Category The Physical Tourist A Science Guide for the Traveler


Travelers differ. At one extreme are random travelers who see what they accidentally bump into. At the other extreme are the lock-step travelers who follow a banner (or a red umbrella) and look when and where a voice tells them to look. Between these extremes are the guide-book travelers who identify the whereabouts of those sites that interest them and they plan their sightseeing accordingly.

If a traveler’s interests are captivated by the arts, guide books can be very helpful. For example, the table of contents of a current guide book for travelers going to Ger­many has sections on architecture, art, literature, music and cinema. The index gives page references for famous writers, musicians, and artists. Yet, while Germany was a dominate force in physical science during the 19th and into the 20th centuries and while the names and photos of prominent German physical scientists who worked in this period are sprinkled through the pages of textbooks, only one scientist is men­tioned by name: Albert Einstein is identified as the most famous citizen of Ulm.

The Physical Tourist is a regular feature of the journal Physics in Perspective. This journal, while it is a scholarly journal, features articles designed to be read by nonspe­cialists; that is, technical jargon is deliberately avoided and ordinary words are employed. Readers report that they read it “cover-to-cover.” In the “Physical Tourist” section, scientific sites in major cities (not nations) are highlighted. Since the number of general-interest sites vary from one city to the next, some entries are short while oth­ers are long. Detailed directions are given that enable tourists to go to sites and, once there, appreciate the significance of what they are seeing.

As an example, let us consider the city of Berlin. Dieter Hoffmann, a research schol­ar in the History of Science at the Max Planck Institute in Berlin and a Professor at Humboldt University (formerly the University of Berlin), has written a guide to Berlin. It is detailed; it is delightful. Walk along Am Kupfergraben to number 7 (which the author tells the reader is just opposite the famous Pergamon Museum) and there is the Magnus Haus, the site of one of the most important schools of physics of the 19th cen­tury. Since 1990 it has been the location of the German Physical Society. “Ring the doorbell” says the author, and inside you will find information on the history of this site and its place in the physics in Berlin. One block away lived the philosopher G. W. Hegel. A few steps away is the entrance to Berlin University (on Unter den Linden) where Max Planck founded the quantum theory. Plaques inform tourists where Ein­stein lived and where he gave one of his early talks on the General Theory of Relativ­ity. Across from Humboldt University is the August-Bebel-Platz where the Nazis burned Einstein’s books and many other books on May 10,1933. And there is more.

Radioactivity was discovered in Paris. Ginette Gablot, formerly Curator of the Insti – tut du Radium and the Joliot-Curies Archives, guides a tour that begins at the Museum

National d’Histoire Naturelle (le Museum) where Henri Becquerel, the discoverer of radioactivity, worked. Across the garden is Georges Cuvier’s house on which is a plaque that identifies the house as the place where Becquerel made his discovery. Located near the Museum is 16 rue Cuvier where Pierre Curie was born. Enter 12 rue Cuvier. This building, currently part of the Universite Pierre et Marie Curie, was the first annex of the Sorbonne. Go to the lecture hall (between classes) and down a hall­way to a courtyard housing the pavilion in which radium was discovered. Pierre Curie gave lectures here and, after his death, Marie got her first true lab. Again, there is more.

Vienna is the city of music and without doubt any tourist visiting this Austrian city will have travel guides that identify sites connected with Mozart, Beethoven, Schubert, Brahms, Strauss, Mahler, Schonberg, and others. It is unlikely, however, that any travel guide will call attention to Christian Doppler who first understood why a train whistle changes pitch as it passes by. Nor will available guides take the tourist to plaques iden­tifying the school that Lise Meitner and Erwin Schrodinger attended, to the residence of Sigmund Freud, to the house where Einstein lived, or to the burial place of Ludwig Boltzmann. A tourist is guided to a courtyard at the University of Vienna where plaques and busts celebrate the university’s outstanding scholars Josef Loschmidt, Boltzmann, Josepf Petzval, Schrodinger, Doppler, Johann Radon, Freud, Friedrich Hasenohrl, and Franz Exner.

The description of scientific sites in the cities of Berlin, Paris, and Vienna are just three examples of the many articles from “The Physical Tourist” that have appeared in the journal Physics in Perspective. The collection in this book offers many significant science-related sites to supplement and expand the more traditional focus of current travel guides. These science sites will enrich your travel experience and give you more to talk about when you return home.

August 2008

John S. Rigden Roger H. Stuewer

The Physical Tourist. A Science Guide for the Traveler edited by John S. Rigden and Roger H. Stuewer © 2009 Birkhauser Verlag Basel, Switzerland

Experimental Resurrection

Forster’s successor as Director of the Physical Institute in 1924 was the experimental physicist and trained concert pianist from St. Gallen Heinrich Greinacher (1880-1974, figure 10).[30] He had a knack for inventing ingenious devices and instruments with the limited resources that were available to him. Greinacher constructed an early ioniza­tion chamber, and his voltage multiplier of 1926 became an important component in particle accelerators.11 His original instrument is part of the Physical Institute’s collec­tion, some of which is on display by the main staircase of the science building at Sidler – strasse 5. There is a bust of Einstein in its central hallway.

Fig. 10. Heinrich Greinacher (1880-1974) was Professor of Physics at the University of Bern from 1924 to 1954. Source: Scandola, et al., Hochschulgeschichte Berns (ref. 7) p. 335.

After the Second World War, the Bernese government, swept up in the global wave of enthusiasm for nuclear energy, finally began to consider physics as a worthwhile investment, and the fortunes of the exact sciences in Bern finally turned around. Thus, in 1952 a physicist of the first order, Friedrich (Fritz) Georg Houtermans (1903-1966, figure 11),12 was attracted to Bern from Gottingen with the prospect of heading a mod­ern department of experimental physics in a state-of-the-art science building.[31] Houter­mans had completed his Ph. D. degree in 1927 at the University of Gottingen and dur­ing the next decade had made fundamental contributions to theoretical nuclear physics, the theory of stellar reactions, the development of electron microscopy, and

Fig. 11. The founder of the “Berner Schule,” Friedrich (Fritz) Georg Houtermans (1903-1966). Source: Landrock, “Houtermans” (ref. 12), p. 187.

other fields of research. In 1941 he proposed a means of producing element 94 (pluto­nium).[32] After the end of the war, he returned to Gottingen, working on neutron physics and on methods to determine the age of rocks.

