Although many people understand the connection between chemistry and biology very well, the intersection between it and physics can be a little harder to grasp. However, the field of so-called biomechanics is a good example of where the two disciplines come together. Understanding the physics of a knee joint, for instance, allows biologists to come up with better treatments for them. When the DNA double helix was first discovered, it was a technique developed in physics – x-ray diffraction - which was behind it. Life scientists now routinely make use of both fields of study together.