This is great, we're seeing these distorted images of lights under the pool, and by looking at the shapes of these, we can work out what the ripples in the water is doing.

The survey team went looking for Dark Matter in exactly the same way, with 1,000 hours of observations on the Hubble Space Telescope.

By looking at distant galaxies halfway across the universe, by looking at their shapes and the distorted images that we see of those, we can work out what ripples there are in space between them and us.

And those ripples in space are caused by the Dark Matter.

The search zone was a thin column of the universe, stretching eight billion light-years from Earth.

The team were on the lookout for distortions in the most distant galaxies.

Whenever you see galaxies distorted into these strange uncharacteristic shapes;

you know that there must be something in between them and you, something really massive, and even if it's invisible, you can still map out where it is by the way it warps that space-time.

The mapping technique revealed a ghostly, hidden universe.

The light from visible galaxies was recast in new and beautiful forms.