In 1952 Houtermans wrote to the Dutch physicist Hendrick Casimir (1909-2000) from Bern: “If you want to see an authentic early-twentieth-century laboratory, come and visit me. But you have to come soon, for I am going to change all that.”13 He founded the internationally renowned Berner Schule whose focus was on applications of radioactivity to the geosciences, astrophysics, and cosmochemistry. Judging from the number of his publications and students he had in Bern, this was his most productive period, despite incurring a disability following a fall in 1962. A few of his coauthored publications were on such topics as cosmic radiation, solar neutrinos, the maser condi­tion in molecular spectra, and health hazards of radioactivity. In 1953, based on his ear­lier research on the age of uranium, Houtermans estimated the age of the Earth to be (4.5 ± 0.3) x 109 years.

One of Houtermans’s former students, Hans Oeschger (1927-1998), described Houtermans’s lectures in general physics as difficult to follow and error-prone but filled with brilliant comparisons to illuminate the underlying physical mechanisms.14 Oeschger and Houtermans developed a sensitive particle counter that became the cen­terpiece of their carbon-dating laboratory, the first one in Switzerland. In 1963 Oeschger became head of a new department of climatology and environmental physics at Bern.

Houtermans’s boisterous and risque sense of humor was legendary. Friedrich Bege – mann (b. 1927), one of his graduate students, tells the story that when the Physical Insti­tute was still housed in the Tellurian Observatory Houtermans occasionally led his “boys” down into the stairwell to wobble the sandstone pillar that was used as the Earth’s axis in practical exercises, shouting, “Let’s go and shake Switzerland a little!” In 1957 the cosmochemist Begemann was the first to determine the age of a meteorite by exposure to cosmic rays; he later became Director of the Max Planck Institute for Chemistry in Mainz. Another of Houtermans’s mischievous pranks was to “borrow” the fire hoses for a dousing after an evening at the pub, which brought down the wrath of the building supervisor. His saving excuse was that he was carrying out an emer­gency drill against radioactive contamination.

Columbia University

If I were allowed to list only one physics site in New York City, it would have to be the Columbia University Physics Department. In a class by itself on the New York physics scene, it has had a glorious history that stretches back over a century – a period of time that perhaps is not so impressive by European standards, but is pretty impressive by American ones. Columbia’s was not among the first physics departments in America, which included those of Harvard, Princeton, and Yale, but at some point it caught up to all of these, and arguably surpassed them, at least for a long stretch of time in the twentieth century. It has now been for decades a domain under the reign of T. D. Lee. Rather than overwhelm the reader with too much information, I simply point to Columbia’s stellar accomplishments by listing below the Nobel Prizes won by Colum­bia faculty members.

Fig. 12. Pupin Hall at Columbia University. Photograph by the author.

Physics at Columbia probably can be dated from the establishment of the School of Mines in 1864, in particular with the appointment of Michael I. Pupin as professor in it. The Physics Department in the College of Arts and Science was established in 1892. The American Physical Society was founded at Columbia in 1899.[93] The present physics building, Pupin Hall (figure 12), was built in 1925 on the north edge of the main cam-

Table 1. Columbia University Nobel Laureates according to the year they received the Nobel Prize in Physics. EKA stands for the Ernest Kempton Adams Fund for Physical Research, which was estab­lished in 1904 by Edward Dean Adams ‘‘as a memorial to his son… who received the degree of Elec­trical Engineering in 1897 and Master of Arts in 1898, and who devoted his life to scientific research.’’ Quoted in Max Planck, Eight Lectures on Theoretical Physics delivered at Columbia University in 1909 (New York: Columbia University Press, 1915), p. iii. I thank Roger H. Stuewer for supplying this infor­mation. Asterisks refer to research performed at Columbia.



Association with Columbia


Hendrik A. Lorentz

EKA Lecturer in Mathematical Physics, 1905-1906


Wilhelm Wien

EKA Lecturer in Mathematical Physics, 1913


Max Planck

EKA Lecturer in Mathematical Physics, 1909


Robert A. Millikan

Columbia Ph. D., 1895 (first Physics Ph. D. awarded)


Enrico Fermi

Faculty, 1939-1946


Isidor I. Rabi*

Columbia Ph. D., 1927;Faculty, 1929-1967;Professor Emeritus, 1967-1988


Hideki Yukawa

Faculty, 1949-1953


Willis E. Lamb*

Faculty, 1938-1951


Polykarp Kusch*

Faculty, 1939-1971


Tsung Dao Lee*

Faculty, 1953-present


Maria Goeppert-Mayer Research Staff and Faculty, 1939-1946


Charles H. Townes*

Faculty, 1948-1961


Julian Schwinger

Columbia B. A., 1936;Columbia Ph. D., 1939


Hans A. Bethe

Visiting Professor, 1948 and 1949


Murray Gell-Mann

Visiting Professor, 1954-1955


Leon N. Cooper

Columbia B. A., 1951;Columbia Ph. D., 1954


Aage Bohr*

Research Staff, 1948-1949


James Rainwater*

Columbia Ph. D., 1946;Faculty, 1946-1986


Samuel C. C. Ting

Faculty, 1965-1969


Arno A. Penzias

Columbia Ph. D., 1962


Steven Weinberg

Faculty, 1957-1959


Val L. Fitch

Columbia Ph. D., 1954


Arthur L. Schawlow

Research Staff, 1949-1951


Carlo Rubbia

Research Staff, 1958-1959


Leon M. Lederman*

Columbia Ph. D., 1951;Faculty, 1951-1979


Melvin Schwartz*

Columbia B. A., 1953;Columbia Ph. D., 1958;Faculty, 1957-1966, 1991-present


Jack Steinberger*

Faculty, 1950-1969


Norman F. Ramsey

Columbia B. A., 1935;Columbia Ph. D., 1937;Faculty, 1942-1946

pus (by 120th Street). Unlike many other thriving physics departments, Columbia’s to this day has not seen fit to move to snazzier quarters. Pupin Hall is now an official national landmark. Columbia’s first Nobel Prize awarded to a regular faculty member went to Harold C. Urey (1893-1981), who received the Nobel Prize for Chemistry in 1934 for his discovery of deuterium three years earlier. In physics, beginning in the early 1930s, I. I. Rabi was the dominant figure. John S. Rigden has discussed Rabi’s pio­neering work on atomic and molecular beams, and that of his amazing coterie of stu­dents, in detail.21 Other Columbia physicists also made stellar experimental and theo­retical contributions to nuclear and particle physics and astrophysics, as epitomized by the awards listed below. Finally, the basement of Pupin occupies a special niche in the history of physics, as this is where Herbert L. Anderson, Eugene T. Booth, John R. Dun­ning, Enrico Fermi, G. Norris Glasoe, and Francis G. Slack performed the first fission experiments in the United States on January 25, 1939. The following year, in March 1940, Dunning, Booth, and Aristid V. Grosse, using a small sample of the separated ura­nium isotopes supplied to them by Alfred O. C. Nier of the University of Minnesota, proved that U-235 is the fissionable isotope. The cyclotron they used was removed from the basement laboratory some years ago.

