Home 
  About Us [2] 
  Events  
  Projects 
  Resources [3] 
  Volunteers 
  People 
  Animals 
  Environment [7] 
  Links 
  News 
  Petitions 
  Site Usage [7] 


Office:

C/o
Greenbank
Neighbourhood
Office,

35, Armada Street,
Greenbank,
Plymouth.
PL4 8LZ

Tel: 01752 290015


Link to Fair Trade webiste. Fair Trade : Guarantees a better deal for third world producers

Choose Products
With The
FairTrade Mark!

The Greenhouse

by Roger Lovejoy

Reflection :

The atoms in some materials hold on to their electrons loosely. In other words, the materials contain many free electrons that can jump readily from one atom to another within the material. When the electrons in this type of material absorb energy from an incoming light wave, they do not pass that energy on to other atoms. The energized electrons merely vibrate and then send the energy back out of the object as a light wave with the same frequency as the incoming wave. The overall effect is that the light wave does not penetrate deeply into the material.

In most metals, electrons are held loosely, and are free to move around, so these metals reflect visible light and appear to be shiny. The electrons in glass have some freedom, though not as much as in metals. To a lesser degree, glass reflects light and appears to be shiny, as well.
http://www.howstuffworks.com/light10.htm

Absorption :

In absorption, the frequency of the incoming light wave is at or near the vibration frequency of the electrons in the material. The electrons take in the energy of the light wave and start to vibrate. What happens next depends upon how tightly the atoms hold on to their electrons. Absorption occurs when the electrons are held tightly, and they pass the vibrations along to the nuclei of the atoms. This makes the atoms speed up, collide with other atoms in the material, and then give up as heat the energy they acquired from the vibrations.

http://www.howstuffworks.com/light9.htm

Extracts from Wikipeadia

Absorption (electromagnetic radiation)

In physics, absorption is the process by which the energy of a photon is taken up by another entity, for example, by an atom whose valence electrons make transition between two electronic energy levels. The photon is destroyed in the process. The absorbed energy may be re-emitted as radiant energy or transformed into heat energy.

Earth surface

The specific phenomena involving absorption of electromagnetic radiation at the Earth's surface have several important aspects. These phenomena include regulating the temperature of the Earth's crust, surface waters and lower atmosphere. Changes in the Earth's crust such as glaciation, deforestation, polar ice melting, will necessarily alter the quantity and wavelength selectivity of electromagnetic absorption at the Earth's surface; correspondingly, changes in climate such as global warming may accompany changes in electromagnetic absorption.
http://en.wikipedia.org/wiki/Absorption_%28optics%29


Added 23rd May, 2007 by Roger

Internal links checked Goto Xenu Link Sleuths' Website on 11th February 2008

 
Valid XHTML 1.0 Strict This site is coded to the  World Wide Web Consortium 's recomendations, to be viewable on all browsers.
Should you find or think there is an error in any page please contact us  Thank you for your help.
You can check the page for HTML and CSS compliance by clicking on the links to the left and right of this text. 		Valid CSS!