They are befooling ignorant people. There is nor their could be antimatter. Read & circulate http://phys.org/news/2013-09-gravity-variations-bigger-previously-thought.html#jCp . This confirms the alternative theory of gravity. The very space-time concept, on which theories of relativity are founded, has been mathematically, theoretically & experimentally proved as baseless and openly challenged on the basis of published scientific articles. Since the very space-time concept has been proved as baseless the question of curvature of space-time being correct does not arise. Gravity has been shown to be an electromagnetic force as foreseen by Maxwell due to the curl/vortices of aether (the electric dipoles) in the published article 'Revised Foundation of Theory of Everything: Non-living Things & Living Things' (www.indjst.org; Sep 2010) Revised version of this article is available on vixra & General Science Journal in my profile. Standing open challenge could be seen at http://www.worldsci.org/php/index.php?tab0=Abstracts&tab1=Display&id=6476&tab=2 and http://gsjournal.net/Science-Journals/Essays/View/4018.