A thorough history of Columbia’s Physics Department, which remains today a very active center of research, can be found at the websites <http:// phys. columbia. edu/his – tory> and <http://phys. columbia. edu/heritage. html>. I reproduce in Table 1 the list of 28 Nobel Laureates who have been associated with the department. Thirteen received the Nobel Prize for theoretical work, fifteen for experimental discoveries; ten were Columbia Ph. D.s in physics, and ten (denoted by an asterisk) performed their prize­winning research in Pupin Hall.


Fig. 5.

The Round Tower (web site <www. rundetaarn. dk>) is the oldest preserved obser­vatory in Europe. It still functions as such; it served as the University of Copenhagen Observatory until 1861, and nowadays in the winter period anyone can observe the night sky through its fine astronomical telescope.

The foundation stone of the Round Tower was laid in 1637, and the building was completed in 1642. The observatory was the first of a complex of three buildings built in the 17th century for use by scholars, the other two being the students’ church (Trini – tatis or Trinity Church, consecrated in 1656) and the university library (above the church). These buildings were commissioned by King Christian IV, who reigned from 1588 to 1648. There is a large and decorative riddle, designed by the King himself, on the outside of the Round Tower, which can be interpreted as follows: ‘‘Lead, O God, learning and justice into the heart of the crowned King Christian IV, 1642.’’ Inside the tower a 209-meter-long spiral ramp leads up to the astronomers’ study, directly under­neath the observation platform, which is reached by a winding staircase. From here the visitor has a magnificent view of the old part of Copenhagen, including the University district, the Latin quarter. The first director of the observatory was Christian Lon – gomontanus (1562-1647), one of Tycho Brahe’s students.

Copenhagen has suffered many fires and bombardments over the centuries. The observatory and the university library burned in the fire of 1728, in which Tycho

Brahe’s celestial globe (which had been returned to Denmark in 1632) melted. Not one of Brahe’s instruments is now to be found in Denmark.

At the end of the spiral ramp there is a planet plotter, installed in 1928, which shows the six inner planets’ orbits around the Sun. The original planet plotter was construct­ed in 1697 by Ole R0mer, who was a convinced Copernican, but out of veneration for Tycho Brahe, R0mer adapted the first planet plotter according to Brahe’s system with the Earth at the center, the Sun moving around the Earth, and the rest of the planets moving around the Sun.

The library hall above the church was used as the university library in the years 1657-1861. It is now used as an exhibition hall. The entrance is halfway up the spiral ramp.

Store Kannikestrade 16 (E5)

This street is part of the University quarter. There is a memorial plaque for Ole R0mer (figure 6) on the front of Store Kannikestrade 16: HER LAA INDTIL 1728/DEN PROFESSOR-RESIDENS HVOR/OLE R0MER/PROFESSOR I ASTRONOMI/ POLITIMESTER I K0BENHAVN/BOEDE TIL SIN D0D 19 SEPTEMBER 1710 (Here stood until 1728 the professorial residence where Ole

Fig. 6. Ole R0mer. Portrait at the Institute of Astronomy, University of Copenhagen. Courtesy of the Ole R0mer Museum.

R0mer, professor of astronomy, chief of police for Copenhagen, lived until his death, 19 September 1710).

Danish astronomer Ole R0mer (1644-1710) studied at the University of Copen­hagen. He assisted Erasmus Bartholin (1625-1698), who is renowned for his study in 1669 of the passage of a beam of light through a crystal of Iceland spar, with the pub­lication of Tycho Brahe’s ‘‘observation plates’’ (which were bought by Danish King Frederik III from Johannes Kepler’s son). From 1671 R0mer continued this work with Jean Picard (1620-1682) in Paris where, among other things, he designed the fountains at Versailles for Louis XIV. In 1676 he wrote what would be his only paper of any importance published during his lifetime – on his discovery of the ‘‘hesitation’’ of light, that is, that light has a finite velocity. He returned to Copenhagen in 1681, where he became the king’s mathematician, professor of astronomy at the university, and there­by director of the observatory at the Round Tower.

R0mer reordered the system of weights and measures in Denmark on the basis of a single unit, thus combining weight and length. Among his numerous public duties, he also was involved in providing street lighting for Copenhagen. He was responsible for introducing the Gregorian Calendar in Denmark in 1700. R0mer was a great instru­ment maker, developing the transit instrument (figure 7) in 1689. His studies on tem­perature corrections led him to invent a thermometer that was based on the freezing and boiling points of water. Daniel Fahrenheit (1686-1736) learned about this idea from R0mer in 1708.

R0mer made his astronomical observations from his home in Kannikestrsde and at a new observatory built to the west of Copenhagen, now the site of the Ole R0mer Museum (see Appendix). Most of R0mer’s papers were destroyed in the fire of 1728.

XI District

Descending the Buda hills we arrive in the XI District on the west bank of the Danube river. Eotvos University is located south of the Petofi-Md (bridge), while the Technical University of Budapest is south of the Szabadsag-Md (bridge). We start at the former.

Pazmany Peter setany (promenade), Faculty of Natural Sciences (figure 3), Eotvos University. The Institute of Physics moved here in 1998 from the Eotvos Building at Puskin utca 5-7 in the VIII District (see below).

