Content uploaded by Gordana Dodig Crnkovic

Author content

All content in this area was uploaded by Gordana Dodig Crnkovic

Content may be subject to copyright.

FromtheClosedClassicalAlgorithmicUniverse

toanOpenWorldofAlgorithmicConstellations

Mark Burgin1 and Gordana Dodig-Crnkovic2

1 Dept. of Mathematics, UCLA, Los Angeles, USA. E-mail: mburgin@math.ucla.edu

2 Mälardalen University, Department of Computer Science and Networks,

School of Innovation, Design and Engineering, Västerås, Sweden;

E-mail: gordana.dodig-crnkovic@mdh.se

Abstract

In this paper we analyze methodological and philosophical implications of al-

gorithmic aspects of unconventional computation. At first, we describe how the

classical algorithmic universe developed and analyze why it became closed in

the conventional approach to computation. Then we explain how new models

of algorithms turned the classical closed algorithmic universe into the open

world of algorithmic constellations, allowing higher flexibility and expressive

power, supporting constructivism and creativity in mathematical modeling. As

Gödel’s undecidability theorems demonstrate, the closed algorithmic universe

restricts essential forms of mathematical cognition. In contrast, the open algo-

rithmic universe, and even more the open world of algorithmic constellations,

remove such restrictions and enable new, richer understanding of computation.

Keywords: Unconventional algorithms, unconventional computing, algorith-

mic constellations, Computing beyond Turing machine model.

Introduction

Te development of various systems is characterized by a tension be-

tween forces of conservation (tradition) and change (innovation). Tradi-

2

tion sustains system and its parts, while innovation moves it forward ad-

vancing some segments and weakening the others. Efficient functioning

of a system depends on the equilibrium between tradition and innova-

tion. When there is no equilibrium, system declines; too much tradition

brings stagnation and often collapse under the pressure of inner or/and

outer forces, while too much innovation leads to instability and frequent-

ly in rupture.

The same is true of the development of different areas and aspects of

social systems, such as science and technology. In this article we are in-

terested in computation, which has become increasingly important for

society as the basic aspect of information technology. Tradition in com-

putation is represented by conventional computation and classical algo-

rithms, while unconventional computation stands for the far-reaching in-

novation.

It is possible to distinguish three areas in which computation can be

unconventional:

1. Novel hardware (e.g. quantum systems) provides material realiza-

tion for unconventional computation.

2. Novel algorithms (e.g. super-recursive algorithms) provide opera-

tional realization for unconventional computation.

3. Novel organization (e.g. evolutionary computation or self-

optimizing computation) provides structural realization for unconven-

tional computation.

Here we focus on algorithmic aspects of unconventional computation

and analyze methodological and philosophical problems related to it,

3

making a distinction between three classes of algorithms: recursive,

subrecursive, and super-recursive algorithms.

Each type of recursive algorithms form a class in which it is possible

to compute exactly the same functions that are computable by Turing

machines. Examples of recursive algorithms are partial recursive func-

tions, RAM, von Neumann automata, Kolmogorov algorithms, and

Minsky machines.

Each type of subrecursive algorithms forms a class that has less com-

putational power than the class of all Turing machines. Examples of

subrecursive algorithms are finite automata, primitive recursive func-

tions and recursive functions.

Each type of super-recursive algorithms forms a class that has more

computational power than the class of all Turing machines. Examples of

super-recursive algorithms are inductive and limit Turing machines, lim-

it partial recursive functions and limit recursive functions.

The main problem is that conventional types and models of algorithms

make the algorithmic universe, i.e., the world of all existing and possible

algorithms, closed because there is a rigid boundary in this universe

formed by recursive algorithms, such as Turing machines, and described

by the Church-Turing Thesis. This closed system has been overtly dom-

inated by discouraging incompleteness results, such as Gödel incom-

pleteness theorems.

Contrary to this, super-recursive algorithms controlling and directing

unconventional computations break this boundary leading to an open al-

gorithmic multiverse – world of unrestricted creativity.

4

The paper is organized as follows. First, we summarize how the closed

algorithmic universe was created and what are advantages and disad-

vantages of living inside such a closed universe. Next, we describe the

breakthrough brought about by the creation of super-recursive algo-

rithms. In Section 4, we analyze super-recursive algorithms as cognitive

tools. The main effect is the immense growth of cognitive possibilities

and computational power that enables corresponding growth of informa-

tion processing devices.

