Bruno Rossi and Cosmic Rays: From Earth laboratories to Physics in Space

Rossi's career paralleled the evolution of cosmic-ray physics. Starting from the early 1930s his pioneering work on the nature and behavior of cosmic rays led to fundamental contributions in the field of experimental cosmic-ray physics and laid the foundation for high-energy particle physics. After the war, under his leadership the Cosmic Ray group at MIT investigated the properties of the primary cosmic rays elucidating the processes involved in their propagation through the atmosphere, and measuring the unstable particles generated in the interactions with matter. When accelerators came to dominate particle physics, Rossi's attention focused on the new opportunities for exploratory investigations made possible by the availability of space vehicles. He initiated a research program which led to the first in situ measurements of the density, speed and direction of the solar wind at the boundary of Earth's magnetosphere and inspired the search for extra-solar X-ray sources resulting in the detection of what revealed to be the most powerful X-ray source in Earth's skies. The discovery of Scorpius X-1 marked the beginning of X-ray astronomy, which soon became a principal tool of astrophysics research.Comment: Upgraded English version of the article published on La Fisica nella scuola, Quaderno 22, 2011, resulting from lessons held during the last School for the history of Physics organized by the Italian Association for the Teaching of Physics (Aosta, November 29-December 4, 2010

From cosmic ray physics to cosmic ray astronomy: Bruno Rossi and the opening of new windows on the universe

Bruno Rossi is considered one of the fathers of modern physics, being also a pioneer in virtually every aspect of what is today called high-energy astrophysics. At the beginning of 1930s he was the pioneer of cosmic ray research in Italy, and, as one of the leading actors in the study of the nature and behavior of the cosmic radiation, he witnessed the birth of particle physics and was one of the main investigators in this fields for many years. While cosmic ray physics moved more and more towards astrophysics, Rossi continued to be one of the inspirers of this line of research. When outer space became a reality, he did not hesitate to leap into this new scientific dimension. Rossi's intuition on the importance of exploiting new technological windows to look at the universe with new eyes, is a fundamental key to understand the profound unity which guided his scientific research path up to its culminating moments at the beginning of 1960s, when his group at MIT performed the first in situ measurements of the density, speed and direction of the solar wind at the boundary of Earth's magnetosphere, and when he promoted the search for extra-solar sources of X rays. A visionary idea which eventually led to the breakthrough experiment which discovered Scorpius X-1 in 1962, and inaugurated X-ray astronomy.Comment: This work was presented at the conference "100 Years Cosmic Ray Physics - Anniversary of the V.F. Hess Discovery", 6-8 August, Bad Saarow/Pieskow, Germany, where Hess landed on August 7, 1912, after discovery of the "H\"ohenstrahlung". To be published in the Astroparticle Journa

The Charm of Theoretical Physics (1958-1993)

Personal recollections on theoretical particle physics in the years when the Standard Theory was formed. In the background, the remarkable development of Italian theoretical physics in the second part of the last century, with great personalities like Bruno Touschek, Raoul Gatto, Nicola Cabibbo and their schools.Comment: 53 pages, 12 figures, to be published in The European Physical Journal H. New version with added text and figure

International scientific cooperation during the 1930s. Bruno Rossi and the development of the status of cosmic rays into a branch of physics

During the 1920s and 1930s, Italian physicists established strong relationships with scientists from other European countries and the United States. The career of Bruno Rossi, a leading personality in the study of cosmic rays and an Italian pioneer of this field of research, provides a prominent example of this kind of international cooperation. Physics underwent major changes during these turbulent years, and the traditional internationalism of physics assumed a more institutionalised character. Against this backdrop, Rossi's early work was crucial in transforming the study of cosmic rays into a branch of modern physics. His friendly relationships with eminent scientists -notably Enrico Fermi, Walther Bothe, Werner Heisenberg, Hans Bethe, and Homi Bhabha- were instrumental both for the exchange of knowledge about experimental practises and theoretical discussions, and for attracting the attention of physicists such as Arthur Compton, Louis Leprince-Ringuet, Pierre Auger and Patrick Blackett to the problem of cosmic rays. Relying on material from different archives in Europe and United States, this case study aims to provide a glimpse of the intersection between national and international dimensions during the 1930s, at a time when the study of cosmic rays was still very much in its infancy, strongly interlaced with nuclear physics, and full of uncertain, contradictory, and puzzling results. Nevertheless, as a source of high-energy particles it became a proving ground for testing the validity of the laws of quantum electrodynamics, and made a fundamental contribution to the origins of particle physics.Comment: 62 pages, 4 figures, revised edition, to be published on Annals of Scienc

