Light Fantastic

Continuous spectrum from sunlight
trapped on my kitchen wall

Toot has a small glass cristal suspended in our south facing kitchen window.  As light from the sun is dispersed in wavelength (violet - 390nm to far red - 720nm), a number of discrete spectra are created and projected onto the walls and ceiling in our kitchen.

The photons in the spectrum were created during the fusion of hydrogen at the centre of the sun (gamma and X-rays at the core).  Mass is lost during the fusion process and converted to energy in the form of photons (E=mc2). The photons do not move from the centre of the sun to its surface at the speed of light because they scatter off electrons and atomic nuclei. In fact, it is calculated that the diffusion of radiation ensures that the average photon takes some 50,000 years to get from the core to the surface of the sun. By the time the photons get there they are of  benign visible wavelength.

Alice and  a Rainbow (Photo Andy Boon)

Nearly all the information astronomers have about the
nature, composition and relative movement of stars in the Universe is based upon measurements of spectra.

Our  home world  is a more beautiful place and we are only here to appreciated it because of the nature of light. Its light fantastic!

Spray from the stern of the 'Maid of the Mist' Niagara Falls (October 2011)

Double Rainbow over Didcot Power Station (Photo Andy Boon)