Contraction and relaxation at the micro and cosmic level

The birth of the universe is one of cosmology's favorite topics. Recently, Anna Ijjas and Steinhardt proposed a new kind of cyclic universe model. This model states that the universe explodes and bounces back to a big crunch in repeated cycles.

The periodic oscillations of parameters imply the universe is undergoing ultra-slow contraction and relaxation; however, the scale factor is increased from one cycle to another exponentially. The transition from contraction to relaxation is so slow that it allows the universe to greatly expand. This model assumes that the universe, with each bounce, would convert gravitational energy to matter and radiation which will be used as the fuel of the next cycle.

Above image: Microscopic and cosmic cycle - Copyright protected by Isha Parlikar.

Similarly, a biological cell, the unit of life, also grows in number by dividing itself and gives rise to two identical daughter cells. Prior to cell division, genetic material is duplicated, condensed, and aligned on the center of the cell. Two sets of chromosomes are segregated between two cells in such a way that each new cell receives a copy of genetic material to continue the identity of the original cell. This sequence of events taking place in the cell is identified as the cell cycle, related to alternate contraction and relaxation, while growing as a cell exponentially.