What is Time?
- [Big Ben, London, United Kingdom - Marchin Nowak]
- Overview
According to Astronomy.com, time is a feature of the relationships between objects and not a feature from outside our universe. On a cosmic scale, time is a consequence of the increasing entropy of the expanding universe since the Big Bang.
Astronomers use different types of time, including:
- Solar standard time
- Mean solar time
- Sidereal time
- Universal Time
- Julian Date
The basic unit of astronomical time is the day. This can be either the solar day, which is based on the Sun, or the sidereal day, which is based on the stars.
Space and time are linked as one. This means that if the universe were to reach a theoretical limit of expansion and begin to contract, then time would reverse.
Quantum entanglement - when the states of two particle are intertwined by the laws of quantum mechanics — has long vexed physicists. But the phenomenon may also hold the key to understanding how time emerged.
[More to come ...]
