The young and the curious wax chemical about what people put around our apples and oranges

There is no doubt that young scientists show boldness in great measure in addressing the big questions of the late 20th century.

Which method of betting on horses is most profitable? Why can't everyone sing? What does the millennium bug eat? Does music interfere with studying?

Answers to these pressing questions and to many more are presented at the 1999 Esat Telecom Young Scientist & Technology exhibition at the RDS.

But forward planners and contemplators of doomsday might like some indication of what happens when we run out of space on Earth, or if it becomes so hostile it won't play home to us any longer.

Three second-year students from St Michael's College, Ballsbridge, Dublin, sought answers by designing a fully functional orbital space station-cum-habitat which includes its own system for life support and artificial gravity.

Undaunted by the demands of this, 13-year-olds Mark Finlay, Marcus Campbell and Galen Mac Caba set about designing a self-sustaining lunar colony, complete with its own oxygen and water supply. As for an energy source, they make a case for extracting hydrogen from ice likely to be readily available.

The elements of these designs they have incorporated into a computer for demonstration purposes, explained Galen. Some time in the future they would like to examine the potential for minerals and metals in the universe's asteroid belt in the belief it could also provide an alternative energy supply to fossil fuels.

Three students from St Malachy's College, Belfast, built a stomach simulator to examine what happen's when a young child consumes a small object; whether it be a plastic brick, bottle top or PVC-containing toy.

They surveyed parents on what is consumed inadvertently by their children, said Aaron Moore (13). They then adapted a water bath to mimic the stomach, complete with motors to imitate its churning movement, and acidic conditions at 37 Celsius. His team is completed by Joe McEvoy (14) and Kevin McNally (14).

With help from scientists at Queen's University, they identified what compounds contained in small items are "best" from a safety perspective, and conclude the constituents of many products should be changed, particularly the form of plastic used.

Any apple or orange sampled by Karen Lynch (17) and Jane Strong (17), fifth-year students at Dundalk Grammar School, was found to contain "applied wax", which is administered after harvesting to prolong shelf-life and improve appearance.

After reading a report in Tomorrow's World magazine about pesticides and organophosphates in fruits, they decided to investigate and focus on the effects of waxes, the use of which is now widespread. "We believe the waxes seal pesticides and organophosphates into fruit, which means higher levels are then consumed," Karen said.

While the various waxes used were considered to be cosmetic, their health effects should be considered more extensively, they suggest, particularly as they found they were very difficult to completely remove.

The prospect of the ultimate in convenience for the motorist has been raised by a team from Terenure College, Dublin, which devised its own "self-repairing wheel" - the motorist does not even have to get out of the car.

The second-year students have incorporated a small plastic tube containing liquid rubber and compressed air inside the standard tyre in their model. When the dreaded puncture arrives, they anticipate the tyre flattening, activating the release of liquid which on entering a perforation seals it, while the additional compressed air reflates the tyre.

The idea came from Brian Lawford (14) who, with the help of John McCambridge (13) and James O'Brien (14), developed it. Their marketing-speak and talk of "safety and convenience" suggest they intend to go all the way.