The Closed Universe of Turing Machines and other Recursive

Algorithms

Historically, after having an extensive experience of problem solving,

mathematicians understood that problem solutions were based on vari-

ous algorithms. Construction algorithms and deduction algorithms have

been the main tools of mathematical research. When they repeatedly en-

countered problems they were not able to solve, mathematicians, and es-

pecially experts in mathematical logic, came to the conclusion that it was

necessary to develop a rigorous mathematical concept of algorithm and

to prove that some problems are indeed unsolvable. Consequently, a di-

versity of exact mathematical models of algorithm as a general concept

was proposed. The first models were λ-calculus developed by Church in

1931 – 1933, general recursive functions introduced by Gödel in 1934,

ordinary Turing machines constructed by Turing in 1936 and in a less

explicit form by Post in 1936, and partial recursive functions built by

Kleene in 1936. Creating λ-calculus, Church was developing a logical

theory of functions and suggested a formalization of the notion of com-

5

putability by means of λ-definability. In 1936, Kleene demonstrated that

λ-definability is computationally equivalent to general recursive func-

tions. In 1937, Turing showed that λ-definability is computationally

equivalent to Turing machines. Church was so impressed by these re-

sults that he suggested what was later called the Church-Turing thesis.

Turing formulated a similar conjecture in the Ph.D. thesis that he wrote

under Church's supervision.

It is interesting to know that the theory of Frege [1] actually contains

λ-calculus. So, there were chances to develop a theory of algorithms and

computability in the 19th century. However, at that time, the mathemati-

cal community did not feel a need of such a theory and probably, would

not accept it if somebody created it.

The Church-Turing thesis explicitly mark out a rigid boundary for the

algorithmic universe, making this universe closed by Turing machines.

Any algorithm from this universe was inside that boundary.

After the first breakthrough, other mathematical models of algorithms

were suggested. They include a variety of Turing machines: multihead,

multitape Turing machines, Turing machines with n-dimensional tapes,

nondeterministic, probabilistic, alternating and reflexive Turing ma-

chines, Turing machines with oracles, Las Vegas Turing machines, etc.;

neural networks of various types – fixed-weights, unsupervised, super-

vised, feedforward, and recurrent neural networks; von Neumann au-

tomata and general cellular automata; Kolmogorov algorithms finite au-

tomata of different forms – automata without memory, autonomous

automata, automata without output or accepting automata, determinis-

tic, nondeterministic, probabilistic automata, etc.; Minsky machines;

6

Storage Modification Machines or simply, Shönhage machines; Random

Access Machines (RAM) and their modifications - Random Access Ma-

chines with the Stored Program (RASP), Parallel Random Access Ma-

chines (PRAM); Petri nets of various types – ordinary and ordinary with

restrictions, regular, free, colored, and self-modifying Petri nets, etc.;

vector machines; array machines; multidimensional structured model of

computation and computing systems; systolic arrays; hardware modifi-

cation machines; Post productions; normal Markov algorithms; formal

grammars of many forms – regular, context-free, context-sensitive,

phrase-structure, etc.; and so on. As a result, the theory of algorithms,

automata and computation has become one of the foundations of com-

puter science.

In spite of all differences between and diversity of algorithms, there is

a unity in the system of algorithms. While new models of algorithm ap-

peared, it was proved that no one of them could compute more functions

than the simplest Turing machine with a one-dimensional tape. All this

give more and more evidence to validity of the Church-Turing Thesis.

Even more, all attempts to find mathematical models of algorithms

that were stronger than Turing machines were fruitless. Equivalence

with Turing machines has been proved for many models of algorithms.

That is why the majority of mathematicians and computer scientists have

believed that the Church-Turing Thesis was true. Many logicians assume

that the Thesis is an axiom that does not need any proof. Few believe

that it is possible to prove this Thesis utilizing some evident axioms.

More accurate researchers consider this conjecture as a law of the theory

of algorithms, which is similar to the laws of nature that might be sup-

7

ported by more and more evidence or refuted by a counter-example but

cannot be proved.

