GET SET · Space
Get Set: Space · Session 1 · Session Support

The Start of the Universe

How did the universe begin, and what does it tell us about our place in it?

45 minutes Session 1 of 12

Got 10 minutes to prep?

Here's all you need to walk in and teach.

Session plan

The full lesson: what pupils will learn, how to run every stage, and all activity instructions and answers.

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Slide deck

Everything you put on the board, in order. Speaker notes included.

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Learner journal

For the plenary. Five-part reflection.

Editable version → Print version →

ITZA pathways

The link you share with the class for the 20 minutes online.

Open ITZA for students →

Main theme

When you look at the night sky you are not seeing the universe as it is. You are seeing it as it was, at many different points in history, all at once.

Teacher tips

Hook

  • Try not to use the word "explosion" yourself when you set up the calendar. It is the image most pupils already have, and once you have said it they tend to hold onto it. Describe it as space itself stretching, everywhere at once.
  • Before you reveal when humans arrive, go back to the most extreme guess. Ask whoever said June why they picked it. The jump to 11:52pm on 31 December means more when pupils have something to measure it against.
  • The bridge question usually pulls pupils towards "we are tiny and insignificant". That is worth hearing, but offer the other reading too. In the last few seconds of that year, the universe produced something able to work out how old it is.

ITZA Platform

  • Circulate with two specific things in mind rather than watching the room generally. Pupils get stuck on the scale of the Milky Way in Pathway 1, and the Moon's 1.3 second delay in Pathway 2 usually produces the best questions.
  • Anyone who finishes both pathways inside ten minutes is skimming. Check with one question they cannot answer from memory: why does a telescope show the past rather than the present?
  • You do not need everyone to finish. Progress saves, anyone who has worked through both pathways has enough to take part in the activity, and pupils can pick up the rest at home.

Class Activity

  • The difficult part is flipping the perspective. Pupils have to imagine looking back at Earth from a distant object, rather than looking out from Earth. Ask them to turn and face the back of the room and picture looking back at where they are sitting. That gets most of them there faster than any explanation.
  • Someone may point out that you could never really see this room from Andromeda, and they are right, no telescope could. Explain that the question is about when the light left, not whether anyone could make out the detail.
  • When you reach Andromeda, do not just confirm the answer and move on. Anyone watching from there right now would see our ancestors making their first stone tools, and the light leaving Earth today will not reach them for another two and a half million years. That usually gets more reaction than anything else in the session.

Plenary

  • Read the lock-in quote out and give pupils five or ten seconds before you say anything else. If there is time, ask two or three of them what they made of it.
  • Pupils tend to write facts in Part 1 and then repeat one of them in Part 2. Worth saying out loud that Part 2 is asking what they think, not what they remember.
  • The plenary is the first thing to get squeezed when the activity overruns. If you are short, prioritise Part 2, the reflective question, and set Part 1 for the start of the next session.

Misconceptions to watch for

They'll say

"The Big Bang was an explosion."

Actually

It wasn't. Space itself stretching very fast, not a bang in the middle of nothing.

They'll ask

"What happened before the Big Bang?"

Actually

There was no "before". Time began with the universe. Like asking what's north of the North Pole.

They'll say

"We see things as they are now."

Actually

A star 1,000 light years away looks as it did 1,000 years ago.

They'll say

"Space is empty."

Actually

Even a blank-looking patch of sky is full of thousands of galaxies, as Hubble showed us.

Extension tasks

Investigate

Ibn al-Haytham's camera obscura experiment. Why does blocking almost all the light from a room actually help you understand how light travels?

S1E1 · How Does Light Travel →
Reflect

Mitochondrial Eve. A tiny mutation in your DNA connects you to a single woman who lived thousands of years ago. What does that tell us about how closely related all humans really are?

S1E2 · The First of Us →

Curriculum links

Physics

Scale of the universe, the Big Bang, light years, telescopes, the expanding universe.

Maths

Very large numbers, scientific notation, ratio and proportion.

Geography

Earth's place in the solar system, conditions for life.

History of science

The story of astronomy, Hubble's discoveries, the space race.

Philosophy & PSHE

Our place in the universe, what we would say to an alien civilisation.

English

Communicating and justifying opinions, forming evidence-based answers.