Self-replication
Encyclopedia

Self-replication is any behavior of a dynamical system
Dynamical system
A dynamical system is a concept in mathematics where a fixed rule describes the time dependence of a point in a geometrical space. Examples include the mathematical models that describe the swinging of a clock pendulum, the flow of water in a pipe, and the number of fish each springtime in a...

 that yields construction of an identical copy of that dynamical system. Biological cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

s, given suitable environments, reproduce by cell division
Cell division
Cell division is the process by which a parent cell divides into two or more daughter cells . Cell division is usually a small segment of a larger cell cycle. This type of cell division in eukaryotes is known as mitosis, and leaves the daughter cell capable of dividing again. The corresponding sort...

. During cell division, DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

 is replicated and can be transmitted to offspring during reproduction. Biological viruses can reproduce, but only by commandeering the reproductive machinery of cells through a process of infection. Harmful prion
Prion
A prion is an infectious agent composed of protein in a misfolded form. This is in contrast to all other known infectious agents which must contain nucleic acids . The word prion, coined in 1982 by Stanley B. Prusiner, is a portmanteau derived from the words protein and infection...

 proteins can replicate by converting normal prions into rogue forms. Computer virus
Computer virus
A computer virus is a computer program that can replicate itself and spread from one computer to another. The term "virus" is also commonly but erroneously used to refer to other types of malware, including but not limited to adware and spyware programs that do not have the reproductive ability...

es reproduce using the hardware and software already present on computers. Self-replication in robotics
Robotics
Robotics is the branch of technology that deals with the design, construction, operation, structural disposition, manufacture and application of robots...

 has been an area of research and a subject of interest in science fiction
Science fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

. Any self-replicating mechanism which does not make a perfect copy will result in the creation of different variants and thus be subject to natural selection
Natural selection
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....

 as the variants which are better at persisting in their environment will outlive and outreproduce variants which are not so suited to their environment.

Theory

Early research by John von Neumann
John von Neumann
John von Neumann was a Hungarian-American mathematician and polymath who made major contributions to a vast number of fields, including set theory, functional analysis, quantum mechanics, ergodic theory, geometry, fluid dynamics, economics and game theory, computer science, numerical analysis,...

  established that replicator
Replicator
Replicator may refer to various things related to replication and self-replication:* The theoretical basic unit of evolution in some schools of evolutionary theory* Replicator * Clanking replicator* DNA replicationIn culture:...

s have several parts:
  • A coded representation of the replicator.
  • A mechanism to copy the coded representation.
  • A mechanism for effecting universal construction within the host environment of the replicator.


Exceptions to this pattern are possible. For example, scientists have successfully constructed RNA that copies itself in an "environment" that is a solution of RNA monomers and transcriptase. In this case, the body is the genome, and the specialized copy mechanisms are external.

However, the simplest possible case is that only a genome exists. Without some specification of the self-reproducing steps, a genome-only system is probably better characterized as something like a crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...

.

Classes of self-replication

Recent research http://www.MolecularAssembler.com/KSRM/5.1.htm has begun to categorize replicators, often based on the amount of support they require.
  • Natural replicators have all or most of their design from nonhuman sources. Such systems include natural life forms.
  • Autotroph
    Autotroph
    An autotroph, or producer, is an organism that produces complex organic compounds from simple inorganic molecules using energy from light or inorganic chemical reactions . They are the producers in a food chain, such as plants on land or algae in water...

    ic replicators can reproduce themselves "in the wild". They mine their own materials. It is conjectured that non-biological autotrophic replicators could be designed by humans, and could easily accept specifications for human products.
  • Self-reproductive systems are conjectured systems which would produce copies of themselves from industrial feedstocks such as metal bar and wire.
  • Self-assembling systems assemble copies of themselves from finished, delivered parts. Simple examples of such systems have been demonstrated at the macro scale.


The design space for machine replicators is very broad. A comprehensive studyhttp://www.MolecularAssembler.com/KSRM/5.1.9.htm to date by Robert Freitas
Robert Freitas
Robert A. Freitas Jr. is a Senior Research Fellow, one of four researchers at the nonprofit foundation Institute for Molecular Manufacturing in Palo Alto, California. He holds a 1974 Bachelor's degree majoring in both physics and psychology from Harvey Mudd College, and a 1978 Juris Doctor degree...

 and Ralph Merkle
Ralph Merkle
Ralph C. Merkle is a researcher in public key cryptography, and more recently a researcher and speaker on molecular nanotechnology and cryonics...

 has identified 137 design dimensions grouped into a dozen separate categories, including: (1) Replication Control, (2) Replication Information, (3) Replication Substrate, (4) Replicator Structure, (5) Passive Parts, (6) Active Subunits, (7) Replicator Energetics, (8) Replicator Kinematics, (9) Replication Process, (10) Replicator Performance, (11) Product Structure, and (12) Evolvability.

