This is the CHaOS demonstrator website, mainly intended for our student volunteers. Click here if you were looking for our main front page.

New Volunteers

Welcome to the CHaOS webpage for new volunteers!

We're always looking for new people, so read on to find out how you can get involved with CHaOS...

Who are CHaOS?

We are a student society who run fun science outreach events outside of term time, with a variety of hands-on experiments for children, each explained by a volunteer student demonstrator.

Our events are run entirely by student volunteers, based on experiments that have been built, bought and borrowed since we ran our first event in 1998. CHaOS events are funded by a number of charitable organisations - helping us out will just take some of your time (and should be fun too!).

Our volunteers come from all science-related subjects (Natscis, Medics and Vets, Engineers, Mathmos and more) and range from first year undergraduates to final year PhD students (and beyond!). Some have explained science to the public before, but most of us did this for the first time at a CHaOS event!

How do I sign up for CHaOS?

As a volunteer at CHaOS events: If you're a Cambridge University student, you can sign up for the CHaOS email list (Soc-chaos-interested) at the mailman system. Log in via Raven and search for 'Soc-chaos-interested' then click 'subscribe'. If you've got any questions you can email us at

As a member of the organising committee: If you're keen on CHaOS and want to get more involved, why not become a member of the organising committee? We're always looking for people with a whole range of skills, such as planning/demonstrating/computing/building experiments, so drop us an email to if you'd like to know more. We've written a few notes about being on the CHaOS committee here.

When are CHaOS events?

We run a number of events just before or after term in Cambridge, such "Crash, Bang, Squelch!" in National Science Week at the end of Lent Term. We also take our experiments on tour each July, when the CHaOS roadshow visits schools, town halls and festivals around the country. There's more information on these events below:

March: "Crash, Bang, Squelch!"

Crash, Bang, Squelch! is our big event in science week (at the end of Lent term), where we have over 50 experiments from all areas of science, demonstrated by over 100 student volunteers.

We take over the teaching labs in the Zoology department, and have over 2,000 people through the doors. You can volunteer for morning or afternoon slots, or the whole day. You can sign up for Crash, Bang, Squelch! from around mid-February each year, and express a preference for experiments nearer the time. We try and allocate everyone to an experiment that they are happy to demonstrate, and have descriptions and explanations of our experiments available to volunteers. Find out more about our "Crash, Bang, Squelch!" here

Cantilever bridges

July/August: CHaOS Summer Roadshow

CHaOS takes experiments on tour to schools and town halls around the country for 1-2 months each summer. We pack our experiments and tents into a van, and about 15 keen volunteers into a minibus. In 2016 the roadshow will run from 27th June to 10th August; you can come on tour for a few days to a couple of weeks (we don't expect anybody to do all 7 weeks!).

You can find out more about the Summer Roadshow by:
1) looking at what we did last year (with plenty of photos) in the shiny roadshow reports here
2) reading our "demonstrator diary" page here
3) watching a short video from our 2009 Summer Roadshow here
4) having a look at the demonstrator advert for the 2011 Summer Roadshow here.

CHaOS covers travel, food and accommodation (mostly camping) - just bring yourself, a sleeping bag, and some enthusiasm! Sign up for specific dates for the CHaOS roadshow will be available in each Easter term - sign up to our mailing list for a reminder!

Also, do let us know if you know have any contacts in schools, town halls or festivals who might like a visit from CHaOS- they might fit nicely in a gap in the roadshow route!

roadshow volunteers

December: CHaOS Cambridgeshire Roadshow

Just after the end of most Michaelmas terms we also visit a few Cambridgeshire schools to run roadshow style events- these are great fun, but sadly there's no camping involved in December! (Most of our volunteers just stay in their college rooms for an extra day or two). We also often run a family event in collaboration with the outreach team at the Physics Dept and the local Institute of Physics. These visits are often the first ones run by the new committee, so are a great way to get involved in making CHaOS happen!

Physics event

Which experiment(s) will I get to demonstrate?

There’s a full list of all our experiments here:


At "Crash, Bang, Squelch!" in March we'll have almost all of them out. At a typical roadshow event it’s not possible to take all of them with us, so here’s a shorter list of ‘recommended reading’ (i.e. old favourites that we almost always have out!).

Biology: Kiwi DNA, Horrible Housemates, Microscopes and Cells, Animal skulls

Engineering: Arch Bridge, Cantilever Bridge

Physics: Hot Air Balloons, Near IR webcam, Polarisation, Resonance, Seeing Sound, Spinning Chair, Vacuums, UV, Electromagnetism

Medicine: Exercise and Heart Rate, Hand Model, Organ vest, Skeleton and Bones, X-rays.

Chemistry: Mini Explosions, Electrolysis.

That's all for now...

We hope to see you at a CHaOS event soon!