[ahayes]

In a sealed vaccuum container, you introduce three sealed bottles. Two contain vaccuums themselves, the third is full of gas. You open all the bottles and the gas from one rapidly fills the bigger container. Tah-dah! You cannot tell which bottle the gas came from, so the arrow of time is irreversible, etc.

Try reading the labels. ;-)

[VadeRetro]

Or just try REMEMBERING, I know!