A self-reproducing computer program

In computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

 a self-reproducing computer program is a computer program that, when executed, outputs its own code. This is also called a quine.
Here is an example program in the Python programming language
Python (programming language)
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...

:
a='a=%r;print a%%a';print a%a


A more trivial approach is to write a program that will make a copy of any stream of data that it is directed to, and then direct it at itself. In this case the program is treated as both executable code, and as data to be manipulated.

This approach is common in most self-replicating systems, including biological life, and is simpler in that it does not require the program to contain a complete description of itself.

In many programming languages an empty program is still a legal program, which executes without producing errors or any other output. The output is thus the same as the source code, so the program is trivially self-reproducing.

Self-replicating tiling

In geometry
Geometry
Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....

 a self-replicating tiling is a tiling pattern in which several congruent
Congruence (geometry)
In geometry, two figures are congruent if they have the same shape and size. This means that either object can be repositioned so as to coincide precisely with the other object...

 tiles may be joined together to form a larger tile that is similar to the original. This is an aspect of the field of study known as tessellation
Tessellation
A tessellation or tiling of the plane is a pattern of plane figures that fills the plane with no overlaps and no gaps. One may also speak of tessellations of parts of the plane or of other surfaces. Generalizations to higher dimensions are also possible. Tessellations frequently appeared in the art...

. The "sphinx" hexiamond is the only known self-replicating pentagon
Pentagon
In geometry, a pentagon is any five-sided polygon. A pentagon may be simple or self-intersecting. The sum of the internal angles in a simple pentagon is 540°. A pentagram is an example of a self-intersecting pentagon.- Regular pentagons :In a regular pentagon, all sides are equal in length and...

. For example, four such concave pentagons can be joined together to make one with twice the dimensions. Solomon W. Golomb
Solomon W. Golomb
Solomon Wolf Golomb is an American mathematician and engineer and a professor of electrical engineering at the University of Southern California, best known to the general public and fans of mathematical games as the inventor of polyominoes, the inspiration for the computer game Tetris...

 coined the term rep-tiles for self-replicating tilings.

Applications

It is a long-term goal of some engineering sciences to achieve a clanking replicator, a material device that can self-replicate. The usual reason is to achieve a low cost per item while retaining the utility of a manufactured good. Many authorities say that in the limit, the cost of self-replicating items should approach the cost-per-weight of wood or other biological substances, because self-replication avoids the costs of labor, capital
Capital (economics)
In economics, capital, capital goods, or real capital refers to already-produced durable goods used in production of goods or services. The capital goods are not significantly consumed, though they may depreciate in the production process...

 and distribution
Distribution (business)
Product distribution is one of the four elements of the marketing mix. An organization or set of organizations involved in the process of making a product or service available for use or consumption by a consumer or business user.The other three parts of the marketing mix are product, pricing,...

 in conventional manufactured goods
Factory
A factory or manufacturing plant is an industrial building where laborers manufacture goods or supervise machines processing one product into another. Most modern factories have large warehouses or warehouse-like facilities that contain heavy equipment used for assembly line production...

.

A fully novel artificial replicator is a reasonable near-term goal.
A NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 study recently placed the complexity of a clanking replicator
Clanking replicator
A clanking replicator is an artificial self-replicating system that relies on conventional large-scale technology and automation. The term evolved to distinguish such systems from the microscopic "assemblers" that nanotechnology may make possible...

 at approximately that of Intel's Pentium 4 CPU. That is, the technology is achievable with a relatively small engineering group in a reasonable commercial time-scale at a reasonable cost.

Given the currently keen interest in biotechnology and the high levels of funding in that field, attempts to exploit the replicative ability of existing cells are timely, and may easily lead to significant insights and advances.

A variation of self replication is of practical relevance in compiler
Compiler
A compiler is a computer program that transforms source code written in a programming language into another computer language...

 construction, where a similar chicken and egg problem occurs as in natural self replication. A compiler (phenotype
Phenotype
A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...

) can be applied on the compiler's own source code
Source code
In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...

 (genotype
Genotype
The genotype is the genetic makeup of a cell, an organism, or an individual usually with reference to a specific character under consideration...

) producing the compiler itself. During compiler development, a modified (mutated
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

) source is used to create the next generation of the compiler. This process differs from natural self-replication in that the process is directed by an engineer, not by the subject itself.

