Tornado in a bottle

[JonathanM]

Tornado in a bottle!

You will need

• Water
• A clear plastic bottle with a cap (that won't leak)
• Glitter or something that can be seen when spinning
• Washing up liquid

Process

Fill the bottle about three quarters full, and then add a few drops of washing up liquid. Put in a pinch or so of glitter so you will be able to see the tornado better, and put the cap on tightly. Spin the bottle in a circular motion to see if you can see the mini tornado forming in the water. You may need to try it a few times before it works.
 
Explanation

Spinning the bottle in a circular motion creates a water vortex which looks like a tornado. The water is rapidly spinning around the centre of the vortex due to centripetal force (an inward force directing an object or fluid such as water towards the centre of its circular path).
 

[Mark Burgus]

Very nice.  Thank you for producing these weather labs.

Mark

[Dale Reid]

The Science Museum of Minnesota had a little plastic connector that allowed you to fasten two 2 liter soda bottles together. I don't  think the threads of a regular PVC pipe connector would do it, but similar.  Extremely simple.  Might be available somewhere on the internet.  You fill one bottle 3/4 full, screw them together with this connection, flip over and spin the upper bottle in a cone like motion.  As the water drained through the connector into the lower bottle, the spin imparted with the swirl got the water going into a tornado likeness.

My kids did this on and off for years whenever they'd find the contraption and then put it away for a few months.  The 5th grade teacher had a couple we gave them and I'd see them in the classroom so I assume the kids were playing with them and getting a little dose of science.

https://www.youtube.com/watch?v=0LfZFGcGc_I

Dale

[niko]

Ebay!