Lesson 1: The Origin of the Universe

-What evidence supports the Big Bang Theory as the leading explanation for the origin of the universe?

-How do scientists use observational data to reconstruct events that occurred billions of years ago?

-How do redshift and galaxy motion data provide evidence that the universe is expanding?

-What does it mean for a scientific model to be supported but not “proven”?

-How do multiple lines of evidence strengthen a scientific explanation of the universe’s origin?

-What are the limitations of our current observations of the early universe?

Big Bang Theory

Universe

Expansion of space

Cosmology

Scientific model

Galaxy redshift

Spectral shift

Cosmic Microwave Background (intro reference)

Astronomical evidence

Scale

Inference

HS-ESS1-2 – Construct an explanation of the Big Bang theory based on astronomical evidence including light spectra, motion of galaxies, and cosmic microwave background radiation

NGSS Crosscutting Concepts

-Cause and Effect

-Systems and System Models

-Stability and Change

-Patterns

-Scale, Proportion, and Quantity

Students will interpret multi-representation scientific data including galaxy redshift graphs, spectral diagrams, and simplified cosmological models.

Students will construct evidence-based explanations requiring synthesis of multiple data sources.

Students will evaluate claims about the origin of the universe using scientific reasoning and textual evidence integration.

Students will analyze astronomical datasets and representations (galaxy redshift patterns, simplified spectral shifts, and expansion models) to construct and defend explanations of the Big Bang Theory.

Rather than focusing on recall of the theory, students will evaluate how multiple independent lines of evidence converge to support a single scientific model.

Students will also critique the strengths and limitations of the Big Bang model, especially regarding observational constraints at extreme scales.

DOK Level: 3–4 (Strategic Thinking to Extended Reasoning)

Students connect modern cosmology to current astronomical research using telescopes (ground- and space-based) and how scientific understanding evolves with improved technology.

They also connect the idea of “looking back in time” through light to how humans interpret history and evidence in other fields such as archaeology and forensic science.

Students may think the Big Bang was an explosion into space rather than an expansion of space itself.

Students may believe the universe has a central point or edge.

Students may assume scientific models are absolute truths rather than evidence-based explanations.

Students may struggle to interpret redshift as evidence of motion rather than color change alone.

-Scaffolded redshift and galaxy motion data interpretation tasks

-Multi-level datasets (simplified vs authentic NASA-style representations)

-Structured CER frameworks with optional extension justification section

-Visual modeling tools for universe expansion (simulations and diagrams)

-Guided annotation of graphs and spectral representations

-Peer discussion protocols focused on evaluating evidence strength

-CER response: “What evidence supports the Big Bang Theory?”

-Multi-source data analysis task (redshift + galaxy motion + model comparison)

-Quiz on vocabulary and conceptual understanding

-Performance task: evaluate strength of evidence supporting expansion of the universe

-Formative checkpoints during data interpretation activities

Galaxy redshift datasets (tiered complexity)

Spectral shift visualizations

Universe expansion simulations

NASA/ESA cosmology images and datasets

Guided CER writing templates (accelerated version)