Did an alien lightsail traverse our solar system in 2017?  Harvard University astronomer Avi Loeb thinks so.  In today’s episode, I welcome Loeb to discuss his bestselling book --- “Extraterrestrial:  The First Sign of Intelligent Life Beyond Earth.”  We chat about why he thinks this object, Oumuamua, is likely to be artificial and why the scientific community at large remains so unreceptive to progressive scientific thinking when it comes to the subject of extraterrestrial intelligence.