In this module you will see some different views on the subject 'Light'. What's happening in the life of a photon from origin to destination? Listen to a quark telling the story of the life of a star! Read the story about the invisible man or learn how to see through your body with 'Visible life'. Just follow the menu and have fun!

Some physics first...

In general physicists have two views on 'Light' : sometimes they describe the phenomenon as waves, but it is also possible to regard light as a stream of particles, called photons. Physicists say they are small packets of energy, depending on their 'wavelength', traveling at the speed of light of course.

In this picture you can see the wave-like behavior of light: different wavelengths correspond to 'color'. Of course the only real light is the part of this spectrum that can be detected by your eyes, with a wavelength of around 0.5 micrometers. The old thermometer shows something different: if you have an object with this temperature it will emit radiation around the wavelength shown in the lower part. Now the photons have an energy inversely proportional to this wavelength, so the X-ray ones are much more energetic.

Now you are ready for the stories....