Stephen Ornes via Astronomy Last spring, a report from the world's largest neutrino telescope — a sprawling grid of detectors woven into Antarctica's ice — coincided with a blaze of hyperbolic headlines. They teased the possibility of an anti-universe where, from our point of view, time runs backward and the Big Bang represents an end, not a beginning. While it's too soon to start searching for our reverse-aging, other-handed doppelgängers, physicists are still wrestling with strange signals coming in from space that, to date, have defied easy explanation. The signals were flagged by a NASA-funded collection of horn radio antennas held aloft over Antarctica by a giant balloon. The device, called the Antarctic Impulsive Transient Antenna (ANITA), picks up radio signals produced when high-energy particles coming from deep space encounter our atmosphere. Some waves skim the Earth before they hit ANITA, and others bounce off the ice. ANITA can tell the difference. During its first float in