Warning: Undefined array key "visitor_referer_type" in /var/www/vhosts/wordinf.com/core/app/libraries/Core.php on line 98 Lawrence M. Krauss - [W]e can weigh systems of...
[W]e can weigh systems of galaxies. The largest bound objects in the universe are called clusters of galaxies. They're maybe ten million light years across. ...We weigh them using gravity because Einstein told us that mass curves space, and we can... use those large clusters as lenses-if there's a light source behind a cluster the light from it can come around and be lensed... and we've weighed these systems and we've found that there's only 30% of the mass needed to make a flat universe... Theorists like me knew that the universe was flat, because it's the only mathematically beautiful universe... but here these observers kept coming up with only 30% of the stuff needed... But then, what we've discovered... is that the universe actually is flat and the rest of the 70% of the energy of the flat universe comes from the energy of nothing.