Science lesson plan · 11th grade (Year 12 in England) · 45 minutes
The expanding universe and the Big Bang
Space
CCSS NGSS.HS-ESS1-2England: KS4 Physics: Space physics (separate science)
Objective and success criteria
Students will: The expanding universe and the Big Bang.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: The life cycle of stars; The electromagnetic spectrum
Leads to: the next skill in this area.
Materials: Torch and ball for a Sun-Earth-Moon model, Space images, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (The life cycle of stars; The electromagnetic spectrum). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- In the life cycle of a star much more massive than the Sun, what comes straight after "protostar"? (main sequence star / neutron star or black hole / red supergiant / nebula) → main sequence starPrompt: Very massive stars end their lives far more violently than the Sun.
- In the life cycle of a star like the Sun, what comes straight after "main sequence star"? (nebula (cloud of dust and gas) / red giant / protostar / white dwarf) → red giantPrompt: The Sun is in its main sequence stage now.
- In the life cycle of a star much more massive than the Sun, what comes straight after "red supergiant"? (supernova / nebula / neutron star or black hole / protostar) → supernovaPrompt: Very massive stars end their lives far more violently than the Sun.
Hook · 5 min
- Ask why we see the Moon change shape over a month.
- Share the objective: The expanding universe and the Big Bang. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: About how old is the universe?
- Step 1: Measurements of the CMB and expansion give an age of about 13.8 billion years.
- Step 2: So the answer is: about 13.8 billion years
- Answer: about 13.8 billion years
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- What is the cosmic microwave background radiation (CMB)? (light from the Moon / leftover radiation from the early universe, seen in every direction / signals from mobile phones / heat from the Sun) → leftover radiation from the early universe, seen in every directionPrompt: It was predicted by the Big Bang theory.
- The Big Bang: which statement is true? (Red-shift means galaxies are moving towards us. / Red-shift is evidence that the universe is expanding. / The Earth is the centre of the universe. / The Big Bang was an explosion at one point in an existing empty space.) → Red-shift is evidence that the universe is expanding.Prompt: Which way are distant galaxies moving?
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- More distant galaxies show greater red-shift. What does this suggest? (Galaxies are standing still / Light slows down over time / The universe is shrinking / The universe is expanding) → The universe is expandingPrompt: Further galaxies are moving away faster.
- The Big Bang: which statement is true? (The Earth is the centre of the universe. / Galaxies further away are generally moving away faster. / The Big Bang was an explosion at one point in an existing empty space. / Red-shift means galaxies are moving towards us.) → Galaxies further away are generally moving away faster.Prompt: Which way are distant galaxies moving?
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: The life cycle of stars.
- Use concrete materials: torch and ball for a sun-earth-moon model.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-11.
Free lesson plan from eurekami.com/lesson-plan-builder