Watching Stars Explode

Scientists have been watching a star explode again ... and again ... and again. The star really only exploded once, about 9 billion years ago on the other side of the universe. But, because light rays from the star were bent and magnified by a galaxy cluster between it and us, the supernova explosion has appeared in our skies four different times; in 1964, 1995, 2014, and now. This Sunday, we bring you stories about telescopes, outer space, and the foibles of time. 1. The Billion-Dollar Telescope Race How three groups are competing to make the first extremely large telescope. By Mark Anderson When Warner Brothers animators wanted to include cutting-edge astronomy in a 1952 Bugs Bunny cartoon they set a scene at an observatory that looks like Palomar Observatory in California. The then-newly unveiled Hale Telescope, stationed at Palomar, had a 5-meter-diameter mirror, the world’s largest. In 1989, when cartoonist Bill Watterson included a mention of the world’s largest telescope in a “Calvin and Hobbes” cartoon, he again set the action at Palomar. Although computers had grown a million times faster during those 38 years, and eight different particle colliders had been built and competed for their field’s top ranking, astronomy’s king of the hill stayed perched on its throne. READ MORE 2. Why Galactic Collisions Are So Beautiful By Amos Zeeberg According to the basic approximation, stars are formed by a stately, gradual process that belies the power it eventually unleashes. Within a great gas cloud, gravity slowly pulls together disparate tendrils into a core that grows ever denser. When the cloud’s mass is enough to overcome the gas’ internal pressure, its gravity suddenly collapses much more material into the relatively small core and begins to fuse hydrogen into helium. READ MORE 3. The Mystery of Time’s Arrow Past and future may not be what they seem. By Julian Barbour As conscious beings, we are constantly aware of the relentless march of time. You can make an egg into an omelet, but you can’t turn an omelet back into an egg. Dropped glasses shatter and do not reassemble themselves. Above all, we age and become decrepit; there is no return to youth. But this is a great scientific mystery. There is nothing in the form of the laws of nature at the fundamental microscopic level that distinguishes a direction of time. READ MORE Subscribe today and get your copy of the latest issue of Nautilus. It includes new features, some of our best online content, and pages of award-winning illustration. Join us on a journey of surprises.