I don't understand how astrology works?

Where is the science behind it? The evidence? I'm just being skeptical here although I haven't written it out completely, but I'm beginning to second guess it. After all, if I think critically, my chart barely even fits me, it can apply to anyone that I know but mind you I'm no expert at astrology so perhaps it's simply that I'm no good at analyzing it. But where do the formulas, so to speak, come from. How was a square aspect determined or a sextile and so forth? How was synastry developed? How does a planet affect us at birth? I personally was born in a closed environment, Venus, my ruling planet could not have possibly magically endowed me with certain traits unless it's gravitational pull was that powerful but even Earth itself is far more powerful yet it has no effect on me. What would happen if I were born on the moon instead? Would Earth substitute as my Moon sign? Just my skeptical mind here at work, a skeptical mind that I can vouch for when my chart cannot. Regardless, I still find it all interesting and have just recently happened upon it so you will forgive any unintentional offenses. I simply ask out of curiosity, like I said I didn't write it out...yet. I'm a person who only seeks the origin of it all and the science behind how it works. I would not wish to believe an old wives' tale until it's proven time and time again to be truth.