Mechanical self-replication

An activity in the field of robots is the self-replication of machines. Since all robots (at least in modern times) have a fair number of the same features, a self-replicating robot (or possibly a hive of robots) would need to do the following:
  • Obtain construction materials
  • Manufacture new parts including its smallest parts and thinking apparatus
  • Provide a consistent power source
  • Program the new members
  • error correct any mistakes in the offspring


On a nano
Nano
Nano- is a prefix meaning a billionth. Used primarily in the metric system, this prefix denotes a factor of 10−9 or . It is frequently encountered in science and electronics for prefixing units of time and length, such as 30 nanoseconds , 100 nanometres or in the case of electrical capacitance,...

 scale, assemblers might also be designed to self-replicate under their own power. This, in turn, has given rise to the "grey goo
Grey goo
Grey goo is a hypothetical end-of-the-world scenario involving molecular nanotechnology in which out-of-control self-replicating robots consume all matter on Earth while building more of themselves, a scenario known as ecophagy .Self-replicating machines of the macroscopic variety were originally...

" version of Armageddon
Armageddon
Armageddon is, according to the Bible, the site of a battle during the end times, variously interpreted as either a literal or symbolic location...

, as featured in such science fiction novels as Bloom
Bloom (novel)
Bloom, written in 1998, is the fifth science fiction novel written by Wil McCarthy. It was first released as a hardcover in September 1998...

, Prey
Prey (novel)
Prey is a novel by Michael Crichton based on a nano-robotic threat to human-kind, first published in hardcover in November 2002 and as a paperback in November 2003 by HarperCollins...

, and Recursion
Recursion (novel)
Recursion is Tony Ballantyne's first novel. It is in the science fiction genre and follows three separate characters and their stories in a futuristic dystopia....

.

The Foresight Institute
Foresight Institute
The Foresight Institute is a Palo Alto, California-based nonprofit organization for promoting transformative technologies. They sponsor conferences on molecular nanotechnology, publish reports, and produce a newsletter....

 has published guidelines for researchers in mechanical self-replication. The guidelines recommend that researchers use several specific techniques for preventing mechanical replicators from getting out of control, such as using a broadcast architecture.

For a detailed article on mechanical reproduction as it relates to the industrial age see mass production
Mass production
Mass production is the production of large amounts of standardized products, including and especially on assembly lines...

.

Fields involving study of self-replication

Most of the research has occurred in a few areas:
  • Biology
    Biology
    Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

     studies natural replication and replicators, and their interaction. These can be an important guide to avoid design difficulties in self-replicating machinery.
  • Meme
    Meme
    A meme is "an idea, behaviour or style that spreads from person to person within a culture."A meme acts as a unit for carrying cultural ideas, symbols or practices, which can be transmitted from one mind to another through writing, speech, gestures, rituals or other imitable phenomena...

    tics studies ideas and how they propagate in human culture. Memes require only small amounts of material, and therefore have theoretical similarities to virus
    Virus
    A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

    es and are often described as viral
    Virus
    A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

    .
  • Nanotechnology
    Nanotechnology
    Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometres...

     or more precisely, molecular nanotechnology
    Molecular nanotechnology
    Molecular nanotechnology is a technology based on the ability to build structures to complex, atomic specifications by means of mechanosynthesis. This is distinct from nanoscale materials...

     is concerned with making nano
    Nano
    Nano- is a prefix meaning a billionth. Used primarily in the metric system, this prefix denotes a factor of 10−9 or . It is frequently encountered in science and electronics for prefixing units of time and length, such as 30 nanoseconds , 100 nanometres or in the case of electrical capacitance,...

     scale assemblers. Without self-replication, capital and assembly costs of molecular machines become impossibly large.
  • Space resources: NASA has sponsored a number of design studies to develop self-replicating mechanisms to mine space resources. Most of these designs include computer-controlled machinery that copies itself.
  • Computer security
    Computer security
    Computer security is a branch of computer technology known as information security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to...

    : Many computer security problems are caused by self-reproducing computer programs that infect computers — computer worm
    Computer worm
    A computer worm is a self-replicating malware computer program, which uses a computer network to send copies of itself to other nodes and it may do so without any user intervention. This is due to security shortcomings on the target computer. Unlike a computer virus, it does not need to attach...

    s and computer virus
    Computer virus
    A computer virus is a computer program that can replicate itself and spread from one computer to another. The term "virus" is also commonly but erroneously used to refer to other types of malware, including but not limited to adware and spyware programs that do not have the reproductive ability...

    es.
  • In parallel computing
    Parallel computing
    Parallel computing is a form of computation in which many calculations are carried out simultaneously, operating on the principle that large problems can often be divided into smaller ones, which are then solved concurrently . There are several different forms of parallel computing: bit-level,...

