Pagina I How fluids unmix 4671 Sengers Voorwerkb 23-09-2002 09:17 Pagina II History of Science and Scholarship in the Netherlands, volume The series History of Science and Scholarship in the Netherlands presents studies on a variety of subjects in the history of science, scholarship and academic insti- tutions in the Netherlands. Titles in this series . Rienk Vermij, The Calvinist Copernicans. The reception of the new astronomy in the Dutch Republic, -. , --- . Gerhard Wiesenfeldt, Leerer Raum in Minervas Haus. Experimentelle Natur- lehre an der Universität Leiden, -. , --- . Rina Knoeff, Herman Boerhaave (-). Calvinist chemist and physician. , --- . Johanna Levelt Sengers, How fluids unmix. Discoveries by the School of Van der Waals and Kamerlingh Onnes, , --- Editorial Board K. van Berkel, University of Groningen W.Th.M. Frijhoff, Free University of Amsterdam A. van Helden, Utrecht University W.E. Krul, University of Groningen A. de Swaan, Amsterdam School of Sociological Research R.P.W. Visser, Utrecht University 4671 Sengers Voorwerkb 23-09-2002 09:17 Pagina III How fluids unmix Discoveries by the School of Van derWaals and Kamerlingh Onnes Johanna Levelt Sengers , Koninklijke Nederlandse Akademie van Wetenschappen, Amsterdam 4671 Sengers Voorwerkb 23-09-2002 09:17 Pagina IV © Royal Netherlands Academy of Arts and Sciences No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photo- copying, recording or otherwise, without the prior written permission of the publisher. Edita , P.O. BOX , Amsterdam, the Netherlands [email protected], www.knaw.nl/edita --- The paper in this publication meets the requirements of « -norm () for permanence This study was undertaken with the support of the Koninklijke Hollandsche Maatschappij der Wetenschappen (‘Royal Holland Society of Sciences and Humanities’) as part of its 250th anniver- sary celebrations in 2002. -
Paul Ehrenfest: De Leidse Onderzoekschool Van Een Fysicus in Diaspora
Paul Ehrenfest: de Leidse onderzoekschool van een fysicus in diaspora He was […] the best teacher in our profession Albert Einstein Eind augustus 1932 ontving Philip Idenburg, secretaris van het curatorium van de Leidse universiteit, een verontrustende brief. De schrijver van het epistel was Albert Einstein, het onderwerp de geestesgesteldheid van de Leidse hoogleraar Paul Ehrenfest. Einstein sprak openlijk zijn zorg uit over Ehrenfest, die naar zijn zeggen gebukt ging onder zware depressies en zou spelen met de gedachte aan zelfmoord. Einstein drong krachtig aan op snelle maatregelen. De oorzaak van Ehrenfests gemoedstoestand moest volgens Einstein gezocht worden in de stormachtige ontwikkelingen binnen de theoretische natuurkunde, Ehrenfests vakgebied. De nieuwe opvattingen karakteriseerde Einstein als ‘heterogeen, verwarrend en logisch onbevredigend, maar door de feiten afgedwongen.’ In deze chaotische situatie was het een theoretisch natuurkundige niet langer mogelijk het vakgebied in zijn geheel te beheersen en aldus als ‘leider en wegwijzer’ te dienen voor de jonge generatie onderzoekers. Voor een veeleisend en gewetensvol leraar als Ehrenfest was deze toestand eenvoudigweg ondraaglijk. Volgens Einstein bestond er maar één uitweg uit dit dilemma: de eventueel tijdelijke aanstelling van een tweede theoretisch natuurkundige. Wellicht zou na een jaar of tien de situatie in de natuurkunde weer genormaliseerd zijn. Hij wees er daarnaast op dat een verdeling van taken in de experimentele natuurkunde reeds gebruikelijk was. Idenburg reageerde voortvarend. Maar ondanks de steun van het College van Curatoren slaagde hij er niet in het gewenste te bewerkstelligen. Het ministerie weigerde extra geld uit te trekken voor de Leidse natuurkunde. Ruim een jaar later werden Einsteins angstige vermoedens bewaarheid. -
In Memory of Josef Král
Mathematica Bohemica Jaroslav Lukeš; Ivan Netuka; Jiří Veselý In memory of Josef Král Mathematica Bohemica, Vol. 131 (2006), No. 4, 427–448 Persistent URL: http://dml.cz/dmlcz/133976 Terms of use: © Institute of Mathematics AS CR, 2006 Institute of Mathematics of the Czech Academy of Sciences provides access to digitized documents strictly for personal use. Each copy of any part of this document must contain these Terms of use. This document has been digitized, optimized for electronic delivery and stamped with digital signature within the project DML-CZ: The Czech Digital Mathematics Library http://dml.cz 131 (2006) MATHEMATICA BOHEMICA No. 4, 427–448 NEWS AND NOTICES IN MEMORY OF JOSEF KRAL´ Jaroslav Luke², Ivan Netuka, Jiří Veselý, Praha On May 24, 2006 a farewell ceremony