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The science behind the water bottle membranophone, including a discussion of how air vibrates the instrument's membrane, producing sound.

PETER WHITEHEAD is an instrument builder, performer, and composer. His singular instruments, often based on folk instruments from around the world, feature unusual found materials. Among his many instruments are the Heart Banjo, made from a baking tin; the Lawn Lyre, made from an old lawnmower and a metal oil pan; and the Spoonharp, made from a five-gallon metal drum, a eucalyptus branch, and kitchen spoons. Originally from England, Whitehead is now based in the San Francisco Bay Area. Founding member of the Mobius Operandi performance group, he also performs regularly with Closer To Carbon, an improvisational trio.

If you’ve ever gone to hear an orchestra play, you know that the performance begins only after a session of tuning. An oft-repeated story tells of a visiting foreigner attending a concert in Paris. Afterwards, when asked which part of the performance he liked best, he replied, “The beginning, just before the man with the stick came in.” Tuning means adjusting the pitch of an instrument. The pitch of a sound depends on its frequency, the number of vibrations per second that produce the sound. For example, plucking a cello string might cause it to vibrate back and forth 200 times each second. You hear that sound as a low pitch of 200 cycles per second, or 200 hertz. An orchestra tunes itself to a very particular frequency, usually 440 hertz, a note known as A 440. The note is played by the oboist, and the rest of the orchestra tunes their instruments to match it. The oboe leads the tuning because of all the instruments, it is least affected by humidity or other weather conditions.

Music is more than meets the ears directly. Just as no sound exists in a vacuum, every space sculpts the sound within it. Like a site-specific equalizer, reflections, absorption, and resonances combine to give each venue a unique acoustic stamp. A subway tunnel is “live” space, rich with reverberations that trap and reflect sound in a well of hard tile. True to their name, “dead” spaces do nothing: The only sound heard is what travels directly from instrument to ear. An open field is the ultimate dead space. As you follow this wandering riff, listen to the changes wrought by environment. Distance is also a factor here—the sound you hear is recorded from the camera’s vantage. Which spaces sound live? Which sound dead? Do the acoustic changes affect the feeling of the music? Saxophonist Michael Pearce plays with the Highwater Blues Band in the San Francisco Bay Area.

Watch as Exploratorium staff and local teachers compete for the title of Iron Science Teacher. Each contestant has 10 minutes to make a science lesson out of a secret ingredient. In this special Halloween edition, today's secret ingredient is: Plastic Bags!

Produced by students from San Francisco's Aim High Program. Today they ask, how do our ears work? Can we communicate without words? How do whales communicate under water? Why don't bats slam into trees as they fly? Middle school students will interview Exploratorium Educator Ken Finn and Biologist Dr. Karen Kalumuck, plus special surprise guests!

This episode of Sedge Thomson's West Coast Live radio show explores the places where science and entertainment intersect. In this broadcast: Singer-songwriter John Gorka; Bert Grant, founder of Grant's Brewery; a view from the studio of artist Meredith Tromble; author of "Fisherman's Son" Michael Koepf.

This episode of Sedge Thomson's West Coast Live radio show explores the places where science and entertainment intersect. In this broadcast: Kevin Kelly of Wired Magazine; Lawrence Weschler, author of "Seeing is Forgetting the Name of Thing One Sees"; The Canadian Brass Ensemble; physics chanteuse Lynda Williams; and Jonathan Schooler with a memory wine-tasting.