[Guille]

Originally Posted by volantis http://www.sciam.com/article.cfm?articleID=000ADA62-D854-137C-962A83414B7F0000&ref=sciam&chanID=sa006 Scientific American: An ECHO of Black Holes [ PHYSICS ] Sound waves in a fluid behave uncannily like light waves in space. Black holes even have acoustic counterparts. Could spacetime literally be a kind of fluid, like the ether of pre-Einsteinian physics? The above article is a front cover story in Scientific American that questions Special Relativity and suggests evidence for an Aether. Dave

Spacetime is a fluid, of course it is: the fluid by which the objects can interact.

And that is the exact difference between the physical and the mental existence: the first has objects, properties and fluids, that is all, but the second only has objects and properties. Minds can't interact because they don't have a fluid. The only way minds can interact is by a physical medium.