Glacier GAK

How Does It Work

The mixture of Elmer’s Glue-All with Borax and water produces a putty-like material called a polymer. In simplest terms, a polymer is a long chain of molecules. You can use the example of cooking spaghetti to better under- stand why the GAK polymer behaves the way it does. When a pile of freshly cooked spaghetti comes out of the hot water and into the bowl, the strands flow like a liquid from the pan to the bowl. This is because the spaghetti strands are slippery and slide over one another. When the water drains off of the pasta, the strands start to stick together and the spaghetti takes on a rubbery texture. Wait a little while longer for all of the water to evaporate, and the pile of spaghetti turns into a solid mass. Drop it on the floor and watch it bounce.

Many natural and synthetic polymers behave in a similar manner. Polymers are made out of long strands of molecules like spaghetti. If the long molecules slide past each other easily, then the substance acts like a liquid because the molecules flow. If the molecules stick together at a few places along the strand, then the substance behaves like a rubbery solid called an elastomer. Borax is the compound that is responsible for hooking the glue’s molecules together to form the putty-like material. There are several different methods for making this putty-like material. Some recipes call for liquid starch instead of Borax soap. Either way, when you make this homemade Silly Putty you are learning about some of the properties of polymers

Take It Further

Adjust the amounts of water, Borax, and glue to see how the consistency of the GAK changes. Remember to change only one ingredient at a time to best determine the effect each ingredient has on the overall consistency of the putty.

Real-World Application

For hundreds of thousands of years, the movement of glaciers has shaped land through erosion and deposition, creating landforms such as U-shaped valleys, moraines, and kettle lakes, to name a few. Motion and change define a glacier’s life, and glaciers grow and shrink in response to a changing climate. Currently, glacial retreat is implicated in the Earth’s changing climate patterns and may have a great impact on sea levels and weather cycles.

The unique, slow moving properties of the GAK simulate the movement of a glacier. At a molecular level, ice is comprised of stacked layers of molecules with relatively weak bonds between the layers. This is similar to the makeup of our GAK molecules. Ice can stretch or break depending on the amount of pressure applied. If there is a lot of pressure or a high strain rate, ice will crack or break (causing crevasses in glaciers). When the pressure is lower or the strain rate is small and constant, ice can bend or stretch. The steady pressure from the bulk of the ice mass and the pull of gravity cause the glacier to flow slowly (so slowly you can’t see it) downhill, bending like a river of ice.

Scientists study glaciers because by their movement, glaciers mark change over an incredible period of time. By monitoring glaciers around the world over time, researchers construct valuable records of glacial activity and their response to climate variation.