One theory I like since their "clocks are stopped" zero time running in their reference frame then length contraction should be infinite. No time or distance in a photon's reference frame (from the photon's point of view). Solves the "spooky action at a distance problem" between two entangled photons because there is no distance between them in their reference frame.
Waiting for the better educated to throw rocks at me ;^)
It's what the universe would look like to us if we could approach the speed of light arbitrarily close. You could go anywhere in the universe in the blink of an eye, from your point of view. But to an outside observer stuck on Pluto, say, (the earth probably won't be here), it'll take you tens of billions of years.
(No, everybody, I'm not a physicist. So if I've got it wrong, pipe in and straighten me out! I'd appreciate it.)