    , it takes a long time to manually load a new program on every node of a large computer cluster or distributed computing
    Distributed computing
    Distributed computing is a field of computer science that studies distributed systems. A distributed system consists of multiple autonomous computers that communicate through a computer network. The computers interact with each other in order to achieve a common goal...

     system. Automatically loading new programs using mobile agent
    Mobile agent
    In computer science, a mobile agent is a composition of computer software and data which is able to migrate from one computer to another autonomously and continue its execution on the destination computer.-Definition and overview:...

    s can save the system administrator a lot of time and give users their results much quicker, as long as they don't get out of control.

Space exploration and manufacturing

The goal of self-replication in space systems is to exploit large amounts of matter with a low launch mass. For example, an autotroph
Autotroph
An autotroph, or producer, is an organism that produces complex organic compounds from simple inorganic molecules using energy from light or inorganic chemical reactions . They are the producers in a food chain, such as plants on land or algae in water...

ic self-replicating machine could cover a moon or planet with solar cells, and beam the power to the Earth using microwaves. Once in place, the same machinery that built itself could also produce raw materials or manufactured objects, including transportation systems to ship the products. Another model
Von Neumann probe
The idea of self-replicating spacecraft has been applied — in theory — to several distinct "tasks". The particular variant of this idea applied to the idea of space exploration is known as a von Neumann probe...

 of self-replicating machine would copy itself through the galaxy, sending information back.

In general, since these systems are autotrophic, they are the most difficult and complex known replicators. They are also thought to be the most hazardous, because they do not require any inputs from human beings in order to reproduce.

A classic theoretical study of replicators in space is the 1980 NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 study of autotrophic clanking replicators, edited by Robert Freitas
Robert Freitas
Robert A. Freitas Jr. is a Senior Research Fellow, one of four researchers at the nonprofit foundation Institute for Molecular Manufacturing in Palo Alto, California. He holds a 1974 Bachelor's degree majoring in both physics and psychology from Harvey Mudd College, and a 1978 Juris Doctor degree...

.

Much of the design study was concerned with a simple, flexible chemical system for processing lunar regolith
Regolith
Regolith is a layer of loose, heterogeneous material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, some asteroids, and other terrestrial planets and moons.-Etymology:...

, and the differences between the ratio of elements needed by the replicator, and the ratios available in regolith. The limiting element was Chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...

, an essential element to process regolith for Aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

. Chlorine is very rare in lunar regolith, and a substantially faster rate of reproduction could be assured by importing modest amounts.

The reference design specified small computer-controlled electric carts running on rails. Each cart could have a simple hand or a small bull-dozer shovel, forming a basic robot
Robot
A robot is a mechanical or virtual intelligent agent that can perform tasks automatically or with guidance, typically by remote control. In practice a robot is usually an electro-mechanical machine that is guided by computer and electronic programming. Robots can be autonomous, semi-autonomous or...

.

Power would be provided by a "canopy" of solar cell
Solar cell
A solar cell is a solid state electrical device that converts the energy of light directly into electricity by the photovoltaic effect....

s supported on pillars. The other machinery could run under the canopy.

A "casting
Casting
In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process...

 robot
Robot
A robot is a mechanical or virtual intelligent agent that can perform tasks automatically or with guidance, typically by remote control. In practice a robot is usually an electro-mechanical machine that is guided by computer and electronic programming. Robots can be autonomous, semi-autonomous or...

" would use a robotic arm with a few sculpting tools to make plaster
Plaster
Plaster is a building material used for coating walls and ceilings. Plaster starts as a dry powder similar to mortar or cement and like those materials it is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after setting,...

 mold
Molding (process)
Molding or moulding is the process of manufacturing by shaping pliable raw material using a rigid frame or model called a pattern....

s. Plaster molds are easy to make, and make precise parts with good surface finishes. The robot would then cast most of the parts either from non-conductive molten rock (basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

) or purified metals. An electric
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

 oven
Oven
An oven is a thermally insulated chamber used for the heating, baking or drying of a substance. It is most commonly used for cooking. Kilns, and furnaces are special-purpose ovens...

 melted the materials.

A speculative, more complex "chip factory" was specified to produce the computer and electronic systems, but the designers also said that it might prove practical to ship the chips from Earth as if they were "vitamins".

