When Did the Grand Canyon Begin to Form?

South Rim, Grand Canyon. Image courtesy of Kimberly Lightle.

This blog post draws from several news sources — washingtonpost.com, The New York Times, and Science Friday. All these sources have stories and photos related to a study published March 7, 2008, in Science by researchers Victor Polyak and Carol Hill (free registration is required to view this article). Science Friday features a 15-minute audio clip of an interview with Polyak. The research suggests that the Grand Canyon began forming 17 million years ago. However, for the past 100 years or so, geologists have agreed, based on a robust data corpus, that the Grand Canyon is probably five to six million years old, even though the rock from which it is carved is up to two billion years old. So what have Polyak and Hill done to upset this long-held theory of the Grand Canyon’s age?

To put it simply, they gathered new data and analyzed it using new technology. That is, they gathered rock samples called mammillaries from caves. These mammillaries are associated with ancient water tables and suggest previous levels of the water table. Polyak and Hill then analyzed these samples with improved rock-dating technology involving the radioactive decay of uranium to lead. The Grand Canyon began forming 17 million years ago at the western end in a west to east direction, and at a rather slow rate. Some time later, the east end of the Grand Canyon began forming from east to west, at a much more rapid rate. Eventually the two ends merged and the Colorado River emerged.

However, some scientists suggest Polyak and Hill’s methods and interpretations may be too narrow or incomplete. For example, their assumption that all the mammillaries examined originated in an ancient water table may not be a safe one. One critic noted that springs do occasionally emerge from the canyon walls and they could produce mammillaries as well. Another point of contention deals with the lack of 17-million-year-old sediment, which would be evidence of a 17-million-year-old river. Hill counter-argues that such sediment may not exist because the scale of the hypothesized 17 million-year-old, western river system would not produce sizable amounts of sediment. In addition, river erosion tends to destroy such potential evidence.

How to Turn This News Event into an Inquiry-Based, Standards-Related Science Lesson
Estimating the age of the Grand Canyon is related to the History and Nature of Science, Science as Inquiry, and the Earth and Space Science content standards of the National Science Education Standards. With respect to the first two standards, several themes emerge. The researchers proposed using improved laboratory techniques and new data sources to make an estimate of the age of the Grand Canyon. In this way, they demonstrated the idea that science advances with new technologies. Science also seeks disconfirming evidence to existing theories as a means of gaining increased certainty regarding what we know about the natural world. If scientists fail in their attempt to find disconfirming evidence, they have succeeded in strengthening the existing theory. If they find disconfirming evidence of existing theories, then they pave the way to new lines of research, which must be further investigated. Eventually, existing theories may be either supplanted or revised in light of the new evidence, or they may be strengthened should the new evidence turn out to be unreliable or invalid.

The news sources related to this research also provide “air time” for scientists who argue alternate interpretations of Polyak and Hill’s data and who point out that Polyak and Hill may be ignoring some facts that impact their conclusion. These presentations underscore the role of argumentation and evidence based logic in advancing scientific knowledge as well as the social nature of science.

Ask your students if they know how old the Grand Canyon is. Ask them if they imagine someone knows, even if they don’t. From here, the discussion is going to go in one of two directions: (1) If they imagine someone knows, how do students imagine the someone knows how old the Grand Canyon is; what kind of evidence might have been used? Entertain all student contributions and stipulate that the students provide some justification for their response. You may need to do quite a bit of guiding and scaffolding here to lead students to support only evidence-based and logical responses. (2) If students imagine no one really knows, ask why not; what prevents human beings from knowing?

Depending on your students’ background knowledge and context you can relate the discussion to a variety of instructional goals and learning objectives. Do you want to emphasize the nature of science, evidence-based argumentation, and the social aspects of doing science? Then choose excerpts from Science Friday’s interview, which highlight these aspects in the context of real scientists doing real science and devise discussion questions for your students to reflect upon in order to increase their awareness of the nature of science.

Maybe you want to highlight some methods of science like rock dating. Perhaps you can use this opportunity to illustrate how new questions can emerge from gathering evidence intended to answer another question, as is illustrated in the final paragraph of the washintonpost.com story.

Or maybe you want to give students practice with science literacy. Put students in small groups and give each group one of the three sources listed in the first paragraph of this blog. Devise two or three open-ended questions for each group to discuss and reach consensus. Have the students jigsaw into new groups and share the consensus of their first group. How does each student now understand the issue of determining the age of the Grand Canyon? How does this issue intersect with the bigger idea of the nature of science?


We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. This post was originally written by Mary LeFever and published March 14, 2008 in the Connecting News to the National Science Education Standards blog. The post was updated 11/16/2011 by Kimberly Lightle.

Newest Issue of Beyond Weather and the Water Cycle Highlights the Science of Climate Study

Scientists recording data on Sperry Glacier. Photo courtesy of glaciernps, Flickr.

The just-published issue of the free, online magazine Beyond Weather and the Water Cycle gives K-5 school teachers a unique opportunity to introduce the science behind weather and climate change to young students with engaging lessons and proven reading strategies.

Each issue of the magazine takes its theme from one of the widely accepted principles of the climate sciences. The theme of the September 2011 issue is “We Study Earth’s Climate.”

Designed to integrate science and literacy instruction for educators in K- grade 5 classrooms, this and earlier issues provide background articles on the related science and literacy topics and their connections to the elementary curriculum. Science and literacy lessons to use in the classroom become a part of unit plans for grades K-2 and 3-5 and are aligned with the national standards for science education and English language arts.

