Watch Water Freeze by Science Museum from £2.61

This pack links to the Materials area of Launchpad and illustrates the amazing colours that appear when water freezing is viewed through special filters. Contents include: 2 squares of polarising film, 1 petri dish.

This pack contains special filters that enable you to see things that are normally invisible. When water turns into ice, it looks clear but in fact it can alter light in strange ways so that it appears coloured if looked at through the filters. Many other things such as crumpled cellophane appear coloured through the filters, and this effect is used by engineers to pinpoint the position of stresses in objects.

Brand: Science Museum, Age Group: 7+