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Sunday, January 14, 2024

Corporal punishment

From Wikipedia, the free encyclopedia
 
A corporal punishment or a physical punishment is a punishment which is intended to cause physical pain to a person. When it is inflicted on minors, especially in home and school settings, its methods may include spanking or paddling. When it is inflicted on adults, it may be inflicted on prisoners and slaves.

Physical punishments for crimes or injuries, including floggings, brandings and even mutilations, were practised in most civilizations since ancient times. With the growth of humanitarian ideals since the Enlightenment, such punishments are increasingly viewed as inhumane in Western society. By the late 20th century, corporal punishment had been eliminated from the legal systems of most developed countries.

In the twenty-first century, the legality of corporal punishment in various settings differs by jurisdiction. Internationally, the late twentieth and early twenty-first centuries saw the application of human rights law to the question of corporal punishment in a number of contexts:

  • Corporal punishment in the home, the punishment of children by parents or other adult guardians, is legal in most of the world. As of 2023, 65 countries, mostly in Europe and Latin America, have banned the practice.
  • School corporal punishment, of students by teachers or school administrators, such as caning or paddling, has been banned in many countries, including Canada, Kenya, South Africa, New Zealand and all of Europe. It remains legal, if increasingly less common, in some states of the United States and in some countries in Africa and Southeast Asia.
  • Judicial corporal punishment, such as whipping or caning, as part of a criminal sentence ordered by a court of law, has long disappeared from most European countries. As of 2021, it remains lawful in parts of Africa, Asia, the Anglophone Caribbean and indigenous communities in several countries of South America.
  • Prison corporal punishment or disciplinary corporal punishment, ordered by prison authorities or carried out directly by correctional officers against the inmates for misconduct in custody, has long been common practice in penal institutions worldwide. It has officially been banned in most Western civilizations during the 20th century, but is still employed in many other countries today. Punishments such as paddling, foot whipping or different forms of flagellation have been commonplace methods of corporal punishment within prisons. This was also common practice in the Australian penal colonies and prison camps of the Nazi regime in Germany.
  • Military corporal punishment is or was allowed in some settings in a few jurisdictions.

In many Western countries, medical and human rights organizations oppose the corporal punishment of children. Campaigns against corporal punishment have aimed to bring about legal reforms in order to ban the use of corporal punishment against minors in homes and schools.

History

Prehistory

Author Jared Diamond writes that hunter-gatherer societies have tended to use little corporal punishment whereas agricultural and industrial societies tend to use progressively more of it. Diamond suggests this may be because hunter-gatherers tend to have few valuable physical possessions, and misbehavior of the child would not cause harm to others' property.

Researchers who have lived among the Parakanã and Ju/'hoansi people, as well as some Aboriginal Australians, have written about the absence of the physical punishment of children in those cultures.

Wilson writes:

Probably the only generalization that can be made about the use of physical punishment among primitive tribes is that there was no common procedure [...] Pettit concludes that among primitive societies corporal punishment is rare, not because of the innate kindliness of these people but because it is contrary to developing the type of individual personality they set up as their ideal [...] An important point to be made here is that we cannot state that physical punishment as a motivational or corrective device is 'innate' to man.

Antiquity

Birching, Germany, 17th century
Depiction of a flogging at Oregon State Penitentiary, 1908

In the Western world, the corporal punishment of children has traditionally been used by adults in authority roles. Beating one's son as a form of punishment is even recommended in the book of Proverbs:

He that spareth the rod, hateth his son; but he that loveth him, chasteneth him betimes. (Proverbs 13:24)

A fool's lips enter into contention, and his mouth calleth for strokes. (Proverbs 18:6)

Chasten thy son while there is hope, and let not thy soul spare for his crying. (Proverbs 19:18)

Foolishness is bound in the heart of a child; but the rod of correction shall drive it from him. (Proverbs 22:15)

Withhold not correction from the child; for if thou beatest him with a rod, thou shalt deliver his soul from hell. (Proverbs 23:13–14)

(Note: it has been debated among scholars as to whether what is encouraged here is the corporeal punishment of a "child" or a "young man". The word translated "child" in most cases in the Bible refers to a young man rather than a child.)