Besides, the Church-Turing Thesis is extensively utilized in the theory

of algorithms, as well as in the methodological context of computer sci-

ence. It has become almost an axiom. Some researchers even consider

this Thesis as a unique absolute law of computer science.

Thus, we can see that the initial aim of mathematicians was to build a

closed algorithmic universe, in which a universal model of algorithm

provided a firm foundation and as it was found later, a rigid boundary

for this universe supposed to contain all of mathematics.

It is possible to see the following advantages and disadvantages of the

closed algorithmic universe.

Advantages:

1. Turing machines and partial recursive functions are feasible math-

ematical models.

2. These and other recursive models of algorithms provide an efficient

possibility to apply mathematical techniques.

3. The closed algorithmic universe allowed mathematicians to build

beautiful theories of Turing machines, partial recursive functions and

some other recursive and subrecursive algorithms.

4. The closed algorithmic universe provides sufficiently exact bounda-

ries for knowing what is possible to achieve with algorithms and what is

impossible.

5. The closed algorithmic universe provides a common formal lan-

guage for researchers.

8

6. For computer science and its applications, the closed algorithmic

universe provides a diversity of mathematical models with the same

computing power.

Disadvantages:

1. The main disadvantage of this universe is that its main principle -

the Church-Turing Thesis - is not true.

2. The closed algorithmic universe restricts applications and in par-

ticular, mathematical models of cognition.

3. The closed algorithmic universe does not correctly reflect the exist-

ing computing practice.

The Open World of Super-Recursive Algorithms and Algorithmic

Constellations

Contrary to the general opinion, some researchers expressed their con-

cern for the Church-Turing Thesis. As Nelson writes [2], "Although

Church-Turing Thesis has been central to the theory of effective decida-

bility for fifty years, the question of its epistemological status is still an

open one.” There were also researchers who directly suggested argu-

ments against validity of the Church-Turing Thesis. For instance, Kal-

mar [3] raised intuitionistic objections, while Lucas and Benacerraf dis-

cussed objections to mechanism based on theorems of Gödel that

indirectly threaten the Church-Turing Thesis. In 1972, Gödel’s observa-

tion entitled “A philosophical error in Turing’s work” was published

where he declared that: "Turing in his 1937, p. 250 (1965, p. 136), gives

an argument which is supposed to show that mental procedures cannot

go beyond mechanical procedures. However, this argument is inconclu-

9

sive. What Turing disregards completely is the fact that mind, in its use,

is not static, but constantly developing, i.e., that we understand abstract

terms more and more precisely as we go on using them, and that more

and more abstract terms enter the sphere of our understanding. There

may exist systematic methods of actualizing this development, which

could form part of the procedure. Therefore, although at each stage the

number and precision of the abstract terms at our disposal may be finite,

both (and, therefore, also Turing’s number of distinguishable states of

mind) may converge toward infinity in the course of the application of

the procedure.” [4]

Thus, pointing that Turing disregarded completely the fact that mind,

in its use, is not static, but constantly developing, Gödel predicted neces-

sity for super-recursive algorithms that realize inductive and topological

computations [5]. Recently, Sloman [6] explained why recursive models

of algorithms, such as Turing machines, are irrelevant for artificial intel-

ligence.

Even if we abandon theoretical considerations and ask the practical

question whether recursive algorithms provide an adequate model of

modern computers, we will find that people do not see correctly how

computers are functioning. An analysis demonstrates that while recur-

sive algorithms gave a correct theoretical representation for computers at

the beginning of the “computer era”, super-recursive algorithms are

more adequate for modern computers. Indeed, at the beginning, when

computers appeared and were utilized for some time, it was necessary to

print out data produced by computer to get a result. After printing, the

computer stopped functioning or began to solve another problem. Now

10

people are working with displays and computers produce their results

mostly on the screen of a monitor. These results on the screen exist there

only if the computer functions. If this computer halts, then the result on

its screen disappears. This is opposite to the basic condition on ordinary

(recursive) algorithms that implies halting for giving a result.

