Cook up some cotton candy. The actual making of the sticky stuff is a great example of a Science experiment in its own right. Sugar is heated to a high temperature (approximately 186 °C or 366.8 °F) so that it melts and is spun through a machine with tiny holes, through which pass strands of the sugar. The force that can be seen making this happen is centrifugal, or an outward force moving away from the center of rotation. In other words, the experiment shows the effects of inertia, or the resistance of the sugar to changing its motion when rotation of the drum is applied to it, in connection with rotation. As they come into contact with air, the sugar strands crystallize. The spun sugar can then be gathered into a ball and placed on a stick. Renting or buying a cotton candy machine is not difficult or crazy expensive (from $40 upwards to purchase). To use it, just pour in the sugar, turn it on and watch the experiment unfold as you collect the cotton candy it creates.
Change the main ingredient of cotton candy for an experiment on what results are produced with different sugars. How does the cotton candy come out if used with brown instead of white sugar, or a sugar substitute? Does the cotton candy weigh less, does it break more easily, does it feel the same or is it more or less sticky than with the original trial? Appearance, stability and taste can all be measured in a class experiment with a sample test group of class size, say 20 to 30 students. The experiment could lead to a second experiment to give a scientifically quantifiable result. For example, to test heaviness, small weighted objects could be hung off the different cotton candy samples to see how much each sample can take before it breaks.
Make a system of capillaries to imitate the network that carries blood to parts of the human body. This experiment is a more complicated structural process for showing how blood flows through our systems. To create a web of tiny tubes, scientists at Cornell University's Nanobiotechnology Center discovered that using cotton candy provided a model that had less limitations than previous models. It is the precise nature of cotton candy's stickiness and its being water soluble that made the model successful when it came to showing blood flow. A cotton candy ball has two sugar rods attached to it; the whole thing is covered in a molten polymer and left to dry and solidify. Next, the sugar is dissolved, leaving a network of channels that has both an inlet and outlet channel that when injected with fluorescent "blood", demonstrates effectively the way that blood flows in the human body.
Demonstrate our early geological beginnings. The nature of the earliest rocks known to our solar system can be accurately depicted using cotton candy. Recent research by scientists at Imperial College London shows that these first rocks formed billions of years ago in the massive gas and dust of the Solar Nebula, before the birth of our solar system, were more like candy floss than the hard rock we have today. Contrary to earlier theories, the study gives credence to the idea that the first solid materials were fragile and porous, and it was only hardened as it was "compacted during periods of extreme turbulence into harder rock, forming the building blocks that paved the way for planets like Earth" (Nature Geoscience Journal, March 2011).