Magazine

Nonfiction Invisibility Cloaks

Cornell University Professor Alexander Gaeta and his team hid an event in time through cloaking with light beams. The research first published in early January 2012 in response to a cloak proposal from Professor Martin McCall of the Imperial College in London.

Researchers at other institutions have also made physical cloaking devices. In 2006, researchers at Duke University produced a doughnut-like object that partially hid microwaves from any object placed within it. Unlike the Cornell team’s product, such devices do not make objects vanish or entirely hide events.

Gaeta developed a split-time lens, which changes speeds of concurrent light beams going through a fiber optic tube to cloak an event within a gap. Basically, two beams of light begin traveling down the tube. Then, the first lens hits the beams and adjusts their wavelength so that one beam accelerates, moving ahead of the other. This creates a gap in time between beams. Working on the assumption supported by current research that space and time are equivalent, an event may be hidden in this gap. The beams then pass through another lens that adjusts their wavelengths, and therefore speeds, back to their initial levels. This may not lead to apparition, but could allow emergency messages to be inserted into signals without disturbing initial transmissions.