Friday, March 19, 2010

Erg - Types of Sand Deserts

The Grand Erg Occidental


Zibar – slightly rolling sandy country, which may extend over considerable distances usually less than 100 feet in elevation.

Barchans – crescentic sand dunes

Sand Seas – vast expanses of sand with very complex pattern resulting form frequent shifting of the winds

Uruq (veins) or Suyuf (swords) – long narrow sand dunes or lines of sand dunes

Sand Mountains – pyramid dunes

Sand Sheets – vast area of sand that is level and smooth

http://en.wikipedia.org/wiki/Barchans

Tuesday, March 9, 2010

Astronomy - Constellations & Planets

Constellations...















Planets...
A part of the sky we, in the Northern Hemisphere, don't see - The Southern Celestial Hemisphere.

A Few Pages of Celestial Mechanics

This is advanced math, but you might be able to see the algebra, geometry, and arithmatic in it.