Those who cannot remember the past are condemned to repeat it. George Santayana
The time was 1847. The place was the Vienna General Hospital. New mothers in the doctors’ wards had been dying of puerperal fever with an extremely high mortality rate – three times that in the midwives’ ward. It was a mystery. It could not be explained. But Ignaz Semmelweis had been observing this for years. Had studied the situation and made some interesting connections.
The situation was very puzzling. There were two clinics in the hospital Semmelweis was the equivalent of a chief resident. Clinic one was the teaching service for medical students; clinic two was where only midwives worked. Why was the presence of doctors apparently killing new mothers? Women were coming to the hospital’s maternity ward for the benefits of the child care they would receive. But the high mortality rates had them try to avoid coming on a day when they would be admitted to the first clinic. In fact, many preferred to have their births in the street, then come to the clinic for the benefits. Surprisingly, the mortality rate for those giving birth in the street was significantly lower than for those giving birth in the doctors’ clinic. It was a mystery, and nothing could explain it.
Until Semmelweis figured out the connection. And proved it – lowering the mortality rate from the 10-35% it had been to 1%. The connection was doctors working on cadavers (it was a teaching hospital) and then going to do their rounds with patients. The solution was Semmelweis instituting the practice of hand disinfection with a chlorinated lime solution he created. The results were dramatic. But his theory was incomplete. He could not explain why it worked. The existence of germs had not been postulated yet, let alone detected.
His theories were scorned. Administrators of hospitals thought the suggested disinfection process would take too much time. Doctors were not eager to admit that they had caused so many deaths. It was not until years after Semmelweis’ death that his theories were accepted – after Pasteur could demonstrate the existence of germs. For more on Semmelweis, see Wikipedia.
How does this relate to us? I would suggest the knowledge of germs to doctors is like the knowledge of flow to software developers. It is not all there is (other things cause disease than germs) but it is pretty important to know. Things that often appear complex and unknowable, are, in fact, complicated but unknown. BTW: I am not suggesting that software development as a whole is not complex, just that not all of it is complex. Furthermore, understanding this non-complex part makes software development much more effective.