An Open Letter to Academia:

The Role of Physics in Teaching Circuit Theory

I graduated from Cal Tech in 1949 with a BS in physics.  Later I obtained an MSEE from USC.  During most of my career I worked in my own company, designing and manufacturing instrumentation amplifiers.  I started in the days of vacuum tubes where one dc amplifier weighed 300 pounds.  I saw the art transformed by transistors, solid state amplifiers and finally microprocessors.  I found myself in the position of designing instrumentation that had to handle small signals that were carried over a thousand feet of cable.  I had to come to grips with utility power, ground connections, shielding, multiple reference conductors, noise and interference.  If signals were noisy, it was blamed on the instrumentation.   I had to find solutions to stay in business.  As a selling tool I wrote small articles for customers describing how interference enters the hardware and what we did to solve the problems.  This eventually resulted in a book called Grounding and Shielding in Instrumentation, which was published in 1967 by John Wiley.  Very little was published on this subject and at its acceptance really surprised me.  The book was about applying basic physics to the world of electronics.  I have rewritten this book every ten years.  The 5th Edition was published in 2007.  The technology changes but the physics stays the same.

My business and later my consulting activity gave me the opportunity to see and visit most of the major aerospace facilities in the US.  I found out how engineers treated the subject of ground.  They felt that the better the earth connection in a facility, the lower the interference levels.  They felt that a good ground improved security by controlling the return paths used by all signals.  I saw the use of single-point grounds where literally a ton of copper was buried in the earth.  What they were doing made no sense to me.  I could not connect my understanding of electrical interference to this pseudo science.  To me, a ground rod controlled interference the way a flagpole controlled sun light.  It didn’t.

This grounding practice was a part of the lore that an engineer meets after he gets out of school.  He does not fight the solution.  He assumes he missed something along the way.  Since this practice seems to work, why fight it? After all, the rules are written by those in authority and even appear in print on  government documents. 

The other day I was asked by an engineer about providing a high frequency ground for a facility.  His boss had asked him to look into it.  It is a little like asking an engineer to buy some negative resistors to keep in the stock room just in case they were needed.  This request for a facility high frequency ground plane is utter nonsense.  The old lore will not die,  and it really is a waste of time and resource.  This letter is written because something needs to change to stop this waste.  We have better ways to use our resources.

I have taught hundreds of seminars on grounding, shielding, and interference control.  I have found that most engineers do not know the relationship between physics and electronics.  When a system fails they turn to trial and error or lore.  They change things until it works.  They order more copper and bury it in deeper holes.  The physics they were taught is not used to help find an answer.  This is because physics and circuit theory are not taught as one subject. 

In most schools, physics is taught to EEs as a separate subject.  The nature of fields makes the subject very mathematical and very difficult.  The student spends most of his time learning just enough mathematics to solve the most elementary problems.  Most students make no connection between this physics and the real electrical world.  In effect, passing the physics course is just an obstacle that makes getting a degree difficult.  This is a very sad state of affairs. 

The bridge to understanding is not found in the material published by various professional groups.  When engineers turn to other engineers or to superiors, they get little help.  This is because these people were educated the same way.  I sense we are in a rut.  I feel there is a real lack of leadership in this area.  I feel that the solution lies in academia and it is my hope that someone will read this letter and begin to take some action. 

I am not an academic, and I have not yet succeeded in getting the attention of anyone in academia. I have written many books, but they are not engineering textbooks, they are for the practicing engineer. But I have seen the problem very clearly. We need to make changes in the way physics is taught to engineers, so they can effectively use it in their work. This should be done and done soon. Even if changes are made today it is going to take a lot of time to see the effects in the professional community.

Every technologic advance has some underlying physics.  Today we are building very fast logic to support the newest computers..  It really can’t be done using trial and error.  It is basic physics that shows us how to proceed.  We should not be trapped into thinking that lore can be our guiding light.  This is looking backward, not forward.  

Academia must find a way to mix electronics and physics so that engineers know how to react to non-circuit problems.  If this goal is met then technical advances will be far less costly.  I look at electronics as the center of the coming age.  We need to be more efficient so that we can use our resources more effectively.

Ralph Morrison Consulting

Engineering expertise from analog to GHz logic