Einstein’s legacy and the search for gravitational waves
Public talk by Prof. Dr. Bruce Allen, Director at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) in Hannover on 9 April 6:00 – 7:30 p.m. at the Neues Rathaus Hannover, Hodlersaal
The general theory of relativity, the modern explanation of gravitation, is Einstein’s legacy. It not only postulates the deflection of a light ray that passes close to our Sun, but also how black holes are born of collapsing stars.
A further dramatic consequence of Einstein’s theory is that rapidly accelerating celestial bodies cause “ripples” in spacetime, which spread with the speed of light. These gravitational waves are expected to be directly measureable for the first time over the next few years thanks to the new generation of large-scale gravitational wave observatories. This will open up a new window onto the universe and herald the start of the era of gravitational wave astronomy.
Bruce Allen’s talk will take place within the framework of the “International Scientists in Hannover” series. Admission is free.
Prof. Bruce Allen studied physics from 1976 to 1980 at Massachusetts Institute of Technology (MIT) and received his doctorate in 1983 from Cambridge University, England, under the supervision of Stephen Hawking with a focus on gravitation and cosmology, particularly the very early universe.
He worked in the area of relativity theory at the University of California at Santa Barbara, USA, Tufts University, and the Observatiore de Paris, France, before being appointed in 1989 Professor of Physics at the University of Wisconsin in Milwaukee. There, Dr. Allen established the largest team to deal with gravitational wave analysis in the USA and headed the development of the Einstein@Home project. Since 2007 Bruce Allen has been Director at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) and Honorary Professor of Physics at Leibniz Universität Hannover.
At the AEI he heads the “Experimental Relativity and Cosmology” Department and operates ATLAS, the world’s biggest computer cluster for the evaluation of gravitational waves.
ATLAS is the most powerful mainframe computer in the world in the LIGO data grid where the data from the internationally linked network of gravitational wave observatories is processed and analyzed. Here is where the measurement data from the American LIGO detectors, the Italian-French Virgo Project and the German-British GEO600 observatory flow together. The data is initially collected and processed at the California Institute for Technology in Pasadena, the National Center of the National Institute for Nuclear Physics (CNAF) in Bologna and at the Max Planck Institute for Gravitational Physics, and then sent on to ATLAS. The Hannover-based scientists make a part of the computer time available for their colleagues in the radio- and x-ray astronomy area, as well as for numerical simulations of cosmic events.
Einstein@Home, the project for shared computing, links up PC users from all over the globe who voluntarily make available their unused computer time from their home and office computers. With over 330,000 participants, it is one of the biggest projects of its kind. Since 2005, Einstein@Home data has been sifting through the data from the gravitational wave detectors for signals from unknown, rapidly rotating neutron stars. Since 2009, Einstein@Home has also been focussing on the search for signals from radio pulsars in the measurement data of the Arecibo Observatory in Puerto Rico and the Parkes Observatory in Australia. After the first discovery of a radio pulsar using this method in August 2010, the global computer network has fished out over 40 as yet unknown radio pulsars from the data. Moreover, since 2011 gamma pulsars are being searched for with Einstein@Home in the data from the gamma satellite Fermi. The search is based on an extremely successful analysis method that, with the AEI computer cluster ATLAS, helped the scientists already at the end of 2011 to detect nine new gamma pulsars which had remained undetected despite previous searches.
The Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) is the world’s biggest research institute that is dedicated to research related to the general theory of relativity. At the two Institute locations, Potsdam and Hannover, research is conducted in the areas of astrophysics, theoretical physics, data analysis, mathematics and experimental aspects of detector development. The AEI in Hannover is a collaborative facility of the Max Planck Society and Leibniz Universität Hannover. In cooperation with British partners, the Institute operates the gravitational wave detector GEO600 in Ruthe near Hannover. It is a partner in the American LIGO Project and plays an important role in the analysis of the data from all interferometric gravitational wave detectors, including the Virgo detector in Italy. The software that is used for the Einstein@Home search for pulsars was developed at the AEI Hannover.