To all the people downvoting: “Law of Attraction” is not a lay person’s way of saying “Law of Gravity”.
It’s the belief online that “if I give off good vibes, good vibes will be attracted back to me. You know, because everything is, like, made up of vibrating strings, and stuff” (that last bit is just the connection to String theory OP mentioned)
OP is not endorsing these beliefs, just observing them.
I’ve been thinking it’s just a rebranding of the idea of karma, which is old as dirt. “The Law of Attraction” is just the way I’ve seen it discussed online in its most recent manifestation (pun intended)