Such big networks as Internet give another important example of a sit-

uation in which conventional algorithms are not adequate. Algorithms

embodied in a multiplicity of different programs organize network func-

tions. It is generally assumed that any computer program is a conven-

tional, that is, recursive algorithm. However, a recursive algorithm has to

stop to give a result, but if a network shuts down, then something is

wrong and it gives no results. Consequently, recursive algorithms turn

out to be too weak for the network representation, modeling and study.

Even more, no computer works without an operating system. Any op-

erating system is a program and any computer program is an algorithm

according to the general understanding. While a recursive algorithm has

to halt to give a result, we cannot say that a result of functioning of oper-

ating system is obtained when computer stops functioning. To the con-

trary, when the operating system does not work, it does not give an ex-

pected result.

Looking at the history of unconventional computations and super-

recursive algorithms we see that Turing was the first who went beyond

the “Turing” computation that is bounded by the Church-Turing Thesis.

In his 1938 doctoral dissertation, Turing introduced the concept of a Tu-

ring machine with an oracle. This, work was subsequently published in

1939. Another approach that went beyond the Turing-Church Thesis was

11

developed by Shannon [7], who introduced the differential analyzer, a

device that was able to perform continuous operations with real numbers

such as operation of differentiation. However, mathematical community

did not accept operations with real numbers as tractable because irra-

tional numbers do not have finite numerical representations.

In 1957, Grzegorczyk introduced a number of equivalent definitions of

computable real functions. Three of Grzegorczyk’s constructions have

been extended and elaborated independently to super-recursive method-

ologies: the domain approach [8,9], type 2 theory of effectivity or type 2

recursion theory [10,11], and the polynomial approximation approach

[12]. In 1963, Scarpellini introduced the class M1 of functions that are

built with the help of five operations. The first three are elementary: sub-

stitutions, sums and products of functions. The two remaining operations

are performed with real numbers: integration over finite intervals and

taking solutions of Fredholm integral equations of the second kind.

Yet another type of super-recursive algorithms was introduced in 1965

by Gold and Putnam, who brought in concepts of limiting recursive

function and limiting partial recursive function. In 1967, Gold produced

a new version of limiting recursion, also called inductive inference, and

applied it to problems of learning. Now inductive inference is a fruitful

direction in machine learning and artificial intelligence.

One more direction in the theory of super-recursive algorithms

emerged in 1967 when Zadeh introduced fuzzy algorithms. It is interest-

ing that limiting recursive function and limiting partial recursive func-

tion were not considered as valid models of algorithms even by their au-

thors. A proof that fuzzy algorithms are more powerful than Turing

12

machines was obtained much later (Wiedermann, 2004). Thus, in spite

of the existence of super-recursive algorithms, researchers continued to

believe in the Church-Turing Thesis as an absolute law of computer sci-

ence.

After the first types of super-recursive models had been studied, a lot

of other super-recursive algorithmic models have been created: inductive

Turing machines, limit Turing machines, infinite time Turing machines,

general Turing machines, accelerating Turing machines, type 2 Turing

machines, mathematical machines, δ-Q-machines, general dynamical

systems, hybrid systems, finite dimensional machines over real numbers,

R-recursive functions and so on.

To organize the diverse variety of algorithmic models, we introduce

the concept of an algorithmic constellation. Namely, an algorithmic con-

stellation is a system of algorithmic models that have the same type.

Some algorithmic constellations are disjoint, while other algorithmic

constellations intersect. There are algorithmic constellations that are

parts of other algorithmic constellations.

Below some of algorithmic constellations are described.

The sequential algorithmic constellation consists of models of sequen-

tial algorithms. This constellation includes such models as deterministic

finite automata, deterministic pushdown automata with one stack, evolu-

tionary finite automata, Turing machines with one head and one tape,

Post productions, partial recursive functions, normal Markov algorithms,

formal grammars, inductive Turing machines with one head and one

tape, limit Turing machines with one head and one tape, reflexive Turing

machines with one head and one tape, infinite time Turing machines,

13

general Turing machines with one head and one tape, evolutionary Tu-

ring machines with one head and one tape, accelerating Turing machines

with one head and one tape, type 2 Turing machines with one head and

one tape, Turing machines with oracles.

