There are two types of body waves: compressional (P) waves and shear (S) waves. Primary waves (P-waves) travel the fastest, so they arrive at the recording station (seismograph) first. Secondary or shear waves (S-waves) travel slower than P-waves so they arrive second.
Modified frequency modulation (MFM) is an encoding scheme used by PC floppy disk drives and older hard drives.
The nutrient MSM (methylsulfonylmethane) is a naturally occurring sulfur compound found in all vertebrates, including humans. MSM is already well-known for its joint health benefits, but it may be important for a whole host of other reasons as well. Rod Benjamin is the director of technical development for Bergstrom Nutrition, the largest producer of the highest quality MSM that is produced by distillation purification.