Emergence

In, , , and , emergence occurs when an entity is observed to have properties its parts do not have on their own. These properties or behaviors emerge only when the parts interact in a wider whole. For example, smooth forward motion emerges when a bicycle and its rider interoperate, but neither part can produce the behavior on their own.

Emergence plays a central role in theories of s and of s. For instance, the phenomenon of  as studied in  is an emergent property of, and  phenomena emerge from the  phenomena of living things.

In philosophy, theories that emphasize emergent properties have been called. Almost all accounts of emergentism include a form of or  irreducibility to the lower levels.

In, emergence is used to describe a property, law, or phenomenon which occurs at macroscopic scales (in space or time) but not at microscopic scales, despite the fact that a macroscopic system can be viewed as a very large ensemble of microscopic systems.

An emergent property need not be more complicated than the underlying non-emergent properties which generate it. For instance, the laws of are remarkably simple, even if the laws which govern the interactions between component particles are complex. The term emergence in physics is thus used not to signify complexity, but rather to distinguish which laws and concepts apply to macroscopic scales, and which ones apply to microscopic scales.

However, another, perhaps more broadly applicable way to conceive of the emergent divide does involve a dose of complexity insofar as the computational feasibility of going from the microscopic to the macroscopic property tells the 'strength' of the emergence. This is better understood given the following definition of emergence that comes from physics:

"An emergent behavior of a physical system is a qualitative property that can only occur in the limit that the number of microscopic constituents tends to infinity."

Since there are no actually infinite systems in the real world, there is no obvious naturally occurring notion of a hard separation between the properties of the constituents of a system and those of the emergent whole. As discussed below, classical mechanics is thought to be emergent from quantum mechanics, though in principal, quantum dynamics fully describes everything happening at a classical level. However, it would take a computer larger than the size of the universe with more computing time than life time of the universe to describe the motion of a falling apple in terms of the locations of its electrons ; thus we can take this to be a "strong" emergent divide.

Some examples include:
 * : The laws of classical mechanics can be said to emerge as a limiting case from the rules of  applied to large enough masses. This is particularly strange since quantum mechanics is generally thought of as more complicated than classical mechanics.
 * : Forces between elementary particles are conservative.  However, friction emerges when considering more complex structures of matter, whose surfaces can convert mechanical energy into heat energy when rubbed against each other.  Similar considerations apply to other emergent concepts in  such as, , , etc.
 * : the distinct, and often symmetrical geometric shapes formed by ground material in periglacial regions.
 * was initially derived using the concept of a large enough that fluctuations about the most likely distribution can be all but ignored.  However, small clusters do not exhibit sharp first order s such as melting, and at the boundary it is not possible to completely categorize the cluster as a liquid or solid, since these concepts are (without extra definitions) only applicable to macroscopic systems.  Describing a system using statistical mechanics methods is much simpler than using a low-level atomistic approach.
 * : The bulk conductive response of binary (RC) electrical networks with random arrangements, known as the, can be seen as emergent properties of such physical systems. Such arrangements can be used as simple physical prototypes for deriving mathematical formulae for the emergent responses of complex systems.

is sometimes used as an example of an emergent macroscopic behaviour. In classical dynamics, a snapshot of the instantaneous momenta of a large number of particles at equilibrium is sufficient to find the average kinetic energy per degree of freedom which is proportional to the temperature. For a small number of particles the instantaneous momenta at a given time are not statistically sufficient to determine the temperature of the system. However, using the, the temperature can still be obtained to arbitrary precision by further averaging the momenta over a long enough time.

in a liquid or gas is another example of emergent macroscopic behaviour that makes sense only when considering differentials of temperature. , particularly, are an example of a system (more specifically, a ) whose structure is determined both by the constraints of the system and by random perturbations: the possible realizations of the shape and size of the cells depends on the temperature gradient as well as the nature of the fluid and shape of the container, but which configurations are actually realized is due to random perturbations (thus these systems exhibit a form of ).

In some theories of particle physics, even such basic structures as, , and are viewed as emergent phenomena, arising from more fundamental concepts such as the  or. In some interpretations of, the perception of a reality, in which all objects have a definite position, momentum, and so forth, is actually an emergent phenomenon, with the true state of matter being described instead by a  which need not have a single position or momentum. Most of the laws of themselves as we experience them today appear to have emerged during the course of time making emergence the most fundamental principle in the universe and raising the question of what might be the most fundamental law of physics from which all others emerged. can in turn be viewed as an emergent property of the laws of physics. (including biological ) can be viewed as an emergent property of the laws of chemistry. Similarly, could be understood as an emergent property of neurobiological laws. Finally, free-market theories understand as an emergent feature of psychology.

According to Laughlin (2005), for many particle systems, nothing can be calculated exactly from the microscopic equations, and macroscopic systems are characterised by broken symmetry: the symmetry present in the microscopic equations is not present in the macroscopic system, due to phase transitions. As a result, these macroscopic systems are described in their own terminology, and have properties that do not depend on many microscopic details. This does not mean that the microscopic interactions are irrelevant, but simply that you do not see them anymore — you only see a renormalized effect of them. Laughlin is a pragmatic theoretical physicist: if you cannot, possibly ever, calculate the broken symmetry macroscopic properties from the microscopic equations, then what is the point of talking about reducibility?

