People still know very little really, over the billions of years the solar systems and Planets have been around yet humans have only been here a short time in comaprrison, I believe there is much more we dont know than what we do know, It is said everything has a beginning and an end, Lets consider Space & time.. when did time start? where does space start and where does it end ?  what is there before Space and after space? Whats there - is it suddenly solid matter, Nothingness or is it a loop right back to where it started? If it truns to nothingness there still has to be something! It can not just be nothing. What is nothing!? All dimensions condidered there is no way it can turn into nothingness. So we understand basically nothing. We are but spec's