A planet in your garage : Simple and memorable experiments to explain complex fluid dynamic phenomenons to non-scientist

Fluid dynamics is everywhere: from small scales in your sink to larger scales when you're watching weather forecast, but it is still a kind of magic for most people. A beautiful magic, but still beyond their understanding. For a scientific event in France, called "Fete de la Science", we have made small visual demonstrations in physical oceanography and fluid dynamics to explain, in a interactive and simple way, how our everyday life works from a fluid dynamicist's point of view. All of our demonstrations and experiments share the same goal: how can we reproduce the ocean and atmosphere in a lab, and how can you try to do the same in your home? From tsunamis to cyclones, from viscous motion to turbulence, most of the time you can understand and test a lot of processes yourself with water, dye and tanks. Using both experiments and pictures, avoiding any equations, people from all walks of life are more likely to be interested in a subject if they are actually taking part in the experiment. That is why we have decided not to teach people what to do, but instead to give them clues about what scientists do in the lab, and then let them play with the tanks. We have divided the demonstration into three parts: what is a viscous flow, and why time scales are important; how waves propagate and how does a tsunami work; and how rotating flows are different from non-rotating ones; We have found that the best way to improve comprehension of non-instinctive physical phenomenon for non-scientists is to design simple but meaningful and memorable experiments without any equations. The hands-on nature of these experiments both improves their understanding of their physical world and of the scientific method (hypothesis - prediction - experimentation - conclusion). These experiments have been designed to be easily reproducible with cheap and readily available equipment that allows most teachers to reproduce them with primary and high school students. This project has been conducted by masters and graduate students from the ENS de Lyon, and is supported by the ENS de Lyon program for Laboratoires Juniors.