iPads can help students grasp tough scientific concepts like astronomical scale by letting them explore 3-D simulations of the universe, U.S. researchers say. A study by researchers at the Harvard-Smithsonian Center for Astrophysics shows students grasp the unimaginable emptiness of space more effectively when they use iPads to explore a 3-D view of space, compared to traditional classroom instruction. "These devices offer students opportunities to do things that are otherwise impossible in traditional classroom environments," study leader Matthew H. Schneps said in a center release Wednesday. "These devices let students manipulate virtual objects using natural hand gestures, and this appears to stimulate experiences that lead to stronger learning." The researchers looked at gains in learning among 152 high-school students who used iPads to explore simulated space, and compared them to 1,184 students who used more traditional instructional approaches. "While it may seem obvious that hands-on use of computer simulations that accurately portray scale would lead to better understanding," study co-author Philip Sadler said, "we don't generally teach that way." Traditional classroom instruction makes use of models and drawings that distort the scale of the universe, "and this leads to misconceptions," he said. Students similarly struggle with concepts of scale when learning ideas in biology, chemistry, physics, and geology, the researchers said, which suggests tablet-based simulations may be beneficial for teaching concepts in many other scientific fields beyond astronomy. The study has been published in the journal Computers and Education.