Molecular manufacturing

Nanotechnologists
Nanotechnology
Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometres...

 in particular believe that their work will likely fail to reach a state of maturity until human beings design a self-replicating assembler of nanometer dimensions http://www.MolecularAssembler.com/KSRM/4.11.3.htm.

These systems are substantially simpler than autotrophic systems, because they are provided with purified feedstocks and energy. They do not have to reproduce them. This distinction is at the root of some of the controversy about whether molecular manufacturing is possible or not. Many authorities who find it impossible are clearly citing sources for complex autotrophic self-replicating systems. Many of the authorities who find it possible are clearly citing sources for much simpler self-assembling systems, which have been demonstrated. In the meantime, a Lego
Lego
Lego is a line of construction toys manufactured by the Lego Group, a privately held company based in Billund, Denmark. The company's flagship product, Lego, consists of colorful interlocking plastic bricks and an accompanying array of gears, minifigures and various other parts...

-built autonomous robot able to follow a pre-set track and assemble an exact copy of itself, starting from four externally-provided components, was demonstrated experimentally in 2003 http://www.MolecularAssembler.com/KSRM/3.23.4.htm.

Merely exploiting the replicative abilities of existing cells is insufficient, because of limitations in the process of protein biosynthesis
Protein biosynthesis
Protein biosynthesis is the process in which cells build or manufacture proteins. The term is sometimes used to refer only to protein translation but more often it refers to a multi-step process, beginning with amino acid synthesis and transcription of nuclear DNA into messenger RNA, which is then...

 (also see the listing for RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....

).
What is required is the rational design of an entirely novel replicator with a much wider range of synthesis capabilities.

In 2011, New York University scientists have developed artificial structures that can self-replicate, a process that has the potential to yield new types of materials. They have demonstrated that it is possible to replicate not just molecules like cellular DNA or RNA, but discrete structures that could in principle assume many different shapes, have many different functional features, and be associated with many different types of chemical species.

For a discussion of other chemical bases for hypothetical self-replicating systems, see alternative biochemistry
Alternative biochemistry
Hypothetical types of biochemistry are forms of biochemistry speculated to be scientifically viable but not proven to exist at this time. While the kinds of living beings we know on earth commonly use carbon for basic structural and metabolic functions, water as a solvent and DNA or RNA to define...

.

Industrial assembly

See also

  • Artificial life
    Artificial life
    Artificial life is a field of study and an associated art form which examine systems related to life, its processes, and its evolution through simulations using computer models, robotics, and biochemistry. The discipline was named by Christopher Langton, an American computer scientist, in 1986...

  • Astrochicken
    Astrochicken
    Astrochicken is the name given to a thought experiment expounded by theoretical physicist Freeman Dyson. In his book Disturbing the Universe , Dyson contemplated how humanity could build a small, self-replicating automaton that could explore space more efficiently than a manned craft could...

  • Autopoiesis
  • Complex system
    Complex system
    A complex system is a system composed of interconnected parts that as a whole exhibit one or more properties not obvious from the properties of the individual parts....

  • DNA replication
    DNA replication
    DNA replication is a biological process that occurs in all living organisms and copies their DNA; it is the basis for biological inheritance. The process starts with one double-stranded DNA molecule and produces two identical copies of the molecule...

  • Life
    Life
    Life is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not, either because such functions have ceased , or else because they lack such functions and are classified as inanimate...

  • Robot
    Robot
    A robot is a mechanical or virtual intelligent agent that can perform tasks automatically or with guidance, typically by remote control. In practice a robot is usually an electro-mechanical machine that is guided by computer and electronic programming. Robots can be autonomous, semi-autonomous or...

  • RepRap
  • Self-replicating machine
    Self-replicating machine
    A self-replicating machine is an artificial construct that is theoretically capable of autonomously manufacturing a copy of itself using raw materials taken from its environment, thus exhibiting self-replication in a way analogous to that found in nature. The concept of self-replicating machines...

    • self-replicating spacecraft
  • Space manufacturing
    Space manufacturing
    Space manufacturing is the production of manufactured goods in an environment outside a planetary atmosphere. Typically this includes conditions of microgravity and hard vacuum.Manufacturing in space has several potential advantages over Earth-based industry....

  • Universal Constructor
    Universal constructor
    A universal constructor may refer to*Universal assembler, a hypothesized nanotechnology device for building a large class of nanomachines including itself, or...

  • Virus
    Virus
    A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

  • Von Neumann machine
    Von Neumann machine
    Von Neumann machine may refer to:.* Von Neumann architecture, a conceptual model of a computer architecture* The IAS machine, a computer designed in the 1940s based on von Neuman's design...

  • Self reconfigurable
  • Final Anthropic Principle
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