I know that long wavelength radio frequencies go through most objects simply because the objects arent longer than the wavelength. But it is saidf that they tend to follow the countour of the earth. Does this mean the same thing or is it something else?..If so why do they do this?... Also why arent eh yused in comkputer network communication??

I believe its their reaction with the Van Allen belts in the Ionosphere, and the other radiation belt in the Magnetosphere that causes this phenomenon.

 

Oh yeah, it is also these Low and Extra low wavelenght frequencies that deflect Radiation out of the Earth's magnetic field.

ELF waves are used in comunications, there`s an entire granite bed in Scotland used as an ELF antenna for global submarine comunications. higher frequencies under certain conditions bounce of the ionosphere and are reflected back to earth (it`s called Skip), that`s why at certain times of day comunications can be heard from very distant places that have no "Line of sight" or point to point contact. even higher frequencies will actualy leave the earth and pass through the ionosphere and head off into space. it`s to do with the packet energy of the photons.

I also believe low frequency tends to bounce instead of being absorbed, so it just "bounces" along around things.