China has every crazy thing! Look what I found in a gift shop in St. Lawrence MG: an hourglass with liquids of different densities, probably oil and water, in the denser form bubbles that move through the action of gravity.
Cost R$12,00 but found it too silly to buy. Thanks for the pictures. This down there looked like Donkey Kong Atari.
Surface tension in a plastic hole form the denser fluid drops and the friction caused by the difference between the liquid viscosity makes colorful oil bubbles remain steady even after fall. An interesting feature of physical interaction between liquids of different densities which ultimately create a nice visual effect.
A closer look at a red dot forming on the top.
When I got the product box to read against description, I found the already popular “made in PRC”, that means something like the people's Republic of China.
This was hard to find this product. I looked in all the famous sites and only on ebay there are some similar. In Focalprice also has one of them.
For you to see the effect, I found a video on youtube with them in operation. Check it out
I left the link from Focalprice down there: