Professor Sampler’s Notes: Disadvantages of Digital Systems

Topics Covered:

  • Disadvantages of Digital Systems

I don’t need a friend who changes when I change and who nods when I nod; my shadow does that much better – Plutarch

Is digital perfect?

No. The great disadvantage of digital systems is that they are not continuous, yet they have to deal with analog data. It is impossible for a system that is discrete by definition to sample a continuous signal and retain all of its information. Similarly, it is also impossible to fully reconstruct an analog signal from a digital signal.

So this becomes the most important criterion in the selection of digital systems: Is the loss from analog to digital and back lesser or equal to analog to analog systems? If yes, digital work fine, otherwise it is a lost cause. Is the loss acceptable? But, acceptable to whom?

Unfortunately, the answer to this question becomes murkier as the complexity of the system increases. In such cases, digital usually wins because once a digital signal is created satisfactorily then it can be reproduced without error. Is this always the case? Hardly.

What if one wanted to make the most accurate recording possible of a particular event or person? If there is a very good analog system in place, then the question arises on whether it is better (with respect to preserving the event for posterity) to use that analog system or move to digital.

Sometimes the result is clear cut, sometimes it isn’t. It is entirely possible for a system to do a stellar job with the math but fail miserably under subjective tests. Health is one good example. We all know the benefit of fruits, vegetables and exercise, but the local junk food stall gets more business than the local gym. There is always a human quotient to every system. Even automated systems are designed by humans. Why fight it?

Ultimately, for this reason, most people end up judging a system’s utility through subjective methods – usually their eyes and ears. Before an artist seeks perfection within their artificial tools, they must first learn to use their natural tools – mainly their eyes, ears and brain. Once you have defined your own standards, you can then confidently begin your quest for the right tools to realize your vision. Life is too short to go in circles, especially circles designed by others.

Trust your eyes and ears. They are really cool tools, and they are better than any camera or headphone!

Are there any more critical disadvantages of digital systems? Yes, one more, possibly fatal. To store digital data, we need analog systems, and these are liable to fail. In fact, it will fail. It’s just a matter of time. Whether it is solid state drives, microwaves, tapes or our memory doesn’t make one iota of a difference to this fact.

In fact, the sad part is that even an isolated atom in vacuum decays after a certain time. Nothing is permanent, and the only semi-reliable solution to preservation is our universe’s own solution to the problem – via reproduction. Unbelievable as it may seem, our universe is one big mother – it reproduces atoms, planets, galaxies, apes, idiots and bad grades with consistent regularity. What are you going to do, sue the universe for copyright violations?

Now that we know digital’s main limitations (there are others, but that’s just nitpicking), let’s find out how to digitize something.

Takeaways:

  • At some point, digital systems have to interact with the analog world, and this is not a happy marriage.
  • Even though in theory digital signals last forever, practically digital signals have to be stored in analog devices or objects. These don’t last forever.

Links for further study:

Next: Professor Sampler’s Notes: Sampling Analog Signals
Previous: Professor Sampler’s Notes: Analog vs Digital

One reply on “Professor Sampler’s Notes: Disadvantages of Digital Systems”

  1. elaborate well and arrange in systematic way of that disadvantages of digital system over analog system

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