Pecha kucha demos

9 08 2016

I was privileged to attend the BIG Event this year in Belfast and I enjoyed their cheekily titled “Best Demo Competition”. 

For those of you that haven’t seen the Best Demo Competition it’s cheekily titled because they don’t limit participation to those presenters who might be considered the best – this year there were novices and early career presenters alongside some demo wrangling stalwarts. They don’t expect the entrants to show a demo – this year just under half the contestants actually performed what might be considered a STEM demo, the rest were more science cabaret or science variety acts. And despite the fact no other events are programmed against it and there’s a trophy given out to the winner at the gala dinner described as “one of the least valuable yet most highly prized honours in UK science communication” there are no voting criteria and those attending the event are told not to take the competition bit seriously (LINK). 

(It really shouldn’t work but I’d recommend anyone go and see one if they can. As long as you don’t take the title at all seriously it is great fun.)

Entrants to the “Best Demo Competition” are given 3 minutes (or so – the winner went minutes over time… another example of how loosely BIG applies the term competition!) and this year most tried to put their demos into some sort of context. I think demo presentations should always have a story but I know this lead to some comments that the best demo competition was more of a best routine competition.

I thought more of a problem was this year most entrants chose to perform single concept-single demo presentations which I thought was a shame. 

Concepts explained with just one demo inevitably end up as being either show then tell or tell then show. Unless the presenter is happy to get on and get off fast there is always large amounts of speaking either before or after we see the demo. 

The time limit is a very good idea because it forces contestants to get on with it. I enjoy watching YouTube videos of the ASTEC Live Demo Hour but I think most of the performances could benefit from a stricter time limit.

The problem with the 3 minutes allotted to the “Best Demo Competition” in almost every case it is still far too long for the presentation of just one or two demos. 

The majority of contestants this year tried to fill or pad their demos with stage business to take up their allotted time. Unfortunately this padding more often than not distracted attention and focus from the demos rather than aid our understanding. I think this was what those people who were unhappy were unhappy with – story isn’t the problem, neither is a routine, but a weak story and/or overly long routine is. 

All but one of those who managed to perform more than one demo in their allotted time performed individual demos that were loosely themed to go together (eg: involving the same fruit or that looked like drinks) rather than scripted tightly to make a single concept-multiple demo presentation or what I would call a demo chain

The contestant I personally thought should have won performed three chained demos, way under time and didn’t resort to costume, dance or song to unnecessarily jazz up what she was trying to demonstrate. 

In her presentation we were shown two demos to explain the science she was trying to communicate (thermoclines). The first demo most of the audience would have been familiar with (see picture below) but the second was new, at least, to me.  Then we were shown a third big finale that combined the previous two demos and reinforced the science underpinning the presentation that I thought was excellent. 

This brings me to Petcha Kutcha

The Petcha Kutcha (PK) format was developed in 2003 to specifically deal with the problem of speakers talking at too few slides for far too long. It was originally conceived for architects but as they say in the PK FAQ we can all fall in the same trap:

Give a microphone and some images to an architect — or most creative people for that matter — and they’ll go on forever! 

The PK format is simple. Each speaker talks whilst 20 slides play in the background for 20 seconds each. This means you avoid the problem of too few slides – everyone has 20; and you limit the time anyone can speak – 6 mins and 40 secs. 

The time limit is part of our “Best Demo Competition” format. Could our presentations benefit from insisting on a certain number of demos as well?

I have been asked to take part in a PK event and instead of talking whilst 20 slides play for 20 seconds each I thought about trying to perform 20 demos instead. 

The only way this would be possible would be to chain my demos so each linked to the demo that came before and after and helped tell one consistent story. There would be no time to explain and perform even one unconnected demo in 20 seconds. What I envisage is a series of linked demos, most using the same equipment, that can be woven together in the way series of card tricks are woven together in a magician’s routine. 

Half the time I think about this 20 seconds seems impossibly fast but then 20 seconds for many PK speakers ends up seeming a very long time when they are on stage. This very talented PK speaker shows this perfectly at 1:50.

If my PK experiment presentation works, next year at the BIG Event I might suggest as session where we explore this further. Perhaps a strict 20 seconds per demo will prove unworkable and unnecessarily rigid but it should be easy to ask people to perform at least three chained demos in two minutes – my favourite “Best Demo Competition” entrant took this long to perform her three demos. 

I’m looking for inspiration towards the work of Steve Spangler who always manages to chain his science demos and magicians like this. 

I count 11 reveals of the same “Ambitous Card” in just 2:40 mins!

I’d be fascinated to hear from you if you’ve tried something like this yourself or if you’ve any footage of someone that has. And as usual I encourage people to post any comments. 