As I noted earlier, the university was founded by Peter Pazmany in 1635 in Nagy – szombat. At that time, it had only two faculties, the Faculty of Theology and the Facul­ty of Arts. The Faculty of Law was established in 1667 and the Faculty of Medicine in 1769. In 1950 the Faculty of Theology was separated from the University, becoming the Peter Pazmany Catholic University, and in 1951 the Faculty of Medicine followed suit, becoming the Semmelweis Medical School. Since 1990 the Institute of Sociology and Social Politics also has enjoyed a certain autonomy within the university.

The Physics Department was established by Empress Maria Theresia in 1770. Its first outstanding faculty member was the Benedictine monk Anyos Jedlik (1800-1895), who taught at the university from 1840-1878. His electrostatic machine, a high-capacity electric condenser, was awarded the Medal for Progress at the Vienna World Exhibition in 1873 on the recommendation of Werner Siemens. Jedlik (figure 4) was the first electrotechnician, the first precision mechanician, and the first physics educator in Hungary. He attached paramount importance to teacher training. His suc­cessor, Roland von Eotvos, founded physical research in Hungary. Eotvos received the Benecke Prize of the University of Gottingen in 1909 for verifying the proportionali­ty of inertial and gravitational mass to a precision of 1 part in 200,000,000 in a series of experiments he carried out with Dezso Pekar (1873-1953) and Jeno Fekete (1880-1943).12 He was nominated for the Nobel Prize in Physics by three people in 1911 and 1914 and by two in 1917, one of the nominators in 1914 being Philipp Lenard (1862-1947), winner of the 1905 Nobel Prize and corresponding member of the Hun­garian Academy of Sciences, who was born in Pozsony (Bratislava) but spent his career in Germany.

Fig. 3. Faculty of Natural Sciences Building, Eotvos University. Photograph by Imre Zsolt Kovacs.

Eotvos and his successors selected their coworkers according to their ability to carry out precision measurements, not according to their scientific originality. Both Gyozo Zemplen (1879-1916) and Zoltan Bay (1900-1992) were assistants in the Physics Department who later became professors and heads of the Physics Department in the nearby Technical University of Budapest.

From 1914-1918 Georg von Hevesy, who later won the Nobel Prize in Chemistry for 1943, taught and carried out research in both the Third Chemical Institute and the Sec­ond Physical Institute of the University of Budapest.13 After Eotvos’s death on April 8, 1919, while Hungary was passing through its short-lived communist revolution, Hevesy was appointed director of the First Physical Institute as well. Hevesy recruited eminent scientists such as Imre Brody (1891-1944) and Pal Selenyi (1884-1954), but after the capitulation of the Soviet government he resigned from his position in October 1919.

Georg von Bekesy (1899-1972) had a research appointment in the Institute for Postal Communications at Zombori u. 2 in the IX District (see below) and also was an outstanding physics teacher at the University of Budapest from 1940-1946. Rudolf Ortvay (1885-1945), head of the Institute of Theoretical Physics, initiated the Ortvay Colloquium in 1929, as mentioned earlier. Cornelius Lanczos (1893-1974) wrote his Ph. D. thesis in 1926 under Ortvay and later worked with Einstein in Berlin from 1928-1929. Tibor Neugebauer (1904-1977) and Pal Gombas (1909-1971) were Ort – vay’s assistants and carried out theoretical research in quantum mechanics. After World War II, Karoly Novobatzky (1884-1967) founded a powerful school of theoret­ical physics at the university that included Gyula Kuti (noted for his sack model of nucleons), George Marx (conservation law of lepton charge), Karoly Nagy (nuclear physics), Ivan Abonyi (plasma physics), Sandor Szalay (cosmology), and Geza Gyorgyi (physical applications of group theory). Experimental physics became stronger at the Technical University of Budapest and at the universities in Debrecen and Szeged.

Pazmany Peter setany (promenade), Chemistry Building, Eotvos University. This build-

Fig. 4. Bust of Anyos Jedlik (1800-1895) in the aula of the Anyos Jedlik Secondary Grammar School at Tancsics Mihaly u. 92 in the XXI District. Photograph by the author.

ing is south of the Buda abutment of the Peto’fi-Md (bridge). In its entrance hall there are plaques dedicated to a number of Hungarian chemists.

Pazmany Peter setany 1/A, Institute of Physics, Eotvos University. In the middle of its entrance hall is a copy of a bust of Eotvos, the original being in the Trefort kert (gar­den) in the VIII District (see below). In the Sphere Hall is the pantheon of the Facul­ty of Natural Sciences, whose bronze busts by various artists were dedicated in 1999, as follows: Karoly Tangl (1869-1940), physicist;[59] Rudolf Ortvay (1885-1945), physicist; Georg von Bekesy (1899-1972), chemist and physicist, Nobel Prize in Physiology or

Medicine for 1961; Georg von Hevesy (1885-1966), chemist and physicist, Nobel Prize in Chemistry for 1943; Bela Lengyel (1844-1913), chemist;[60] Gusztav Buchbock ( 1 869-1 935) , chemist;[61] Rado Kovesligethy (1862-1 939) , geophysicist;[62] Jozsef Szava-Kovats (1898-1980), meteorologist;[63] Laszlo Detre (1906-1974), astronomer; Anyos Jedlik (1800-1895), physicist; Karoly Than (1834-1908), chemist;[64] and Lajos Winkler (1863-1939), chemist.******

To the right of Eotvos’s bust is the so-called Harmony Room with Endre Ratkay’s fresco, Annales I, II, III, in it. The scientists depicted on it are as follows: Democritus, Aristotle, Pythagorus, Ptolemy, Giordano Bruno, Nicolaus Copernicus, Tycho Brahe, Johannes Kepler, Galileo Galilei, Peter Pazmany, Isaac Newton, Janos and Farkas Bolyai, Roland von Eotvos, Kitaibel Pal, Anyos Jedlik, Miksa Hell, Albert Einstein, Roland von Eotvos (again), Max Planck, Max von Laue, James D. Watson, Marie Curie, Erwin Schrodinger, Werner Heisenberg, and Niels Bohr.

Eotvos’s Certificates of Acknowledgment are on display in the library. They came to light when the Institute of Physics moved here from another building. A huge gypsum statue of Jedlik also is in the library, which probably is the gypsum mold of the bronze statue in the Jedlik Technical Secondary School in Gyor.