Robert McCole Wilson argues that, "Probably this attitude comes, at least in part, from the desire in the patriarchal society for the elder to maintain his authority, where that authority was the main agent for social stability. But these are the words that not only justified the use of physical punishment on children for over a thousand years in Christian communities, but ordered it to be used. The words were accepted with but few exceptions; it is only in the last two hundred years that there has been a growing body of opinion that differed. Curiously, the gentleness of Christ towards children (Mark, X) was usually ignored".

Foot whipping an offender, Persia, 1910s

Corporal punishment was practiced in Egypt, China, Greece, and Rome in order to maintain judicial and educational discipline. Disfigured Egyptian criminals were exiled to Tjaru and Rhinocorura on the Sinai border, a region whose name meant "cut-off noses." Corporal punishment was prescribed in ancient Israel, but it was limited to 40 lashes. In China, some criminals were also disfigured but other criminals were tattooed. Some states gained a reputation for their cruel use of such punishments; Sparta, in particular, used them as part of a disciplinary regime which was designed to increase willpower and physical strength. Although the Spartan example was extreme, corporal punishment was possibly the most frequent type of punishment. In the Roman Empire, the maximum penalty which a Roman citizen could receive under the law was 40 "lashes" or 40 "strokes" with a whip which was applied to the back and shoulders, or 40 lashes or strokes with the "fasces" (similar to a birch rod, but consisting of 8–10 lengths of willow rather than birch) which were applied to the buttocks. Such punishments could draw blood, and they were frequently inflicted in public.

Quintilian (c. 35 – c. 100) voiced some opposition to the use of corporal punishment. According to Wilson, "probably no more lucid indictment of it has been made in the succeeding two thousand years".

By that boys should suffer corporal punishment, though it is received by custom, and Chrysippus makes no objection to it, I by no means approve; first, because it is a disgrace, and a punishment fit for slaves, and in reality (as will be evident if you imagine the age change) an affront; secondly, because, if a boy's disposition be so abject as not to be amended by reproof, he will be hardened, like the worst of slaves, even to stripes; and lastly, because, if one who regularly exacts his tasks be with him, there will not be the need of any chastisement (Quintilian, Institutes of Oratory, 1856 edition, I, III).

Plutarch, also in the first century, writes:

This also I assert, that children ought to be led to honourable practices by means of encouragement and reasoning, and most certainly not by blows or ill-treatment, for it surely is agreed that these are fitting rather for slaves than for the free-born; for so they grow numb and shudder at their tasks, partly from the pain of the blows, partly from the degradation.

Birching on the buttocks

Middle Ages

In Medieval Europe, the Byzantine Empire blinded and denosed some criminals and rival emperors. Their belief that the emperor should be physically ideal meant that such disfigurement notionally disqualified the recipient from office. (The second reign of Justinian the Slit-nosed was the notable exception.) Elsewhere, corporal punishment was encouraged by the attitudes of the Catholic church towards the human body, flagellation being a common means of self-discipline. This had an influence on the use of corporal punishment in schools, as educational establishments were closely attached to the church during this period. Nevertheless, corporal punishment was not used uncritically; as early as the 11th century Saint Anselm, Archbishop of Canterbury was speaking out against what he saw as the excessive use of corporal punishment in the treatment of children.

Modernity

From the 16th century onwards, new trends were seen in corporal punishment. Judicial punishments were increasingly turned into public spectacles, with public beatings of criminals intended as a deterrent to other would-be offenders. Meanwhile, early writers on education, such as Roger Ascham, complained of the arbitrary manner in which children were punished.

Peter Newell writes that perhaps the most influential writer on the subject was the English philosopher John Locke, whose Some Thoughts Concerning Education explicitly criticised the central role of corporal punishment in education. Locke's work was highly influential, and may have helped influence Polish legislators to ban corporal punishment from Poland's schools in 1783, the first country in the world to do so.

