Victor Grippi – The Atomic Writer

Hello Readers,

Today marks the day all national television stations stop broadcasting analog signals. Just over an hour ago analog signals that have been broadcast as the standard for over sixty years have been switched off and replaced by a digital broadcast signal. Like the vinyl record, cassette tape, and vacuum tube amplifier, the move to digital is not without cost. What is the significance of this change? Aren’t digital recordings more sharp, crisp, and interference free?

First, let’s touch on some basic electronic terminology to help me explain to you what this difference is all about. An analog signal can be represented by a sine wave that continual changes it’s amplitude, or voltage, as the signal moves through time. The signal starts at zero then rises to a positive peak where it then falls in voltage back down to zero. Once at zero the voltage swings negative and continues to a negative peak, usually at the same voltage level as the positive peak. The following diagram illustrates a varying sinusoidal wave. The vertical or Y axis represents voltage, while the horizontal or X axis represents time:

The above picture shows an analog signal that varies in amplitude over time and is typical of the type of signal that TV used to broadcast. The red arrows indicate points in time where the analog signal is to be sampled. The process is known and sample and hold and electronic circuits exist to carry this out. Basically, at each red arrow point, voltage is measured and then stored as a value represented by a digital number. Later these numbers can be reconverted back to analog if needed. In digital TV’s the digital signal is used to turn on and off the picture elements or pixels that make up the picture we see.

The following diagram illustrates sample and hold:

If we look at the red line moving in 90 degree blocks throughout the above signal, we see what is basically a digital signal. This becomes the signal that is now being broadcast by TV stations. The area between the sample points become artifacts that are forever lost.

What gives vacuum tube amplifiers and vinyl records that buzz or hum that people miss from earlier days are just these artifacts that are lost during the sample and hold digitizing process. When the signal is converted back to analog, like in the case of an audio signal, for TV or for an mp3 or CD player, the lost artifacts are unknown and therefore the only option is to
average out the signal and approximate what might have been in the signal at that point in time.

The same is true for video. The video MPEG (Motion Picture Expert Group) standards use a block averaging algorithm to blur neighboring pixels whenever the signal quality degrades or drops out during playback or transmission. The attempt is made to make it seem like everything is normal and we have all seen those times when our digital cable, or satellite video picture becomes blocky and pixelated in large blurry patches. This is the MPEG algorithm trying to approximate what it thinks the picture should have looked like.

Analog signals are more natural and capture more of the nuance found in naturally occurring speech and vision. The human eye needs approximately 24 frames per second in order to overcome persistence of vision. The human ear is only sensitive up to 40KHZ. That’s 40,000 cycles, or an analog signal whose voltage peaks positive and negative 40,000 times a second. CD quality audio, for example uses a sample and hold rate of 44 KHZ so that we hear the highest quality sound possible. But this is a sanitized sound. A sound that has been artificially massaged in order to improve it.

This brings up a point that The Atomic Writer would like to explore. As science improves the reproduction quality of audio and video, how will it change us? What is lost in the electrical artifacts that we remove? What, if anything will take their place? Digital technology makes it very easy to supplant subliminal messages into the extra spaces in digital transmissions. I’ll stop at just the mere mention of this since my point is to not be paranoid, only to call it like it is. We already have high definition TV and radio, that attempts to fill these spaces with extra bandwidth to provide clearer, crisper, cleaner, sharper, more realistic images. But the human senses can only detect a fraction of the full electromagnetic spectrum. What have we’ve been missing in the sights and sounds that impinge us? Or have we missed it?

Perhaps our eyes, ears, and physical bodies do pick up frequencies outside the detectable range? Perhaps the buzz and hum of a classic rock recording or live performance is detected by the human body. An illicit internal response that mimics the natural sound of nature. A sight and sound more attune with the human experience. Not the artificial rendering of a machine.

Ah, I’ve hit the central theme of this post. Should machines render the world we hear and see? Will we change as humans and become more machine like in our thoughts and minds? Aren’t we providing our reality to machines in their natural language? Will reality one day be dictated by machines? And if so, will we know the difference?

Remember, never stop looking up at the night sky and asking…what if.

Victor Grippi
The Atomic Writer