For centuries, scientists have imagined a vacuum as the ultimate form of nothingness—a region completely devoid of matter, particles and activity. But modern physics has long suggested that the vacuum of space may be far stranger than it appears. Now, astronomers studying one of the most extreme objects in the universe may have found the strongest evidence yet that empty space can actually change the way light travels. The discovery centers on a bizarre quantum phenomenon known as vacuum birefringence,...Click for full post