The concurrent algorithmic constellation consists of models of con-

current algorithms. This constellation includes such models as Petri nets,

artificial neural networks, nondeterministic Turing machines, probabilis-

tic Turing machines, alternating Turing machines, Communicating Se-

quential Processes (CSP) of Hoare, Actor model, Calculus of Communi-

cating Systems (CCS) of Milner, Kahn process networks, dataflow

process networks, discrete event simulators, View-Centric Reasoning

(VCR) model of Smith, event-signal-process (ESP) model of Lee and

Sangiovanni-Vincentelli, extended view-centric reasoning (EVCR)

model of Burgin and Smith, labeled transition systems, Algebra of

Communicating Processes (ACP) of Bergstra and Klop, event-action-

process (EAP) model of Burgin and Smith, synchronization trees, and

grid automata.

The parallel algorithmic constellation consists of models of parallel

algorithms and is a part of the concurrent algorithmic constellation. This

constellation includes such models as pushdown automata with several

stacks, Turing machines with several heads and one or several tapes,

Parallel Random Access Machines, Kolmogorov algorithms, formal

grammars with prohibition, inductive Turing machines with several

heads and one or several tapes, limit Turing machines with several heads

and one or several tapes, reflexive Turing machines with several heads

and one or several tapes, general Turing machines with several heads

14

and one or several tapes, accelerating Turing machines with several

heads and one or several tapes, type 2 Turing machines with several

heads and one or several tapes.

The discrete algorithmic constellation consists of models of algo-

rithms that work with discrete data, such as words of formal language.

This constellation includes such models as finite automata, Turing ma-

chines, partial recursive functions, formal grammars, inductive Turing

machines and Turing machines with oracles.

The topological algorithmic constellation consists of models of algo-

rithms that work with data that belong to a topological space, such as re-

al numbers. This constellation includes such models as the differential

analyzer of Shannon, limit Turing machines, finite dimensional and gen-

eral machines of Blum, Shub, and Smale, fixed point models, topologi-

cal algorithms, neural networks with real number parameters.

Although several models of super-recursive algorithms already existed

in 1980s, the first publication where it was explicitly stated and proved

that there are algorithms more powerful than Turing machines was [13].

In this work, among others, relations between Gödel’s incompleteness

results and super-recursive algorithms were discussed.

Super-recursive algorithms have different computing and accepting

power. The closest to conventional algorithms are inductive Turing ma-

chines of the first order because they work with constructive objects, all

steps of their computation are the same as the steps of conventional Tu-

ring machines and the result is obtained in a finite time. In spite of these

similarities, inductive Turing machines of the first order can compute

much more than conventional Turing machines [14, 5].

15

Inductive Turing machines of the first order form only the lowest level

of super-recursive algorithms. There are infinitely more levels and as a

result, the algorithmic universe grows into the algorithmic multiverse

becoming open and amenable. Taking into consideration algorithmic

schemas, which go beyond super-recursive algorithms, we come to an

open world of information processing, which includes the algorithmic

multiverse with its algorithmic constellations. Openness of this world

has many implications for human cognition in general and mathematical

cognition in particular. For instance, it is possible to demonstrate that not

only computers but also the brain can work not only in the recursive

mode but also in the inductive mode, which is essentially more powerful

and efficient. Some of the examples are considered in the next section.

Absolute Prohibition in The Closed Universe

and Infinite Opportunities in The Open World

To provide sound and secure foundations for mathematics, David Hilbert

proposed an ambitious and wide-ranging program in the philosophy and

foundations of mathematics. His approach formulated in 1921 stipulated

two stages. At first, it was necessary to formalize classical mathematics

as an axiomatic system. Then, using only restricted, "finitary" means, it

was necessary to give proofs of the consistency of this axiomatic system.

Achieving a definite progress in this direction, Hilbert became very

optimistic. As a response to the Latin dictum: "Ignoramus et

ignorabimus" or "We do not know, we cannot know", in his speech in

Königsberg in 1930, he made a famous statement:

Wir müssen wissen. Wir werden wissen.

(We must know. We will know.)

16

Next year the Gödel undecidability theorems were published [15].

