Lost and found in the universePosted: May 21, 2008
Space may not be so empty after all. Astronomers are reporting that they have discovered material forming a ‘backbone’ for the universe, along which the galaxies we can see are arrayed, and that this is a store house of regular baryonic matter (protons, neutrons & electrons making up familiar atoms).
Again, the way this study has been done is really clever. The scientists were looking at the light coming from stars and studying the way it was changed as it travelled towards Earth. Along the way, baryonic matter absorbed light at predicatble wavelengths in fairly consistent ways allowing the observers to draw very solid conclusions about the nature and quantity of the ‘stuff’ filling up space.
BTW, don’t confuse this stuff with dark matter. Baryons are attracted to the gravitational influence of dark matter to form the ‘cosmic web’ but that’s a whole ‘nother story…
(illustrations from Space Telescope Science Institute, STSI, at NASA)