Our favourite demos: Demo Day

by science made simple

We hope that you are enjoying National Science and Engineering week!

We have all been on the road performing STEM shows to schools across the country, and even Hong Kong but we couldn’t let today (Demo Day) pass without celebration.

Check out David performing one of his favourite demos and each staff member writes about their most loved demo. We also have a fab resource of demos for you to try!

Can you put a mobile phone inside a balloon?


demo day 1


science made simple have teamed up with other science communication experts to share their knowledge on performing demonstrations! The British Science Association have taken these tips and combined them into this handy e-book. (Half way down the page.)





What are our favourite demos?

Here are, science made simple‘s favourite demos written up for Demo Day :


Our director started science made simple with a show about music and science (Music to your Ears) and she continues to be endlessly fascinated by the physics (and biology and chemistry and engineering) of music.


Play us a tune! Image: science made simple (CC-BY-NC)


Her choice is a simple demonstration that often catches people out!  Take a wine glass and fill it with water.  Dip your finger in the water and run it gently around the rim of the glass.  As your finger sticks and slips, the glass (and the water) vibrates, creating a sound.

Now remove some of the water from the glass.

Have a slurp, why not!


How does volume affect the sound? Photo: science made simple (CC-BY-NC)



What do you think will happen?  Will the sound change?  If it does, how will it change?

Once you’ve practiced you might even be able to play this simple instrument as well as this musician!




Our lovely bookings person/trainee presenter is leaving us shortly  but she’s going out with a BANG!  From an aerosol rocket.

Abigail says this is her top demo because

“It’s easy to make and it creates an explosion!!!!”

Bang! Image: science made simple (All Rights Reserved)

Plus, it was one of the first demos she was shown at science made simple.

The demo requires an aerosol, a cylinder with a hole in one end and a pop-off lid on the other and a piezo-electric spark.  It’s a great way of showing combustion and we also use it to help demonstrate how petrol engines work.



Whoosh! Image: science made simple (All Rights Reserved)





If you put a bit of extra effort into decorating your props you can even create a rocket with plunger, like the one Zoë’s using in this photo.




Our sms East presenter’s suggestion speaks of a troubled relationship with the pickling process. It’s Gherkin electrocution!

“This is a shocking effect which produces an awful smell as well as a bright yellow light.”

The effect is caused by excitation of electrons in the sodium ions present in the salty pickle.


Gaz forms one half of our Experimentrics/Visualise team, excelling in the beauty, spectacle and wonder of science in a show without words.  He’s chosen the fire tornado, partly, he says, because it links nicely to lots of other interesting things you can do with vortices, but also

“because it is actually a really beautiful thing to behold.”

Gaz and the fire tornado from Visualise (Photo: © Kiran Ridley 2007)

Gaz and the fire tornado from Visualise (Photo: © Kiran Ridley 2007- All Rights Reserved)

ketchup diver

Your kit. Image: science made simple (CC-BY-NC)


For Simon, the demo he used in his interview for sms clearly has fond memories.  He’s chosen the Cartesian Diver.  He says: ‘I think it’s my favourite as it’s portable, can be easily home-made, involves audience participation and leads clearly to an explanation – that air (gas) can be squashed and water (liquid) can’t, and that squashed air is more dense.’

You can find out how to make one yourself and discover why Simon is so taken with this yourself on our activities pages.


Our Cardiff Manager and presenter can often be found sporting a pair of fetching pink wellies. Her chosen demo, the water balloon and candle, might go some way to explaining why. She says:

‘It is great finale demo with lots of room for improvising with the volunteer and getting massive reactions from the audience.

“The heat capacity of water means you can not possibly burst it with a candle…scissors on the other hand…SPLASH!’

Water balloon and a candle, what could possibly go wrong? (photo: Mandy Tulloch Mud Pies)

Water balloon and a candle, what could possibly go wrong? (photo: Mandy Tulloch Mud Pies- All Rights Reserved)


on your marks sport

Your kit. Image: science made simple (All Rights Reserved)

Lots of demos rely on something unexpected happening and there’s certainly always an element of the unexpected in this demo.  Take a basket ball and a tennis ball (or a ping pong ball) and bounce each one.  Then hold them both in the air with the smaller ball standing on top of the the larger one (as Wendy is demonstrating in the picture to the right).

Let them both drop together. What do you think will happen? This demo also has an unexpected element for the presenter:


“You never quite know where the balls will end up!”


It’s always a surprise to see how much the smaller ball bounces. That extra bounce comes from the transfer of the bigger ball’s momentum to the smaller (lighter) ball. Rosie says:

‘I love the way the surprisingly big bounce you get from the tennis ball demands an explanation- the audience just has to know what’s going on’.


Ruth says she chose this demo because:

“Almost everyone has one, they all sound different, the sound is so unexpected, and you have to look silly to hear it, but no one minds!”

What on earth could she be talking about?  For this one you’re going to need to raid the kitchen, well, the oven anyway.  Take the metal grill from an oven and two pieces of string. tie one piece of string to each of two of the corners.  Wrap the end of one piece of string around your right index finger and the other round your left index finger.  Put your fingers in your ears.  Gently bang the oven grill against something.  What can you hear?  What can the people around your hear?  Will your friends ever look at you in the same way again?!


Our science busking supremo has chosen a classic demo for grabbing peoples attention because of ‘the wow it gets when people see it and again when they have a go at it.’  It’s the spinning cups: a great demo for showing how adding spin to an object can make it change direction, or even give it lift.

“It’s made out of everyday materials so why not have a go yourself?”

spinnning cups

Image: science made simple (CC-BY-NC)


We love simple, classic demos which can be done with kit you might have in your cupboards but sometimes you see something that just makes you smile.  Zoë has chosen a banana piano made using Makey Makey for her demo.

She says: I saw a video of a ‘bananamophone’ online, and just had to try it for myself. The great thing is, you can use anything that conducts electricity – bananas, plasticine, even a pencil drawing.

“The only limit to this demo is your imagination!”


If you’re a teacher and you’d like more ideas on why and when to use demos in your lessons make sure you watch Demo: The Movie from our friends at Storycog (Alom Shaha and Jonathan Sanderson)

We hope you enjoy demo day, pledge a demo and get set … DEMONSTRATE!

sms group shot with props smallWe are science made simple, a social enterprise who perform science, maths and engineering shows to school, festival and public audiences.
You can find out more about what we do, check out  our exciting range of shows, or sign up to our newsletter to keep updated on what we are up to!
Tagged with: , , ,
Posted in Activity, Exploring Science, News
Related pages