They undermined Hilbert’s statement and his whole program. Indeed,

the first Gödel undecidability theorem states that it is impossible to vali-

date truth for all true statements about objects in an axiomatic theory that

includes formal arithmetic. This is a consequence of the fact that it is

impossible to build all sets from the arithmetical hierarchy by Turing

machines. In such a way, the closed Algorithmic Universe imposed re-

striction on the mathematical exploration. Indeed, rigorous mathematical

proofs are done in formal mathematical systems. As it is demonstrated

(cf., for example, [16]), such systems are equivalent to Turing machines

as they are built by means of Post productions. Thus, as Turing machines

can model proofs in formal systems, it is possible to assume that proofs

are performed by Turing machines.

The second Gödel undecidability theorem states that for an effectively

generated consistent axiomatic theory T that includes formal arithmetic

and has means for formal deduction, it is impossible to prove consisten-

cy of T using these means.

From the very beginning, Gödel undecidability theorems have been

comprehended as absolute restrictions for scientific cognition. That is

why Gödel undecidability theorems were so discouraging that many

mathematicians consciously or unconsciously disregarded them. For in-

stance, the influential group of mostly French mathematicians who wrote

under the name Bourbaki completely ignored results of Gödel [17].

However, later researchers came to the conclusion that these theorems

have such drastic implications only for formalized cognition based on

rigorous mathematical tools. For instance, in the 1964 postscript, Gödel

17

wrote that undecidability theorems “do not establish any bounds for the

powers of human reason, but rather for the potentialities of pure formal-

ism in mathematics.”

Discovery of super-recursive algorithms and acquisition of the

knowledge of their abilities drastically changed understanding of the

Gödel’s results. Being a consequence of the closed nature of the closed

algorithmic universe, these undecidability results lose their fatality in the

open algorithmic universe. They become relativistic being dependent on

the tools used for cognition. For instance, the first undecidability theo-

rem is equivalent to the statement that it is impossible to compute by Tu-

ring machines or other recursive algorithms all levels of the Arithmetical

Hierarchy [18]. However, as it is demonstrated in [19], there is a hierar-

chy of inductive Turing machines so that all levels of the Arithmetical

Hierarchy are computable and even decidable by these inductive Turing

machines. Complete proofs of these results were published only in 2003

due to the active opposition of the proponents of the Church-Turing

Thesis [14]. In spite of the fast development of computer technology and

computer science, the research community in these areas is rather con-

servative although more and more researchers understand that the

Church-Turing Thesis is not correct.

The possibility to use inductive proofs makes the Gödel’s results rela-

tive to the means used for proving mathematical statements because de-

cidability of the Arithmetical Hierarchy implies decidability of the for-

mal arithmetic. For instance, the first Gödel undecidability theorem is

true when recursive algorithms are used for proofs but it becomes false

when inductive algorithms, such as inductive Turing machines, are uti-

18

lized. History of mathematics also gives supportive evidence for this

conclusion. For instance, in 1936 by Gentzen, who in contrast to the se-

cond Gödel undecidability theorem, proved consistency of the formal

arithmetic using ordinal induction.

The hierarchy of inductive Turing machines also explains why the

brain of people is more powerful than Turing machines, supporting the

conjecture of Roger Penrose [20]. Besides, this hierarchy allows re-

searchers to eliminate restrictions of recursive models of algorithms in

artificial intelligence described by Sloman [6].

It is important to remark that limit Turing machines and other topolog-

ical algorithms [21] open even broader perspectives for information pro-

cessing technology and artificial intelligence than inductive Turing ma-

chines.

The Open World of Knowledge and The Internet

The open world, or more exactly, the open world of knowledge, is an

important concept for the knowledge society and its knowledge econo-

my. According to Rossini [12], it emerges from a world of pre-Internet

political systems, but it has come to encompass an entire worldview

based on the transformative potential of open, shared, and connected

technological systems. The idea of an open world synthesizes much of

the social and political discourse around modern education and scientific

endeavor and is at the core of the Open Access (OA) and Open Educa-

tional Resources (OER) movements. While the term open society comes

from international relations, where it was developed to describe the tran-

sition from political oppression into a more democratic society, it is now

19

being appropriated into a broader concept of an open world connected

via technology [22]. The idea of openness in access to knowledge and

education is a reaction to the potential afforded by the global networks,

but is inspired by the sociopolitical concept of the open society.