for our teacher, colleague and friend Josef Král was held in the Church of St. Wenceslas in Pečky. He died on May 13, 2006, before his seventy-fifth birthday. Josef Král was an outstanding mathematician, ex- ceptional teacher, model husband and father, and above all, a man of extraordinary human qualities. The results of his research place him among the most important Czech mathematicians of the second half of the twentieth century. His name is asso- ciated with original results in mathematical analysis and, in particular, in potential theory. In 1967 Josef Král founded a seminar in Prague on mathematical analysis, with a particular emphasis on potential theory. He supervised a number of students and created a research group, which has been called The Prague Harmonic Group by friends and colleagues. At first lectures were organised, somewhat irregularly, at the Mathematical Institute of the Czechoslovak Academy of Sciences, Krakovská 10. -
Download PDF Van Tekst
Literatuur. Geschiedenis en bloemlezing. Deel 2. Omstreeks 1880 tot heden H.J.M.F. Lodewick bron H.J.M.F. Lodewick, Literatuur. Geschiedenis en bloemlezing. Deel 2. Omstreeks 1880 tot heden. L.C.G. Malmberg, 's-Hertogenbosch 1968 (22ste druk) Zie voor verantwoording: http://www.dbnl.org/tekst/lode004lite08_01/colofon.php © 2017 dbnl / erven H.J.M.F. Lodewick 5 Voorwoord Wie de euvele moed heeft een literatuur-geschiedenis tot en met 19-NU te schrijven, zal op moeilijkheden stuiten die hij slechts ten dele voorzien had, en die hij slechts ten dele kan oplossen. Niet om van dit Voorwoord een klaagmuur te maken, maar omdat zekere moeilijkheden nu eenmaal consequenties meebrengen voor opzet en uitwerking van Literatuur II, willen wij enkele ervan hier aanstippen. Bij de indeling hebben wij ons laten leiden door de overwegingen dat 1. de leerlingen de grote lijnen moeten kunnen blijven zien. Wij boden dus - op een enkele uitzondering na - weerstand aan de verleiding bepaalde auteurs over meer dan één paragraaf te ‘verdelen’ (Couperus b.v. bij impressionisme, naturalisme en neo-romantiek), en vermeden al te veel met ‘generaties’ te werken (socialistische auteurs als Henriëtte Roland Holst en A. van Collem b.v. werden niet van elkaar gescheiden, evenmin realisten als Herman Robbers en Ina Boudier-Bakker); 2. uit de compositie van het geheel moet blijken hoe de literatuur van Noord- en Zuid-Nederland geleidelijk één onscheidbaar geheel gaat vormen. Dat Literatuur II veel meer geeft dan de leerlingen behoeven te weten is ons bekend. De uitvoerigheid is echter in dubbel opzicht van belang: voor de leraar doordat deze aldus in staat gesteld wordt een keuze te doen en dié auteurs te behandelen die hij het belangrijkst acht; voor de leerling (en elke belangstellende lezer) omdat Literatuur II ook een naslagwerk wil zijn, waarin men iets vindt over niet-zo-bekende of minder-belangrijke schrijvers. -
Nobel Prize Awards in Radiochemistry
Radiochim. Acta 100, 509–521 (2012) / DOI 10.1524/ract.2012.1953 © by Oldenbourg Wissenschaftsverlag, München Nobel Prize awards in Radiochemistry By J.-P. Adloff∗ University of Strasbourg, 63 Rue Saint Urbain, 67100 Strasbourg, France Dedicated to the memory of late Karl H. Lieser, Gerhard L. Stöcklin and Alfred P. Wolf with whom the author shared the editorial work of Radiochimica Acta from 1977 to 1995 (Received October 10, 2011; accepted in revised form January 19, 2012) (Published online March 26, 2012) Nobel Prize / Chemistry / Physics Summary. In 1996 the Editors of Radiochimica Acta brought out a special volume of the journal to celebrate the hundredth anniversary of the discovery of radioactivity [1]. On the occasion of the 50th anniversary of Radiochimica Acta, which follows closely upon the centenary of Marie Curie’s second Nobel Prize in 1911, the author has the privilege to informally review “Radiochemistry and Nobel Prize Awards”, including discoveries of radioelements and new fields in chemistry based on radiochemical methods. 1. The beginning The Nobel Prizes in Physics and Chemistry were estab- lished in 1901, six years after the discovery of radioactivity and three years after the discoveries of the elements polo- Fig. 1. Antoine Henri Becquerel (1852–1908). nium and radium. They are awarded by Kungliga Veten- skapakademien (the Royal Swedish Academy of Sciences) on the basis of proposals made by respective Committees rays when he thought the subject was exhausted. By the end on Physics and Chemistry, which receive recommendations of 1897 radioactivity was something of a dead horse: it was from Swedish and foreign scientists [2].