Microscopes are used to investigate different materials that the human eye cannot see. I took this photo of my brother Nickolas investigating the differences between a dog hair and a human hair. To do this, he put the two different hairs on separate slides. He was able to find that there were differences such as air pockets and different colored lines to determine what kind of hair it was. One of the greatest tools for investigations is the microscope. People like doctors, crime scene workers, scientist, and even my brother can use them to perform their own investigations.