Then science happened, and shit got cray-cray.
I searched the reliable online dictionaries but I can not find any definition. Though I found meaning of cray:
a short form of "crazy" used by some young people
but I still can not understand the meaning of the phrase excactly.
So, could you please explain it to me?
The fuller text:
Everything revolved around the Church (or synagogue or temple or mosque or whatever). Priests and holy men were the arbiters of social life because they were the arbiters of hope. They were the only ones who could tell you what God wanted, and God was the only one who could promise any salvation or a better future. Therefore, these holy men dictated everything that was of value in society. Then science happened, and shit got cray-cray. Microscopes and printing presses and internal combustion engines and cotton gins and thermometers and, finally, some goddamn medicine that actually worked. Suddenly, life got better. More important, you could see life getting better. People used better tools, had access to more food, were healthier, and made more money. Finally, you could look back ten years and say, “Whoa! Can you believe we used to live like that?”