Has 'dark fluid' saved Earth from oblivion?
By Zeeya Merali FRESH battle lines are being drawn in the debate over whether dark matter is needed to explain the structure of galaxies. Those physicists who would like to throw out dark matter in favour of a controversial new form of gravity are facing one of their biggest challenges yet. It seems that if their theory is valid, the Earth should have been swallowed up long ago by black holes that would regularly appear in our solar system. Dark matter’s opponents are not ready to give up just yet,