Bruno Touschek in Germany after the War: 1945-46

Bruno Touschek was an Austrian born theoretical physicist, who proposed and built the first electron-positron collider in 1960 in the Frascati National Laboratories in Italy. In this note we reconstruct a crucial period of Bruno Touschek's life so far scarcely explored, which runs from Summer 1945 to the end of 1946. We shall describe his university studies in Gottingen, placing them in the context of the reconstruction of German science after 1945. The influence of Werner Heisenberg and other prominent German physicists will be highlighted. In parallel, we shall show how the decisions of the Allied powers, towards restructuring science and technology in the UK after the war effort, determined Touschek's move to the University of Glasgow in 1947

Bruno Touschek and AdA: from Frascati to Orsay

This paper is dedicated to the memory of Bruno Touschek, who passed away forty years ago, in Innsbruck, Austria, on May 25th, 1978. The first electron-positron collisions in a laboratory were observed in 1963-1964 at the Laboratoire de l'Accelerateur Lineaire d'Orsay, in France, with the storage ring AdA, which had been constructed in the Italian National Laboratories of Frascati in 1960, under the guidance of Bruno Touschek. The making of the collaboration between the two laboratories included visits between Orsay and Frascati, letters between Rome and Paris, and culminated with AdA leaving Frascati on July 4th, 1962 to cross the Alps on a truck, with the doughnut degassed to 10−9mmHg through pumps powered by heavy batteries. This epoch-making trip and the exchanges which preceded it are described through unpublished documents and interviews with some of its protagonists, Carlo Bernardini, Franc¸ois Lacoste, Jacques Ha¨ıssinski, Maurice Levy

Bruno Touschek in Glasgow: The making of a theoretical physicist

In the history of the discovery tools of last century particle physics, central stage is taken by elementary particle accelerators and in particular by colliders. In their start and early development, a major role was played by the Austrian born Bruno Touschek, who proposed and built the first electron positron collider, AdA, in Italy, in 1960. In this note, we present a period of Touschek's life barely explored in the literature, namely the five years he spent at University of Glasgow, first to obtain his doctorate in 1949 and then as a lecturer. We shall highlight his formation as a theoretical physicist, his contacts and correspondence with Werner Heisenberg in Gottingen and Max Born in Edinburgh, as well as his close involvement with colleagues intent on building modern particle accelerators in Glasgow, Malvern, Manchester and Birmingham. We shall discuss how the Fuchs affair, which unraveled in early 1950, may have influenced his decision to leave the UK, and how contacts with the Italian physicist Bruno Ferretti led Touschek to join the Guglielmo Marconi Physics Institute of University of Rome in January 1953

Bruno Touschek with AdA in Orsay and the first direct observation of electron-positron collisions

We describe how the first direct observation of electron-positron collisions took place in 1963-1964 at the Laboratoire de l'Accelerateur Lineaire d'Orsay, in France, with the storage ring AdA, which had been proposed and constructed in the Italian National Laboratories of Frascati in 1960, under the guidance of Bruno Touschek. The obstacles and successes of the two and a half years during which the feasibility of electron-positron colliders was proved will be illustrated using archival and forgotten documents, in addition to transcripts from interviews with Carlo Bernardini, Peppino Di Giugno, Mario Fascetti, Francois Lacoste, and Jacques Haıssinski