When can I travel upside down Author:The Southwestern Company Learn about Science. Do you know snowballs melt in your hand, or what is invisible but covers the Earth, or if ghosts make spooky noises at night? Cartoons will give young children hours of laughter. Different features will keep their minds busy. Sound travels faster than a fighter plane-bridges get longer when it is hot-the first computers wer... more »e as big as rooms. Whish statement is trus, which is falst? Do you know?« less