Air Date: Week of June 9, 2000
Cynthia Graber reports on how sound waves can keep our food cold.
GRABER: Refrigeration has changed the way we eat. We can store food for long periods of time and ship it around the world. But it's come with a price. The chemicals used in refrigeration, chlorofluorocarbons, deplete the protective ozone layer. CFCs are being phased out, but the chemicals that are replacing them contribute to global warming. So scientists are looking at ways to refrigerate without chemicals. One option gathering increasing attention is sound. When sound waves are pushed through gases, the gases heat up as they compress, and when the gases expand they cool down. In a refrigerating system, a tube with thin plates of plastic can transfer the heating and cooling effects produced by sound waves. One end of the tube gets hot, the other end gets cool. Cool enough to keep food from spoiling. Scientists are now trying to make these sound fridges as energy-efficient as their chemical counterparts, and protect the atmosphere, too. And that's this week's technology update. I'm Cynthia Graber.
Living on Earth wants to hear from you!
P.O. Box 990007
Boston, MA, USA 02199
Newsletter [Click here]
Donate to Living on Earth!
Living on Earth is an independent media program and relies entirely on contributions from listeners and institutions supporting public service. Please donate now to preserve an independent environmental voice.
Sailors For The Sea: Be the change you want to sea.
Innovating to make the world a better, more sustainable place to live. Listen to the race to 9 billion
The Grantham Foundation for the Protection of the Environment: Committed to protecting and improving the health of the global environment.
Energy Foundation: Serving the public interest by helping to build a strong, clean energy economy.
Contribute to Living on Earth and receive, as our gift to you, an archival print of one of Mark Seth Lender's extraordinary wildlife photographs. Follow the link to see Mark's current collection of photographs.
Buy a signed copy of Mark Seth Lender's book Smeagull the Seagull & support Living on Earth