We asked our very own Communications team boss, Ian Wilson to tell us about one of his favourite exhibits from the hundreds you can play with in the Science Mall. Hes picked out a little gem and had this to say about it... “Cartesian Divers show some fascinating physics as well as being fun. The diver has a bubble of air inside it, so it displaces more weight of water than its own weight and floats – that’s Archimedes principle for you! But – here comes another science bit – in general liquids can’t be compressed, whilst gasses can be. So, exert a compressing force on the liquid the diver is floating in and you compress the bubble inside the diver to a smaller volume. As the bubble shrinks the volume it occupies is replaced by the water, so the diver now displaces less weight of water that its own weight and sinks. Release the pressure, the bubble expands and the wee fella starts to float again! Professional swimmers who free-dive without use of SCUBA start to feel this effect too. As they descend, the weight of the water above them compresses the air in their lungs and they become less buoyant the deeper they go. SCUBA divers don’t have to worry so much about this because the tanks fill their lungs with gas at the local pressure surrounding them. Instead they wear weight belts to counteract their natural buoyancy. Make one yourself one rainy Saturday (heres an example of how to make one youtu.be/s5eIRjmor1w ), or come and play with ours at the Science Centre. Cheers Ian! Whats your favourite exhibit? Why not take a pic or a video when you visit, tell us about it and why you like it so much.
Posted on: Mon, 25 Aug 2014 10:30:00 +0000
Trending Topics
Recently Viewed Topics
© 2015