I'm not going to attempt to read that. Can you tell me, after they've stopped it, can they start it again? I mean re-start the same light they've stopped? And when it's stopped, what does it look like? If it's not moving, how is it still light? And don't I stop light every time I turn off the light switch at night?
OK, they're only half-serious questions, but to me a statement that someone has stopped light inside a crystal is basically meaningless.