Corporal punishment in a women's prison in the United States (ca. 1890)
Batog, corporal punishment in the Russian Empire
Husaga (the right of the master of the household to corporally punish his servants) was outlawed in Sweden for adults in 1858.

A consequence of this mode of thinking was a reduction in the use of corporal punishment in the 19th century in Europe and North America. In some countries this was encouraged by scandals involving individuals seriously hurt during acts of corporal punishment. For instance, in Britain, popular opposition to punishment was encouraged by two significant cases, the death of Private Frederick John White, who died after a military flogging in 1846, and the death of Reginald Cancellor, killed by his schoolmaster in 1860. Events such as these mobilised public opinion and, by the late nineteenth century, the extent of corporal punishment's use in state schools was unpopular with many parents in England. Authorities in Britain and some other countries introduced more detailed rules for the infliction of corporal punishment in government institutions such as schools, prisons and reformatories. By the First World War, parents' complaints about disciplinary excesses in England had died down, and corporal punishment was established as an expected form of school discipline.

In the 1870s, courts in the United States overruled the common-law principle that a husband had the right to "physically chastise an errant wife". In the UK, the traditional right of a husband to inflict moderate corporal punishment on his wife in order to keep her "within the bounds of duty" was similarly removed in 1891. See Domestic violence for more information.

In the United Kingdom, the use of judicial corporal punishment declined during the first half of the twentieth century and it was abolished altogether in the Criminal Justice Act, 1948 (zi & z2 GEo. 6. CH. 58.), whereby whipping and flogging were outlawed except for use in very serious internal prison discipline cases, while most other European countries had abolished it earlier. Meanwhile, in many schools, the use of the cane, paddle or tawse remained commonplace in the UK and the United States until the 1980s. In rural areas of the Southern United States, and in several other countries, it still is: see School corporal punishment.

International treaties

Human rights

Key developments related to corporal punishment occurred in the late 20th century. Years with particular significance to the prohibition of corporal punishment are emphasised.

The notion of children's rights in the Western world developed in the 20th century, but the issue of corporal punishment was not addressed generally before mid-century. Years with particular significance to the prohibition of corporal punishment of children are emphasised.

  • 1923: Children's Rights Proclamation by Save the Children founder. (5 articles).
    • 1924 Adopted as the World Child Welfare Charter, League of Nations (non-enforceable).
  • 1959: Declaration of the Rights of the Child, (UN) (10 articles; non-binding).
  • 1989: Convention on the Rights of the Child, UN (54 articles; binding treaty), with currently 193 parties and 140 signatories. Article 19.1: "States Parties shall take all appropriate legislative, administrative, social and educational measures to protect the child from all forms of physical or mental violence, injury or abuse, neglect or negligent treatment, maltreatment or exploitation . . . ."
  • 2006: Study on Violence against Children presented by Independent Expert for the Secretary-General to the UN General Assembly.
  • 2007: Post of Special Representative of the Secretary-General on violence against children established.

Modern use

Laws on corporal punishments in the world
  Prohibited altogether
  Prohibited in schools
  Not prohibited in schools nor in a home, but prohibited in at least one setting
  Not prohibited at any setting
  Depends on state (USA)
School corporal punishment in the United States

Corporal punishment of minors in the United States

  Corporal punishment prohibited in public schools
  Corporal punishment not prohibited in public schools
Legality of corporal punishment of minors in Europe
  Corporal punishment banned altogether
  Corporal punishment banned in schools only
  Corporal punishment not prohibited in schools or in the home

Legal status

66 countries, most of them in Europe and Latin America, have prohibited any corporal punishment of children.

The earliest recorded attempt to prohibit corporal punishment of children by a state dates back to Poland in 1783. However, its prohibition in all spheres of life – in homes, schools, the penal system and alternative care settings – occurred first in 1966 in Sweden. The 1979 Swedish Parental Code reads: "Children are entitled to care, security and a good upbringing. Children are to be treated with respect for their person and individuality and may not be subjected to corporal punishment or any other humiliating treatment."

