MONDAY 22nd February 1999 [INLINE] [INLINE] * Online * BBC Homepage * BBC Site Map [INLINE] Search * [INLINE] Horizon [INLINE] Home [INLINE] Archive [INLINE] Contact [INLINE] [INLINE] Other BBC Science Sites [INLINE] Tomorrow's World [INLINE] Royal Institution Christmas Lectures [INLINE] * Services * Web Guide * TV Listings * Radio Listings * Online Channel [INLINE] BBC Ticker [INLINE] Feedback * Help * Horizon navigation bar This week on Horizon From Here to Infinity Thursday, 28th January 1999 at 9.30pm [INLINE] In a story named "breakthrough of the year" in science journals, Horizon investigates the latest discovery about the fate of our universe. Until now, we have not known whether the universe would expand to infinity or contract in a cosmic crunch. From Here to Infinity looks at how scientists claim they have now found the answer and how, in the process, they have also discovered something else - something quite unexpected: a mysterious energy in the universe, an energy that had never been seen before. Its a discovery that challenges our understanding of the fundamental laws of physics. Every few seconds, a dying star explodes somewhere in the universe. These stellar explosions, or supernovae, are short lived and can only be seen for a few weeks. They are so random, and so fleeting in the vastness of space, that scientists have had great difficulty catching sight of them. But they would prove to be a vital tool for examining the cosmos. If enough of these distant supernovae could be found, and their various speeds calculated and compared, then scientists could find out how the universe would end. [INLINE] An international team of scientists, headed by a young physicist, Saul Perlmutter, believe they have perfected a technique for tracking these very rare and distant supernovae. They take a snap shot of the sky, capturing thousands of galaxies in a single image, then return to the telescopes a few weeks later and photograph exactly the same patch of sky. By comparing these two sets of images they can search for a new spot of light which has appeared during the few weeks gap - a potential supernova. But they have to be quick and study these stellar explosions in detail, before their light fades from the universe forever. Many in the scientific community were sceptical that the team could find enough distant supernovae to find out the fate of the universe. Unperturbed and armed with powerful equipment Saul Perlmutter and his team demonstrated it was possible to catch sight of these very distant stars on demand, whenever they went to their telescopes. The astronomical community was buzzing with excitement and soon a rival team of supernovae hunters joined the chase. Astronomers knew if they could find enough of these exploding stars they could answer one of the biggest questions in cosmology. [INLINE] For years scientists believed that the universe was slowing in its expansion due to the powerful force of gravity tugging on it. But as each team aimed their telescopes at stars exploding half way across the universe something quite extraordinary was coming to light. The distant supernovae were behaving in a way no-one had ever imagined. They were 20% dimmer than expected, therefore further away than they should have been according to the known laws of gravity. This could only mean one thing. The universe was not slowing down; it was speeding up. It was accelerating and it was accelerating quickly. Something extraordinary and unexpected had to be causing this. What cosmologists discovered was that there was a strange unknown energy pushing against the force of gravity, flinging the universe apart faster and faster. Programme transcript Further Information The Supernova Cosmology Project Saul Perlmutter Greg Aldering Gerson Goldhaber Robert A. Knop Peter Nugent Susana Deustua Don E. Groom Matthew Y. Kim Julia C. Lee Carl R. Pennypacker Robert Quimby Institute for Nuclear and Particle Astrophysics E. O. Lawrence Berkeley National Laboratory Berkeley California 94720 USA Dr. Saul Perlmutter Email: saul@LBL.gov Richard S. Ellis Mike Irwin Richard G. McMahon Institute of Astronomy Cambridge England Isobel M. Hook Institute for Astronomy Royal Observatory Edinburgh Scotland Contact: Prof. Richard Ellis Email: rse@ast.cam.ac.uk Dr. Ariel Goobar Department of Physics University of Stockholm Stockholm Sweden Email: ariel@physto.se Dr. Reynald Pain Sebastien Fabbro LPNHE CNRS-IN2P3 & University of Paris VI & VII Paris France Alex G. Kim PCC CNRS-IN2P3 & College de France Paris France Contact: Dr. Reynald Pain Email: rpain@lpnax1.in2p3.fr Chris Lidman European Southern Observatory La Silla Chile Pilar Ruiz-Lapuente Department of Astronomy University of Barcelona Barcelona Spain Nic Walton Isaac Newton Group La Palma Spain Brad Schaefer Department of Astronomy Yale University New Haven Connecticut USA Brian J. Boyle Anglo-Australian Observatory Sydney Australia Andrew S. Fruchter Nino Panagia Space Telescope Science Institute Baltimore Maryland USA Space Sciences Department European Space Agency Heidi J. M. Newberg Fermi National Laboratory Batavia Illinois 60510-0500 USA Warrick J. Couch University of New South Wales Sydney Australia The High Z Supernova Search team Brian Schmidt Team Leader Australian National University Mt Stromlo Observatory Australia Email: mailto:brian@mso.anu.edu.au Alex V. Filippenko Department of Astronomy University of California Berkeley CA USA Email: alex@wormhole.berkeley.edu Adam Riess Department of Astronomy University of California Berkely CA USA Email: ariess@salmo.berkeley.edu Robert Kirshner Harvard Smithsonian Centre Boston Massachusetts USA Email: kirshner@cfa.harvard.edu External Links: The Supernova Cosmology Project http://www-supernova.lbl.gov European Space Agency http://www.esrin.esa.it/ Australian National University http://online.anu.edu.au/ University of California, Berkley http://www.berkeley.edu/ The LBNL Institute for Nuclear and Particle Astrophysics http://stokstad.lbl.gov/ Astronomy and Astrophysics at the University of California http://ucowww.ucsc.edu/uceduc.html Harvard Smithsonian Centre http://cfa-www.harvard.edu/cfa-home.html Cambridge Astronomy and the Institute of Astronomy http://www.ast.cam.ac.uk/ The Royal Observatory, Edinburgh http://www.roe.ac.uk/index.html University of Stockholm http://www.su.se/english/ University of Barcelona (Catalan) http://www.ub.es/dhtml/index.htm Isaac Newton Group http://www.ast.cam.ac.uk/ING/PR/leaflet.html Yale University http://www.yale.edu/ The Anglo-Australian Observatory http://www.aao.gov.au/ Space Telescope Science Institute http://www.stsci.edu/stsci/index.html Fermilab http://www.fnal.gov/ University of New South Wales http://www.unsw.edu.au/ The BBC is not responsible for the content of external internet sites.