Links

One of the premiere sites with information on Earth's geologic and climate history is Christopher Scotese's Paleomap Project which includes atlases, animations and a variety of time slices of Earth's history. While not all geologists would necessarily agree with the details of Scotese's maps, the resource provides an overview of how Earth has change....and will continue to change in the future.

Another related effort is the Paleogeographic Atlas Project at the University of Chicago.

For a background on the history of the universe, check out the Tufts University Cosmic Evolution website which goes "from Big Bang to Humankind" and was developed at the Wright Science Education Center. The director of the project, Eric J. Chaisson, has also written a book entitled Cosmic Evolution:
The Rise of Complexity in Nature.

PBS has a The Mysteries of Deep Space Timeline site that goes "From the Big Bang to the End of the Universe" and includes classroom activities and trivia challenges.

And author Eric Schulman has come up with The History of the Universe in 200 Words or Less which has been translated into more than thirty languages.


Image from Hubble Telescope, NASA

Inquiry

The Water Planet's Chilly Past

Over the course of Earth's 4.55 billion orbits around the sun, there were periods when major continental ice sheets were dominant and periods when temperatures were higher and so were sea levels. Some researchers theorize that during a prolonged icehouse period between 850-550 million years ago the world was dominated by ice. This has been called the "Snowball Earth Hypothesis." (Hoffman, 1998).

Other researchers claim that the geologic record does not support the theory of a one prolonged period of 300 million years, but rather was between two and four periods of glaciation with sustained "interglacial" warm period lasting tens of millions of years (Kennedy, 1998).

Image above from Ruddiman, 2001 used by permission of W. H. Freeman & Co