Annotating shows

30 07 2016

This is a picture of a page from one of my numerous notebooks where I have annotated a science show.

I’m not in a position to describe my annotation system in any detail at the moment but I will soon.

If you are reading this because of a thread on BIG chat this post will make more sense…



Keep to time

10 06 2016

An absolutely essential skill for every science presenter is the ability to keep to time. 

Often you will be sharing a stage with other presenters, or your audience will have another talk to get to, it is essential that you don’t overrun. 

A couple of minutes might seem like nothing to you, perhaps your audience was late arriving so you feel you have the right to go on a bit longer, but the sign of a professional presenter is one who selflessly gets the program back on track not selfishly compounds the problem. 

I think the best way to think of your overrun isn’t just as the time you go over but the time you go over multiplied by the number of people you’ve kept back. All of a sudden those 3mins you stole look more of a problem when you multiply them by 50 (or perhaps many more). 

At one British Science Festival event I was performing to groups of 300 (10 classes of 30). Another presenter in the session before me was presenting to just one class that were then sent on to me. He was mortified to learn that what he thought had been his harmless 5-10 minute overruns for 30 had actually been consistently delaying over 250 people in the next session. He had no idea where the group was going to next and he felt entitled to “steal back” the time as the audience was arriving late to him. To give him his due when he found out he fixed the problem but there should never have been a problem in the first place. However frustrating I found cutting my material, and however justified I might have felt to take extra time to compensate for what I’d lost, I never did. This was noticed by the organisers and the teachers who’d brought their children and made me look more not less professional. 

The first way to avoid overruns is to be absolutely sure what time your session must end. I will ask the organiser the time I have to finish and write that time in large figures on my notebook. I leave it open on my props table so when I inevitably forget I can glance down and check.  

Ensure the organiser has included the time the audience might need to get to their next appointment. Often “finish at 1pm” on further investigation actually means “finish at 12:50pm” because it will take that time to move the audience on. 

Be wary of clocks in your performance space. Often they will be many minutes out and it’s all too easy to go over because of it. When you ask what time you need to finish it’s a good idea to check everyone is working off the same time too. 

Be prepared to cut or stretch your material to deal with unexpected timing issues. There are always times when you might be delayed starting your presentation or there might be a delay (like a fire alarm) once you’ve started. 

At the most extreme you might have to drop a whole section. It’s easier to stretch. You can ask for questions at the end and no one really minds things ending a little early. If you’ve lost thine there are ways to speed things up:

For instance instead of doing three demos in a chain you might do just two. Instead of asking a question can just state the fact. And carrying out a demo by yourself instead of (announcing, selecting, moving, instructing, thanking and then re-moving) a volunteer can save many valuable minutes. 

Yes, you’ve compromised your material, but only you will be aware of the fact. Getting back on track and finishing on time is much more important. 

Speaking groups like Toastmasters quite rightly put great store on talking to time. They will use devices to help speakers know the time they have left. Sometimes you see such devices at political conferences. 


Tools like PClock can help with timekeeping. I have copies on both my iPhone and iPad and I’ll use them to help keep me on time.   

You can set the countdown in three sections. The colours change (and the device vibrates) to show you the section change. 

Here I can see I’ve got lots of time left. Even if I don’t read the figures I can see they’re green. At 10:00 they are programmed to go yellow. 

If they’ve gone red that means I’m into my last 5:00 and I’d better think about how I’m going to bring things to a halt. 

If I’m being honest normally I can just rely on my watch. I’d only use PClock myself if it was a new show or if time was extremely important (ie: I’ve got to finish to the second and I can’t go over or under).

Every now and again I’ll meet a presenter who goes on stage without any way to check the time. Sometimes they’ll even be proud of the fact they don’t even have a watch. Don’t be like them. It’s not big or clever. Going over is rude and selfish. Even if the organiser says nothing at the time it’s a sure fire way to not get booked again. 

If you really struggle I’ve seen presenters that wear devices like vibrating watches so they can’t miss their allotted stopping time. 


Sometimes if you are going over the organiser will make signs at you. If you see an organiser circling their pointed finger it means “wrap it up”. If you see hands in the shape of a T it means “time to stop, now”. 


TV has a series of signs used to communicate information. If you ever get the chance to appear on TV it is well worth making yourself aware of those. 

If you do you’ll avoid having to be cut off like I was at the end of this section of TV in Ireland. 


European peace visualised

6 06 2016

“If watching the news doesn’t make us feel hopeful about where we are heading watching the numbers might.”

My grandad was a product of his time. In the late 1980s as I was trying to find my adult political feet he was turning 70 and we would argue regularly about the issues of the day.  

We passionately disagreed about Margaret Thatcher and privatisations; Nelson Mandela and apartheid; and Alf Garnet and what one could acceptably say in public. 

