With the frozen ground of late, on Monday, January 4th, I was able to show many students how freezing moisture in the ground causes a frost heave, as crystals grow up within the soil and break the soil apart.

frost heave

Later in the week I showed Division 4 and 5 a YouTube video put out by Chris Agnos, founder of Sustainable Human, a non-profit organization with some interesting ideas on ways to make the world more sustainable.  What really interested me in this video however, were the connections that were made to the impact that every choice, every action, and every element of nature has on its environment.  This short video shows how introducing wolves back into Yellowstone National Park, which had been absent for 70 years, changed the patterns of the wildlife and these changes lead to changes in the physical geography.  The changes in the physical geography lead to less soil erosion by the rivers, and a change in the very rivers themselves.  An interesting idea and perspective and the discussion afterwards with students was truly thought provoking.  The students made many connections.