In physical cosmology, the Big Rip is a hypothetical cosmological model which describes the ultimate fate of the universe. According to this theory all the matter of the universe from stars and galaxies to atoms and subatomic particles, and even spacetime itself will be torn apart by the expansion of the universe at a certain time in the future, until distances between particles will become infinite. According to the standard model of cosmology the scale factor of the universe is known to be accelerating and, in the future era it will increase more rapidly. However, this expansion is similar for every moment of time (hence the exponential law – the expansion of a local volume is the same number of times over the same time interval), and is identified by an unchanging, small Hubble constant which is ignored by any bound material structures. Similarly in the Big Rip scenario the Hubble constant increases to infinity in a finite time.