Wednesday, December 1, 2010

Interesting Elements

Rocks Make Life and Vice Versa
An interesting seven minute Robert Krulwich interview on NPR Thursday discussed the coevolution of rocks and life.  Elements formed early in the life of the universe began combining to form different minerals we see today.  While life also developed from these elements, what effect has that life had in the development of rocks?

I think you will find the effects of life on rock evolution fascinating.  I won't spoil the surprise ending for you but here is a hint.  "The more life there is, the more rocks there are."

Cocktails from the Past
Ice Core- from Wikimedia
Krulwich's blog has explored more interesting science, including the taste of 10,000 year old soda water.  Dr. Paul Mayewski, director of the Climate Change Institute at the University of Maine, told about core drilling through glaciers to sample glacial ice cores.  This ice is formed from compacted snow that fell in the distant past, pressed into ice in the depths, literally frozen in time.
"A hundred and thirty-eight feet down, there is snow that fell during the time of the American Civil War; 2,500 feet down, snow from the time of the Peloponnesian Wars, and 5,350 feet down, snow from the days when the cave painters of Lascaux were slaughtering bison.  As the snow is compressed, its crystal structure changes to ice. But in most other respects, the snow remains unchanged, a relic of the climate that first formed it."
When asked if they ever tasted the ice, he explained that after they have fully studied and archived the cores, the excess cores will just be discarded.  At that point they will occasionally taste the ice from a known level.
"Probably the most exciting thing about it is when you have real ice — that's where the snow has been gradually compacted and eventually formed into ice, and the density has increased. When that happens, if the ice is old, it will often trap air bubbles in it. Those air bubbles can contain carbon dioxide from ten thousand years ago or even a hundred thousand years ago. And when you put an ice cube of that ice in a glass of water, it pops. It has natural effervescence as those gas bubbles escape. You get a little a puff of air into your nostrils if you have your nose over the glass. It's not as though it necessarily smells like anything — but when you think about the fact that the last time that anything smelled that air was a hundred thousand years ago, that’s pretty interesting. "
How does this relate to Missouri?  Studying ice cores is a way of determining what climate changes occurred in the past and give us some clues about what to expect in the future.  The technology and challenges of ice core sampling is described in this blog.

More technical information than you need is in this Wikipedia article.

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