MAM2000 (People/Webb)

Thompson Webb studies the ecology of the Midwest ten thousand years ago by analyzing a one-dimensional slice of space and time. But boring straight down into a lake bed, he obtains a sample of the pollen from trees that grew there millennia ago, and maps the ranges of forests and grasslands. From this he and his colleagues in paleoecology can tell the temperature variations that indicate patterns in global warming and cooling. Although this science begins with one-dimensional samples, ultimately the analysis leads to scientific visualization in three and four dimensions, studying the migration of the prarie-forest boundary over time, then slicing the data set a different way to see variations along a ridge through time and space.

	Isopoll curves connect points with the same percentages of forb pollon 6000 years ago. Each curve represents a slice of the four-dimensional data.

For a further description of the way different dimensions enter into the work of Prof. Webb, see chapter five of Beyond the Third Dimension. In that chapter there is an extended discussion of the way dimensions enter into paleoecology.

The Grand Canyon provides a slice through a large block of rocks representing the geological history of the region. The Grand Staircase site gives maps and cross sections and even photos of the rocks from Bryce Canyon down to the Grand Canyon.

Here is a site with Global Earth History maps to illustrate each geological period and its global geography. If your stack those global maps up on top of each other, then a space-time box emerges.

Math Awareness Month 2000 Last modified: 26 Mar 2000 17:36:12 Comments to: thomas_banchoff@brown.edu Hosted by: The Math Forum

Richard Tapia MAM2000 Home Page John Tukey