Steroids and other medications. Long-term use of oral or injected corticosteroid medications, such as prednisone and cortisone, interferes with the bone-rebuilding process. Osteoporosis has also been associated with medications used to combat or prevent: Seizures; Gastric reflux; Cancer; Transplant rejection; Medical conditions
The main functions of using a compass are: 1  tell which direction you are traveling - your heading. 2  tell which direction an object is from you - its bearing. 3  keep you following a straight line of travel. 4  orient a map - aligning a map with the actual land.  triangulation - determining your location with a map.
Any student can tell you that a compass is used to determine which direction is north, but when paired with some basic trigonometry, the compass can be used to actually measure the strength of the magnetic field due to a nearby magnet or current-carrying wire.