To Brian DeFacio

All of the professors in the physics department at the University of Missouri had a substantial impact on who and what I am. Three, however, deserve special mention, because they had an outsized influence on me both as the physicist and teacher that I am.

David Cowan, my research advisor, taught me to see science as one big picture. Henry White demonstrated much confidence and a lot of patience in a graduate student and allowed me to be one of the first two graduate students to teach an undergraduate course.

Brian DeFacio. I could always count on him for a conversation. In my acknowledgment section of my dissertation, I included a joke that that only those who knew Brian will get. 

I thank Dr. Brian DeFacio for innumerable conversations.

These never occurred in his office. Sometimes in the hallway, sometimes before or after class, but usually in the physics department lounge. Breaking news in physics? Brian would be all too happy to discuss it with you. An interesting problem in a course? He wouldn’t necessarily help you with it, but he would put his own special spin on it. 

Sometimes he would relate personal stories. A favorite - Brian was serving in the armed forces, Army I think, and stationed at a Nike missile facility. There was this young lieutenant who didn’t think too highly of Brian and often pulled rank. Brian was on guard duty one night when this officer came by his post. Brian challenged him, and the officer did not respond with the correct counter phrase. He then ordered the officer onto the ground and held him at gun point until others arrived.

What you should take from this story is how he treated people. Brian always treated us grad students as colleagues. He never used his position as anything other than teacher, mentor, and friend.

In the classroom, he was a wonder. No one could fill a blackboard like him. Room 305 held at most eighteen people, and it had boards on three walls. Brian would start at the front on the left, and after half an hour would reach his starting point, and we would then start the next lap. I remember inventing a DeFacio dictionary that I kept in my head. Note taking because much easier. So when I wrote “linear, isotropic, and homogeneous,” I just thought something like “the usual case.”

One day, halfway through the lecture, someone caught a sign error. After correcting it, he told my favorite story of one night while working at home, his wife asked him if something was wrong. Brian said that he was trying to find a missing minus sign. She asked him why don’t you ever try to find a missing plus sign.

Brian also had a way of making you come up to his standards. I was in his Condensed Matter I course. We had two homework assignments and a final exam. I didn’t do every well on the first homework set, but I did all right on the second. I missed one class that semester. He saw me the next day and said I had missed the best lecture he ever gave, one on Anderson localization.

When the final came along, there were two facts of life. Because I did poorly on the first homework, I had to do well, and I had to know Anderson localization. I nailed that test. Perfect answer on Anderson localization. After checking with some classmates, I suspected I had the highest score on the final. So I was a little miffed when Brian gave me a B, but that lasted about 30 seconds, because he was right. I blew off the first assignment; he knew it, and I knew it. He wanted us to do the best we could at all times.

Toward the end of my comprehensive exam, Brian raised his hand to ask a question. Now I was prepared for this exam. I knew my research topic. I could have answered nearly anything the committee could throw at me. So what did he ask? 

Calculate the power output of a fly.

I haven’t seen or spoken to Brian in twenty years. Now there are no more opportunities for discussions, but in a way, that’s okay, because of all those conversations that were too many to count.