“Or another candidate is an even more exotic particle called the axion.”

“In 2006 a possible sighting was reported of a predicted but previously unobserved fundamental particle called the axion.”

“Named after a popular laundry detergent, the axion would blot out the stain.”

“Unlike photons, axions would pass directly through the wall to the other side.”

“Since axions can be produced from light, the sun and other stars should generate them copiously.”

“Since the wall is opaque, it should block the x-rays completely. However, x-rays are high-energy photons, so if PVLAS is producing axions, some of these photons should also turn into axions along the way.”