Einstein's theory of relativity does a fantastic job for explaining big things. Quantum mechanics is fantastic for the other end of the spectrum - for small things.
Brian GreenePhysicists have come to realize that mathematics, when used with sufficient care, is a proven pathway to truth.
Brian GreeneHow can a speck of a universe be physically identical to the great expanse we view in the heavens above?
Brian GreeneThe revelation we've come to is that we can trust our memories of a past with lower, not higher, entropy only if the big bang - the process, event, or happening that brought the universe into existence - started off the universe in an extraordinarily special, highly ordered state of low entropy.
Brian Greene