Dr. Roberts reviews an article by Alan Dressler, astronomer at the Observatories of the Carnegie Institution, entitled "In the grip of the great attractor: probing the puzzling masses that move galaxies." Walter Orr Roberts informal series, "Provocations." Each issue consists of provocative comme... Show moreDr. Roberts reviews an article by Alan Dressler, astronomer at the Observatories of the Carnegie Institution, entitled "In the grip of the great attractor: probing the puzzling masses that move galaxies." Walter Orr Roberts informal series, "Provocations." Each issue consists of provocative comments related to scientific issues that mostly focus on weather, climate, the sun, or near space, with the aim of creating a forum for discussion. Show less