IMAGINE hundreds of teenagers flinging paper darts across the expanse of the Queen Elizabeth Stadium, or throwing eggs off a tall building to watch them crash on to the ground below. A riot? An out-of-control student prank? No, it's science - real, active, practical science. In fact, says Dr Fang Ming of the research centre of the Hong Kong University of Science and Technology, it's fun science. Dr Fang is one of the inspirations behind the annual Fun Science Competition, which reaches its climax on Sunday at the Baptist University in Kowloon Tong. The competition is open to high school students of all ages and the idea is to 'promote solving of problems scientifically and systematically - in other words, how to do research without going to graduate school', Dr Fang says. Each year the entrants have to make something - sometimes in one of two categories - environmentally friendly, using wood, paper, string or glue, or not, as the case may be. Applications closed for this year's competition in December, after hopeful entrants took part in a workshop to make sure of the rules. Now they are working furiously to complete their designs for this week's finals. Dr Fang and his partner Dr George Greene of the University of Hong Kong devised the contest when they became dismayed by the lack of interest in science among students studying for their degrees. The main sponsor is the K P Tin Foundation, with the Association for Science and Mathematics Education, the Association of Hong Kong Scholars and the Association of Hong Kong (School) Principals organising it each year. 'I returned to the university [of Hong Kong] after several years in the US and found the quality . . .' Dr Fang rolled his eyes by way of finishing the sentence. 'They just wanted a degree, they had no interest in the subject.' He is scathing about school counselling for university, which only seemed to ask what courses students wanted to do or were good at, but not to touch on the wider importance of what interested them, where they wanted to go in life. 'Some of the kids don't even know why they are in engineering,' he said. 'They suffer, they don't like it, they just drag themselves through three years of torture, in my opinion.' He hit on the Fun Science Competition as a way to revive enthusiasm and instil the joy of learning and finding out in the young. But seeing his eyes twinkle as he describes the four competitions run so far, you wonder who finds it more fun - the competitors or organisers. 'Some of these kids are so smart, much better than me,' Dr Fang said. 'They'll make much better scientists.' Which, he says, is the idea. If the territory is to move forward, its people must improve. This year's requirement is to build a vehicle - powered by a rubber band weighing only 0.15 grams - less than 15 centimetres wide, tall and long. There are no other limitations. The carriage has to travel along a reverse Z-shaped track produced by the organisers, with the central strip at a 10:1 gradient. The trick, says Dr Fang, is to ensure that the steepness of the hill can be altered at the final to get a decent number of winners. Macau had problems at its preliminaries because it could not change the gradient enough, he said. They had to reduce more than 100 entrants to eight finalists, but 'they found nearly all the entrants passed'. 'They hadn't allowed for changing the gradient enough,' he said. 'When I heard about it I went and talked to the guy making the track for the finals and worried him that he'd have to start again. I told him he'd better plan for a steeper gradient.' Every year the entrants have come up trumps - and Dr Fang is bowled over by their enthusiasm and talent. In 1990, the inaugural year, they had to devise a system for dropping an egg - supplied by the organisers to prevent cooking - 14 metres, or roughly from the fifth floor of a standard building, without it breaking. Simple, you think. But the winner was the one using the least material. There were three categories: a frame structure without walls, a container-type structure with walls and a parachute - but the latter had to reach a one-metre square target. 'It's not easy to do that,' Dr Fang said. 'A lot of them ended up in the crowd. 'You should have seen some of the structures they thought of. One lad made a thing like a witch's hat, with a cone that compressed flat. He sat the egg in the space level with the brim, held it with the cone upside-down, gave it a little spin as he threw it - and when it hit the ground, the cone just squashed upwards, taking all the impact.' This lad didn't win. The winners in two categories and runners-up in the third were a team of girls from St Mary's Canossian College who used a paper cube in two halves, like a box. As it flew, it lengthened, to collapse back when it hit the ground. What impressed Dr Fang was their logical method. 'They had studied more than 100 eggs and found that all eggs were not the same,' he said. 'When we gave them the egg they put it into a big tray containing about 50 moulds to find which one it fit - then they altered their mounts.' A paper plane contest drew 517 teams - with three people per team. 'Crowd control was a nightmare,' Dr Fang said. The winning planes - which caused four aeronautical engineers much heartache beforehand, coming up with a definition - flew about 40 metres, taking them into the seating area of the Queen Elizabeth Stadium. Another year contestants had to make bridges of spaghetti. The distance was chosen so that the spaghetti had to be spliced - yet in some cases the judges, checking for the join, had to ask the contestants to show it to them, so well was it done. Breaking the bridges took heavy weights. Last year, contestants had to devise a mechanical timer that ran for exactly 100 seconds, had an obvious start and stop point and could not use electronics or electrical power. The environmental category was silent; the other had to produce audible clicks at the start, after 50 seconds and at the end, using a single switch. One budding 14-year-old inventor had three canes with string attached that wrapped round a notched gearwheel. The strings unwound one by one, each one producing the required click against the gear wheel. It managed an accuracy of 98 or 99 seconds. Yet it didn't win. 'He brought it on himself,' Dr Fang smiled. 'The trouble was, he played with it too much. He didn't understand about variable elasticity.' By the time it came for the big test, the young lad had reduced the accuracy of his clock to about 94 seconds. 'I explained it to him afterwards. He was very disappointed that he didn't win.' Other designs used water or ball-bearings running down slopes. The winning design - which Dr Fang regrets that he did not see - managed an accuracy of 100.08 seconds. The prizes have changed over the years, from one first and second in 1990 to four of each now, plus one each for the best design and best workmanship in each of the environmental and 'anything goes' categories - 12 in all. The first prizes are $1,500, the rest $1,000. At the end of this year's contest, there will be a final prize for the winner of a knockout tug-of-war between all the losing vehicles. There are 88 entries expected. A second round will be between the top 25 from the first. They will have a short time between rounds to improve their designs, which Dr Fang says makes a huge difference. So is the idea behind the contest - to revive youngsters' interest in how things work and to draw them back to what scientists consider the joy of finding out - working? Dr Fang says it's hard to know. But he knows of some contestants who have always taken part and who are attending university now; some have come to see him for careers advice. This year is a bit of a gamble, as there have been no Hong Kong preliminary rounds - the date planned for them was double booked. 'I think it could be a difficult one,' he said.