What exactly is Big Data? This video defines and explains Big Data as well as Hadoop and MapReduce in simple language.
Rating Newest Oldest. Best Answer: Time is an illusion in that it's not a real, *natural* feature of the universe. Time is not absolute, meaning there's no Cosmic Master Clock that ticks off the correct time for the entire universe.
An astronomical clock with dials for showing both sidereal and solar time. Sidereal time /saÉªËdÉªÉriÉl/ is a time-keeping system that astronomers use to locate celestial objects. Using sidereal time it is possible to easily point a telescope to the proper coordinates in the night sky. Briefly, sidereal time is a time scale that is based on Earth's rate of rotation measured relative to the fixed stars rather than the Sun.