The swirling mass of water that forms in the tube is known as a vortex.
Once you have started the water moving round, the energy comes from the water flowing downwards.
The vortex has a hole in the centre. As the water flows up to replace it
If you didn't spin the bottle, the water would glug downwards as the water and sir changed places.
$12.95 $14.95Your USB Astro Light is the perfect space age accessory for any budding astronaut or explorer! Plug him into the USB socket of your computer and he will float on the end of his cord ready to light up! Pull back his space suit visor to illuminate your darkened office and position him to float and light your way! Complete with 30cm poseable USB cord, you can move and bend him any direction you choose! Perfect for use when working at night or on public transport.
36 pieces includes moon, satellite and The Hubble Space Telescope.
Space poster included
69cm x 66cm
The Bacteria Farm is a great first biology kit for any budding scientist. Cultivate & observe bacteria from different samples with a variety of experiments.
Recommended ages 8+