floor is now home to meandering train tracks. All manner of minerals are mined to the benefit of mankind and the lost city of Atlantis (if real) is exposed. All ocean life becomes extinct and the earth's climate undergoes dramatic, yet positive, change. IF Science Reached the Earth's Core (Oct. 1938) – Neutronium allows humans to penetrate to the earth's core, which is not molten, but a gravity-free haven where "vacationers enjoy the thrill of being weightless." IF —! is credited with the first use of the phrase "zero-gravity," a science fiction mainstay, where "Space Travel is solved. Starting at the zero-gravity of Earth's core, accumulative acceleration is easily built up in a four-thousand-mile tube. The ship's reach Earth's surface where gravitation !|is strongest with an appreciable velocity that makes the take-off a simple process of continuation!" IF Earth's Axis Shifted (April 1940) – An astronomical telescope points towards the night sky revealing that the planets have aligned and caused the earth's axis to shift. Tidal waves sweep cities away. North America in now a tropic zone, while Siberia is balmy and Antarctica swarms with immigrants wanting to harvest the now accessible coal and metal. "Next Issue: IF the World were Ruled by Intelligent Robots!" Contents and reception When Air Wonder Stories was launched in the middle of 1929 there were already pulp magazines such as Sky Birds and Flying Aces which focused on aerial adventures. Gernsback's first editorial dismissed these as being of the "purely 'Wild West'-world war adventure-sky busting type". By contrast, Gernsback said he planned to fill Air Wonder solely with "flying stories of the future, strictly along scientific-mechanical-technical lines, full of adventure, exploration and achievement." Non-fiction material on aviation was printed, including quizzes, short popular articles, and book reviews. The letters column made it clear that the readership comprised more science fiction fans than aviation fans, and Gernsback later commented that the overlap with Science Wonder readers was 90% (a figure that presumably referred only to the subscription base, not to newsstand sales). Gernsback frequently ran reader contests, one of which, announced in the February 1930 issue of Air Wonder Stories, asked for a slogan for the magazine. John Wyndham, later to become famous as the author of The Day of the Triffids, won with "Future Flying Fiction", submitted under his real name of John Beynon Harris. Later that year a contest in Science Wonder Quarterly