"God hypothesis" has been around for thousands of years
And how is that a good thing? It's a hypothesis coming from times when humanity was basically scientifically illiterate by today's standards. We've looked at like... 99.83% of the things it attempts to explain and found the natural explanations behind all of those things. You're clinging to the 0.17% that we haven't (fully) explained yet. I mean imagine that.. we as a species have pushed our scientific understanding of the universe so far, that the "common logic" that we've evolved with is no longer sufficient to fully understand what lies beyond the boundaries that we're exploring, but the greatest minds of our time are still pushing us forward and slowly but sure pealing away the layers of a world that works by different rules.
And you're reading a book that was written by ancient peasants.
and it gave us morals and philosophy. Try to imagine living in the world without morality. The world without morals is animal and practically unbearable or its a world where the technologicaly advanced animals have destroyed themselves and their environment and turned everything into (radioactive) desert. I dont know anything about string theory but if it doesnt explains morals and human psychology it explains only a portion of reality leaving the most important aside in which case it may serve as a nice temporary consolation for an atheist but thats likely all.
No, String Theory does indeed not explain morality - a bummer for something that runs under the banner of the "Theory for everything", isn't it? 8)
But thankfully, we have other working theories for where morality came from. The basic concepts are not even hard to imagine or understand. You take the social behaviors that are inherent to any animal (especially pack animals like humans), add a mind that has a sense of their place within their "society", and what consequences their actions will have on others and themselves, and there you go, the beginnings of morality.
And yes, what we think is moral is subjective in this framework, and changes over time. That's a good thing, because we can revise problems. Were morality objective and derived from the Bible, we would forever be stuck with the many immoral things in the moral framework of the bible, such as homosexuality being a sin, and being raped but not screaming loud enough meaning that you should be stoned. What a terrible book.