So one Sunday after lunch when I asked what he thought about Europe (at the height of the ERM crisis) I was shocked at his reply:

The European Union is the best thing that’s happened to this country. 

I was a teenager looking for a good argument – I didn’t expect him to say that. 

His reasoning was simple:

My father fought in a world war. I fought in a world war. Because of the EU my children and my grandchildren haven’t had to. 

On 23rd June we will get to vote in the EU Referendum and I will be voting to keep the UK in. Whatever your opinion and voting intention I’d recommend watching this video. 

It is a powerful visualisation of the numbers of people who died in Europe and across the world in WW2. It belongs on this blog as a brilliantly simple piece of data visualisation. If it contributes some interesting information that might help you make up your mind about which way to vote all the better. 

[If you don’t have time for it all watch from 3:15 to 7:00 to see the staggering numbers of German and Russian military deaths or from 7:30 to 12:00 European civilian deaths.]

As we are shown and told in the video:

More people died in WW2 than in all the wars since despite the world’s population having increased threefold. 

The largest 44 economies of the world have not battled since WW2. And

Sometimes we need to reminded of the horrors of war to notice the peace that we now enjoy. 

I can’t guess how my grandad would have voted if he was still with us but I suspect, despite all the things we’d be still disagreeing about, we’d both agree to vote “In”. Whatever the faults of the EU it’s helped give us peace since WW2 and that’s a very good thing. 

Science nuggets

23 03 2016

My three evaluation questions are What’s the Story? Who’s the Audience? and Where’s the science?

Today I’d like to think a little about the third question. 

Every science demo we perform relies on or reveals an essential nugget (for want of a better term) of science. The way we explain that nugget of science depends on our Audience and the Story we have chosen to tell. Nevertheless each demo is still underpinned by a nugget of science and if we fail to get that across we might as well not bother with anything else. 

Take this classic demo.

You probably know what’s going to happen. The little ball is going to rocket up off bigger ball. It’s a spectacular self-working demo that requires cheap non-specialist equipment. No wonder it is such a popular choice for presenters. 

The demo is comprehensively described on the page where I took that picture from. What is the nugget of science in this demo?

Most times I see this performed the balls are dropped, the little ball shoots off, we are asked to marvel at what happened, often we are shown it happen again, then it is explained. 

But what’s the nugget?

It doesn’t matter who your Audience is or what your Story the nugget here is that 

the basketball doesn’t bounce as high with the tennis ball on top

If your presentation of this demo doesn’t get across this simple point that the basketball will bounce to one height by itself but a lower height with the tennis ball on top then you’ve missed the nugget. 

All the talk of conservation of energy and transfer of momentum will mean nothing if the different bounce heights haven’t been noticed. 

Once you’ve identified the nugget then then the best presentation of the demo should be clear. In this demo we need to show the balls dropped separately then together. 

This video does a very good job of explaining it. 

It should be clear from watching this video that explaining this demo takes time and you can cover many science topics with it. What they do well is show the nugget: the basketball doesn’t bounce as high with the tennis ball on top.  

This video gives another example to stress the point. Someone double bouncing someone on a trampoline will send the other person higher but they won’t go as high. 

We must search for the nugget in every demo we perform. Every demo has one single piece of scientific information in it that, however we choose to present it, must be got across. 

I’ve just had the pleasure of spending a week working with liquid nitrogen. The context for the show was space and I was able to use the LN2 to demonstrate alien atmospheres, the formation of clouds, changes of state, reversible and irreversible reactions, fractional distillation and water content in living cells but I was careful to not lose sight of LN2’s science nugget:

liquid nitrogen is the coldest substance you will ever encounter

If you are working with LN2 and your audience hasn’t grasped that liquid nitrogen is unbelievably cold then whatever else you’ve tried to get across won’t have been properly understood. 

I know reading this that probably sounds obvious to you. If you’ve managed to get your hands on a dewar of LN2 then your training will have stressed the extreme cold to you. Remember though the audience might not have seen LN2 before and even if they have it was probably at another science event where it’s properties might not have been properly explained. 

Just as with the ball on ball demo height difference you must cover the extreme cold of the LN2. How do you know if you’ve covered the nugget? Ask your audience. 

If I was being honest I’d say more than half, maybe even three quarters of the LN2 demos I’ve watched over the years haven’t stressed the extreme cold enough that the audience has grasped it. I always get someone in the audience of a LN2 show I’ve watched to tell me something about the LN2? Too often, even after prompting, they can’t tell me that it is incredibly cold. If someone in the audience of a show I’ve done can’t tell me I immediately review how I’ve explained it. 