On the first floor in Seminar Room 1.125 of the Department of Theoretical Physics is a bust of Karoly Novobatzky (1884-1967). In the department head’s office and in the dean’s meeting room are two more paintings of Eotvos. In the hall on the third floor of the Department of Nuclear Physics is a bronze bust of Georg von Hevesy (1885-1966) and one of Lajos Janossy (1912-1978). In Room 384 is a bust of Eugene Wigner (1902-1995). The Theodor von Karman Laboratory also is in this building.

Muegyetem rakpart (embankment),Technical University of Budapest. In 1782 Emper­or Franz Joseph II established the Institutum Geometricum as part of the Faculty of Liberal Arts at the University of Buda. This was the direct predecessor of the Techni­cal University of Budapest, the first university in Europe to award engineering degrees in land surveying, river control, and road construction. In 1850 the Institutum Geo­metricum merged with the Joseph College of Technology to become in 1862 the Royal Joseph University. Its present name, the Technical University of Budapest, became offi­cial in 1949.Today more than 110 departments and institutes operate within the frame­work of its seven faculties. There are some novelties. A separate department was set up for Gyozo Zemplen (1879-1916) who taught theoretical physics; the large lecture hall of the Institute of Physics (figure 5) is named after him. Also, the Department of Atom­ic Physics was established with the support of the Tungsram Company with Zoltan Bay (1900-1992) as its head.

In the garden of the Technical University of Budapest next to the Institute of Physics are bronze busts of John von Neumann (1903-1957), Theodor von Karman (1881-1963), and Eugene Wigner (1902-1995), all cast by Ilona Barth and all donated by the Alumni Association of Hungarians in America with headquarters in Buffalo, New York. Elsewhere in the garden is a bronze bust of Geza Pattantyhs-Abraham (1885-1956) and one of Dennis Gabor (1900-1979) that was unveiled in 2000. In the aula of the central building overlooking the Danube river is a statue of Kalman Szily (1838-1924), and at the entrance of Building F from the inner park is a bust of Zoltan Gyulai (1887-1968) that was dedicated in 2000.

Lagymanyosi tot 21-23. There is a limestone statue here of Janos Irinyi (1817-1895) bearing the inscription:

Janos Irinyi 1817-1895. Scientist, Chemist, Freedom Fighter

Menesi tot 7. This is where Eugene Wigner once lived. In 1963, three decades after his move to Princeton University, Wigner received the Nobel Prize in Physics “for his con­tributions to the theory of the atomic nucleus and elementary particles, particularly through the discovery and application of fundamental symmetry principles.”

Menesi tot 11-13, Jozsef Eotvos Boarding House. When Roland von Eotvos was Minis­ter of Culture and Education, he founded this boarding house and named it after his father. In it is a marble bust that was erected to commemorate Eotvos as its founder, as well as a marble plaque in remembrance of those who fell during World War I, for instance, Gyozo Zemplen (1879-1916).

Beregszaszi tot 10, Jozsef Oveges Vocational and Technical Secondary School. To the right of its entrance is a black marble plaque that was erected in 1991 with the inscrip­tion:

Jozsef Oveges 1895-1979 Space is Endless for the Creative Man

Oveges was a famous physics teacher (see the plaque dedicated to him at Varsanyi Udvar 2 in the II District above), and there is a well-known caricature of him engraved on a large plastic plate here.

Gellert-hegy (hill), Citadel. In 1753 Miksa Hell (1720-1792) established an astronomi­cal observatory at the university in Nagyszombat (Trnava), which in 1779 moved with the university to the Royal Palace in Buda. A new observatory, the Gellert Hill Urani – ae (for the sky) was opened on October 15, 1815. Its construction and operation is linked to Janos Pasquich (1753-1829). A monument that commemorates the former

Fig. 5. The Institute of Physics of the Technical University of Budapest. This old photograph shows the building as it also appears today. Credit: Courtesy of Fizikai Szemle (Physics Review), the journal of the Eotvos Society.

observatory was dedicated in 1972.The celestial globe on it has a plaque on its pedestal that reads:

The First Exact Map of Hungary was drawn based on the Scientific Contributions of the Astronomer Imre Daniel Bogdanich (1762-1802). Erected by the Geodetic and Cartographical Society and the Institute for Astronomical Observations of the Hungarian Academy of Sciences in 1972 in Commemoration of His Scientific Work and to Mark the Place where the Observatory Uraniae once stood

Hegyalja dt. 96. The marble plaque on the wall here reads:

Imre Fenyes (1917-1977) lived Here from 1954 until his Death. Outstanding Culti­vator and Professor of Modern Theoretical Physics. Erected by the Council of the XI District, Budapest, 1993

Kaposvar u. 13-15, National Museum of Technology. This museum has a few temporary exhibitions in Buda Castle and exhibit rooms in the Szechenyi Palace in Nagycenk and throughout Hungary. Among the exhibits in the museum, the ones on Creative Hun­garians in the History of Technology and Science and Masterpieces of Hungarian Sci­ence are outstanding. These exhibits include artifacts such as a copy of the 1841 metal camera of Jozsef Petzval (1807-1891); the world’s first carburetor for the stationary engine that Donat Banki (1859-1922) and Janos Csonka (1852-1939) patented on Feb­ruary 11,1893; and the first barium-cathode electric tube of the Tungsram Company, the heavy-duty P415 output pentode of 1927. The museum also possesses oil paintings of Tivadar Puskas (1844-1893) and Rado Kovesligethy (1862-1939).These paintings, as well as Eotvos’s torsion balances and Jedlik’s electrical instruments, are only occasion­ally on display. Also preserved by the museum is Zoltan Bay’s coulometer, the single surviving instrument used in his Moon-Radar experiment of 1946.14

Petzval Jozsef u. 33. There is a commemorative plaque here of the optician and pioneer of photography Jozsef Petzval (1807-1891), who was a professor at the Technical Uni­versity of Budapest and the University of Vienna.

The Park between Menyecske u. and Kero’ Ut. The so-called Time Machine, a digital clock with a metal ring 6 meters in diameter and set in concrete, was made by Tibor Vilt in 1983. The metal cylinders, 50 centimeters in diameter, that indicate the numbers on the clock are decorated with metal reliefs depicting the signs of the zodiac.

