I like Expanding Earth (EE) theory. RA Wilson liked it too (although it is impossible to tell if he was serious or joking, eh?) that's where I learned about it.
That matter is spontaneously created is a proven science. It is instantly destroyed by the anti-matter that is created alongside it though. But suppose at the bottom of a gravity well (the core of a planet for example) the matter remained & the anti-matter went somewhere else? That planet or sun would increase in mass! And volume too.

So over billions of years the Earth, sun and every large thing has been increasing in mass. The orbits would stay the same, probably, even as gravity increased. Growing from the inside explains a few things that tectonic theory glazes over. It also explains why dinosaurs were huge: gravity was weaker back then. Why are rotation is slowing: increasing mass will do that.
It's just a theory though, very hard to prove!