The day is finally here! My new book, The Universe in the Rearview Mirror, is being released today! Many of the topics in the book were prompted by all of the great questions from the io9 community, and I wanted to thank you again by offering you this free excerpt.
Now you can ask a physicist your nagging questions about the inner workings of the cosmos. This twice-monthly column will, at very least, allow you to sound smart at cocktail parties.
Noted time-travel expert Dave Goldberg, a physics professor at Drexel University, just saw Hot Tub Time Machine and was - disturbed. Here he explains the "egregious number of inviolable paradoxes" in the film, in an open letter to its creators.