But, that astronomer argues, the flare can’t account for all the extra light. So he still thinks the dust-ring theory might hold up.

For people who can’t avoid lost sleep, scientists still don’t have a nutritional way to help them heal, Smith says. If you want to heal faster, your best bet for now is to get more “vitamin Z.”

Why didn’t nutrition help healing time? Smith can think of a few possibilities. The healthy drinks may have helped a little — just not enough to show up clearly in the relatively small numbers of men and women tested here. There was also a big difference in healing time between individual participants, which could have made it harder to see a small effect due to nutrition.

Sleep expert Clete Kushida didn’t find the results all that surprising.

“It’s a tour de force of experimental demonstration,” says Oleg Godin.

Still, he says, “I’m less impressed by the suggestions and implications about its uses.” He describes them as mostly “wishful thinking.”

The device is not yet ready for prime time, its developers note. For instance, it doesn’t work on sound that arrives at the device from an angle. On the surface of a lake or ocean, therefore, it would transmit sounds only from the small area directly below it. The device also works for only a small range of sounds. Those with a higher or lower pitch would still reflect off the underside of it instead of passing through the water’s surface.