I have decided to start a new monthly feature on sciencetasticblog, called Science questions answered. It will answer some (hopefully) interesting science questions. If you have any questions that you would like me to answer, please leave a comment, and I will try to answer as many as I can. So here goes Science questions answered: can water flow uphill?
I had a whole argument over this one with my dad. He and my sister were singing “Five little ducks went swimming one day”, and he sang “five little ducks went swimming one day, over the pond and far away”, so I protested that it was “over the hills and far away”. He argued that rivers can’t flow uphill. I said that there was nothing in the song to suggest that the ducks were in a river, and he proposed that a hill isn’t a hill once you cover it with water. And so the argument continued… In the end, we came to the conclusion that the song would have to be “over the underwater hills and far away”, and that water can’t flow uphill. Unless…
You have something called a hydraulic jump.
A hydraulic jump happens when a fast flow of water with lots of kinetic (movement) energy encounters an obstruction, and is slowed down, losing its energy. However, this energy has to go somewhere, because of the law of conservation of energy. So the kinetic energy is converted into potential energy (energy that is stored up, having the potential to do something) by raising the water level.
By User Zeimusu on en.wikipedia (James Kilfiger took this picture) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)%5D, via Wikimedia Commons
Here is a video of a hydraulic jump (if it does not appear, here is a link: https://www.youtube.com/watch?v=v5gXfyViGIE).
Thank you for reading, and I hope you have learnt something from this post.
PS. I am starting to write a book on climate change (click here to see my post on the subject), so if you have any ideas or tips, I would be very grateful if you could share them with me.