Norwich
DAY ONE
Harry White is excited. 鈥淭his is a place for wild ideas,鈥� he says, holding an empty soft drink bottle in one hand and a light bulb in the other. The 鈥減lace鈥� is the base of a large astronomical dome at Herstmonceux Science Centre in East Sussex. All around him a small band of dedicated men and women are unpacking tools and equipment and preparing for the work ahead. Their raw materials are simple: ideas, ingenuity and a large pile of battered bicycles, old ladders and chairs, even torn dishcloths and jam jars. Junk, in any ordinary person鈥檚 parlance.
But this is no ordinary group of people. Harry and the others are 鈥渇abricators鈥�, an eclectic mix of exhibit builders who met last month to design, build and demonstrate hands-on science experiments. Not the kind of experiment you鈥檇 find in any conventional lab, mind you. Their aim is to come up with fascinating, inspiring and occasionally mind-boggling experiments that communicate some kind of scientific concept or idea to anyone who cares to try them.
The demonstrators are competing for the prize of Best Demo awarded at the end of the meeting by the organiser, the British Interactive Group, an association for people involved in hands-on science communication. The best demonstrations may even end up as exhibits in the growing number of science centres and museums that are popping up all over the world. During the next four days their demos will slowly take shape in the form of strange devices and machines that rock, blow, sing or burn.
Advertisement
Harry is already hard at work. His wild idea involves 鈥渞heoscopic fluid鈥�-a gloopy, silvery liquid that he has brought with him specially. Rheoscopic fluid is a liquid containing reflective particles-fish scales, for example-that make flow patterns visible. It鈥檚 also the ingredient that gives shampoo and conditioner their sheen. 鈥淚鈥檓 going to put the fluid in the bottles. Put the bottles on top of the light bulb and see what happens,鈥� he explains enthusiastically. His idea is that heat from the bulb will create weird and wonderful convection patterns and that the rheoscopic fluid will make them visible. Harry says it will be a lava lamp for the Nineties and gets to work.
Andrea Aird will also be working with fluids. Andrea is Australian. She is planning to drink her own urine to demonstrate that, well, it can be done. 鈥淚t鈥檚 extremely good for you,鈥� she explains. A small group of Ethiopian observers from a science centre in Addis Ababa seem unpersuaded. Her demo is scheduled for tomorrow.
Meanwhile, Steve Pizzey, managing director of an educational charity called Science Projects, has created his first demonstration outside. It consists of a ladder balanced across an office swivel chair. A few sandbags the size of bags of sugar lie piled up nearby. 鈥淚 hope I don鈥檛 hurt anyone,鈥� he says, asking for three volunteers. Surprisingly, nobody appears willing so I head back to the dome.
Inside, Malcolm Mackie is building a science puzzle. Malcolm works at Satrosphere, a science centre in Aberdeen, and is an old hand at this kind of thing. His demonstration is a little more ambitious than the others, at least in terms of its construction. The puzzle consists of a large container the shape of a lemon slice that can rock backward and forward. The container has a hole high up at each end and there are two golf balls rolling about inside. By rocking the device it is possible to get one golf ball into a hole. The puzzle is how to get both balls into their respective holes at the same time. 鈥淵ou have to spin it so that centripetal force pushes the balls into the holes,鈥� says Malcolm. 鈥淎t least, that鈥檚 the idea. We鈥檒l see what happens.鈥�
Everybody is keen to discuss ideas, propose new demos and improve the ones that are already being built. It鈥檚 this kind of brainstorming that fabricators鈥� events are all about.
Back outside, I find Steve surrounded by a large group of curious onlookers. Somehow he has managed to persuade two volunteers to clamber on to each end of the ladder so that they face in opposite directions. He throws a sandbag at the volunteer at one end, who tosses it back. He ropes me in to do the same at the other end. As the bags are tossed back and forth, the volunteers, the ladder and the chair begin to turn. Soon Steve and I have to run to keep up. 鈥淚t鈥檚 action and reaction,鈥� he shouts, to the amusement of the crowd.
DAY TWO
Andrea Aird looks worried. Her turn is rapidly approaching but the crucial ingredient has yet to materialise. I leave her to concentrate on the task at hand and bump into Harry, who looks glum.
His lava lamp is proving more difficult to perfect than he had imagined. 鈥淚鈥檝e found a lot of things that don鈥檛 work,鈥� he says. His problems began with the rheoscopic fluid, which reflected light so strongly that it prevented light passing through the mixture completely. But by diluting it he has got better results. I leave him comparing the merits of Ribena bottles with Fruits of the Forest jam jars, which are fatter and so have a larger surface area to conduct heat.
