Main Question or Discussion Point
I've seen the images of a large mass creating a dent in the space-time fabric, and I've read the analogies as how the objects "fall in" towards the dent, causing gravity. But this is just an analogy, not an explanation. The objects would only fall in if there was gravity, so this cannot be an explanation; you can't use the term you're defining in the definition. So what actually causes the gravity?