As of 2021, corporal punishment of children by parents (or other adults) is outlawed altogether in 63 nations (including the partially recognized Republic of Kosovo) and 3 constituent nations.

Countries that have completely prohibited corporal punishment of children:
Country Year
 Sweden 1979
 Finland 1983
 Norway 1987
 Austria 1989
 Cyprus 1994
 Denmark 1997
 Poland 1997
 Latvia 1998
 Germany 1998
 Croatia 1999
 Bulgaria 2000
 Israel 2000
 Turkmenistan 2002
 Iceland 2003
 Ukraine 2004
 Romania 2004
 Hungary 2005
 Greece 2006
 New Zealand 2007
 Netherlands 2007
 Portugal 2007
 Uruguay 2007
 Venezuela 2007
 Spain 2007
 Togo 2007
 Costa Rica 2008
 Moldova 2008
 Luxembourg 2008
 Liechtenstein 2008
 India 2009
 Tunisia 2010
 Kenya 2010
 Congo, Republic of 2010
 Albania 2010
 South Sudan 2011
 North Macedonia 2013
 Cabo Verde 2013
 Honduras 2013
 Malta 2014
 Brazil 2014
 Bolivia 2014
 Argentina 2014
 San Marino 2014
 Nicaragua 2014
 Estonia 2014
 Andorra 2014
 Benin 2015
 Ireland 2015
 Peru 2015
 Mongolia 2016
 Montenegro 2016
 Paraguay 2016
 Aruba 2016[40]
 Slovenia 2016
 Lithuania 2017
   Nepal 2018
 Kosovo 2019
 France 2019
 South Africa 2019
 Jersey 2019
 Georgia 2020
 Japan 2020
 Seychelles 2020
 Scotland 2020
 Guinea 2021
 Colombia 2021
 South Korea 2021
 Wales 2022
 Zambia 2022
 Mauritius 2022

For a more detailed overview of the global use and prohibition of the corporal punishment of children, see the following table.

Summary of the number of countries prohibiting corporal punishment of children

Home Schools Penal system Alternative care settings
As sentence for crime As disciplinary measure
Prohibited 67 130 156 117 39
Not prohibited 131 68 41 77 159
Legality unknown 1 4

Corporal punishment in the home

Domestic corporal punishment (i.e. the punishment of children by their parents) is often referred to colloquially as "spanking", "smacking", or "slapping".

It has been outlawed in an increasing number of countries, starting with Sweden in 1979. In some other countries, corporal punishment is legal, but restricted (e.g. blows to the head are outlawed, implements may not be used, only children within a certain age range may be spanked).

In all states of the United States and most African and Asian nations, corporal punishment by parents is legal. It is also legal to use certain implements (e.g. a belt or a paddle).

In Canada, spanking by parents or legal guardians (but nobody else) is legal, with certain restrictions: the child must be between the ages of 2–12, and no implement other than an open, bare hand may be used (belts, paddles, etc. are prohibited). It is also illegal to strike the head when disciplining a child.

In the UK (except Scotland and Wales), spanking or smacking is legal, but it must not cause an injury amounting to actual bodily harm (any injury such as visible bruising, breaking of the whole skin, etc.). In addition, in Scotland, since October 2003, it has been illegal to use any implements or to strike the head when disciplining a child, and it is also prohibited to use corporal punishment towards children under the age of 3 years. In 2019, Scotland enacted a ban on corporal punishment, which went into effect in 2020. Wales also enacted a ban in 2020, which has gone into effect in 2022.

In Pakistan, Section 89 of Pakistan Penal Code allows corporal punishment.

Corporal punishment in schools

Corporal punishment in schools has been outlawed in many countries. It often involves striking the student on the buttocks or the palm of the hand with an implement (e.g. a rattan cane or a spanking paddle).

In countries where corporal punishment is still allowed in schools, there may be restrictions; for example, school caning in Singapore and Malaysia is, in theory, permitted for boys only.

In India and many other countries, corporal punishment has technically been abolished by law. However, corporal punishment continues to be practiced on boys and girls in many schools around the world. Cultural perceptions of corporal punishment have rarely been studied and researched. One study carried out discusses how corporal punishment is perceived among parents and students in India.