Take the fizzy tablet dropped into a film canister demo. Here’s the wonderful Steve Spangler performing this demo. What’s the nugget?

Here the nugget is when the tablets get wet they fizz. He demonstrates this simply by putting a couple of tablets in a glass of water. 

It is too easy to assume that your audience will know what an Alca Seltzer tablet does and forget to stress this nugget. If you don’t show the tablets fizzing then everything that follows might be misunderstood. 

What you then do with the nugget is up to you. Acid plus base reactions, build up of pressure, solids and liquids taking up less space than gases, compressibility of gases, friction and seals can a be discussed but just as with the LN2 and the balls if you’ve not covered the nugget you’ve massively reduced your chances of your audience understanding anything of what you are doing. 

the basketball doesn’t bounce as high… the LN2 is extremely cold… the tablets will fizz when they get wet

Find your nuggets in all your demos. Take the time to cover them clearly. Only then go on to show or explain what you’d planned. 

There’s one more excellent example at the start of the Steve Spangler clip. He demonstrates the cornflour on a speaker. 

What’s the nugget with the speaker demo? The speaker is vibrating

Steve takes the time to show this using some ping pong balls. That bounce out of the speaker. 

It’s such an obvious and simple thing to show but in all the times you’ve seen this demo being performed ask yourself how many times have you seen a presenter take the time to show this absolutely vital piece of information? 

Too many stories

22 03 2016

In my last post I spoke about Lawrence Bragg who recommended presentations aim to get across just one main point. In the parlance of this blog we’d say a presentation should have one clear story

A few months ago I was performing a new show at a festival. I struggled at the start of the week and it wasn’t until two days in I realised why. My presentation had two stories instead of just one. 

I’d started out writing a show about one theme and then been totally smitten by another theme that emerged from my research. I tried to deal with the new theme within the context of the first and it was a mess. 

Just when I was making progress with my first theme I’d feel like I was ignoring the second so I’d jarringly switch to cover that. Then the same would happen in reverse. 

It was confusing for me and watching back a video I shot of the show on day two I could see it was confusing for the audience as well. 

The reason I’m not being more specific is that whilst my show was confused and confusing I fixed it by day three*. At the same event there was another show that had a worse problem. 

This was an established show by an experienced performer who has never asked for feedback so I’m not going to out them here but their show had three competing stories. 

It was really frustrating to watch as there was so much good about the show. The presenter should be applauded for trying to include story in their presentation. There was just too many stories competing with each other. 

Lawrence Bragg really was correct when he said there should ideally be just one. Too many stories can be as bad as none. 

* I fixed my presentation by splitting the show’s themes between two different age groups. I’d use the same equipment and mostly the same demos for two different age groups but use one story for the younger ones and the other for the older ones. 


Potpourri revisited

7 03 2016

A while back I wrote about what I like to call Potpourri Shows. A potpourri is an assembly of dried flowers and spices that smells good but it also refers to

a mixture or medley of things

Now that sounds good. We could maybe write a science show that was a selection, an assemblage, a melange even a miscellany of demos and concepts?

But hang on. Maybe if we did that our show could end up as more of a ragbaga hotchpotch and a mishmash than an attractive smorgasbord.

And as our job is to enlighten and inspire we certainly wouldn’t want to put on a jumble or, heaven forbid, a farrago

These last few weeks I’ve had the pleasure of seeing no less than four very competent performers present shows that fell well short of the standards they should and could be achieving because their chosen show titles were little more than potpourri camouflage.

You should be able to describe the story, the theme, the big underlying idea of your presentation in a single sentance. A potpourri show by definition will fail this test because by its very nature as it jumps from unrelated demo to unrelated demo it brings in far too many competing concepts. (However carefully its real nature has been disguised with a clever title that gives the impression of a theme like “Science Magic!” or “Chemical Chaos!”).

If you won’t take this advice on my say this is what Lawrence Bragg of the Royal Institution has to say on the matter:

How many main points can we hope to ‘get over’ in an hour? I think the answer should be one. If the average member of the audience can remember with interest and enthusiasm one main theme, the lecture has been a great success. 


Sir Lawrence Bragg (1891-1971) winner of a Nobel Prize at 25, Cavendish Professor of Experimental Physics at Cambridge and, most importantly in this context, Resident Professor at the Royal Institution for 13 years and the founder of the weekly ‘Schools Lectures’ for children. 

If just one main point was good enough for the man who presented his lectures to an estimated 100,000 children over the years at the RI then it should be good enough for us as well. 

Ditch the potpourri shows, find a compelling story to tell and take the time to tell that one story so we go away feeling your enthusiasm and excitement. 

It is all to easy to set out to make a delicious olla podrida but end up instead with a right gallimaufry. And no one wants that.