QUANTA

Sunday, November 27, 2011

 Femtotech: computing at the femtometer scale using quarks and gluons

By Hugo de Garis

How the properties of quarks and gluons can be used (in principle) to perform computation at the femtometer (10^-15 meter) scale.

I’ve been thinking on and off for two decades about the possibility of a femtotech. Now that nanotech is well established, and well funded, I feel that the time is right to start thinking about the possibility of a femtotech.

You may ask, “What about picotech?” — technology at the picometer (10-12m) scale. The simple answer to this question is that nature provides nothing at the picometer scale. An atom is about 10-10 m in size.

The next smallest thing in nature is the nucleus, which is about 100,000 times smaller, i.e., 10-15 m in size — a femtometer, or “fermi.” A nucleus is composed of protons and neutrons (i.e., “nucleons”), which we now know are composed of 3 quarks, which are bound (“glued”) together by massless (photon-like) particles called “gluons.”

Hence if one wanted to start thinking about a possible femtotech, one would probably need to start looking at how quarks and gluons behave, and see if these behaviors might be manipulated in such a way as to create a technology, i.e., computation and engineering (building stuff).

In this essay, I concentrate on the computation side, since my background is in computer science. Before I started ARCing (After Retirement Careering), I was a computer science professor who gave himself zero chance of getting a grant from conservative NSF or military funders in the U.S. to speculate on the possibilities of a femtotech. But now that I’m no longer a “wager,” I’m free to do what I like, and can join the billion strong “army” of ARCers, to pursue my own passions.

So I started studying QCD (quantum chromodynamics), the mathematical physics theory of the strong force, or as it is known in more modern terms, the “color force.”

Since I have a computer science background, I knew what to look for when sniffing through QCD text books, to be able to map computer science concepts to QCD phenomena.

Bits and logic gates : the heart of computation

If you want to compute at the femto level, how do you do that? What would you need? To me, the essential ingredients of (digital) computing are bits and logic gates.

A bit is a two-state system (e.g., voltage or no voltage, a closed or open switch, etc.) that can be switched from one state to another. It is usual to represent one of these states as “1” and the other as “0,” i.e., as binary digits. A logic gate is a device that can take bits as input and use their states (their 0 or 1 values) to calculate its output.

The three most famous gates, are the NOT gate, the OR gate, and the AND gate. The NOT gate switches a 1 to a 0, and a 0 to a 1. An OR gate outputs a 1 if one or more of its two inputs is a 1, else outputs a 0. An AND gate outputs a 1 only if the first AND second inputs are both 1, else outputs a 0.

There is a famous theorem in theoretical computer science, that says that the set of 3 logic gates {NOT, OR, AND} are “computationally universal,” i.e., using them, you can build any Boolean logic gate to detect any Boolean expression (e.g. (~X & Y) OR (W & Z)).

So if I can find a one to one mapping between these 3 logic gates and phenomena in QCD, I can compute anything in QCD. I would have femtometer-scale computation. That was the big prize I was after.

So, I set out to find phenomena in QCD that I could map bits and logic gates to. I was quickly rewarded. It was a case of “low hanging fruit.” I just happened to be the first person (as far as I know) wandering around the QCD orchard with a very specific type of cherry picking in mind.

Read more: http://goo.gl/c2VA4

Global Source and/or and/or more resources and/or read more: http://goo.gl/zvSV7 ─ Publisher and/or Author and/or Managing Editor:__Andres Agostini ─ @Futuretronium at Twitter! Futuretronium Book at http://goo.gl/JujXk