The warnings were kindly meant: "If feeling weightless causes queasiness, close your eyes for a few seconds and when you open them you will feel fine. If you wish to leave the auditorium, our staff will be on hand to help you."
None of the 400 guests made for the exit of the British Film Institute London IMAX Cinema. Ex-Monty Python actor Terry Jones introduced his "signature" film, shown with all programmes at this latest IMAX cinema, newly opened on a roundabout at the south end of Waterloo Bridge.
Inside the pound;20 million drum is the largest cinema screen in Britain at 26 metres wide and 20 metres high - nearly five times as tall as a double-decker bus. The projector is "the largest and most sophisticated ever made". Big, then, and expensive, but has it anything else to shout about? The IMAX experience is a combination of over-the-top spectacle and serious educational intent. Terry Jones's little - well huge-but-short - film, gives you statistics but also has an unforgettable shot of John Cleese being blown sky-high out of the cinema roof with the world spread below him. The immensity of the screen and the fact that it reaches beyond the spectator's peripheral vision ensure there is no escape from total involvement. Mind trip cinema is how the publicity describes it. Some films are in 3D and, for these, natty spectacles are provided.
Filmed over four months off the California coast, Into the Deep brings you face to face with crabs, jelly fish, sea lions and lobsters which seem to make straight for your eye. Destiny in Space gives you the sensation of being on board - or even outside - the space shuttle with the astronauts.
School groups will be able to combine IMAX with the nearby Museum of the Moving Image, and teachers who book can receive free curriculum-related materials at all levels, including for special needs students. For information about screenings and educational events and to join the mailing list: 0171 902 1220.
Back at the human level, BT National Connections is under way. In 11 theatres, from Clwyd to Belfast, Stirling to Nottingham, 150 youth theatre groups are performing 10 specially commissioned plays from writers as diverse as Alan Ayckbourn, Christina Reid and Sharman Macdonald. This year's national festival - the third - is at the National Theatre from July 7 to 13.
Two years ago, Nigerian writer Wole Soyinka provided one of the plays. This time the international element is European: Italian Dario Fo has written The Devil in Drag, and the German partnership Tankred Dorst and Ursula Ehler offer a surreal piece called Don't Eat Little Charlie.
Cambridge Arts Theatre's three-day festival included performances of all 10 plays. On the Thursday evening, Charlie was presented by Stagedoor, a Norwich youth theatre group, and Winsome Pinnock's Can You Keep a Secret? by Rainsford High School, Chelmsford.
Stagedoor tackled their challenging material with gusto. Olmo, who eats everything, including cups, saucers, masonry and, if he can catch him, his younger brother Charlie, outgrows the house; Pug is a sparky, chattering pet dog; Fizzipizzi appears from nowhere and crackles with electricity. Into this household come a two-headed man and a creature which might be a bird, a dog or possibly a matador. Concentration and pizazz are required of the cast, and these they provided in abundance.
Can You Keep a Secret? is a tense, emotional piece which might have been inspired by today's newspapers. A black teenager is killed in a street fight and the culprit's identity is kept secret by his friends. The pain of learning when to put loyalty second to greater considerations was convincingly acted by Carla Wise in a company which shows a talent for ensemble work.
There are two regional festivals to go, at the Theatre Royal, Plymouth (June 2-12) and the Young Vic in London (June 21-26). Information about BT Connections: 0171 452 3320. The plays will be published by Faber in July under the title NewConnections 99.
Keep the teaspoons out of sight next Tuesday at the Jewish Museum in Camden Town, north London. Uri Geller will open Angels and Demons, an exhibition of Jewish magic and mysticism. Exhibits will include charms, amulets, kabbalistic diagrams and a life-size model of the Golem, the monster allegedly created in the 16th century by Rabbi Loew to protect his community in Prague. For children's activities don't rely on telepathy, ring 0171 284 1997.