Monthly Archives: July 2012

The Nyquist–Shannon Sampling Theorem

Nyquist-Shannon SamplingAt a Meetup group last week, one of the conversationalists mentioned the Nyquist-Shannon Sampling Theorem.

As applied to sound waves, this theorem states that if you want to know everything there is to know about a sound, you must measure (“sample”) it twice as frequently as the highest-frequency pitch it contains.

I immediately thought of the increasing rate of information-flow in our society. In the old days, knowledge came at us much more slowly. You didn’t have to take stock of it all that often.

These days, according to a study out of Berkeley, we produce about 5 exabytes of information every year. That’s the equivalent of 37,000 Libraries of Congress. Every year. And the deluge is only accelerating.

This is happening in every field, including whatever field is most prominent in your worldview.  If you want to have a clue, you must sample this information more frequently than ever.

Fifty years ago, a man would take a serious look at his beliefs maybe once in his life. It was called a midlife crisis — a one-time episode of questioning and irresponsibility. Now I think we can say that a midlife crisis is irresponsible because it’s only one-time! With 5 exabytes of information coming at us every year, we ought to be questioning continually.

We can’t spend every day in crisis, obviously, but at a minimum we can learn something every day, right?

Now that you know what the Nyquist-Shannon Sampling Theorem is, you have met today’s obligation. Congratulations! My wish for you is that tomorrow will bring more learning or, better yet, more questions.