Science is never exactly easy, but it’s especially tough when you can’t see, touch or even really interact with your subject. Consider the plight of a geophysicist interested in the makeup and structure of Earth’s interior. Without being able to dig up a sample of our planet’s ultrahot, ultra-pressurized mantle, how can they figure out what makes our planet work?
The answer, in part, is seismic waves. When the ground shakes, as in an earthquake, the vibrations go through and interact with all the materials in their way. This can provide scientists with a means of imaging all those materials, allowing them to virtually peer beneath the surface.