Medical professionals have urged putting an end to the practice, noting the danger of injury to children's hands especially.

Judicial or quasi-judicial punishment

  Countries with judicial corporal punishment
A member of the Taliban's religious police beating an Afghan woman in Kabul on 26 August 2001

Around 33 countries in the world still retain judicial corporal punishment, including a number of former British territories such as Botswana, Malaysia, Singapore and Tanzania. In Singapore, for certain specified offences, males are routinely sentenced to caning in addition to a prison term. The Singaporean practice of caning became much discussed around the world in 1994 when American teenager Michael P. Fay received four strokes of the cane for vandalism. Judicial caning and whipping are also used in Aceh Province in Indonesia.

A number of other countries with an Islamic legal system, such as Saudi Arabia, UAE, Qatar, Iran, Brunei, Sudan, and some northern states in Nigeria, employ judicial whipping for a range of offences. In April 2020, the Saudi Supreme Court ended the flogging punishment from its court system, and replaced it with jail time or fines. As of 2009, some regions of Pakistan are experiencing a breakdown of law and government, leading to a reintroduction of corporal punishment by ad hoc Islamicist courts. As well as corporal punishment, some Islamic countries such as Saudi Arabia and Iran use other kinds of physical penalties such as amputation or mutilation. However, the term "corporal punishment" has since the 19th century usually meant caning, flagellation or bastinado rather than those other types of physical penalty.

In some countries, foot whipping (bastinado) is still practiced on prisoners.

Effects

According to a study headed by Harvard researchers, corporal punishment like spanking could affect the brain development of children. These affects are similar to the more severe form of violence.

Rituals

In parts of England, boys were once beaten under the old tradition of "Beating the Bounds" whereby a boy was paraded around the edge of a city or parish and spanked with a switch or cane to mark the boundary. One famous "Beating the Bounds" took place around the boundary of St Giles and the area where Tottenham Court Road now stands in central London. The actual stone that marked the boundary is now underneath the Centre Point office tower.

In the Czech Republic, Slovakia, and some parts of Hungary, a tradition for health and fertility is carried out on Easter Monday. Boys and young men will spank or whip girls and young women on the bottom with braided willow branches. After the man sings the verse, the young woman turns around and the man takes a few whacks at her backside with the whip. 

In popular culture

The Flagellation, by Piero della Francesca

Art

Film and TV

See: List of films and TV containing corporal punishment scenes.

Ultimate fate of the universe

From Wikipedia, the free encyclopedia

Observations made by Edwin Hubble during the 1930s–1950s found that galaxies appeared to be moving away from each other, leading to the currently accepted Big Bang theory. This suggests that the universe began very dense about 13.787 billion years ago, and it has expanded and (on average) become less dense ever since. Confirmation of the Big Bang mostly depends on knowing the rate of expansion, average density of matter, and the physical properties of the mass–energy in the universe.

There is a strong consensus among cosmologists that the shape of the universe is considered "flat" (parallel lines stay parallel) and will continue to expand forever.

Factors that need to be considered in determining the universe's origin and ultimate fate include the average motions of galaxies, the shape and structure of the universe, and the amount of dark matter and dark energy that the universe contains.

Emerging scientific basis

Theory

The theoretical scientific exploration of the ultimate fate of the universe became possible with Albert Einstein's 1915 theory of general relativity. General relativity can be employed to describe the universe on the largest possible scale. There are several possible solutions to the equations of general relativity, and each solution implies a possible ultimate fate of the universe.

Alexander Friedmann proposed several solutions in 1922, as did Georges Lemaître in 1927. In some of these solutions, the universe has been expanding from an initial singularity which was, essentially, the Big Bang.

Observation

In 1929, Edwin Hubble published his conclusion, based on his observations of Cepheid variable stars in distant galaxies, that the universe was expanding. From then on, the beginning of the universe and its possible end have been the subjects of serious scientific investigation.

