Nanocomputers

speed=distance/time

Pretty simple, eh? But the implication of this within the context of the nanoscale will revolutionize the computer industry.

If you picture a modern day computer processor, it would most likely fit nicely into the palm of your hand. For every operation required of it, electrical signals must travel a given distance within the computer hardware before sending an answer. Most simple calculations on personal computers nowadays take a fraction of second, but then again things like multimedia intensive, stuff like 3-d rendering programs, often take minutes to complete a complicated task. This is because (not taking into account network speeds, just within ONE computer) the electrical signals take time to fly around processor, and when a recursive task is given to the computer, or one where the computer has to do pretty much the same thing over and over again until it is instructed to stop, the time delay is very noticable. After all, compared to the size of an electron, the processor is pretty big, even at the speeds electrons travel.

Without taking into consideration the exact construction of a computer on the nanoscale, only its size, from the modified version of the equation above:
time=distance/speed
let's say that the speed is the constant speed of electrons traveling through a medium (or a virtual positive charge), time is the amount of time it takes for a calculation to be performed and distance is the distance required of electrons to travel in the processor (let's just say this is determined by the size of the processor).

To quote Drexler from Engines of Creation:

With components a few atoms wide, though, a simple mechanical computer would fit within 1/100 of a cubic micron, many billions oftimes more compact than today's so-called microelectronics. Even with a billion bytes of storage, a nanomechanical computer could fit in a box a micron wide, about the size of a bacterium. Andit would be fast. Although mechanical signals move about 100,000 times slower than the electrical signals in today's machines, they will need to travel only 1/1,000,000 as far, and thus will faceless delay. So a mere mechanical computer will work faster than the electronic whirl-winds of today. Electronic nanocomputers will likely be thousands of times faster than electronic microcomputers - perhaps hundreds of thousands of times faster, if a scheme proposed by Nobel Prize-winningphysicist Richard Feynman works out. Increased speed through decreased size is an old story in electronics.

The equation I noted above I related to a nanoelectrical computer instead of a mechanical one. Because the distance the electrical signals (or parts in the case of the mechanical comp.) have to travel is so dramatically reduced, the time which a calculation takes is also dramatically reduced, as can be inferred from the time=distance/speed equation.

With the advent of nanotechnology scientists have now developed structures called 'nanotubes', which are molecular tubes made out of rolled up sheets of carbon atoms, nanometers thick. If constructed correctly, the tubes can be made to serve as a type of semiconducter, such that electricity will flow in one direction of these tubes. In contrast with the copper wires, other metals, and silicon, these nanotubes give little or no resistance.

Therefore, the implementation of these nanotubes would greatly increase speed in the above equation.

So, nanotechnology will permit the size of processors to be vastly diminished, greatly shortening the distance for electrons or mechanical parts to travel, as well as the lowering the resistance of conductive parts of nanoelectric computers, increasing the speed of processes. These both result in normal calculations in a much shorter time.

Sources:
Engines of Creation by K. Eric Drexler
Nanotubes:
Carbon Nanotube Research of the UNC-CH Physics Program (good)
Studies on Doubling the Diameter of Single-Wall Nanotubes
Why are Nanotube such excellent field emitters? at Foresight's page

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