While astronomers are largely baffled by the question of how the universe began, they should probably hurry up and figure it out. In the far future, most of the evidence will be long gone, a new study suggests. Though future astronomers will likely have the benefit of advanced technology and a more sophisticated understanding of physics, they won't be able to take advantage of the last vestiges of evidence left over from the Big Bang. The trace signals from the explosion that set the universe in motion 13.7 billion years ago will likely be all gone 1 trillion years from...