I vaguely remember learning somewhere somehow sometime that gravity doesn't just dent space-time inwards, it also swirls space-time just a bit. I remember learning this because it was visually depicted using honey. However, now that I try to find out more, I can't seem to find any reference to this swirling effect at all, either positive or negative. It's simply never mentioned. Is it actually true? And if so, why? Why does gravity swirl?