"I haven't seen any hard scientific evidence that it's not a placebo effect. There hasn't been enough real research on it yet to say that it's doing anything," said Katherine Creath, research professor of optical sciences and medicine at the University of Arizona.
"But whether or not it's the placebo effect or the light, I don't think that matters as long as people feel like they are having a positive effect, then it's worth it to them to do it," she added.
The Chapins are eager for researchers to use the site to determine if moonlight does have any demonstrable applications in areas including medicine, plant biology and certain industrial processes. They also welcome visits by skeptics to the site.
Meanwhile, visitors continue trek out to the imposing installation and listen to ambient music as they wait for a break in the clouds to step into the moonlight. For them, it is a very enjoyable experience in itself.
"You feel almost like you are in heaven," said Aranka Toniatti, a cancer patient who has driven from Colorado twice to stand in the moonlight. "It's a gorgeous feeling."
