How do “blue water boxes” from zoos and other places actually work? How can a small figure stand on the “blue water”?


I have no idea what they are actually called, but I have one of them with two penguins on it, and I wonder how they stand on the blue liquid?

In: 5

Like the toy where the penguin figures float between clear and blue liquid? The blue liquid is denser than the clear liquid and the penguin figures have a density between the two, so the float on the border of the two liquids.

The blue water has a type of salt/oil in it, the clear water is regular water. Because the blue water has the extra material, it’s “heavier” and thus “sinks” in the clear water, the figure is more sense than the clear water, but less dense than the blue water causing it to sink in the clear, but float on the blue. I believe it would be a type of ‘density toy’

I guess that is is a container like on [this page]( but with figures in it.

the blue liquid is water with a blue dye and the transparent part is oil, like baby oil. Oil and water do not mix and oil is less dense so it floats above.

The figures will be of plastic and less dense than water so they float above. If the density is the same and the oil they can flote anywhere in it, If you make them slightly denser then the oil the will sunk and just touch the water, If you make the feet part denser then the heat they will always flots in the correct orientation.

You can get the same effect in water and air. Because air is less dense than the oil you need an object that has a lower density, So for example use a balloon filled with he

>I have no idea what they are actually called, but I have one of them with two penguins on it, and I wonder how they stand on the blue liquid?

You mean something like [this](

They’re called paperweights. The clear liquid is an oil, and the blue liquid is water with a dye. Oil and water don’t mix, so even if you shake the thing, the liquids don’t mix. The figurine is dense enough to sink in the oil, but not dense enough to sink in the water. So it floats on the interface between the two liquids.

They use two liquids that are specifically chosen for two properties.

One is that they do not mix together – so even when shaken up they still stay separate like oil and vinegar.
Alongside this, one is always slightly more dense than the other, so when they separate they will float one on top of the other.

Have you ever noticed how if you pour an oil into a pan of water, the oil will form bubbles on the surface rather than mixing together? These toys use exactly the same effect.

The second part is they need to be very specific in the design of the small toy inside – specifically it’s boyancy. There more dense a liquid is, the easier it is to float on it – this is why it is easier to float on seawater than it is in a pool. This means that because the two liquids are of different densities, by controlling the boyancy of the toy, you can set where it will float – too heavy and it will sink to the very bottom, too light and it will float at the very top, but just right and it will sink in the upper fluid, but float on the bottom one.