Things that make you go Boom! Exploding science

Things that make you go Boom! Exploding science

It started, as so many of these things do with a simple question: “Andy, do you think you could…?” To which the answer is always “Of course I can.” Followed by wondering how to do it. In this case it was could do something about Southsea Castle for a group of non-engaging teenagers. “Of course I can.”

Where to begin?

Things were complicated by the short timescale involved: I had a day to create and prepare, ready to deliver the following afternoon at a site I don’t know that well. No problem. There was absolutely no possibility of this exploding in my face. None at all.

Anyway, down to business.

The morning was dispatched bringing my knowledge of the castle up to date. Apparently, the history of Southsea Castle can mostly be characterised by the following: “Quick, build a fortress: the French are coming! Actually, I don’t think they are after all. As you were.” Over, and over again.

So, I had an hour and a half to fill with activity around a fort that kept gearing up for invasions that never came. A process that ensured it was always obsolete by the time it was (re)built.

There wasn’t a lot to go on There weren’t even that many things exploding to keep people’s interest.

When in doubt, do science

Like it says: sometimes, history isn’t always the way into a subject. Sometimes, science is a better engager. After all, you only need to be impressed by the exploding thing for it to be interesting. You don’t need to know the chemical formula for it.

So, science it was then.

What was the best science thing to do to link to an artillery fort…?

It took an embarrassingly long time to land on the obvious answer: guns and explosions.

Years ago, I designed a family session based on vinegar and baking soda rockets. The idea was simple: use the reaction of an acid & a carbonate to produce carbon dioxide. Keep that CO2 enclosed in a bottle until there’s enough to bow a cork out of a bottle. That failure produces propulsion that launches the bottle through the air.

Dead simple. Dead easy. Reliable activity.

One small problem: I was building this from scratch and had no materials. No bottles, no acid, no launch tube, no nothing. And I had until close of play to assemble all of this mysterious kit. No pressure.

Shopping for an exploding grapefruit

Ok. Now to build a session round these rockets.

Not a massive problem. Southsea Castle is an artillery fort, so we can talk about gunnery, we can talk about obsolescence, and we can do gun-loading drill. That will lead nicely into launching stuff across the common.

So, all I need is a pair of cannon that have a deep tube at one end and a shallow tube at the other. One that’s big enough to be impressive for teenagers who are well versed in not being impressed. Oh, and I need a stand to put it on.

Got it! Drainpipe. Not the stuff that goes from your gutter to the ground but the big brown ones that go underground. 110mm diameter tube. 3m long. We have a winner. A quick bit of sawing and gluing later and I had something that looked like a cannon, albeit a brown one.

Cannon, apparently

Cannon, apparently

Bags of gunpowder came courtesy of some crafty sewing and some sand.

Powder bags

Powder bags

The only thing remaining is something to use as shot…Something that looks sensible in an 11cm tube. This is supposed to be fun. I know: grapefruit. Let’s fire some grapefruit! That’ll be a lot of fun.

The baking soda rockets requires a trip to the baking isle at Tesco (other supermarkets are available) and some corks that I keep in the bottom of a cupboard. A few odd bits and pieces to make it work and we’re good to rock and roll.

Gun battery

Gun battery

Now to make it an exciting afternoon for disinterested teenagers.

No plan survives contact…

It was a hot day in Portsmouth, ideal for people being grumpy and low energy.

It was pretty clear in about 10 seconds that the tour I’d written was going out of the window. Instead we talked about the bizarreness of this fort that kept being built and rebuilt for an enemy that never came. In between neglect and incompetence let it descend into near ruin. This lead to one of the memorable quotes of the afternoon:

“Were all people in history thick as pig…?”

On the basis of this story, many of them appeared to be. It was going better than it might but there was still a palpable lack of energy.

Move on.

And now for something completely different

Let’s go outside and blow things up.

I’ll be honest, the gun loading drill was a bit flat. They were talking to me and moving around but there wasn’t what you might call “engagement”. They kept asking about whether there was going to be any exploding.

Ok, let’s blow some stuff up then.

Under normal circumstances I might have talked about the chemistry of the reaction, or of the physics of the propulsion. In this case, that went in the bin. They wanted the big bang and as little preamble as possible.

So we built our rockets. There was the usual level of not listening to instructions, and things being dropped, which warmed the atmosphere notably and began to generate some enthusiasm for the task in hand.

Eventually, we were ready to start firing. The range was clear, they were enthused (though cautiously) and ready to go.

The danger of it exploding in the face

There’s always a hint of trepidation at this point, no amount of testing guarantees something as “shed science” as this is going to work properly. It’s quite susceptible to people not doing it right. I’m always nervous.

However, there was nothing to worry about. The first participant looked, worryingly, as though he knew exactly what he was doing. And it launched brilliantly, fired a good twenty yards across the field and was described as “bare wicked”.

Not everyone’s worked properly, but that’s part of the charm. Particularly the instruction to “shake once and then quickly into the tube” seemed to go in one ear and out the other. Several of them had their rocket go off in their hand, which caused huge hilarity. One of them pushed the cork in so hard it went into the bottle and were perplexed as to why it didn’t work.

It was great fun. Everyone seemed to be enjoying themselves and talking to me. I couldn’t have asked for more.

And the moral of the story

This session was great fun. It’s going to become something I offer to schools as a science of forces experiment session.

But, the real point of it was that when someone asked “Andy, do you think you could…?” the answer was “of course I can.” Yes, I ran around trsying to make it happen. Yes, I had to rebuild the session on the fly. Yes, it wasn’t what I had planned. But the point is that it worked.

Some of them even wrote that they had “fun” on their evaluation.

So, if you fancy having some exploding learning fun. You know where I am.

Posted by Past Participants Andy in Session reports, 0 comments
STEAM Powered girls

STEAM Powered girls

Last week I delivered a science session where two 9 year old girls were overheard explaining the concept of ground pressure to each other.


OK, let’s go right back to the beginning.

Away back in the depths of time, by which I mean a few years ago, there was maths, there was, science, there was engineering. These subjects, or ones closely related, were taught at schools. Someone cottoned onto the fact that they were not seen as cool, and that they were not popular for students. So they decided to find a way of making them cool. They grouped them together and called them STEM (science, technology, engineering and maths). Someone in government noticed this and, as well as realising that scientists, engineers and mathematicians were economically valuable, decided that this was something worth funding.

So people started focussing on making STEM exciting for people, in the hope that they would choose them for further study or, at least, have a reasonable understanding of them. And people began to take notice. Cool things aimed at teaching “STEM” began to appear and everything was cool.

Except that it wasn’t. Whilst some STEM teaching was amazing and fascinated people, there was a perception that it was easy to make reductive. It began to be seen as boring. More concerningly, it gained a perception as being “for boys”. It gained a perception (rightly or wrongly) as turning off creatively-minded people. Particularly girls.

So some other people decided to do something about it. They decided to put the creativity back in. They added “arts” to the mix. This created STEAM, a much more pleasing acronym if nothing else.

STEAM was taken to mean using science and maths creatively, using science and maths in an entrepreneurial way (whatever that actually means), taking these subjects out of the lab and the classroom into a more freeform environment. It was specifically aimed at telling people that “science and maths are for you, even if you find that kind of thinking difficult.” It was particularly aimed at enticing girls.

And that attracted money.

Which is where I come in.

Reaching out

Hampshire Cultural Trust secured some money for developing STEAM activities at some of its museums with the goal of widening participation in the north of the county. They hired a group of learning people to design those activities. One of those professionals was me.

I was asked to work with Aldershot Military Museum to create something.

After a long chat with the people at Aldershot, we decided that they’d really like something about their military vehicles. For a very small site, their collection of military vehicles is really impressive. Particularly for someone like me who is definitely not an engineer.

I didn’t even know there was such a thing as a “favourite tank fact”, much less actually have one.

It’s been a steep learning curve.

We designed a session where the students play members of a fictional regiment who have to create vehicles to get to remote villages to deliver aid after a natural disaster. They are given a problem but they can solve it any way they like.

The idea is that they go and look at the actual vehicles and use them as inspiration and to help their understanding of the concepts involved.

There are all sorts of links to the STEAM areas of the National Curriculum but they are lurking under the surface during the session as the children focus on getting help to stranded people in time.

 Making models

In my wisdom and in possession of a reasonable budget I decided that we would give the students kits to actually build the models of the vehicles to meet the challenge. I found a German manufacturer of meccano-like kits for education and set to work on putting kits together.

My first attempts to build something with the kits is detailed in embarrassing detail in this post.

After that, I honed in on what we wanted to learn and built some kits that the students would use to build their vehicles. Each of those kits takes about an hour to put together from the box (apart from the bits that need glue: they take a little longer). Which is fine except that there are six of them.

Knowing how much each bit weighs and how big some of them are I could make calculations about what properties different configurations might have.

Now all I had to do was design a session that would help children understand weight, power:weight ratio and ground pressure.

(Ground pressure is the footprint of an object divided by its weight. It’s a measure of how much force is put through each metre square of a surface it’s on.)

If you will excuse the pun: no pressure.

The heat of combat

The first test of the session showed that the session was sound but needed a lot of work. I had tried to introduce too many things at once and things got confused. Not back to the drawing board, but a rethink of the process.

So I created this amazing map of the island they are supposed to be on and a series of small missions so that they work through the concepts as well as giving more people a chance to get their hands on the metal.

It looked great and there were some funky, if I do say so myself, materials I’d designed to go with it.

Second time of asking: STEAM hot

The second test was a very different affair. We walked through the concepts, literally in one case. We managed to clear up the footprint and feet are not necessarily the same thing. We even managed to talk about ground pressure and why it’s important.

Then we set them loose with the kits and chaos ensued. Don’t get me wrong, they were having a blast and learning. But it was bedlam all the same. They all managed to build something that came in under the target weight.

The second mission saw them trying to build something with a certain power to weight ratio. That caused issues, but they understood that they were trying to build something as light and as powerful as possible. They actually got through that with the minimum of fuss.

Then came the acid test: could they build something with a ground pressure low enough that their vehicle wouldn’t sink in a bog? Actually, can they understand what ground pressure is? The answer is yes, even if the term kilopascal causes all kinds of confusion.

This is where the two girls were observed explaining it to each other. It was priceless. Not because it was funny but because they had clearly understood it perfectly. Even if one of them couldn’t remember what it was called. We also saw a number of girls actively wrestle the build kits away from the boys because they wanted to do some engineering. Really.

You cannot buy that kind of engagement.

Operation: forces

It was a great session and a few minor tweaks away from being spot on. It’s even got a name now: Op: forces.

So, if you are looking to engage people with STEM then STEAM with its emphasis on problem solving and creativity may well be what you’re looking for.

For more information on the session, look here. There might well be offers on for early adopters.

Favourite tank facts

Remember that?

I now have two:

  1. My bicycle (158kPa) has a higher ground pressure than a 70 tonne M1 Abrams Main Battle Tank (105kPa).
  2. The British army has more horses than tanks.

So, now you know.

Posted by Past Participants Andy in Session reports, 2 comments