February 20, 2019 updates Posted on February 20, 2019June 28, 2020 by Doug Loss Breakthrough Propulsion Study https://www.centauri-dreams.org/2019/02/15/breakthrough-propulsion-study/ Stellar spectroscopy in the near-infrared with a laser frequency comb https://www.osapublishing.org/optica/abstract.cfm?uri=optica-6-2-233 Multiverse Predictions for Habitability: Number of Habitable Planets https://arxiv.org/abs/1902.06784 Tropical and Extratropical General Circulation with a Meridional Reversed Temperature Gradient as Expected in a High Obliquity Planet https://arxiv.org/abs/1902.06832 PDS 70: A transition disk sculpted by a single planet https://arxiv.org/abs/1902.07191