Open Access (OA) is a knowledge-distribution model by which schol-

arly, peer-reviewed journal articles and other scientific publications are

made freely available to anyone, anywhere over the Internet. It is the

foundation for the open world of scientific knowledge, and thus, a prin-

cipal component of the open world of knowledge as a whole. In the era

of print, open access was economically and physically impossible. In-

deed, the lack of physical access implied the lack of knowledge access -

if one did not have physical access to a well-stocked library, knowledge

access was impossible. The Internet has changed all of that, and OA is a

movement that recognizes the full potential of an open world metaphor

for the network.

In OA, the old tradition of publishing for the sake of inquiry,

knowledge, and peer acclaim and the new technology of the Internet

have converged to make possible an unprecedented public good: "the

world-wide electronic distribution of the peer-reviewed journal litera-

ture" [23].

The open world of knowledge is based on the Internet, while the In-

ternet is based on computations that go beyond Turing machines. One of

the basic principles of the Internet is that it is always on, always availa-

ble. Without these features, the Internet cannot provide the necessary

support for the open world of knowledge because ubiquitous availability

of knowledge resources demands non-stopping work of the Internet. At

20

the same time, classical models of algorithms, such as Turing machines,

stop after giving that result. This contradicts the main principles of the

Internet. In contrast to classical models of computation, as it is demon-

strated in [5], if an automatic system, e.g., a computer or computer net-

work, works without halting, gives results in this mode and can simulate

any operation of a universal Turing machine, then this automatic (com-

puter) system is more powerful than any Turing machine. This means

that this automatic (computer) system, in particular, the Internet, per-

forms unconventional computations and is controlled by super-recursive

algorithms. As it is explained in [5], attempts to reduce some of these

systems, e.g., the Internet, to the recursive mode, which allows modeling

by Turing machines, make these systems irrelevant.

Conclusions

This paper shows how the universe (the world) of algorithms became

open with the discovery of super-recursive algorithms, providing more

powerful tools for computational cognition and artificial intelligence.

Here we considered only some of the consequences of the open world

environment of unconventional algorithms and algorithmic constella-

tions for mathematical (computation-theoretical) cognition. It would be

interesting to study other consequences of current break through into an

open world of unconventional algorithms and computation.

It is known that not all quantum mechanical events are Turing-

computable. So, it would be interesting to find a class of super-recursive

algorithms that compute all such events or to prove that such a class

does not exist.

21

It might be methodologically and philosophically interesting to con-

template relations between the Open World of Algorithmic Constella-

tions and the Open Science in the sense of Nielsen [24]. For instance,

one of the pivotal features of the Open Science is accessibility of re-

search results on the Internet. At the same time, as it is demonstrated in

[5], the Internet and other big networks of computers are always working

in the inductive mode or some other super-recursive mode. Moreover,

actual accessibility depends on such modes of functioning.

One more interesting problem is to explore relations between the Open

World of Algorithmic Constellations with the theoretical framework of

Info-computationalism, a synthesis of Pancomputationalism (Naturalist

Computationalism) with Informational Structural Realism – the model of

a universe as a network of computational processes on informational

structures. Info-computationalism connects algorithms with interactive

computing in natural (physical) systems [25,26][28]. Connecting new

unconventional models of super-recursive algorithms and Algorithmic

Constellations with unconventional computations performed by natural

systems opens new possibilities for the development of innovative mod-

els of physical computation with “Trans-Turing” algorithms and “Non-

Von” computing architectures. [27].

22

Acknowledgements

The authors would like to thank Andree Ehresmann, Hector Zenil and

Marcin Schroeder for useful and constructive comments on the previous

version of this work.

References

1 G. Frege, Grundgesetze der Arithmetik, Begriffschriftlich Abgeleitet, Viena

(1893/1903)

2 R. J. Nelson, Church's thesis and cognitive science, Notre Dame J. of Formal Logic,

v. 28, no. 4, 581—614 (1987)

3 L. Kalmar, An argument against the plausibility of Church's thesis, in Constructivity

in mathematics, North-Holland Publishing Co., Amsterdam, pp. 72-80 (1959)

4 K. Gödel, Some Remarks on the Undecidability Results, in G¨odel, K. (1986–1995),

Collected Works, v. II, Oxford University Press, Oxford, pp. 305–306 (1972)

