Heat death of the universe

Heat death of the universe

The heat death of the universe is one of the last fate of the universe in which the universe has evolved without any thermodynamic free energy in a state and hence can not maintain the entropy enhancement processes. Summer death does not mean any special full temperature; For this, it is only necessary that the temperature difference or other processes should not be tapped to work now. In the language of physics, this is when the universe reaches a thermodynamic balance (maximum entropy).

If the topology of the universe is open or flat, or if dark energy is a positive cosmological constant (both are in accordance with current data), the universe will continue to expand forever, and there is hope of a summer death with the universe. Cooling to balance at very low temperatures after a very long period.

The concept of heat death William Thompson stems from the views of 1 Baron Calvin (Lord Kelvin), who took the theory of heat in the 1850s as a mechanical energy loss in nature (embodied in the first two laws of thermodynamics) and It was extrapolated. For large processes on a universal scale.

Origins of the idea of Heat death

The idea of heat death stems from the second law of thermodynamics, in which one version states that the entropy grows in a separate system. This influences the hypothesis that if the universe stays for sufficient time, then it will reach a state where all the energy is evenly distributed. In other words, according to this hypothesis, there is a trend in nature for the dissipation (energy change) of mechanical energy (speed) in thermal energy; Therefore, by extrapolation, this view exists that, in time, the mechanical movement of the universe will go down because the work changes due to the second law.

It is estimated that all bodies in the universe are cooled down, eventually cooling down to support life, it appears that for the first time, French astronomer Jean Silvell Bailey in 1777 with his compositions and Voltaire on the history of astronomy In front of the correspondence was put forward. . In Belly's idea, all planets have internal heat and now it is in some special condition. For example, Jupiter is still very hot to be born there for thousands of years, while the moon is already very cold. The final position is described in this scenario as one of "balance", in which all the speed is stopped.

The idea of the death of heat as a result of thermodynamic rules, however, was first proposed in 1851 by William Thomson in loose words, on the ideas of the mechanical energy loss of Plain Carnot (1824), James Joule (1843) and Insisted. , And Rudolf Clausius (1850). Thomson's ideas were further explained by Hermann von Helmholtz and William Rankin in the next decade.

Current status of the heat death of the universe 

Proposals about the final state of the universe depend on the assumptions made about its final destiny, and these beliefs vary significantly in the beginning of the 20th and the beginning of the 21st century. In an envisaged "open" or "flat" universe, which extends indefinitely, either heat is expected to be a summer or a big rip. If the cosmological constant is zero, then the universe will reach full zero temperatures for a very long time. However, if the cosmological constant is positive, as happened in recent observations, then the temperature will increase in the form of non-zero positive values, and the universe will move towards the position of the maximum entropy.

If a big rip is not long ago, the "heat death" situation can be avoided if there is any method or mechanism for reviving hydrogen atoms from radiation, dark matter, dark energy, zero-point energy, or other sources. , So that due to the subsequent evaporation of the substances in the energy and heavy elements of stellar processes and the absorption of the substance by the black hole and the Hawking radiation, Star formation in order to avoid a subsequent part of Mand and heat transfer can continue.

The time frame for the heat death of the universe

At present, through the Big Bang, substances and dark matter in the universe are believed to have been concentrated in stars, galaxies, and galactic clusters, and are considered to continue so well in the future. Therefore, the universe is not in thermodynamic balance, and objects can do physical function. Due to Hawking radiation, the time of the decay of the supermassive black hole of approximately 1 galaxy mass (10^11 solar mass) is in the order of 10^100 years, hence atrophy can be produced at least by that time. Some monster black holes in the universe are estimated to increase to possibly 10^14 M collapse during the collapse of superclusters of galaxies. Even they will evaporate during the time of 10^106 years. After that time, the universe enters the so-called Dark Era and is mainly composed of a thin gas of photon and leptons. With only a very diffused substance remaining, the activity in the universe will be extremely low energy level and will be dramatically closed for a very long time. Specifically, it is possible that the universe can enter a second era of inflation, or assuming that the current vacuum state is a false vacuum, the vacuum can cause decay in a less energy condition. It is also possible that entropy production will be stopped and the universe will reach the death of heat. Another universe may be made by random quantum fluctuation or quantum tunneling, which is roughly  10^10^10^56  Year. In the vast duration of time, a smooth entropy reduction will eventually be through the Poincar Recycle theorem, thermal fluctuation, and fluctuation theorem. However, such a scenario has been described as "extremely speculative, perhaps wrong and completely unstable". Sean M. Carroll, originally an advocate of this idea, does not support it anymore.

Controversies about the heat death of the universe

Max Planck has written that the phrase "entropy of the universe" has no meaning because it does not consider any precise definition. More recently, Grady writes: "Speaking about the entrance of the universe is more appropriate, about which we still think very little, and we wonder how the thermodynamic entropy for a universe and its major components is defined Can be done which has never been in balance. " His whole existence "According to Tiza:" If a separate system is not in balance, then we can not combine an entropy with it. "Butchal" is a completely inaccurate assumption that the universe can be considered as a closed thermodynamic system. "According to Galawotti:" ... even in a steady state, there is not a universally accepted concept of entropy for systems beyond balance. "Normally non-balancing Discussing the question of entropy for the states, Lib and Yingwans expressed their opinion as follows: "Despite the fact that most physicists believe in such a Nokwilabriya entropy, it is still clearly satisfactory It has been proved impossible by defining it. "In Landsburg's opinion:" The third misconception is that the concept of thermodynamics, and in particular, the entropy can be applied to the entire universe without further investigation ... these questions have a certain charm, but the speculation of the speculation Are, and lie. Beyond the scope of this book. "

A recent analysis of entropy says that "the entropy of a normal gravitational field is still unknown" and "it is difficult to determine the gravitational entropy". The analysis takes into account many possible assumptions, which are necessary for estimates and show that in the observable universe, it is understood more than before. This is because the analysis concludes that the supercomputer black hole is the biggest contributor. Lee Smolin goes on to say: "It has been known for a long time that gravity is important to keep the universe out of thermal equilibrium. Gravitational binding systems have negative specific heat - that is, when energy is removed, their components The velocity increases ... ... a system like a homogeneous equilibrium does not develop towards the state, instead, it becomes increasingly structured and odd. This group because it is divided into sub-systems.