The sleeping direction of science is north and south. The geomagnetic field affects people's sleep depth and health. Because the geomagnetic field will affect the bioelectricity of human body and the distribution of iron ions in hemoglobin. Don't be superstitious about Feng Shui.
How to determine the north-south direction, use a compass or a small magnetic needle (compass) to subtract a magnetic declination from the direction pointed by the small magnetic needle.