Not really sure I have the right forum for this but here goes. This is for self education and nothing more. When I left school (25 years ago) I thought I understood physics. Since that time physics seems to have exploded. Particles have got smaller, string theory has appeared in the public eye, dimensions seem to be popping up everywhere. Most of the mass and energy in the universe has disappeared. ie. dark matter and energy. Are we as a species anywhere close to getting the complete solution ? Is there a calculation that will take the current mass/energy thought to be present in the universe and divide it up in to the current number of dimensions according to string theory, super string theory etc. What are stings ? Are there more particles to be discovered ? Is gravity weaker than it should be ? If so, do we know why ? What should I read to start to get an over view for a non technical Joe. Thanks.