Big Bang and Steady State theories

In 1927, Georges Lemaître set out a theory that has since come to be called the Big Bang theory of the origin of the universe. In 1948, Fred Hoyle set out his opposing Steady State theory in which the universe continually expanded but remained statistically unchanged as new matter is constantly created. These two theories were active contenders until the 1965 discovery, by Arno Penzias and Robert Wilson, of the cosmic microwave background radiation, a fact that is a straightforward prediction of the Big Bang theory, and one that the original Steady State theory could not account for. As a result, the Big Bang theory quickly became the most widely held view of the origin of the universe.

Cosmological constant

Einstein and his contemporaries believed in a static universe. When Einstein found that his general relativity equations could easily be solved in such a way as to allow the universe to be expanding at the present and contracting in the far future, he added to those equations what he called a cosmological constant ⁠— ⁠essentially a constant energy density, unaffected by any expansion or contraction ⁠— ⁠whose role was to offset the effect of gravity on the universe as a whole in such a way that the universe would remain static. However, after Hubble announced his conclusion that the universe was expanding, Einstein would write that his cosmological constant was "the greatest blunder of my life."

Density parameter

An important parameter in fate of the universe theory is the density parameter, omega (), defined as the average matter density of the universe divided by a critical value of that density. This selects one of three possible geometries depending on whether is equal to, less than, or greater than . These are called, respectively, the flat, open and closed universes. These three adjectives refer to the overall geometry of the universe, and not to the local curving of spacetime caused by smaller clumps of mass (for example, galaxies and stars). If the primary content of the universe is inert matter, as in the dust models popular for much of the 20th century, there is a particular fate corresponding to each geometry. Hence cosmologists aimed to determine the fate of the universe by measuring , or equivalently the rate at which the expansion was decelerating.

Repulsive force

Starting in 1998, observations of supernovas in distant galaxies have been interpreted as consistent with a universe whose expansion is accelerating. Subsequent cosmological theorizing has been designed so as to allow for this possible acceleration, nearly always by invoking dark energy, which in its simplest form is just a positive cosmological constant. In general, dark energy is a catch-all term for any hypothesized field with negative pressure, usually with a density that changes as the universe expands. Some cosmologists are studying whether dark energy which varies in time (due to a portion of it being caused by a scalar field in the early universe) can solve the crisis in cosmology.  Upcoming galaxy surveys from the Euclid, Nancy Grace Roman and James Webb space telescopes (and data from next-generation ground-based telescopes) are expected to further develop our understanding of dark energy (specifically whether it is best understood as a constant energy intrinsic to space, as a time varying quantum field or as something else entirely). 

Role of the shape of the universe

The ultimate fate of an expanding universe depends on the matter density and the dark energy density

The current scientific consensus of most cosmologists is that the ultimate fate of the universe depends on its overall shape, how much dark energy it contains and on the equation of state which determines how the dark energy density responds to the expansion of the universe. Recent observations conclude, from 7.5 billion years after the Big Bang, that the expansion rate of the universe has probably been increasing, commensurate with the Open Universe theory. However, measurements made by the Wilkinson Microwave Anisotropy Probe suggest that the universe is either flat or very close to flat.

Closed universe

If , the geometry of space is closed like the surface of a sphere. The sum of the angles of a triangle exceeds 180 degrees and there are no parallel lines; all lines eventually meet. The geometry of the universe is, at least on a very large scale, elliptic.

In a closed universe, gravity eventually stops the expansion of the universe, after which it starts to contract until all matter in the universe collapses to a point, a final singularity termed the "Big Crunch", the opposite of the Big Bang. If, however, the universe contains dark energy, then the resulting repulsive force may be sufficient to cause the expansion of the universe to continue forever—even if . This is the case in the currently accepted Lambda-CDM model, where dark energy is found through observations to account for roughly 68% of the total energy content of the universe. According to the Lambda-CDM model, the universe would need to have an average matter density roughly seventeen times greater than it's measured value today in order for the effects of dark energy to be overcome and the universe to eventually collapse. This is in spite of the fact that, according to the Lambda-CDM model, any increase in matter density would result in .

