Models

History of Science
Environmental & Science Education

by Edward Hessler

This file comes from Wellcome Images, a website operated by
Wellcome Trust, a global charitable foundation based in the
United Kingdom.

A recent issue of ScienceEXPRESS from the National Science Teachers Association called attention to the World Digital Library (WDL), a joint project of the Library of Congress (LC) and UNESCO. At WDL you can search 14416 items about 193 countries between 8000 BCE and 2000 CE, numbers that are sure to change.

Lee Ann Potter, Director of Educational Outreach at the LC wrote a short essay about Francis Crick's original sketch of DNA from the WDL. This sketch, a graphical model, led Francis Crick and James Watson to make a physical model of the molecule. And as is said, the rest is history.

What I particularly like about Crick's sketch is that it provides students an idea of how scientists use models to help them represent available data...summarize their thinking. I especially like this particular sketch because it shows just how "sketchy" such representations often are. I think just by seeing this first paper-and-pencil model might help students with their own  attempts, making them feel comfortable with their first models. 

Models at this stage, are not artistic renditions but renditions in transition. Such models are used as tools for thinking, as a basis for further work, for deepening conceptualizations and ultimately developing better data-based models.

The model that appeared in the now classic paper on DNA, A Structure for Deoxyribose Nucleic Acid was drawn by Odile Crick, an artist as well as the wife of Francis Crick. This, though, remains a non-artistic model. It is for publication and is also based on additional evidence, the best the authors had when they submitted the paper for publication.