Brrrr, that's cold...

Tuesday night's NOVA broadcast can help to put the cold Wisconsin winters into an interesting perspective. Airing at 7 is the first part of "Absolute Zero." The show, which will conclude next week Tuesday, explores a scientific race to reach the coldest temperatures physically possible.

People have been trying create artificial coldness since a court magician for England's King James I invented a rudimentary form of air conditioning. Now scientists aim for an even chillier goal of absolute zero -- -273 degrees Celsius.

Just how cold is that? And how does absolute zero stack up to what Wisconsin folks consider to be winter's bitterest cold? See this interactive tool to find out. And, if cold isn't quite your thing, take a look at the warmer, opposite scale.

And if the program has you intrigued to learn more about the scientists aiming to reach absolute zero, visit the project's official Web site, where you will find further information, educator's materials, and even temperature crosswords and sodoku puzzles to keep you busy.