An original story, titled  How Do We Study Climate?, gives young listeners and readers chances to use their comprehension skills on informational text. The story is available at two reading levels and in three different formats.  Selected children’s books on climate and weather are highlighted in a bookshelf feature.

Two articles are devoted to teaching young people to evaluate information from web sites and to use video clips from agencies that work with weather satellites, balloons, and buoys to learn about data collection.

Readers are welcome to add their ideas and suggestions on articles by leaving comments. They can also easily share and bookmark content by using the embedded AddThis buttons.

Beyond Weather and the Water Cycle is funded by a grant from the National Science Foundation (NSF) and produced on the campus of The Ohio State University (OSU) in Columbus, Ohio.  All past issues of the magazine are available from the homepage of the magazine.

Kimberly Lightle, director of digital libraries in OSU’s College of Education and Human Ecology, School of Teaching and Learning is the principal investigator of the project as well as a contributing writer. Jessica Fries-Gaither is the project director of Beyond Weather and the Water Cycle as well as the award-winning sister publication, Beyond Penguins and Polar Bears.


We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. Post
updated 12/07/2011.

Celebrate Women’s History Month with STEM Stories

The STEM Stories website features a growing collection of digital resources that highlight the lives and work of individuals involved in STEM fields (mainly women). It combines compelling personal stories and multimedia to interest intermediate and middle school students in STEM subjects and careers.

From the In the Spotlight menu, you’ll meet 10 present-day women who are featured in depth, with interviews, photo albums and more.  They include dolphin communication researcher Diana Reiss, atmospheric chemist Susan Solomon, biologist and astronaut Millie Hughes-Fulford, and robotics engineer Heather Knight. (Heather helped work on the Rube Goldberg machine sequence for the OK-Go music video This Too Shall Pass).  On the Clips tab, the database includes short videos that introduce individuals working in varied STEM careers.  The Profiles tab lets you search biographies about women working in STEM fields throughout history.  Some include photo albums, such as Mary Pennington, Rachel Carson, and Virginia Apgar. (Tip:  double-click on images to see a larger view).

The project team, headed by Lois McLean and Rick Tessman (McLean Media) created STEM Stories with girls in mind, drawing on design ideas from an after-school club for at-risk middle and high school girls. In a 2010 pilot, more than 200 students (Grades 4–7) in Nevada County, California, used the site in classroom activities. In one school, fourth- and seventh-grade students worked in pairs to create pop-up books based on featured individuals. Survey results found no major differences between the responses of boys and girls. In fact, teachers reported that students did not even comment on or question the site’s emphasis on women. And, although the website focuses on personal stories, most students also reported learning something new about science and engineering.

STEM Stories was funded through a grant from the NSF’s Research on Gender in Science in Engineering Program (#HRD-0734004). New content is being added every month, including more current and historical photos, profiles, videos, and interactives.

To introduce your students to the STEM Stories site, try these activities:

STEM Stories Treasure Hunt

STEM Stories Crossword Puzzle

STEM Stories Lesson Ideas


We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. Post updated 4/19/2012.

Beyond Penguins Wins SPORE Award

Beyond Penguins and Polar Bears has been awarded the Science Prize for Online Resources in Education (SPORE) by Science Magazine. The magazine, which is published by the American Association for the Advancement of Science, developed the prize to spotlight the best online materials in science education.

Science editors and a panel of teachers and researchers in the fields select the prize winners. Kimberly Lightle and Jessica Fries-Gaither of the Beyond Penguins and Polar Bears staff were invited to write an essay about the project’s history and goals. The essay, Penguins and Polar Bears Integrates Science and Literacy, appears in the January 28 issue of Science.

Even though the magazine is directed at K-5 teachers, much of the content is applicable to the middle grades. Each of the 20 issues covers science concepts such as rocks and minerals, the water cycle, seasons, states and changes of matter, and plants, all in the context of the Arctic and Antarctica. Each issue highlights a literacy strategy, misconceptions, ideas on integrating technology, the research that is going on at the polar regions, and much more! Project staff have also written informational texts that have been differentiated in terms of reading level. The books are available in three versions – including an electronic version with an audio track. The Stories for Students link in the header of the site will take you to all versions of the books.

Print Issues of Beyond Penguins Are Half Price on Black Friday

Readers of the online issues of Beyond Penguins and Polar Bears can now access the content in different formats. For example, you can have highlights of issues mailed to you as a full-color, print magazine, or you can download the highlights version on your iPad. The print and electronic versions are generously illustrated with photographs and contain many of the articles from the original online production. We are using MagCloud — a print-on-demand service from Hewlett-Packard that in addition to the print-on-demand service has an iPad application that allows you to download issues from MagCloud onto an iPad for free.

For the print version, you pay printing (20 cents/page) and mailing costs – issues are from $4.80 to $7.20 to print and ship depending on the page count. However, on Black Friday you can save 50% during MagCloud’s Red Friday Mega Sale! From midnight until 12 pm (PST) on Friday November 26th MagCloud will be slashing the production costs on all full-priced magazines by 50%. And don’t worry if the turkey-hangover causes you to miss the mega sale, you can still take advantage of MagCloud’s 25% Off Holiday Sale from 12 pm November 26th through December 31st. You can browse all the Beyond Penguins Highlights on MagCloud at http://bit.ly/aQUTn9.