Ratz Laszlo u. 4, Leo Weiner Musical Secondary School. There is a marble plaque erected in 1997 on its wall that reads:

Laszlo Ratz 1863-1930 Mathematician, Director and Teacher of the Budapest Lutheran Gymnasium in the (Varosligeti) Fasor, Editor of the Mathematical Review for Secondary Schools. Erected by the Council of the XI District, Budapest and the Budapest Lutheran Gymnasium in 1997

Erdi Ut Cemetery (also known as the Farkasreti Jewish Cemetery in the XII District, since one entrance is on Nemetvolgyi Ut; see above). The grave of Karoly Zipernowsky (1853-1942) is in this cemetery.

We now cross the Danube river on the Chain Bridge (LancMd), one of the oldest bridges in Budapest, and arrive on the Pest side of the city.

Through Dahlem

The establishment of this new society for the advancement of science in Dahlem, a southwestern suburb of Berlin – today you can go there easily by taking the subway line U1 – harked back to plans of Friedrich Althoff (1839-1908), the ‘‘omnipotent’’ ministerial director in the Prussian Ministry of Culture and Education. Around the turn of the century, Althoff conceived the idea of transforming the Prussian domain of Dahlem into a leading research center, a ‘‘German Oxford.’’

Just one year after the founding of the Kaiser Wilhelm Gesellschaft, its first insti­tutes were opened, and during the following decades several more were, for example, those for Biology (1916), Fiber Chemistry (1922), Metals Research (1923), Anthropol­ogy, Human Genetics and Eugenics (1927), and Cell Physiology (1930). These institutes established Dahlem as the main site of the Kaiser Wilhelm Gesellschaft until the sec-

Fig. 6. Observatorium building for the Physical Department of the Physikalisch-Technische Reich – sanstalt. Courtesy of the Physikalisch-Technische Bundesanstalt, Braunschweig.

ond world war. In October 1912, the Kaiser Wilhelm Institutes for Chemistry and for Physical Chemistry and Electrochemistry were opened in a joint ceremony by the Ger­man Emperor Wilhelm II. Both institutes (figure 7) played important roles in the his­tory of physics. The KWI for Chemistry, located at Thielallee 63, was where Otto Hahn and Lise Meitner, moving from the “Holzwerkstatt’’ in Emil Fischer’s Institute of Chemistry at the University of Berlin,5 continued their research on radioactivity. The KWI for Chemistry had three departments; Otto Hahn became head of the radioac­tivity department, which was soon divided into two more or less independent sections for chemical and physical investigations led respectively by Hahn and Meitner. (In 1926 Hahn also became director of the entire KWI for Chemistry.) One of Hahn and Meitner’s early successes was their discovery of the new element protactinium in 1917, but the most important discovery that was made in this institute was that of nuclear fis­sion in the fall and winter of 1938. Two plaques outside of the building (figures 8a and 8b) commemorate that discovery. The upper one (figure 8) is similar to a plaque inside the building on the first floor and was installed in 1956 at the behest of Max von Laue;

rtoiffr-Wilhelm:.lnftitut fur phnWtalifdic (Sbfnuo
unh (Slthirpdifmir

«aifcr. Will) fur 6l)rrmr

Fig. 7. Kaiser Wilhelm Institute for Chemistry (left) and for Physical Chemistry (right) with the direc­tors’ villas (far left and far right) just after their opening. Courtesy of the Archiv der Max-Planck – Gesellschaft, Berlin-Dahlem.

both mentioned only Otto Hahn and Fritz Strassmann. Decades later, in 1997, a second plaque (figure 9) was added that pays tribute to Lise Meitner’s role in this revolution­ary discovery; it also recalls that Max Delbruck, one of the pioneers of molecular genetics, worked there as an assistant to Meitner from 1932 to 1937. On the second floor of the building you also will find a sculpture of Meitner. This building was dam­aged in an air raid in 1944; it was reconstructed after the war and is used today by the Institute of Biochemistry of the Free University of Berlin.

Only a few steps away from the old KWI for Chemistry one finds the building of the KWI for Physical Chemistry and Electrochemistry at Faradayweg 4-6. There is a good overview of the institute’s buildings (old and new) from the so-called ‘‘Haber Linden Tree’’ (figure 10) in the inner courtyard. A plaque commemorates the planting of this tree on the occasion of Haber’s 60th birthday on December 9,1928; actually, the pre­sent tree is a replacement for the original one, which was damaged in a storm after the war. As mentioned above, this institute was opened along with the KWI for Chemistry in October 1912. Its first director was Fritz Haber, who was well known as a pioneer in physical chemistry and for his discovery of the process for fixing nitrogen from the atmosphere and making it available for the synthesis of ammonia. Before the develop­ment of the institute could be completed, World War I broke out, and Haber immedi­ately oriented the work of the institute towards military research serving national goals. This expanded the staff of the institute enormously – by the end of the war about 150 scientists and 2000 staff members were employed, working mostly on the develop­ment of poison gases and protection from them. In the midst of the war, the institute became a center for such research and one of the earliest examples of Big Science. After the war, the institute was demilitarized and Haber was temporarily banned by the western allies as a war criminal, although he was never convicted as one.

Fig. 8. Plaque commemorating the discovery of nuclear fission: Otto Hahn and Fritz Strassmann. Pho­tograph by the author.

The 1920s were the ‘‘golden years’’ of the institute and Haber, who received the Nobel Prize for Chemistry in 1918, attracted many prominent scientists to the insti­tute, among them the future Nobel Prize winners James Franck, Georg de Hevesy and

Fig. 9. Plaque for Lise Meitner and Max Delbruck. Photograph by the author.

Eugene Wigner, as well as Karl Friedrich Bonhoeffer, Herbert Freundlich, Paul Harteck, Hartmut Kallmann, Rudolf Ladenburg, and Michael Polanyi. This successful period came to an abrupt end when Hitler came to power. No other institute in Ger­many was hit as hard. Most of its famous scientists were forced to leave as a conse­quence of the Law for the Restoration of the Career Civil Service of April 1933. As a soldier at the front in World War I, Haber himself was exempted from this Law, but he resigned his post nonetheless. As he wrote in a letter to the ministry, ‘‘My tradition demands that in my choice of colleagues I take into account the professional and per­sonal attributes of applicants to an academic position without inquiring after their racial characteristics. You will not expect a man of 65 years of age to reject a mentali­ty that has guided him in the past 39 years of his academic life….’’6 After a while, Peter Adolf Thiessen, an accomplished physical chemist and alte Kampfer for Hitler, took over the directorship and developed the institute into a ‘‘National Socialist Model Plant.’’ At the end of the war, he left Germany for a ten-year stay in the Sovi­et Union to take part in the Soviet atomic weapons’ program, after which he returned and began a new and successful career in the German Democratic Republic. Thiessen’s successors as director of the KWI for Chemistry were after the war Robert Havemann and Karl Friedrich Bonhoeffer; from 1951 until his death in 1960 the Insti­tute was directed by Max von Laue who renamed the institute the ‘‘Fritz Haber Insti­tute.”