Open universe

If , the geometry of space is open, i.e., negatively curved like the surface of a saddle. The angles of a triangle sum to less than 180 degrees, and lines that do not meet are never equidistant; they have a point of least distance and otherwise grow apart. The geometry of such a universe is hyperbolic.

Even without dark energy, a negatively curved universe expands forever, with gravity negligibly slowing the rate of expansion. With dark energy, the expansion not only continues but accelerates. The ultimate fate of an open universe with dark energy is either universal heat death or a "Big Rip" where the acceleration caused by dark energy eventually becomes so strong that it completely overwhelms the effects of the gravitational, electromagnetic and strong binding forces. Conversely, a negative cosmological constant, which would correspond to a negative energy density and positive pressure, would cause even an open universe to re-collapse to a big crunch.

Flat universe

If the average density of the universe exactly equals the critical density so that , then the geometry of the universe is flat: as in Euclidean geometry, the sum of the angles of a triangle is 180 degrees and parallel lines continuously maintain the same distance. Measurements from the Wilkinson Microwave Anisotropy Probe have confirmed the universe is flat within a 0.4% margin of error.

In the absence of dark energy, a flat universe expands forever but at a continually decelerating rate, with expansion asymptotically approaching zero. With dark energy, the expansion rate of the universe initially slows down, due to the effects of gravity, but eventually increases, and the ultimate fate of the universe becomes the same as that of an open universe.

Theories about the end of the universe

The fate of the universe may be determined by its density. The preponderance of evidence to date, based on measurements of the rate of expansion and the mass density, favors a universe that will continue to expand indefinitely, resulting in the "Big Freeze" scenario below. However, observations are not conclusive, and alternative models are still possible.

Big Freeze or Heat Death

The heat death of the universe, also known as the Big Freeze (or Big Chill), is a scenario under which continued expansion results in a universe that asymptotically approaches absolute zero temperature. Under this scenario, the universe eventually reaches a state of maximum entropy in which everything is evenly distributed and there are no energy gradients—which are needed to sustain information processing, one form of which is life. This scenario has gained ground as the most likely fate.

In this scenario, stars are expected to form normally for 1012 to 1014 (1–100 trillion) years, but eventually the supply of gas needed for star formation will be exhausted. As existing stars run out of fuel and cease to shine, the universe will slowly and inexorably grow darker. Eventually black holes will dominate the universe, which themselves will disappear over time as they emit Hawking radiation. Over infinite time, there could be a spontaneous entropy decrease by the Poincaré recurrence theorem, thermal fluctuations, and the fluctuation theorem.

The heat death scenario is compatible with any of the three spatial models, but it requires that the universe reaches an eventual temperature minimum. Without dark energy, it could occur only under a flat or hyperbolic geometry. With a positive cosmological constant, it could also occur in a closed universe.

Big Rip

The current Hubble constant defines a rate of acceleration of the universe not large enough to destroy local structures like galaxies, which are held together by gravity, but large enough to increase the space between them. A steady increase in the Hubble constant to infinity would result in all material objects in the universe, starting with galaxies and eventually (in a finite time) all forms, no matter how small, disintegrating into unbound elementary particles, radiation and beyond. As the energy density, scale factor and expansion rate become infinite the universe ends as what is effectively a singularity.

In the special case of phantom dark energy, which has supposed negative kinetic energy that would result in a higher rate of acceleration than other cosmological constants predict, a more sudden big rip could occur.

Big Crunch

The Big Crunch. The vertical axis can be considered as expansion or contraction with time.

The Big Crunch hypothesis is a symmetric view of the ultimate fate of the universe. Just as the theorized Big Bang started as a cosmological expansion, this theory assumes that the average density of the universe will be enough to stop its expansion and the universe will begin contracting. The result is unknown; a simple estimation would have all the matter and space-time in the universe collapse into a dimensionless singularity back into how the universe started with the Big Bang, but at these scales unknown quantum effects need to be considered (see Quantum gravity). Recent evidence suggests that this scenario is unlikely but has not been ruled out, as measurements have been available only over a short period of time, relatively speaking, and could reverse in the future.

