Here's another one, from the other side of things:

This happened a long time ago in an engineering school not so far away..

There was a prof at that school who was in his 70s and knew his stuff inside out, backwards and forwards and upside down. And he could teach it to 18-22 year olds, too.

This prof had graduated in 1921, had worked on

the Differential Analyzer and other famous projects, and had been on hand when ENIAC was built. He'd also done lots of work in industry.

The students thought they were sharp and fast but had a hard time keeping up with him. Often the lessons were not exactly what was expected. "Prof. W" taught all sorts of classes from electrostatics to power generation and distribution, but it didn't really matter because one took his classes as much for the experience of learning as the material.

There was a 400 level Power class he taught. Generation, transmission, distribution. Textbook was written by a Brit named Weedy. Good book too, even though it stretched the class to learn terms

like "earthing" and "speedgear" and to do some problems that weren't 60 Hz.

Prof W. felt that giving tests on a subject as involved as Power was useless, so marks came entirely from the homeworks. One per week, 4 to

5 problems, due on a specific day, so many points per problem. Students were on their our honor not to cheat, and didn't. Getting the right answer was only part of the process anyway, you had to show how you got it and why it was right. The class knew the prof well enough to know that he'd see right through any faking or copying. The problems were all from the book - the ones that

didn't have answers.

2 or 3 weeks into the course came this problem:

"A 220 kV 60 Hz three phase transmission line is 200 miles long and has the following constants per phase per mile:

Inductance 2.1 mH

Capacitance 0.14 uF

Resistance 0.25 ohms

Ignore leakage conductance.

If the line is to deliver a load of 300 A, 0.8 power factor lagging, at a voltage of 220 kV, calculate the sending-end voltage."

There's a couple of ways to solve a problem like that. But each method gave an answer that didn't make any sense - and a *different* nonsense answer. None of the methods produced a reasonable result.

It became clear that some folks in the class had found the answer, or thought they had, because they weren't working on the homework as long as

everyone else. The rest of the students with any sense finally wound up showing all three results, with an explanation that they were all wrong, but not why.

Came the day to hand them in, and after Prof. W collected them, the class asked how to do #5. He went to the board and wrote a very simple equation that relates the inductance and capacitance of a line to the speed of light - something very basic in EE.

It took a few moments for the mental lightbulbs to go on, but one by one the students realized

the connection. The transmission line parameters given in the book could not exist in reality, because they violated the equation on the board. The capacitance should be 0.014 uF per mile, not 0.14 uF. That's why the nonsense answers.

Students were outraged - they'd been had because of a misprint in a book! They protested, but Prof W. simply asked:

"Didn't you check that the data supplied were reasonable? People make mistakes in the real world, and dropping a decimal place is one of the

easiest. Just because it's in a book doesn't mean it's right!"

Then he capped it:

"Next thing you'll tell me is that you believe everything that comes out of a computer!"

That year a teaching award was created in his honor, given to the best teacher in the school, as judged by the students.

Most of the students went on to work in areas other than power transmission. No one forgot Problem #5.

He passed away a few years ago at the age of 98. The award continues.