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CONDUCTED NOVEMBER 2001
Question 1: Tell us a little about yourself. What is your background, and how did you first become interested in cellular automata and unconventional computing?
I’ve got formal degrees in biology, physics and mathematics, and theoretical computer science. As you see my background is pretty comprehensive. I’ve firstly encountered CA [Cellular Automata] in the early eighties. In early nineties I published my first book on identification of cellular automata. I did not do too much for theory of CA. I’ve been keen in applications. I found that some CA algorithms can be interpreted in terms of reaction-diffusion and excitation; and, most active non-linear media are simulated in CA. Clearly, this experience in CA helped me to develop framework of wet-ware computers.
Question 2: When you speak of "wet" systems, what exactly do you mean?
“My sperm cells have two tails – one for the wetware and one for the software”. Gotcha! No, my “wet” has little to do with Rucker’s wicked creatures. My term is a generalization for varieties of chemical and molecular processors. They include stirred chemical reactors, thin layer reaction-diffusion systems and monomolecular arrays. I prefer them wet because they do not compute when dried.
Question 3: Tell us about your current work.
My group is starting laboratory experiments on the wet-ware for autonomous robots. The idea is simple. Got a robot? Put a dish on top of it. Mix chemicals that make light-sensitive excitable medium. Pour the liquid in the dish. Make robot “feel” spreading phase waves in the medium. Switch light on. The medium is excited, waves of excitation spread from the excited sites, indicating thus a relevant direction toward the light source. The robot looks at the waves and thus figures out where the light is. It’s so god damn easy. Obviously, image-processing etc. in excitable media can be done as a by-product of the experiments. As to theoretical stuff, I’m developing a formal framework for “parachemistry of mind”. This is my brand new thought. Emotional and cognitive states are seen as reagents of some chemical solution. Simulated dynamic is impressive. You know the rest… There are also students in my lab, they do all kinds of research: from robotic polymers to flying swarms. Mostly I generate ideas and then let somebody else to implement them…
Question 4: What do you believe to be the ultimate potential of reaction-diffusion processors? Do you think that chemical processors could eventually replace silicon as a computing medium?
A reaction-diffusion processor is a massively parallel computing device. Look at well-known Belousov-Zhabotinsky reaction in a thin layer. Such chemical reactor can do almost all basic operations of image processing; assuming the image is optically projected onto the reactor. A standard Petri dish contains thousands and thousands of elementary micro-volumes. That is we have thousands of elementary processing units. Also, the spatially distributed chemical processors are fault tolerant. No one can destroy the processor by removing a drop or two of the reaction liquid, or by splashing a surface of the reactor. However, the chemical processors are very slow, because usually diffusion is involved in the information processing. So, they do not and will not compete with silicon computers. Chemical processors rather complement silicon processors. Actually, the chemical processors are just one of many members of non-linear medium computers.
Question 5: What exactly do you mean by "non-linear media" and what are the advantages of computing in non-linear media?
I would suggest you to browse though chapters of my recent book “Computing in non-linear media…” at the Institute of Physics web site at or via this link. There are many examples of non-linear media: form excitable lattices to insect populations. Wave dynamics and emergent behavior are computationally useful properties of the media. Problems with natural parallelism are solved in non-linear media in a naturally parallel way. For example, to find a path in a labyrinth we physically cut the labyrinth of some excitable media. Then we excite the medium somewhere inside the labyrinth. The waves of excitation spread around. Path of the wave, which reaches the exit first, is the required solution.
Question 6: How much longer, do you believe, conventional approaches to computing (such as conventional lithography and non-parallel computing) will continue? How do you see a crossover between conventional approaches and non-linear approaches?
For ages… The term “conventional” is misleading. As Toffoli wrote: “a computing scheme that today is viewed as unconventional may well be so because its time hasn't come yet - or is already gone”. When people talk about non-standard computing they usually mention cellular automata. Rubbish! CA are as standard as we are. Zuse’s computing universe. Neuman’s cellular spaces. VLSI, systolic arrays, they are cellular automata essentially. They are used everywhere now. As to the “wet” ware and non-linear media computers – they do not mean to compete with PCs. They are extravagant, slow, reliable accomplices of our brains.
Question 7: What is your opinion of Molecular Nanotechnology (MNT)? Do you consider your work to be related to or a form of MNT?
Obviously, most basic results are obtained years and years ago. A general public started to be excited about it just recently. You know, the same things happened many times before. If someone wants to found a “new” field of science he simply invents a new name. Thus, for example, a good old cybernetics was renamed to artificial life in early eighties, and, hop, now we have a new “science”. The reason is obvious, no company will give you their hard-earned money to pursue research in “outdated” bionics, however they like artificial life; no manager would appreciate your projects in molecular design, molecular nano-technology is more intriguing. Nevertheless, MNT is appealing to me because of nano-computers and nano-robots. We can do without them however it is nice to have something small to talk about...
Question 8: How does the potential of reaction-diffusion media compare with other unconventional computing techniques such as DNA computing?
Reaction-diffusion computing belongs to the field of physics-based computation. Here we talk advanced materials. So, such “unconventional” techniques as evolutionary computation and genetic algorithms are out of competition. DNA computing employs chemistry as well. However, you know, not too much problems have been solved in DNA computers. Adepts of DNA computing prefer to talk then to do… And after all DNA is nothing more than another modification of simulated annealing method.
Question 9: How does the overall research effort for advancing computing technologies in the U.K. compare with that of the U.S.?
The science is international. Commonly, advanced projects involve scientists and financiers from both sides of the ocean. So, there is not too much difference.
Question 10: Do you think that your work on unconventional computing could ever lead to sentient machines?
Yes, I do. This will be a kind of a gooware, an amorphous homogeneous matter, looking like an amoeba but enormously intelligent. It will have parallel perception, massively parallel information processing and distributed acting. The gooware will be able to think, to express emotions; to reproduce itself … This will be like another-life form.
Question 11: What organizations do you collaborate with? Do any large semiconductor companies, such as Intel or IBM, fund or know about your work?
Yes, a lot of organizations “know” about my works; not everyone collaborates. No, I do not have formal links with Intel or IBM.
Question 12: What are your future plans?
Future is promising. Forthcoming years will bring us working prototypes of liquid chemical brains for robots, intelligent sheets (excitable media plus electro-active polymers), logical processors in molecular arrays, and self-organizing robotic polymers. As to the theory, we are preparing multi-author book on computing via colliding localizations, which will be a very good reading. Also I will continue shaping the parachemistry of mind, however would not like to go into details now, because it is too exciting…
This interview was conducted by Sander Olson. The opinions expressed do not necessarily represent those of CRN.
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