During the postwar period, the future of this institute and the other Kaiser Wilhelm Institutes in Dahlem (most of which were moved into the western parts of Germany

Fig. 10. The entrance of the Institute for Physical Chemistry with the Haber Linden Tree. Courtesy of the Archiv der Max-Planck-Gesellschaft, Berlin-Dahlem.

during the final years of the war) stood on shaky ground. First, the very existence of the Kaiser Wilhelm Gesellschaft in general was threatened; second, the institutes were poorly financed first by the local Berlin government and later by the Deutsche Forschungsgemeinschaft (German Research Association) under a plan proposed by

Fig. 11. Air view of the Harnack House in Berlin-Dahlem. Courtesy of the Archiv der Max-Planck – Gesellschaft, Berlin-Dahlem.

Fritz Karsen, the director of the U. S. Department of Education. This period of insecu­rity came to an end in 1952, when the institutes were integrated into the Max Planck Gesellschaft, which was founded in 1948 as the successor to the old Kaiser Wilhelm Gesellschaft. The war damages could now be repaired in general, and the Fritz Haber Institute could be improved in particular. For example, a new sub-institute for electron microscopy was founded with its own building at Van’t Hoff Strasse 9, the so-called Ernst Ruska Building, named after its first director and the future Nobel Laureate in Physics of 1986. The research being pursued in the present Fritz Haber Institute more or less follows along its early lines, but of course using different theories and experi­mental methods.

We next walk to the former Kaiser Wilhelm Institute for Physics at Boltz – mannstrasse 18-20. Along the way you can see the other old institutes as well as the impressive directors’ villas (shown on the far left and far right of figure 7) of the ‘‘Ger­man Oxford’’7 and the so-called ‘‘Harnack House’’ (figure 11), which was opened in 1929 as an ‘‘International Institute’’ to serve as a residence for visiting foreign scientists and as a club house for the staff of the Kaiser Wilhelm Institutes in Dahlem.8 Its lec­ture room was the place for many famous talks and meetings. For instance, the famous commemorative celebration for Fritz Haber in 1935 was held there, as well as the important meeting of the German Uranium Club in 1942.

After the war, until 1994, Harnack House was used by the U. S. Army as an officer’s club; now it is once again used by the Max Planck Society. Although the Kaiser Wil­helm Gesellschaft had its own Institute of Physics since 1917, its building was con­structed only in 1936. Earlier, the Institute of Physics, directed by Albert Einstein, was more a foundation for the financial support of physical research than a real institute in the usual sense;9 it was more or less located in Einstein’s house on the Haberland – strasse. At the end of the 1920s, there were some efforts made to establish a new insti­tute of physics, but the economic crisis undercut such plans by the Kaiser Wilhelm Gesellschaft. The Rockefeller Foundation was prepared to support these plans by providing a substantial part of the necessary money, but it was not possible to obtain the balance needed from the German government. This situation changed after the Nazi seizure of power, but now the American sponsors were not eager to send money to Nazi Germany.10 Not least thanks to the efforts and personality of Max Planck was the construction finally started in 1935. In May 1938, the institute was opened under the directorship of Peter Debye (instead of the emigrated James Franck, who was favorite candidate prior to 1933). The institute was designed in the shape of an ‘‘L’’ (figure 12), whose shorter wing facing the Boltzmannstrasse contains the entrance, the library, and some offices and laboratories. Most of the laboratories were located in the longer wing, which was completed with a tower containing some high-voltage equipment for nuclear experiments. Debye’s directorship lasted only until 1939,11 when he also emigrated, and the institute then was taken over by the Army Office of Weaponry (Heereswaffenamt) for the German nuclear power project under Kurt Diebner.12

In 1942 the Kaiser Wilhelm Gesellschaft again took over full control of the KWI Institute of Physics, and Werner Heisenberg was appointed as director. Heisenberg continued the nuclear research (he had been its scientific director from the begin­ning) and focused on the construction of a uranium pile, for which large-scale exper-

Fig. 12. Kaiser Wilhelm Institute for Physics. Courtesy of the Archiv der Max – Planck-Gesellschaft, Berlin-Dahlem.

iments were carried out in the institute in Dahlem, especially in a newly constructed shelter near the tower. Owing to the heavy bombardment and the advancing allied armies, the institute was evacuated during the winter of 1944-1945 to southwestern Germany, where in a wine cellar in Haigerloch the final, but still unsuccessful exper­iments aimed at bringing a reactor to criticality were conducted. This wine cellar is now a museum – called the Atomkeller-Museum Haigerloch – which is open to the public daily from May to September and on Saturdays and Sundays during March, April, October, and November (telephone +49-(0)7474-697 26/27). Diebner also con­tinued his nuclear experiments under the auspices of the Army in Gottow – not far from Berlin and located inside a weapons’ test area of the German Army.13 After the war, this area came under the control of the Soviet Army and was used by them until the beginning of the 1990s. Today you can visit this area, and in the village of Kum – mersdorf you will find a small museum (telephone/fax +49-33703-77048) that com­memorates this site, which is not far from where Wernher von Braun also launched his first rockets in the middle of the 1930s. After the end of the war, the KWI’s equip­ment remaining in Dahlem was dismantled by the Soviet Red Army. Today part of the old Institute of Physics (especially the high-voltage tower) is occupied by the Archives for the History of the Max Planck Gesellschaft, but most of the Archives are located in the old Kaiser Wilhelm Institute for Cell Physiology at Boltz – mannstrasse 14, which was built for Otto Warburg in 1930 also with money from the Rockefeller Foundation. You should look inside this marvelous building, which hous­es many important documents and other materials pertaining to the history of mod­ern physics.14 One also should mention the famous Kaiser Wilhelm Institute for Brain Research, where the Russian biophysicist Nikolaj V. Timofeeff-Ressovsky carried out his important experiments on gene mutation. This institute was not located in Dahlem, but in Berlin-Buch, a northeastern suburb of Berlin accessible by the S – Bahn. After World War II, this institute was restructured and became part of a large complex of biomedical institutes of the East German Academy of Sciences. One of its early directors was Walter Friedrich, the co-discoverer of X-ray diffraction and a pioneer in modern biophysics. Today the complex houses the Max Delbruck Center for Molecular Medicine, one of Germany’s National Research Centers. Most of the old Kaiser Wilhelm Institute’s buildings in Dahlem are used today by the Free Uni­versity of Berlin. This third university in Berlin was founded in 1948 as a result of the Cold War, when students of the Humboldt University on Unter den Linden, located in the Russian zone of Berlin, did not want to accept political indoctrination and moved to the American sector of Berlin. With the help of the U. S. Military Govern­ment, they founded in Dahlem a Free University and were allowed to use many of the scientific buildings there.15 In subsequent years, the Free University expanded more and more (you can see it on a walk through Dahlem) and developed into one of Germany’s largest universities.

