A chemical computer, also called reaction-diffusion computer, BZ computer or gooware computer is an unconventional computer based on a semi-solid chemical "soup" where data is represented by varying concentrations of chemicals. The computations are performed by naturally occurring chemical reactions. So far it is still in a very early experimental stage, but may have great potential for the computer industry. A chemical reaction is a process that results in the interconversion of chemical substances [1]. The substance or substances initially involved in a chemical reaction are called reactants. ...

Rationale

The simplicity of this technology is one of the main reasons why it in the future could turn into a serious competitor to machines based on conventional hardware. A modern microprocessor is an incredibly complicated device that can be destroyed during the production by no more than a single airborne microscopic particle. In comparison a cup of chemicals is a simple and stable component that is cheap to produce.^{[citation needed]} Microprocessors, including an Intel 80486DX2 and an Intel 80386. ...

In a conventional microprocessor the bits are behaving much like cars in city traffic; they can only use certain roads, they have to slow down and wait for each others in crossing traffic and only one driving field at once can be used. In a BZ solution the waves are moving in all thinkable directions in all dimensions, across, away and against each others. These properties might make a chemical computer able to handle billions of times more data than a traditional computer. An analog would be the brain; even if a microprocessor can transfer information much faster than a neuron, the brain is still much more effective for some tasks because it can work with a much higher amount of data at the same time.^{[citation needed]} Comparative brain sizes In animals, the brain, or encephalon (Greek for in the head), is the control center of the central nervous system. ... Drawing by Santiago Ramón y Cajal of cells in the pigeon cerebellum. ...

Historical background

Originally chemical reactions were seen as a simple move towards a stable equilibrium which was not very promising for computation. This was changed with the 1950s discovery of Boris Belousov, a Soviet scientist. He created a chemical reaction between different salts and acids that swing back and forth between being yellow and clear because the concentration of the different components changes up and down in a cyclic way. At the time this was considered impossible because it went against the second law of thermodynamics, which says that in a closed system the entropy will only increase over time, causing the components in the mixture to distribute themselves till equilibrium is gained and making any changes in the concentration impossible. But modern theoretical analyses shows sufficient complicated reactions can indeed comprise wave phenomena without breaking the laws of nature.^{[citation needed]} (A convincing directly visible demonstration was achieved by Anatol Zhabotinsky with the Belousov-Zhabotinsky reaction showing spiraling colored waves.) Boris Pavlovich Belousov (1893 - 1970) was a Soviet chemist / biophysicist who discovered the Belousov-Zhabotinsky reaction (BZ reaction) in the early 50s. ... State motto (Russian): Пролетарии всех стран, соединяйтесь! (Transliterated: Proletarii vsekh stran, soedinyaytes!) (Translated: Workers of the world, unite!) Capital Moscow Official language None; Russian (de facto) Government Federation of Soviet republics Area  - Total  - % water 1st before collapse 22,402,200 km² Approx. ... The second law of thermodynamics states that which is equivalent to this scientific statement: The Second Law is a statistical law and thus applicable only to macroscopic systems. ... In physics and thermodynamics, entropy, symbolized by S, is a differential term dQ/T, where dQ is the amount of heat absorbed reversibly by a thermodynamic system at a temperature T. German physicist Rudolf Clausius introduced the mathematical concept of entropy in the early 1850s to account for the dissipation... A Belousov-Zhabotinsky reaction, or BZ reaction, is one of a class of reactions that result in the establishment of a nonlinear chemical oscillator. ...

Basic principles

The wave properties of the BZ reaction means it can move information in the same way as all other waves. This still leaves the need for computation, performed by conventional microchips using the binary code transmitting and changing ones and zeros through a complicated system of logic gates. To perform any conceivable computation it is sufficient to have NAND gates. (A NAND gate has two bits input. Its output is 0 if both bits are 1, otherwise it's 1). In the chemical computer version logic gates are implemented by concentration waves blocking or amplifying each other in different ways. The term binary code can mean several different things: There are a variety of different methods of coding numbers or symbols into strings of bits, including fixed-length binary numbers, prefix codes such as Huffman codes, and other coding techniques including arithmetic coding. ... A logic gate is an arrangement of controlled switches used to calculate operations using Boolean logic in digital circuits. ... NAND gates have the property, along with NOR gates, to be able to be combined to form any other kind of logic gate. ...

Current research

In 1989 it was demonstrated how light-sensitive chemical reactions could perform image processing.^[1] This led to an upsurge in the field of chemical computing. Andrew Adamatzky at the University of the West of England has demonstrated simple logic gates using reaction-diffusion processes.^[2] Furthermore he has theoretically shown how a hypothetical "2⁺ medium" modelled as a cellular automaton can perform computation. ^[3] It has been suggested that digital image processing be merged into this article or section. ... The University of the West of England (abbrev. ... A cellular automaton (plural: cellular automata) is a discrete model studied in computability theory, mathematics, and theoretical biology. ...

The breakthrough came when he read a theoretical article of two scientists who illustrated how to make logic gates to a computer by using the balls on a billiard table as an example. Like in the case with the AND-gate two balls represents two different bits. If a single ball shoots towards a common colliding point, the bit is 1. If not, it is 0. A collision will only occur if both balls is sent toward the point, which then is registered in the same way as when two electronic 1's gives a new and single 1. In this way the balls works together like an AND-gate.^{[citation needed]} Adamatzkys' great achievement was to transfer this principle to the BZ-chemicale and replace the billiard balls with waves. If it occurs two waves in the solution, they will meet and create as third wave which is registered as a 1. He has tested the theory in practice and has already documented that it works. For the moment he is cooperating with some other scientists in producing some thousand chemical versions of logic gates that is going to become a form of chemical pocket calculator.^{[citation needed]} One of the problems with the present version of this technology is the speed of the waves; they only spreads with a few millimeters per minute. According to Adamatzky, it can be eliminated by placing the gates very close to each others, to make sure the signals is tranferred quick. Another possibility could be new chemical reactions who is spreading much faster in the component. Is these child diseases is cured, a chemical computer is going to have clear advantages to an electronic computer.^{[citation needed]}

An inceasing number of individuals in the computer industry is starting to realize the potential of this technology. IBM is at the moment testing out new ideas in the field of microprocessing, a research with many similarities to the basic principles of a chemical computer. If succeeding, we will see computers with amazing processing powers in the future, far exceeding the present ones.^{[citation needed]} Big Blue redirects here. ...

References

• "Introducing the glooper computer" - New Scientist article by Duncan Graham-Rowe (Restricted access)

1. ^ L. Kuhnert, K. I. Agladze, V. I. Krinsky (January 1989). "Image processing using light-sensitive chemical waves". Nature 337: 244 - 247. DOI:10.1038/337244a0.
2. ^ Adamatzky, Andrew and De Lacy Costello, Benjamin (October 2002). "Experimental logical gates in a reaction-diffusion medium: The XOR gate and beyond". Phys. Rev. E 66 (4): 046112. DOI:10.1103/PhysRevE.66.046112.
3. ^ Andrew I. Adamatzky (1997). "Information-processing capabilities of chemical reaction-diffusion systems. 1. Belousov-Zhabotinsky media in hydrogel matrices and on solid supports". Advanced Materials for Optics and Electronics 7 (5): 263-272.