Readers, please enjoy this guest blog post by Shawn Martin Scanlon, author of Everything You Want to Know About Magick (But Were Afraid to Ask). In 1952, Ray Bradbury wrote a short story about time travel. This classic story, one of the most re-published science fiction stories of all time, deals with a man of the future who takes a time travel safari tour to prehistoric times. His goal is to shoot a T-Rex, but he chickens out and runs back to the time machine when the time comes to kill the great dinosaur. Running back to the time machine he steps off the walkway, which he was explicitly warned not to do, where he inadvertently kills a single butterfly. When he returns to his own time,