About Links

The main portions of this text contain five different types of links. The links can be generalized as follows:

1. Notecard Links - Links to tidbits of information or small amounts of detail that can be included or left out. These pages open in their own windows, which you can close to return to your place. (ex. "Nuclear fusion is a nuclear reaction in which hydrogen nuclei fuse together to form helium nuclei and release energy.")
   
   
2. Subsection Links - Links to more extensive peices of information that give more detail on a topic, but are not necessary to instruction of material. These pages open in their own windows, which you can close to return to your place. (ex. "Certain gases in the atmosphere (known as greenhouse gases) do not allow this longer wavelength radiation to pass through as easily as the shorter-wavelengths that entered.")
   
   
3. External Links - Links to pages outside of our site that offer expanded explanations or applicable examples. These pages open in their own windows, which you can close to return to your place. (ex. "Thus the upper layers of the atmosphere are also called the ionosphere because they contain ions (or charged atoms and molecules)."
   
   
4. Internal Links - Links to more information within our site, which are probably portions of different sections containing applicable information. These pages open in the current window; use the "Back" button on your browser to return to your place. (ex. More information on human impacts on the food chain and on ecological economies can be found in the Ecological System.")
   
   
5. Source Links - Links to sources of information, like graphics or quotations. These pages open in their own windows, which you can close to return to your place. (ex. "Figure 5: Composite of satellite images showing the extent of outdoor lighting in the continental United States. Source: Defense Meteorological Satellite Program (DMSP).")