- Published on 16 April 2018
Personal recollections of an astrophysicist shed new light on the 1995 discovery on 51 Pegasi b
In recent history, a very important achievement was the discovery, in 1995, of 51 Pegasi b, the first extrasolar planet ever found around a normal star other than the Sun. In a paper published in EPJ H, Davide Cenadelli from the Aosta Valley Astronomical Observatory (Italy) interviews Michel Mayor from Geneva Observatory (Switzerland) about his personal recollections of discovering this exoplanet. They discuss how the development of better telescopes made the discovery possible. They also delve into how this discovery contributed to shaping a new community of scholars pursuing this new field of research. In closing, they reflect upon the cultural importance that the 51 Pegasi b discovery had in terms of changing our view of the cosmos.
- Published on 27 February 2018
The personal memories of Jayant Narlikar point to the need for restoring cosmology as the flagship of astronomy
"Cosmologists are often wrong but never in doubt”, Russian physicist Lev Landau once said . In the early days, astronomers began by observing and modelling stars in different stages of evolution and comparing their findings with theoretical predictions. Stellar modelling uses well-tested physics, with concepts such as hydrostatic equilibrium, law of gravitation, thermodynamics, nuclear reactions etc. Yet in contrast, cosmology is based on a large number of untested physical assumptions, like nonbaryonic dark matter and dark energy whose physics has no proven link with the rest of physics. In a recent paper published in EPJ H, Jayant V. Narlikar, professor emeritus at the Inter-University Centre for Astronomy and Astrophysics in Pune, India, shares his personal reminiscences of the evolution of the subject of cosmology over six decades. He tells of the increase in our confidence in the standard model of cosmology to the extent that it has become a dogma.
- Published on 05 December 2017
The personal recollections of a physicist involved in developing a reference model in particle physics, called the Standard Model, particularly in Italy
Understanding the Universe requires first understanding its building blocks, a field covered by particle physics. Over the years, an elegant model of particle physics, dubbed the Standard Model, has emerged as the main point of reference for describing the fundamental components of matter and their interactions. The Standard Model is not confined to particle physics; it also provides us a guide to understanding phenomena that take place in the Universe at large, down to the first moments of the Big Bang, and it sets the stage for a novel cosmic problem, namely the identification of dark matter. Placing the Standard Model in a historical context sheds valuable light on how the theory came to be. In a remarkable paper published in EPJ H, Luciano Maiani from the University of Rome and the National Institute of Nuclear Physics, Italy, shares his personal recollections with Luisa Bonolis from the Max Planck Institute for the History of Science, Berlin, Germany. During an interview recorded over several days in March 2016, Maiani outlines the role of those researchers who were instrumental in the evolution of theoretical particle physics in the years when the Standard Theory was developed.
- Published on 26 June 2017
Journey into the post-war transformation leading to the return of General Relativity within physics
Einstein’s 1915 theory of gravitation, also known as General Relativity, is now considered one of the pillars of modern physics. It contributes to our understanding of cosmology and of fundamental interactions between particles. But that was not always the case. Between the mid-1920s and the mid-1950s, General Relativity underwent a period of stagnation, during which the theory was mostly considered as a stepping-stone for a superior theory. In a special issue of EPJ H just published, historians of science and physicists actively working on General Relativity and closely related fields share their views on the process, during the post-World War II era, in particular, which saw the “Renaissance” of General Relativity, following progressive transformation of the theory into a bona fidae physics theory.
EPJ H Highlight - Historical account of how donut-shaped fusion plasmas managed to decrease adverse turbulence
- Published on 20 February 2017
Achieving fusion has become more realistic since plasma flow was identified as regulating turbulence in the 1980s
Fusion research has been dominated by the search for a suitable way of ensuring confinement as part of the research into using fusion to generate energy. In a recent paper published in EPJ H, Fritz Wagner from the Max Planck Institute for Plasma Physics in Germany, gives a historical perspective outlining how our gradual understanding of improved confinement regimes for what are referred to as toroidal fusion plasmas –- confined in a donut shape using strong magnetic fields-- have developed since the 1980s. He explains the extent to which physicists’ understanding of the mechanisms governing turbulent transport in such high-temperature plasmas has been critical in improving the advances towards harvesting fusion energy.
- Published on 12 October 2016
History shows experiments to be just as key as theory in gravity physics
In the 1950s and earlier, the gravity theory of Einstein's general relativity was largely a theoretical science. In a new paper published in EPJ H, Jim Peebles, a physicist and theoretical cosmologist who is currently the Albert Einstein Professor Emeritus of Science at Princeton University, New Jersey, USA, shares a historical account of how the experimental study of gravity evolved.
- 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.