Don't think that if your heart rate falls below 60 that something is wrong. It is not uncommon while at rest, to have your HR dip below 60. Some people have rates that drop into the 30'3&40's while sleeping. Our heart rates will fluctuate which, for most, is a normal variable.on't think that if your heart rate falls below 60 that something is wrong. It is not uncommon while at rest, to have your HR dip below 60. Some people have rates that drop into the 30'3&40's while sleeping. Our heart rates will fluctuate which, for most, is a normal variable.
The initial purpose of the GPS system was military but with the free availability of GPS signals and the availability of cheap GNSS receivers, the GPS technology is having a pervasive use in civil, industrial, scientific areas.
Learn about the different types of telescopes that astronomers use: x-ray, radio, gamma ray, reflecting and refracting. Learn what the differences are between them and what different things they show us about the universe.