5 M. Burgin, Super-recursive Algorithms, Springer, New York/Heidelberg/Berlin

(2005)

6 A. Sloman, The Irrelevance of Turing machines to AI Aaron Sloman. In M. Scheutz

(ed.), Computationalism: New Directions. MIT Press. http://www.cs.bham.ac.uk/~axs/

(2002)

7 C. Shannon, Mathematical Theory of the Differential Analyzer, J. Math. Physics,

MIT, v. 20, 337-354 (1941)

8 S. Abramsky, A. Jung, Domain theory. In S. Abramsky, D. M. Gabbay, T. S. E.

Maibaum, editors, (PDF). Handbook of Logic in Computer Science. III. Oxford Uni-

versity Press. (1994).

9 A. Edalat, Domains for computation in mathematics, physics and exact real arithme-

tic, Bulletin Of Symbolic Logic, Vol:3, 401-452 (1997)

10 K. Ko, Computational Complexity of Real Functions, Birkhauser Boston, Boston,

MA (1991)

11 K. Weihrauch, Computable Analysis. An Introduction. Springer-Verlag Berlin/ Hei-

delberg (2000)

12 M. B. Pour-El, and J. I. Richards, Computability in Analysis and Physics. Perspec-

tives in Mathematical Logic, Vol. 1. Berlin: Springer. (1989)

23

13 M. Burgin, The Notion of Algorithm and the Turing-Church Thesis, In Proceedings

of the VIII International Congress on Logic, Methodology and Philosophy of Science,

Moscow, v. 5, part 1, pp. 138-140 (1987)

14 M. Burgin, Nonlinear Phenomena in Spaces of Algorithms, International Journal of

Computer Mathematics, v. 80, No. 12, pp. 1449-1476 (2003)

15 K. Gödel, Über formal unentscheidbare Sätze der Principia Mathematics und

verwandter System I, Monatshefte für Mathematik und Physik, b. 38, s.173-198 (1931)

16 R.M. Smullian, Theory of Formal Systems, Princeton University Press (1962)

17 A.R.D. Mathias, The Ignorance of Bourbaki, Physis Riv. Internaz. Storia Sci (N.S.)

28, pp. 887-904 (1991)

18 H. Rogers, Theory of Recursive Functions and Effective Computability, MIT Press,

Cambridge Massachusetts (1987)

19 M. Burgin, Arithmetic Hierarchy and Inductive Turing Machines, Notices of the

Russian Academy of Sciences, v. 299, No. 3, pp. 390-393 (1988)

20 Penrose, R. The Emperor’s New Mind, Oxford University Press, Oxford (1989)

21 Burgin, M. Topological Algorithms, in Proceedings of the ISCA 16th International

Conference “Computers and their Applications”, ISCA, Seattle, Washington, pp. 61-64

(2001)

22 C. Rossini, Access to Knowledge as a Foundation for an Open World, EDUCAUSE

Review, v. 45, No. 4, pp. 60–68 (2010)

23 Budapest Open Access Initiative: <http://www.soros.org/openaccess/read.shtml>.

24 M. Nielsen, Reinventing Discovery: The New Era of Networked Science, Princeton

University Press, Princeton and Oxford (2012)

25 Dodig-Crnkovic, G. and Muller, V.C. A Dialogue Concerning Two World Systems,

in Information and Computation, World Scientific, New York/Singapore, pp. 107-148

(2011)

26 G. Rozenberg, T.H.W. Bäck & J.N. Kok (Eds.): Handbook of Natural Computing.

Heidelberg, Germany, Springer (2012)

27 Dodig Crnkovic G. and Burgin M., Unconventional Algorithms: Complementarity

of Axiomatics and Construction, Entropy, Special issue "Selected Papers from the

Symposium on Natural/Unconventional Computing and its Philosophical Significance"

http://www.mdpi.com/journal/entropy/special_issues/unconvent_computing, forthcom-

ing 2012

24

28 Dodig-Crnkovic G., Significance of Models of Computation from Turing Model to

Natural Computation. Minds and Machines, ( R. Turner and A. Eden guest eds.) Vol-

ume 21, Issue 2 (2011), Page 301.

All the links accessed at 08 06 2012