Two Famous Serbs and an American from the Midwest

Near the end of the nineteenth and beginning of the twentieth century, America was a hotbed of invention and technological innovation. For our purposes I single out three extraordinary people, each of whom became famous for some practical developments, and all of whom were connected with New York City. These were the inventors Thomas Alva Edison (1847-1931),2 Nikola Tesla (1857-1943),3 and Michael Idvorsky Pupin (1858-1935),4 all of whom were involved, in one way or another, with electrical phe­nomena. Edison was of Midwestern stock, while both Tesla and Pupin were Serbian, with strong roots in Serbia and Croatia, respectively. All three were self-made men, coming from either modest or, in the case of Pupin, impoverished backgrounds, and had no connections to academia or pure science. While none of these highly talented individuals could be claimed to be a ‘‘true’’ physicist, each made practical contributions that turned out to be of significant value to physics.

Edison’s purest scientific discovery was the ‘‘Edison effect,’’ that is, thermionic emis­sion, although in keeping with his generally practical outlook on research he never fully understood or exploited this discovery, which was taken advantage of much better by others. While his research laboratory was famously located in Menlo Park, New Jersey, his power-generating and distribution plants were in New York, at 65 Fifth Avenue and 255-257 Pearl Street, respectively.

Tesla arrived in New York in 1884, bearing a letter of introduction to Edison, who immediately hired him. However, in later years they had a falling out, primarily because of the controversy regarding the use of alternating (ac) versus direct (dc) cur­rent for electric power. Tesla achieved considerable renown when he developed prac­tical ac generators, and most impressively, three-phase generators and motors. These had a profound influence on heavy industry in New York and elsewhere. A famous struggle developed, particularly in New York, between proponents of dc electric power, notably Edison and what evolved eventually into General Electric, and ac electric power, championed by Tesla among many others, and what evolved eventually into the Westinghouse Corporation. Even today, dc-power generators exist in New York because some industrial motors, mainly in elevators in old buildings, still require dc, although Con Ed (Consolidated Edison), responsible for supplying virtually all New York power, does not itself possess dc generators any longer. Physicists are familiar with the Tesla coil, used in elementary – lecture demonstrations. Tesla possessed 700 patents.

Over time Tesla ran several laboratories in downtown Manhattan, notably first at 33-35 South Fifth Avenue (renamed La Guardia Place) and then at 8 West 40th Street, which was conveniently close to the main branch of the New York Public Library at 42nd Street and Fifth Avenue. In keeping with the long tradition in New York of tear­ing down old buildings and replacing them with bigger and better ones, a huge New York University apartment complex now sits at 33-35 South Fifth Avenue where the Tesla Electric Company formerly sat.

Tesla led a very colorful life in New York. For a time he was a darling of the social set, and at his peak lived luxuriously in the Waldorf-Astoria Hotel at 301 Park Avenue. Altogether he lived in seven different hotels, most of which no longer exist. There are amusing stories about some of Tesla’s claims, for example, that he had developed a death ray, something like a laser but of course with no real basis in reality. Tesla made a strong mark on turn-of-the-century life in New York, but in later years he became more and more eccentric, and even mentally disturbed. His reputation fell lower and lower. He died in 1943, in debt, in the Hotel New Yorker (corner of 34th Street and Seventh Avenue), where he had an apartment and laboratory on the top floor.

Of these three great inventors, Michael Pupin stands out as being the one with the most impressive scientific credentials, which led to his achievements in electromagnet­ism, radiation and electric-transmission theory, and radio research, based upon a solid background in physics. His rise from poverty and ignorance, from a tiny Serbian village in Croatia, with illiterate parents, to his final eminence as professor of electrical engi­neering at Columbia University, is well articulated in his autobiography, From Immi­grant to Inventor. Pupin pulled himself up by his own bootstraps. When he first arrived in New York, in 1868, after several years working on farms in Delaware and elsewhere, he worked in factories during the day and attended lectures at Cooper Union (see below) at night. He had great ambitions, at first centered on attending Princeton Uni­versity, but later changing his allegiance to Columbia. I quote from his autobiography: ‘‘[In choosing Columbia over Princeton, the] fact that the college was located in the city of New York carried much weight, because New York appealed to my imagination

Fig. 1. Bust of Michael I. Pupin (1858-1935) at the Serbian Orthodox Cathedral of St. Sava, 12 West 25th Street. Photograph by the author.

more than any other place in the world.’’5 After receiving his undergraduate degree at Columbia College, he pursued higher education at the University of Cambridge, and finally received a Ph. D. degree from the University of Berlin. In his later years he lived in the famous Dakota apartment house on Central Park West (1 West 72nd Street). There is a statue of him (figure 1) at the Serbian Orthodox Cathedral of St. Sava, 12 West 25th Street. The greatest monument to Michael Pupin in New York, however, is the Columbia Physics Building, named after him, and now on the list of national his­toric landmarks of the U. S. Department of the Interior. He died in 1935 and is buried in Woodlawn Cemetery (Section 86, Locust Plot) in the Bronx.

Fig. 2. The Colonnade of the Hall of Fame for Great Americans. Photograph by the author.