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Science and Engineering Practices
Analyzing and Interpreting Data | Analyze data using tools, technologies, and/or models (e.g., computational, mathematical) in order to make valid and reliable scientific claims. Apply concepts of statistics and probability (including determining function fits to data, slope, intercept, and correlation coefficient for linear fits) to scientific questions, using digital tools when feasible. Consider limitations of data analysis (e.g., measurement error, sample selection) when analyzing and interpreting data. Evaluate the impact of new data on a working explanation and/or model of a proposed process or system.
- Students create a Hubble plot for galaxies in the local Universe, then fit data and use the slope of the best-fit line as an estimate for the rate of expansion of the Universe.
- Students apply scientific reasoning to assess how data limitations and the addition of new data affect their interpretation of the expansion rate of the Universe.
- Students evaluate how the expansion rate of the Universe has changed over time.
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Constructing Explanations | Construct an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future. Apply scientific reasoning, theory, and/or models to link evidence to the claims to assess the extent to which the reasoning and data support the explanation or conclusion.
- Students evaluate the results of Hubble plot data of nearby galaxies and use a model from the viewpoint of different galaxies to discover that the Universe is observed to expand at the same rate regardless of location, leading to the additional conclusion that the Universe has no center.
- Students describe how their observations and interpretations support the Big Bang theory.
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Developing and Using Models | Develop, revise, and/or use a model based on evidence to illustrate and/or predict the relationships between systems or between components of a system.
Students use a model from the viewpoint of different galaxies to discover that the Universe is observed to expand at the same rate regardless of location, leading to the additional conclusion that the Universe has no center.
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Disciplinary Core Idea
ESS1.A: The Universe and Its Stars | - The study of stars’ light spectra and brightness is used to identify compositional elements of stars, their movements, and their distances from Earth.
- The Big Bang theory is supported by observations of distant galaxies receding from our own.
Students use galaxy redshifts and supernovae distances to create Hubble plots, then use these plots to support the claim that the Universe is expanding, which is a predicted observational outcome of the Big Bang Theory. |
Crosscutting Concepts
Scale, Proportion, and Quantity | Patterns observable at one scale may not be observable or exist at other scales.
Students compare Hubble plots made with different data sets (one set of nearby galaxies, and one set of distant galaxies) to compare patterns in the rate of expansion of the Universe over time.
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Stability and Change | Much of science deals with constructing explanations of how things change and how they remain stable. Change and rates of change can be quantified and modeled over very short or very long periods of time.
Students compare Hubble plots made with different data sets (one set of nearby galaxies, and one set of distant galaxies) to compare patterns in the rate of expansion of the Universe over time. They conclude that the expansion rate has changed, and that the Universe is accelerating its rate of expansion.
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Connections to Engineering
Interdependence of Science, Engineering, and Technology
| Science and engineering complement each other in the cycle known as research and development (R&D). Many R&D projects may involve scientists, engineers, and others with wide ranges of expertise.
The innovative engineering design of the Rubin Observatory telescope and camera system will enable discoveries of millions of far away galaxies and many faint nearby galaxies, helping to better refine the Hubble plot and understand the nature of dark energy.
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Connections to Nature of Science
Scientific Knowledge Assumes an Order and Consistency in Natural Systems | Science assumes that objects and events in natural systems occur in consistent patterns that are understandable through measurement and observation. Scientific knowledge is based on the assumption that natural laws operate today as they did in the past and they will continue to do so in the future. Science assumes the universe is a vast single system in which basic laws are consistent.
Regardless of location in the Universe, galaxies are observed to expand away from each other, leading to the understanding that the Universe has no center.
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