Ant writes "ABC News report that astronauts on spacewalks will never, ever be able to whistle while they work in space. Former NASA astronaut, Dan Barry has seven hours of spacewalking time to his credit. He tried whistling during his spacewalk on STS-96 in May 1999. "It wasn't something I hadn't planned — I thought of it on the fly. It turned out that it didn't work." he said. "You can't whistle because the air pressure in the suit is only 4.3 [pounds per square inch], and normal atmospheric pressure is 14.7 psi, so there are not enough air molecules blowing by your lips to make a sound," he said. Seen on Blue's News."