Actually it doesn't, because the Big Bang Theory just explains the process AFTER the universe already began.
Also, you are confusing a black hole's singularity and what astrophysicists call the initial singularity, or the big bang's singularity, as being basically the same thing........when they are not. With a black hole's singularity, gravity is so strong, because there's an unbelievable amount of mass confined to an extremely small area of space, that space-time breaks down (the math "proves" this one). So technically, there's no gravity here either because you need space-time for the realization of said gravity.
Where as with the initial singularity, the concept "sounds" kind of similar because all of the matter in the universe was packed into the space smaller than an atom ~13.7 Billion years ago, but that's it. The extent of our knowledge stops right at the point the big bang begins, because physics and math as we know it didn't come about till AFTER the big bang occurred, along with our concept of space-time..............so as of now, we have NO clue what was going on BEFORE the big bang.
This link helps explain the differences between the two "singularities".
Actually, we know exactly where the Earth came from and how it was born. Our Solar System, the Earth and everything else, came from EGG's (Evaporating Gaseous Globules) deep within a nebula ~4.7 Billion years ago (~9 Billion years after the Big Bang). How do we know this is how it happened? Because we are seeing this happening all through out the Milky Way, most noticeably in the Eagle Nebula (also known as the 'Pillars of Creation') and the Orion Nebula.
The Stages of Star Birth:
Eagle Nebula:
Orion Nebula:
Evaporating Gaseous Globules (Eagle Nebula):
Evaporating Gaseous Globules (Orion Nebula):
Protoplanetary Disks in a Nebula:
Who knew DNA and Genetics was circumstantial evidence?