Browsing 120 - 130 results of 161 programs for subject - Physics
Exploratorium Senior Scientist, Dr. Paul Doherty, takes us through the Photoelectric Effect and the "invention" of photons. Using a simple ball-bearing model, Exploratorium Senior Scientist Dr. Paul Doherty demonstrates Brownian Motion and explains how it proves the existence of atoms. Watch as Exploratorium staff and local teachers compete for the title of Iron Science Teacher. Each contestant has ten minutes to make a science lesson out of a secret ingredient. Today's secret ingredient-potatoes! Watch as the best teachers on the planet battle it out for the title of Iron Science Teacher. In this zany competition teachers will have ten minutes to create a science activity. This week’s “secret” ingredient: Milk! Watch as the best teachers on the planet battle it out for the title of Iron Science Teacher. In this zany competition teachers will have ten minutes to create a science activity. This week’s “secret” ingredient: Clothespins! Watch as the best teachers on the planet battle it out for the title of Iron Science Teacher. In this zany competition teachers will have ten minutes to create a science activity. This week’s “secret” ingredient: CD cases! 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. Stepping is rhythmic movement that uses the hands and feet as an instrument. Known best among African American fraternities and sororities, stepping draws on a long African tradition of using the body to make music.
Synchronized movement and chants are coordinated by the leader, or step master. Sometimes improvising, always cultivating their own distinctive moves and rhythms, step teams reflect and reaffirm both the unity and the unique style of their group. Join the Live@ crew and NASA scientists as we delve into the ancient knowledge of the Chacoans, daily sky watchers who amassed a great knowledge about the movements of the sun. And learn why today's astronomers and solar physicists continue to watch the sun, using modern ground-based observatories and orbiting space telescopes.