Our mind and consciousness does nothing but just merges what our sense organs sense. Quoting JK Rowling who said it in Harry Potter and the Deathly Hallows from the mouth of Dumbledore, "Of course it is happening inside your head, Harry, but why on earth should that mean that it is not real?" Everything we think that we know, we imagine and are seeing are just formed in our brain from scratches of information our sense organs sense. Even Einstein got his famous equation E=mc^2 from his dreams. So brilliant are our minds!
Well, coming back from Philosophy, we still don't know if there are 12 dimensions. The String Theory isn't proved yet. It is still a theory like Relativity. We do not yet have the M-theory. And also, @Truthseeker007
, we are focused on the first four, not only on the third. Special Relativity said that nothing can move at the speed of light, but if you think paradoxically, you'll get that you can't move at the speed of light but less or more than that. It's due to the theory of acceleration, that we can't move more than the speed of light. But hey, some parts of space is expanding more than the speed of light. So, we don't we know everything.