This scenario allows the Big Bang to occur immediately after the Big Crunch of a preceding universe. If this happens repeatedly, it creates a cyclic model, which is also known as an oscillatory universe. The universe could then consist of an infinite sequence of finite universes, with each finite universe ending with a Big Crunch that is also the Big Bang of the next universe. A problem with the cyclic universe is that it does not reconcile with the second law of thermodynamics, as entropy would build up from oscillation to oscillation and cause the eventual heat death of the universe. Current evidence also indicates the universe is not closed. This has caused cosmologists to abandon the oscillating universe model. A somewhat similar idea is embraced by the cyclic model, but this idea evades heat death because of an expansion of the branes that dilutes entropy accumulated in the previous cycle.

Big Bounce

The Big Bounce is a theorized scientific model related to the beginning of the known universe. It derives from the oscillatory universe or cyclic repetition interpretation of the Big Bang where the first cosmological event was the result of the collapse of a previous universe.

According to one version of the Big Bang theory of cosmology, in the beginning the universe was infinitely dense. Such a description seems to be at odds with other more widely accepted theories, especially quantum mechanics and its uncertainty principle. Therefore, quantum mechanics has given rise to an alternative version of the Big Bang theory, specifically that the universe tunneled into existence and had a finite density consistent with quantum mechanics, before evolving in a manner governed by classical physics. Also, if the universe is closed, this theory would predict that once this universe collapses it will spawn another universe in an event similar to the Big Bang after a universal singularity is reached or a repulsive quantum force causes re-expansion.

In simple terms, this theory states that the universe will continuously repeat the cycle of a Big Bang, followed up with a Big Crunch.

Cosmic uncertainty

Each possibility described so far is based on a very simple form for the dark energy equation of state. However, as the name is meant to imply, very little is now known about the physics of dark energy. If the theory of inflation is true, the universe went through an episode dominated by a different form of dark energy in the first moments of the Big Bang, but inflation ended, indicating an equation of state far more complex than those assumed so far for present-day dark energy. It is possible that the dark energy equation of state could change again, resulting in an event that would have consequences which are extremely difficult to predict or parameterize. As the nature of dark energy and dark matter remain enigmatic, even hypothetical, the possibilities surrounding their coming role in the universe are currently unknown.

None of these theoretic endings for the universe are certain. In other words, considering the universe is only around 14 billion years old, extrapolating the trends observed in the cosmic history so far to a considerably longer timescale can be criticized as being insufficiently substantiated.

Other possible fates of the universe

There are also some possible events, such as the Big Slurp, which would seriously harm the universe, although the universe as a whole would not be completely destroyed as a result.

Big Slurp

This theory posits that the universe currently exists in a false vacuum and that it could become a true vacuum at any moment.

In order to best understand the false vacuum collapse theory, one must first understand the Higgs field which permeates the universe. Much like an electromagnetic field, it varies in strength based upon its potential. A true vacuum exists so long as the universe exists in its lowest energy state, in which case the false vacuum theory is irrelevant. However, if the vacuum is not in its lowest energy state (a false vacuum), it could tunnel into a lower-energy state. This is called vacuum decay. This has the potential to fundamentally alter our universe; in more audacious scenarios even the various physical constants could have different values, severely affecting the foundations of matter, energy, and spacetime. It is also possible that all structures will be destroyed instantaneously, without any forewarning.

However, only a portion of the universe would be destroyed by the Big Slurp while most of the universe would still be unaffected because galaxies located further than 4,200 megaparsecs (13 billion light-years) away from each other are moving away from each other faster than the speed of light while the Big Slurp itself cannot expand faster than the speed of light.

Observational constraints on theories

Choosing among these rival scenarios is done by 'weighing' the universe, for example, measuring the relative contributions of matter, radiation, dark matter, and dark energy to the critical density. More concretely, competing scenarios are evaluated against data on galaxy clustering and distant supernovas, and on the anisotropies in the cosmic microwave background.

Inequality (mathematics)

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