Where will you be when the world runs out of helium?

It’s surprising how many scientists and nonscientists alike are oblivious of the pending helium shortage. But it is a fact—we will run out of helium. According to the Committee on the Impact of Selling the Federal Helium Reserve, formed from members of the Board on Physics and Astronomy and the National Materials Advisory Board of the National Research Council, the question is when, not if, this will happen. Conservative estimates of the helium remaining indicate that the U.S. private reserves may run out by 2015, assuming the rate of helium consumption stays constant at the 1998 rate (1). Obviously, a continued increase in helium demand could significantly advance the date when the world’s supply becomes critical.

Many people might say that their lives are not greatly influenced by the available helium supply, but the loss of this unique resource is not likely to go unnoticed. Helium, which primarily exists as the 4He isotope, is a gas under standard temperature and pressure conditions. The low density of this gas has uses ranging from circumnavigating the world in a Rozier balloon to upper atmosphere probes to festive party balloons.

Liquid helium displays very unusual properties. Helium becomes liquid when it is cooled below 4.2 K (–269 °C). When cooled to even lower temperatures,