harry potter time travel device Time travel is the concept of moving between different points in time in a manner analogous to moving between different points in space. Time travel could hypothetically involve moving backward in time to a moment earlier than the starting point, or forward to the future of that point without the need for the traveler to experience the intervening period (at least not at the normal rate). Time travel can form the central theme of a book or it can simply be a plot device to drive a story. Time travel in fiction can ignore the possible effects of the time travelers actions or it can explote its repercussions (ie: paradoxes)..

fundamental concepts in programming languages This best-selling book, now in its fourth edition, provides a wide-ranging and in-depth discussion of programming language concepts. As in previous editions, the author describes fundamental concepts of programming languages by presenting design issues of the various language constructs, examining the design choices for these constructs in a few common languages, and critically comparing the design alternatives. The book covers the most widely used methods of syntax description and introduces the most common approaches to describing the semantics of programming languages. Discussions of implementation methods and issues are integrated throughout the book..

is flight a true story Writer Rinker Buck looks back more than 30 years to a summer when he and his brother, at ages 15 and 17 respectively, became the youngest duo to fly across America, from New Jersey to California. Having grown up in an aviation family, the two boys bought an old Piper Cub, restored it themselves, and set out on the grand journey. Buck is a great storyteller, and once you get airborne with the boys you find yourself absorbed in a story of adventure and family drama. And Flight of Passage is also an affecting look back to the summer of 1966, when the times seemed much less cynical and adventures much more enjoyable..