At the end of most school years only a handful of events stand out in the children's memories. Like the day the maths teacher tripped and banged his head on the board, and of course that morning in early spring when tree-frogs, starfish and aliens came to school in the back of a big, white van.
"The man from the Science Festival put a starfish on my hand," explains Cathy, "and it had wee feet under its arms with lots of suckers. And he told us the starfish wraps its arms around a mussel and sticks on with its suckers, then it pulls the mussel open, turns it into soup and eats it. And he said a rock-pool is a nasty place for animals to live, because it's so warm in the sunshine it's hard to breathe. And when the tide comes in the first wave picks you up and bashes you against a rock."
Explore the Sea, one of 20 shows in last year's Edinburgh International Science Festival's schools programme, is hard to forget. So is the rainforest that sprouted in the school gym.
"Close your eyes," botanist Julie Jones tells the children, "and imagine you're sitting on the forest floor, with leaves and insects all around and huge trees above you. Feel how warm and damp it is. Listen to the rain."
Suddenly there is a sound like a drumbeat. "One day a friend and I were walking through the rainforest and we heard that," says Julie, "so we climbed a tree and this is what we saw." She shows a slide of a green frog with bright red eyes. "These little creatures live their whole lives in pools of water inside plants that grow high in the treetops."
Then there was the scary trip on the Starship Eureka piloted by those funny aliens, Captain Zogon and Ensign Thuff, in their orange spacesuits and purple boots, with their big pointy heads making them look so intelligent.
They steered the ship around the solar system, calling at Venus, Mars, Jupiter and all the other planets. But it turned out they weren't as smart as they thought they were, and the dopey captain crashed Eureka while trying to land it back on Earth.
The good news is that all these shows are part of EISF's schools programme again this year, as well as other favourites like The Body Builders, which introduces genetics. "All our DNA is in little packages like this called chromosomes," the scientist explains, twisting a piece of string around and around till it becomes a tight little ball, "and each cell of our bodies contains enough if it was unwound to stretch from here to Moscow."
Good Vibrations is all about sound and music. "Sound is little vibrations, wobbles that come through the air to our ears. But do we need the air, I wonder?" Liam investigates by pulling on goggles and immersing his head in a bucket of water.
And Little Giants tells the story of the honeybee - Fuzzy the bee talks about insect senses ad points out the different sections of his body, but he suddenly becomes agitated as a masked figure, clothed in white, net in one hand and smoker in the other, bursts on the scene.
There is also a set of brand new shows, devised in response to feedback from teachers, such as:
* Wacky Waterworks, in which Dr U-Bend wades through the water-cycle and splashes about in sewage;
* Don't Forget Your Toothbrush, which shows how teeth grow in humans, sharks and elephants, and how to keep them healthy;
* Hot-Air Balloons, in which the children make large, colourful models of the Montgolfier brothers' design and watch them defy gravity; and * Day and Night, which uses the Starlab portable planetarium to demonstrate why it is still midnight in Times Square when the sun is rising over Princes Street.
One of the most ambitious of this year's new shows is Great Expectations, funded by the Millennium Commission and devised by science communicator Lish Hogge, which explores technology and biology in the coming century, with the help of a time machine, and a glitzy gameshow host called Fance Pance and his beautiful assistant.
"The gameshow host has a camera on his head," Hogge explains, "so he goes out and captures all the children's faces and they see themselves on a big screen. Then they're asked to imagine the future and Bobbi the assistant goes off in the time-machine. She makes three visits, each time going further into the next century, and of course it gets more difficult to predict each time. A volunteer wears an imagination-collector on his head, which gathers the children's thoughts.
"When Bobbi comes back she shows the stuff from the future, and everybody gets a capsule they can swallow containing 50,000 nanobots, tiny molecular machines that you can't see which clean blood cells and kill bacteria.
"There are two separate shows, one on genetic engineering and biology, the other on technology and computers. I guess the message is, whatever the children can imagine can actually happen."
The science shows in EISF's primary schools programme have all been designed to connect to the 5-14 curriculum. The links are outlined in the programme brochure, with full details provided in the teachers' notes, sent when a booking is confirmed. Touring begins on January 24 and schools outside a 40-mile radius of Edinburgh are asked to make a nominal contribution towards travelling costs.
* Douglas Blane will write a weekly column from the science festival schools programme, starting next Friday.
To book a show call the box office, Monday to Friday, 8.45am to 4pm, tel: 0131 473 2070. Edinburgh International Science Festival, 8 Lochend Road, Edinburgh, EH6 8BR. Email email@example.com.
The EISF schools programme is sponsored by the Discovery Channel and funded by the Scottish Executive and the City of Edinburgh Council. Printed materials are sponsored by TES Scotland.