Emergence and evolution
is a major source of complexity, and is the major process behind the varying forms of life. In this view, evolution is the process describing the growth of complexity in the natural world and in speaking of the emergence of complex living beings and life-forms, this view refers therefore to processes of sudden changes in evolution.

is thought to have emerged in the early when  chains began to express the basic conditions necessary for natural selection to operate as conceived by : heritability, variation of type, and competition for limited resources. of an RNA replicator (its per capita rate of increase) would likely be a function of adaptive capacities that were intrinsic (in the sense that they were determined by the nucleotide sequence) and the availability of resources. The three primary adaptive capacities may have been (1) the capacity to replicate with moderate fidelity (giving rise to both heritability and variation of type); (2) the capacity to avoid decay; and (3) the capacity to acquire and process resources. These capacities would have been determined initially by the folded configurations of the RNA replicators (see “”) that, in turn, would be encoded in their individual nucleotide sequences. Competitive success among different replicators would have depended on the relative values of these adaptive capacities.

Regarding in evolution  observes: "Synergistic effects of various kinds have played a major causal role in the evolutionary process generally and in the evolution of cooperation and complexity in particular... Natural selection is often portrayed as a “mechanism”, or is personified as a causal agency... In reality, the differential “selection” of a trait, or an adaptation, is a consequence of the functional effects it produces in relation to the survival and reproductive success of a given organism in a given environment. It is these functional effects that are ultimately responsible for the trans-generational continuities and changes in nature."

Per his, Corning also addresses emergence and evolution: "[In] evolutionary processes, causation is iterative; effects are also causes. And this is equally true of the synergistic effects produced by emergent systems. In other words, emergence itself... has been the underlying cause of the evolution of emergent phenomena in biological evolution; it is the synergies produced by organized systems that are the key."

is a well-known behaviour in many animal species from to  to. Emergent structures are a common strategy found in many animal groups: colonies of ants, mounds built by termites, swarms of bees, shoals/schools of fish, flocks of birds, and herds/packs of mammals.

An example to consider in detail is an. The queen does not give direct orders and does not tell the ants what to do. Instead, each ant reacts to stimuli in the form of chemical scent from larvae, other ants, intruders, food and buildup of waste, and leaves behind a chemical trail, which, in turn, provides a stimulus to other ants. Here each ant is an autonomous unit that reacts depending only on its local environment and the genetically encoded rules for its variety of ant. Despite the lack of centralized decision making, ant colonies exhibit complex behavior and have even demonstrated the ability to solve geometric problems. For example, colonies routinely find the maximum distance from all colony entrances to dispose of dead bodies.

It appears that environmental factors may play a role in influencing emergence. Research suggests induced emergence of the bee species. In this species, the bees emerge in a pattern consistent with rainfall. Specifically, the pattern of emergence is consistent with southwestern deserts' late summer rains and lack of activity in the spring.

Organization of life
A broader example of emergent properties in biology is viewed in the of life, ranging from the  level to the entire. For example, individual s can be combined to form s such as chains, which in turn  and refold to form s, which in turn create even more complex structures. These proteins, assuming their functional status from their spatial conformation, interact together and with other molecules to achieve higher biological functions and eventually create an. Another example is how cascade reactions, as detailed in, arise from individual genes mutating respective positioning. At the highest level, all the in the world form the biosphere, where its human participants form societies, and the complex interactions of meta-social systems such as the stock market.

Emergence of mind
Among the considered phenomena in the evolutionary account of life, as a continuous history, marked by stages at which fundamentally new forms have appeared - the origin of sapiens intelligence. The emergence of mind and its evolution is researched and considered as a separate phenomenon in a special system knowledge

Spontaneous order
Groups of human beings, left free to each regulate themselves, tend to produce, rather than the meaningless chaos often feared. This has been observed in society at least since in ancient China. Human beings are the basic elements of social systems, which perpetually interact and create, maintain, or untangle mutual social bonds. Social bonds in social systems are perpetually changing in the sense of the ongoing reconfiguration of their structure. A classic  is also a good example, with cars moving in and out with such effective organization that some modern cities have begun replacing stoplights at problem intersections with traffic circles, and getting better results. and projects form an even more compelling illustration.

Emergent processes or behaviors can be seen in many other places, such as cities, and  phenomena in economics, organizational phenomena in s and. Whenever there is a multitude of individuals interacting, an order emerges from disorder; a pattern, a decision, a structure, or a change in direction occurs.

Economics
The (or any market for that matter) is an example of emergence on a grand scale. As a whole it precisely regulates the relative security prices of companies across the world, yet it has no leader; when no is in place, there is no one entity which controls the workings of the entire market. Agents, or investors, have knowledge of only a limited number of companies within their portfolio, and must follow the regulatory rules of the market and analyse the transactions individually or in large groupings. Trends and patterns emerge which are studied intensively by ..