Electricity, the foundation of Computing

David Bartolomei

Daily, we are in contact with more than twenty electronic devices and we take most of them as granted. From our nervous system, threw thunderstorms, electricity is on everything that has electrons that can be move by move between two points. The funny part is that without the discovery of new techniques and properties of how to manipulate and control electricity our lifestyle would be very different. 

We study many electric circuits, their components and interactions but the main invention related to computing is the transistor. The transistor is the primary building block of electronic devices. It is a semiconductor device that is used to amplify and switch electronic signals. To be able to control electronic system, the binary mathematical language was develop. It main purpose is to represent the presence and absence of current in a circuit. In binary system consist of only two numbers 1 as HIGH and 0 as LOW. 

In digital circuits are many electronic components that are able to handle these signals and are built using transistors. To have a basic idea of how digital system works, I would like to introduce three basic logic gates or components.

AND			OR			NOT
IN-A	IN-B	OUT	IN-A	IN-B	OUT	IN	OUT
0	0	0	0	0	0	0	1
0	1	0	0	1	1	1	0
1	0	0	1	0	1
1	1	1	1	1	1

The logic behind these gates is very simple. In the AND gate, if one of the inputs is LOW the output will be LOW, because it need both inputs to be HIGH to output a HIGH value. The OR gate is different, because with only one input at HIGH, the output will be HIGH. The NOT gate, is just that, the output is the opposite of the input.

By combining a few of these components you can develop all algebraic functions (addition, subtraction, division, multiplication) but actually, everything is handle by the addition function. Sadly, this topic is so vast that is out of the scope of this writing. But the point that I’m trying to make is that, with the basic concept of presence and absence of electric current, I’m able to write this text in front of a screen rather than in a piece of paper. 

Embedded systems are usually a circuit that receives a limited amount of inputs and produce an output. A good example is a soda-can production line. IF a pressure sensor detects that the empty can is on top of it, it activates the mechanism to fill in the soda, IF NOT, It will not open. The sensor produces a signal that an embedded circuit will react according to it.

A computer, in the other hand, is a combine system of microcontrollers. It is a programmatic system that allows the user to specify with task to execute and how it will react to any input.  The essence of a computing system is performing arithmetic iterations really, really fast. This is the base of everything from Facebook, to Microsoft Word, cellphones, gaming consoles and TVs. 

Every year, transistors are becoming smaller and smaller, and you can fill in more in a processing unit closer together, but there is a limit on that and is called the Moore’s Law that establish a limit in with interference will occur between transistors because they will be so close that electrons will jump and get out of route.

So we are good now, what is next? What will do things even smaller? 

The answer is Quantum Computing. A field that comes from Quantum Mechanics an obscure field of physics combines with chemistry. I barely understand the concept so I will like to introduce you to my definition:

Quantum Computing a concept based on the electron spins in the different orbitals of an atom and how you can manipulate them to produce multi-states signals that will revolutionize how we know computing and will solve many now-unsolved problems. 

With electricity we have conquer the skies and now starting with other planets, develop a world-wide communication network, well, computing is everywhere but at the end electricity is what actually “power” everything in our world, even our brains.