An overview of "Crash, Bang, Squelch!" 2019 for volunteers

Sign-ups for CBS 2019 are open! Click here to sign up!

The biggest CHaOS event of the year is "Crash, Bang, Squelch!", which happens on the first Saturday after lectures finish in Lent term (for 2019, this is Saturday March 16th). We'll take over the Zoology Department in the New Museums site (right next to the whale), and fill it with lots of own exciting hands-on experiments. We need lots of enthusiastic student volunteers to help demonstrate them to the public, which is where you could fit in! It involves as many as about 150 student volunteers, and we manage to fit about 2,000 visitors in during the day, which is as many as we can safety let through! As this Saturday is always after the end of lectures, so you can have great fun helping out without worrying about work! It's a lot of science and a lot of fun in one place!

What exactly does it involve?

We've got a huge number of hands-on experiments, almost 200 at the last time we counted, that we've designed to demonstrate interesting scientific principles. On the day of the event each of these is explained to children and families by student volunteers. You might find yourself demonstrating how bridges stay up, pulling the DNA out of a kiwi or even introducing children to Boris the friendly skeleton! The ideas are simple, but with enthusiastic and interested demonstrators we can show children that science isn't a 'boring' subject. Check out our experiments here

You can choose to demonstrate in the morning or afternoon (the event is open to the public 10am-5pm), and if you choose to do the whole day we'll even provide you with a free lunch (whoever said there was no such thing?). Even better, there is a free party after the event for all those who help!

If you want to see a few pictures, our reports of what happened at "Crash, Bang, Squelch!" in previous years can be downloaded from here (2012) , here (2013) and here (2014).

I've never done anything like this before... will I be any good?

No experience is necessary, and every year we have loads of people who haven't done CHaOS before. If you're a scientist (including mathmos, vets, medics, engineers, compscis,...) you already know more than enough to demonstrate. The experiments have interesting and useful descriptions to explain the science and if you are unsure you can always ask one of the friendly committee members. We'll also run several briefing sessions just before the event so you know exactly how everything will work on the day.

How to sign up

Click here to sign up!

We release a sign up form for "Crash, Bang, Squelch!" in Lent term each year. This will be linked from our main demonstrator homepage, which you can find here. If you sign up to our mailing list (instructions are here) you'll get an email telling you when the signup form is available, and about any other events we're doing!


If you've got any questions about Crash Bang Squelch!, or about CHaOS generally, please get in touch with us at

[Note: In previous years people have confused Crash, Bang, Squelch! and other Science Festival events, some of which also happen on the same Saturday ... Obviously we think Crash, Bang, Squelch! is the most fun, but it makes everyone's life easier if you make sure you're not double booked!]