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# Concepts across the Sciences: Stability and Change

This post is by Jacqueline Katz, the 2022-2023 Albert Einstein Distinguished Educator Fellow at the Library of Congress.

In all scientific disciplines, there are examples of stability and change. Stability refers to the tendency of an object or system to stay the same, while change occurs when objects or systems become different. Changes that occur in the various scientific disciplines can happen over extremely short or long time intervals.

Students learning about human population can observe both stability and change. Data on economics, geology, and the U.S. human population can be found in national atlases published throughout the nation’s history (1874-1997). The 1970 Atlas includes a graph that explores “Death Rates for Selected Causes.” Present this graph to students along with questions selected from the Teachers Guide: Analyzing Charts and Graphs to help guide students who may become overwhelmed by the amount of information on this graph. Once students understand what the graph is showing, ask them to classify the lines as representing a pattern of stability or change.

Because none of the lines are perfectly flat or stable, this could serve as an opportunity to discuss pattern identification. Prompt students to determine the death rate by cancer in 1914 and compare it to the rate in 1955. If the numbers are not the same, ask students if the difference is enough to classify the line as a change. This conversation could lead to a deeper exploration of statistics and variability in science.

To link this primary source to content about population dynamics, assign groups of students to research one of the causes of death to explain why a pattern of stability or change is being observed over the time period. Students might look into the development of treatments for the disease or public health measures that were enacted. Research on these topics could lead to a discussion about the crossover between science, society, and politics when addressing human health. Students could collect more data about a certain disease by referring to additional atlases in the Library’s online collections (1870 and 1890).

Another key feature of this graph to address with your students is the distinction between individuals classified as “white” and those classified as “Negro and other races.” Students will likely recognize that the death rate for several diseases is shown as higher for “Negro and other races” compared to “white” for the entirety of the time tracked. Ask students:

• Why do you think the difference exists?
• Based on available evidence, have these differences been stable over time or have they changed?
• How could these differences be mitigated?
• Have you heard of these differences in relation to any current events?

Population dynamics is just one topic that lends itself to a discussion of stability and change. Maps displaying weather patterns across the U.S., such as the rain distribution map of 1872, can also provide a context for the discussion of stability and change, and might launch the class into a discussion of climate change.

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