Monday, March 16, 2015

Melting Ice means Gravity Shift for Antartica

Somehow I missed this Slate article published last fall that reported on the European Space Agency's conclusion that loss of ice between 2009 and 2012 caused a dip in the gravity field over the West Antartica:
Though we all learned in high-school physics that gravity is a constant, it actually varies slightly depending on where you are on the Earth’s surface and the density of the rock (or, in this case, ice) beneath your feet. During a four-year mission, the ESA satellite mapped these changes in unprecedented detail and was able to detect a significant decrease in the region of Antarctica where land ice is melting fastest.
The change may not be not felt by the average penguin, but the changing water level, coast lines and weather patterns brought about by the melting ice is being felt by us all.

Monday, March 2, 2015

Alison's Shifting Center of Gravity

My wife told me recently that one of the most remarkable experiences of gravity she had was during her pregnancies, the shift in her center of gravity, the extra weight causing her to renegotiate her body's sense of balance, effecting her sleeping patterns, daily commute, the picking up fallen objects, etc.  I have fond memories of watching her work out her new and constantly changing balance.  I found this photo of her being swung in a hammock by my daughter, two days before she delivered our 10 pound son, two weeks after his due date: