image credit: Raina Khatri; larger image

Strings, standing waves and harmonics - Nov 16, 2009

What makes a violin sound like a violin and a flute sound like a flute? These waveforms give us a clue. They were generated using recordings of a violin (upper waveform) and tin whistle (lower waveform) playing the same note, yet the shapes of the waveforms are very different. Learn more about the qualities of musical sound here.

Violins and flutes produce sound in very different ways. See how stringed instruments work at Strings, standing waves and harmonics , and compare strings with woodwinds after reading How Do Woodwind Instruments Work?.

image credit: Creative Commons; image source; larger image

Why The French Like Nuclear Energy - Nov 1, 2009

This photo shows the Centrale Nucléaire de Saint-Laurent. You can find a satellite image here.

Nuclear power plants generate 75% of the electricity consumed in France. Read this Frontline article to learn about France's conversion from fossil fuels to nuclear power. For more detailed information about nuclear power in France, see this US News article.

One reason other countries hesitate to adopt nuclear power is the possibility of a serious accident. Learn about the devastating accident at Chernobyl here.

image credit: George Taylor; image source; larger image

X-ray Photography: Inner Beauty - Oct 16, 2009

This graceful picture is actually the x-ray image of a nautilus shell. Read more about x-ray photography at X-ray Photography: Inner Beauty, and learn the basics behind x-ray light at this NASA site. Be sure to check out more x-ray photographs from the featured artist above here.

image credit: Andrew Davidhazy; image source (#8664); larger image

What Wavelength Goes With a Color? - Oct 1, 2009

White light is actually full of color, and we can see these colors by shining white light through a prism. For a more detailed explanation, with diagrams, see this HyperPhysics page. For the correspondence of color and wavelength, see What Wavelength Goes With a Color?. Check out this page from the Sloan Digital Sky Survey for an interactive animation showing how color changes with wavelength.

Look at the photo above and see whether the prism bends red light or purple light more.

image credit: Troy Shinbrot, courtesy of the American Institute of Physics; image source; larger image

Spontaneous Separation of Charged Grains - Sep 16, 2009

These red and blue sand grains are mixed together--for now. Click the image to see what happens next. These differently colored sand grains aren't being sorted with any outside help, they're sorting themselves by charge. Find out why at Spontaneous Separation of Charged Grains.

Check out this Physics Central article to explore granular materials further. Don't miss the video on the research page of the standing wave made by shaken particles.