Key Stage 4 - Particle Detectives
Looking back in time
Notes for teachers
At a glance
In this lesson, students explore how physicists are collecting and using evidence from the Large
Hadron Collider (LHC) to learn more about the origins of the Universe. They begin by watching an
animation set in the LHC, and learn that physicists are using the LHC to try to recreate the conditions
immediately after the Big Bang.
In the main part of the lesson, students take part in a jigsaw activity in which they use selected web
sites to research the roles of four LHC detectors. Which particles are each detector designed to
detect? Which theories are physicists testing? To conclude, students discuss some important
questions, including the role of international collaboration in science, and what happens if newlycollected data does not agree with established theory.
Learning Outcomes
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Students understand that physicists are trying to learn more about how the universe started.
Students understand that physicists do this by trying to recreate the conditions immediately
after the Big Bang, examine the data thus produced and then refine our models of the
universe and the Big Bang.
www.oxfordsparks.net/animations/lhc
Possible Lesson Activities
1. Starter activity
 Show the animation ‘A quick look around the LHC’ to the class.
 Pause the Animation at the point where we see the ATLAS detector from the outside, with
the collisions about to take place [1 min 41 sec]. Explain to the group that physicists use
telescopes to make direct observations and measurements of the Universe. Over several
hundred years, this has enabled physicists to work out the relative sizes, positions and
motion of the objects in our Solar System and of distant stars and galaxies.
 By examining this model of the Universe, physicists have developed theories about how
our universe has developed, with the central idea being the Big Bang. However, although
we can model the universe since the moment of the Big Bang, we don’t really understand
what happened during the Big Bang. Physicists use the LHC to recreate the conditions of
the Universe fractions of a second after the Big Bang to find out more about the particles
that were present and their properties.
2. Jigsaw Group activity: Researching the different LHC detectors
 Divide the class into three groups and provide each with Pupil Worksheet 1, 2 or 3. Ask
each group to research a different LHC detector:
 Group 1: Worksheet 1 - CMS and ATLAS [products of high energy collisions in general]
 Group 2: Worksheet 2 - LHCb
[matter and anti-matter]
 Group 3: Worksheet 3 - ALICE
[conditions fractions of a second after Big Bang]
 Ask each group to explore which theories each detector is testing and how. You might like
to show them the LHC rap as an overview (see our top external links). Each group
completes their own section of Worksheet 4 for sharing in the next stage.
 Home groups are now formed so there is a member from each of the groups in the first
stage. The expert from groups 1, 2 and 3 feed back their research in turn and pupils fill out
that section of Worksheet 4. By the end, Worksheet 4 should be completed by all pupils.
3. Plenary
 Once the class have completed Worksheet 4, ask them to discuss the following questions:
 What is the name of the theory or model that scientists are trying to test at the LHC?
 Would scientists be able to test this theory with only one of these detectors?
 Would one group of scientists from any one country be able to develop these experiments
on their own?
 Are there other big scientific projects/experiments which need to be designed like CERN in
order to succeed?
 What happens if the scientists take measurements that don’t agree with the existing
theory?
www.oxfordsparks.net/animations/lhc