Kiss my Analog: An introduction to analog and its past

Analog: A message defined by a varied frequency added to a signal of a given frequency of an electromagnetic current.

Sound confusing? Actually, it's quite simple. Analog is simply a form of transmission that is created using an electromagnetic signal, which is then sent to its destination. Take this as an example of what an analog signal may look like:

Analog actually fluctuates between frequencies, just like how the Alternating Current(AC) of electricity does, because it's relatively the same thing.

Dreaming in Digital: Or is it reality?

Digital is something that's been around for quite some time now. One of the earliest methods of Digital transmission was something we listen to everyday: The Compact Disc(CD). The CD was originally developed by James T. Russell, a man who decided one day that he wanted to invent a higher quality standard for music. The first Digital-to-Optical device was first patented by him in 1970. His original method of a "digital music disc" was to read a disc without any physical contact to the disc itself, so only one thing came to mind, and that was light. The light would reflect off the surface of the disc, which have small white and black spots, each 1 micron(A unit of length equal to one millionth (10xE6) of a meter) in diameter, each representing a binary digit of 0(black) and 1(white). This was the first step into the digital world.

The definition of digital isn't "A person talking on their cellphone in their car, who then proceeds to cut you off without using a turn signal(although, most of us think that)". Here's the informal definition of Digital:

Digital: a signal that consists of binary digits rather than electromagnetic current.

May sound confusing also, but the transmission of a digital signal is more direct and straight foreword than that of analog tranmission. Take a look at an example of a digital signal:

Ok, so which is better? Analog or Digital?

Good question. With all the advertising for phones, cellphones, camera, and computers, you are probably leaning towards the direction of digital being better. In most and almost all cases, it's actually better. So whay is digital better?
The reason digital is better is for one reason: no electromagnetic distortion. The reason analog isn't too popular anymore is because since analog runs on electromagnetic currents, it is susceptible to distortion and inaccuracy due to other signals. Take an old cell phone for instance. You either heard of or personally experienced the crackling sound when talking into an old phone. That is because the analog signal between the phone and the radio tower is being interrupted by another signal. You also saw in the picture above that the analog signal is varying up and down from positive to negative. That signal is easily interrupted. This is why analog isn't used as much anymore.

Digital on the other hand is much more verstile and powerful. There is no electromagnetic distortion. Taking the cellphone instance again, the new digital phones work much better because the signal sent from the phone to the tower is in binary form, which is understood better by the computers at the other end. Here's a small list of devices which would use digital transmission:

That's where DVD comes into hand. The video standard was developed by a group called MPEG(Moving Picture Experts Group). DVD is encoded in MPEG-2, the compression standard for digital versatile discs. VideoCD's are only MPEG-1, which is 4x less quality than DVD quality. Another form you are all familiar with by now is the DivX codec. This takes high quality movies and compresses it down into a ridiculously small file size, but with very high quality. Another factor that comes into play with video is interlacing, but that's for a later time. I hoped this little article helped you understand the differences between analog and digital.

Written by: Brian Dappolone

Resources: whatis.com, dictionary.com, ask.com

Question? Comments? Email the author here