A few weeks ago my work flew me out to Chicago for a meeting with Kmart. On the plane to Chicago I sat next to a girl that appeared to be about 14 years old. She watched her ipod video the whole time while I read a book. During the flight she opened up her bottled water and drank about half, capped it and set it on the floor next to her.
When we landed she picked up her bottle. She looked at the concaved bottle with a puzzled look. Then she squeezed the sides of the bottle to try and pop the sides back out to its original shape. With no luck she put the bottle in her lap.
Smirking, I told her that
“When we are in flight at 30,000 feet the atmospheric pressure is a lot less then it is on the ground. When you put the cap on your bottle you trapped a certain amount of air in the bottle and when we came back down the air inside the bottle is not sufficient to withstand the greater atmospheric pressure. The sides of the bottle get sucked in from the vacuum created.”
She looked at me as if I told her Paris Hilton scored a 1500 on her SAT. Realizing my intentional amusement at her expense was great than previously expected I told her. “All you have to do is open the bottle and the sides will pop back out.”
After seeing her face when she opened the bottle I thought that it couldn’t get any better but then she said, “They should really teach that in school.” To this day I laugh at this every time I think about it.