- Published on 22 March 2016
On the evolution of how we have defined time, time interval and frequency since antiquity
The earliest definitions of time and time-interval quantities were based on observed astronomical phenomena, such as apparent solar or lunar time, and as such, time as measured by clocks, and frequency, as measured by devices were derived quantities. In contrast, time is now based on the properties of atoms, making time and time intervals themselves derived quantities. Today’s definition of time uses a combination of atomic and astronomical time. However, their connection could be modified in the future to reconcile the divergence between the astronomic and atomic definitions. These are some of the observations made by Judah Levine, author of a riveting paper just published in EPJ H, which provides unprecedented insights into the nature of time and its historical evolution.
- Published on 02 December 2015
The Abraham Pais Prize for History of Physics is given annually to recognize outstanding scholarly achievements in the history of physics. Professor Allan Franklin, who is an Editor of EPJ H and author of the Springer book The Rise and Fall of the Fifth Force, receives the 2016 Abraham Pais Prize for History of Physics for "path-breaking historical analyses of the roles of experiment in physics and for explicating the nature of evidence and error in scientific argument".
- Published on 27 October 2015
Ephraim Fischbach revisits the wealth of research emerging from the quest for the fifth force, which he hypothesised in the 1980s as being a new fundamental force in nature
Discovering possible new forces in nature is no mean task. The discovery of gravity linked to Newton’s arguably apocryphal apple experiment has remained anchored in popular culture. In January 1986, Ephraim Fischbach, Physics Professor from Purdue University in West Lafayette, Indiana, had his own chance to leave his mark on collective memory. His work made the front page of the New York Times after he and his co-authors published a study uncovering the tantalising possibility of the existence of a fifth force in the universe. In an article published in EPJ H, Fischbach gives a personal account of how the existence of the gravity-style fifth force has stimulated an unprecedented amount of research in gravitational physics - even though its existence, as initially formulated, has not been confirmed by experiment.
- Published on 11 November 2014
Find out how Roger Penrose and Stephen Hawking won recognition for their work on space time singularities back in the sixties, suggesting an initial start to the universe
In 1966, it was Roger Penrose who won the prestigious Adams prize for his essay: An Analysis of the Structure of Space Time. The Adams prize—named after the British mathematician John Couch Adams—is awarded each year by the Faculty of Mathematics at the University of Cambridge to a young, UK-based mathematician. At the same time, Stephen Hawking won an auxiliary to the Adams prize for an essay entitled Singularities and the Geometry of Spacetime, shortly after completing his PhD. A copy of the original submission has now been reproduced in EPJ H.
- Published on 26 February 2014
Italian physicist Carlo Di Castro shares his thoughts on the development of theoretical condensed matter physics in Rome from the 1960s until the beginning of this century.
Italian physicist Carlo Di Castro, professor emeritus at the University of Rome Sapienza, Italy, shares his recollections of how theoretical condensed matter physics developed in Rome, starting in the 1960s. Luisa Bonolis, a researcher at the Max Planck Institute for the History of Science in Berlin, Germany invited Di Castro to reflect upon his research career, which he did in an interview published in EPJ H.
In this unique document, Di Castro talks about his upbringing during the second World War. He also explains how this childhood experience later influenced his philosophy, which he aptly summarises as follows: “the fear of the unknown must be overcome through knowledge and reason.” Ultimately, this approach guided the career choices that led him to become a condensed matter physicist.
- Published on 05 February 2014
New insights into Einstein’s view of the cosmos from the translation and study of one of his least known papers
A paper published in EPJ H provides the first English translation and an analysis of one of Albert Einstein’s little-known papers, “On the cosmological problem of the general theory of relativity”. Published in 1931, it features a forgotten model of the universe, while refuting Einstein’s own earlier static model of 1917. In this paper, Einstein introduces a cosmic model in which the universe undergoes an expansion followed by a contraction. This interpretation contrasts with the monotonically expanding universe of the widely known Einstein-de Sitter model of 1932.
- Published on 05 February 2014
Albert Einstein accepted the modern cosmological view that the universe is expanding, only long after several of his contemporaries had demonstrated it with astrophysical observations
Until 1931, physicist Albert Einstein believed that the universe was static. An urban legend attributes this change of perspective to when American astronomer Edwin Hubble showed Einstein his observations of redshift in the light emitted by far away nebulae—today known as galaxies. But the reality is more complex. The change in Einstein’s viewpoint, in fact, resulted from a tortuous thought process. Now, in an article published in EPJ H, Harry Nussbaumer from the Institute of Astronomy at ETH Zurich, Switzerland, explains how Einstein changed his mind following many encounters with some of the most influential astrophysicists of his generation.
- Published on 23 April 2013
Earlier this year Francesco Guerra, who had been a member of the editorial board of EPJ H - Historical Perspectives on Contemporary Physics since its launch in 2010, joined Wolf Beiglböck in managing the journal.
Prof. Francesco Guerra, a graduate from the University of Naples, is full professor of theoretical physics at the University of Rome 'La Sapienza'. He has served on many national academic evaluation committees and is currently a member of the Physics Panel of the National Agency for the Evaluation of Universities and Research.
His scientific interests include quantum field theory and elementary particles, stochastic methods in quantum mechanics, stochastic variational principles, statistical mechanics of spin glasses and complex systems, and the history of modern physics (in particular nuclear physics). In 2008, he was the recipient of the Italian Physical Society’s Prize for History of Physics.
- Published on 04 February 2013
A new study reveals the contribution of a little known Austrian physicist, Friedrich Hasenöhrl, to uncovering a precursor to Einstein famous equation
An American physicist outlines the role played by Austrian physicist Friedrich Hasenöhrl in establishing the proportionality between the energy (E) of a quantity of matter with its mass (m) in a cavity filled with radiation. In a paper just published in EPJ H, Stephen Boughn from Haverford College in Pensylvannia argues how Hasenöhrl’s work, for which he now receives little credit, may have contributed to the famous equation E=mc2.
- Published on 04 April 2011
The work behind the discovery of cosmic rays, a milestone in science, involved many scientists in Europe and the New World fascinated by the puzzling penetrating radiation, and took place during a period characterized by lack of communication and by nationalism caused primarily by World War I. It took eventually from the turn of the century until 1926 before the extraterrestrial nature of the penetrating radiation was generally accepted.