The Grand Canyon has always been one of my favorite places. Twenty (much younger and fitter) years ago, I hiked down and back in one day not knowing at the time I was pregnant. Although I've slowed down considerably a lot since then, my husband and I are thrilled that our kids have had the chance to explore the Canyon with us.
Soon there will be another reason to visit: The Trail of Time.
(More after the jump.)
Aptly named, the trail was designed to help visitors shift their perspective on time from a personal time scale (years) to historic time scales (tens and hundreds of years), then to archaeological time scales (thousands of years), and finally the geologic time scale of millions of years. It uses the 2-km stretch of existing paved walking trail that edges the South Rim between Yavapai Observation Station, which houses a recently remodeled geology museum, and Grand Canyon Village. Upon completion in 2010 it will be the world's largest interpretive geosciences exhibit.
The trail will be marked with bronze plaques every meter, each meter representing 1 million miles of Earth's history.
Imagine that one long stride represents a million years, and you have to take 2,000 of those strides just to get to the age of the oldest rock in the Grand Canyon, which is less than half the age of the Earth. By walking this timeline trail, visitors get a physical as well as intellectual sense of how long geologic time is. A grasp of the magnitude of geologic time is the foundational knowledge needed to construct an understanding of many aspects of our planet from earth science and evolutionary biology to astronomy.
It is tough to get students to think of the world in terms of millions and billions of years instead of thousands. Shifting their perspective by such orders of magnitude is aided by having the students build their own geologic timeline, one where 1.0 mm of distance on a roll of paper represents 1.0 million years. At this scale, the entire history of the earth is represented by about 15 feet on the roll of paper. With only 1.0 mm to represent the most recent 1 million years, students quickly realize that the last 10,000 years of human civilization doesn't even leave a scratch.
"Our hope is that Trail of Time visitors will walk away with a better understanding of how human time scales relate to geologic time scales." - Steve Semken, assistant professor in the School of Earth and Space Exploration at Arizona State University and a long-time member of the Trail of Time team
But the Grand scale of the Trail of Time at the Canyon shows in its ambitious plans:
"Though we don't have the funding yet, we would someday like to extend it all the way out to Maricopa point which will be 4.5 km," says Semken. "That would bring people out to the very beginning of the earth, 4.5 billion years."
This project is funded by the National Science Foundation, so of course there are oodles of documents available with more details.
. . . and the child I was expecting on that hike twenty years ago has always had the uncanny ability to send me climbing the walls. Just sayin' . . .
(If you
posted by Cheryl Shepherd-Adams
