Presenters:   Elio Caccavale   Dawn Danby   Olaf Dreyer   Juan Geuer   Rob Godman   John Hatch   Kenneth A. Huff   Mantissa   Miroslav Lovric   Sally McKay   Eric Raymond   S. David Rosner   Mariano Sardón   Frederic P. Schuller   Krister Shalm   Lydia Sharman &   Stephen Morris   Donald Spector   Joseph Thywissen   Marion Tränkle   Koala Yip Symposium Stars in the laboratory by S. David Rosner University of Western Ontario http://www.physics.uwo.ca/~rosner/ For most people, looking at stars does not evoke images of scientists at work in basement laboratories shining lasers at atoms. In fact the phrase 'laboratory astrophysics' may sound a little like 'organic Twinkies'. Nevertheless, astrophysicists who really do observe stars with telescopes want to understand how those stars formed in the first place, what elements they are made of, and how they will evolve in time. They do this primarily by looking at the light coming from the surface of the star. In its array of colours and the brightness of each colour (information collectively known as its 'spectrum'), this light reveals the makeup of the star, and can even tell us something about what is going on deep inside it, where we can never look directly. None of the information contained in the starlight could be interpreted without extensive laboratory measurements to characterize each atom in the periodic table. In our basement lab, we shine laser light at beams of atoms to find out, for example, what specific colours of light a particular atom absorbs -- its unique signature that will identify it in the starlight. Without these laboratory data, we would still be moved by the beauty of the night sky and the wonderful Hubble images of distant galaxies, but we could not probe beyond this beauty to satisfy our curiosity about how our universe works. Biography: Dr. S. David Rosner has been studying properties of atoms and molecules from his graduate student days at Harvard University to the present, mainly at the University of Western Ontario in London. His other interests are classical music, piano, and gardening. He is married to the visual artist, Thelma Rosner.   Page Top Copyright © 2004 Subtle Technologies Festival