دانلود کتاب Back to Astronomy Cafe

How fast does gravity travel? When will the sun go nova? Who invented the light year? Will we ever travel to the stars? These are just some of the unusual and popular questions NASA astronomer Sten Odenwald answers in Back to the Astronomy Caf?, based on his award-winning website "for the astronomically disadvantaged." Since his acclaimed earlier book The Astronomy Caf? published in 1998, the space community has been turned on its head with entirely new discoveries: ion propulsion, dark matter, gravity and magnetic reversals, the Cosmic Dark Ages, and over 100 new planets. In the all-new Back to the Astronomy Caf?, Odenwald answers the latest and most-asked questions relating to these recent discoveries. His highly personal and authoritative style makes understanding the cosmos less intimidating, exciting, and fun.Since he opened his website "The Astronomy Caf?" in 1995, Odenwald has answered over 50,000 e-mailed questions. His individual answers have been downloaded over 7.5 million times, making him the most sought-after "answer man" for astronomy in human history.