The demos are coming thick and fast now. Frances Geesin, a textile researcher who lives nearby, has connected a piece of antistatic fabric to a mysterious box with a speaker. Crumpling or stretching the material creates a whooping, crackling sound. She explains that antistatic fabrics are made from fibres that conduct electricity. Her device passes a tiny oscillating current through the fabric to the speaker. As the material moves, the fibres rub together, creating thousands of short circuits. 鈥淭hat鈥檚 what you can hear,鈥� she says.
Nearby, Wendy Sadler from Techniquest, Britain鈥檚 largest science centre in Cardiff, puts some water and an Alka Seltzer tablet into a small plastic film canister. She pops the lid on and places it bottom up on the table in front of her. As the tablet fizzes, the canister fills with carbon dioxide. The pressure inside grows until the canister explodes with a tiny pop and flies a metre or so into the air. Everyone agrees this is neat and simple and I make a mental note to try this as soon I get home.
All of a sudden in the workshop, the conversation is drowned out by the sound of angry cats wailing. Steve has stretched a number of elastic bands between pegs on a workbench and is blowing air over them using an industrial fan. The airflow causes them to vibrate. And by varying the tension in the bands it is possible to change the frequency of the sound they produce. 鈥淭his is just how the larynx works,鈥� he yells.
Meanwhile, an air of expectation has been building slowly. Andrea is about to perform and the audience is restless. 鈥淲here is her sample?鈥� 鈥淲ill she really drink it?鈥� Andrea walks in holding a surprisingly large glass of what appears to be flat lager-almost half a pint of the stuff. But it鈥檚 not lager. 鈥淎nd it鈥檚 still warm,鈥� she pronounces. The audience is spellbound.
Andrea does not spare us any details. When you produce the sample, it鈥檚 important to collect only a certain portion of the fluid, she says. This requires a careful aim and considerable dexterity with the cup. The initial liquid flushes the urethra of any bacteria that has collected there, so avoid that. The last few drops may have dribbled over God knows what, so avoid that too. But the rest, Andrea assures us, is perfectly palatable.
Timing is important too. The body produces its best urine at about 2 am. The reason is that it contains high concentrations of melatonin, a chemical produced in the brain that regulates sleeping patterns and also relieves stress. Saving this urine and drinking it later can have a calming effect, she explains.
The audience look as though they could do with some calming. The moment comes. Andrea grasps the glass firmly and, without flinching, drains the amber nectar with a few swift gulps.
That night in the local pub, Andrea celebrates, but not without a good deal of ragging from the other fabricators. 鈥淪o that鈥檚 two pints of lager, a Guinness and a Tetleys. And Andrea, you can have mine when I鈥檝e finished with it.鈥�
DAY THREE
The next morning, some of Wendy鈥檚 Alka Seltzer finds a more conventional use. But Harry is still not happy. Now that he can see into his lava lamp, he discovers that there鈥檚 not much to look at. At first, dramatic plumes of hot liquid rise through his jam jar, but within minutes the system settles into an equilibrium in which the flow appears almost static. Hoping to spice things up, Harry wants to add a heat sink to draw heat away. But time is running out. 鈥淎t least it鈥檚 pretty,鈥� he says.
James Piercy is having more luck. James is a demonstrator at Inspire, the science centre in Norwich that I run and is passing 240 volts through a pickle. It glows bright orange, lighting up his face. Each pickle lasts a minute or two before burning out. He reckons that the sodium ions in salt solution cause the orange glow. 鈥淛ust like street lamps,鈥� he says.
DAY FOUR
The results of the Best Demo contest are announced today. Malcolm鈥檚 lemon slice is spinning freely and the golf balls are lodging successfully in their allotted holes. The sound of Steve鈥檚 wailing rubber bands is punctuated by the crackling of antistatic material. And an orange glow fills one corner of the room. Sadly, Harry鈥檚 lava lamp is out of the running. 鈥淚 didn鈥檛 have any heat sinks with me,鈥� he says, bravely. 鈥淢aybe next year.鈥�
When the results are announced, Wendy鈥檚 exploding film canisters take first prize. Simple, original and easy to perform, say the judges. The kind of thing that anybody can play around with at home safely. I can only agree. I tried it when I got back and I have a tip: try vinegar rather than water, it works a treat.
