Einstein's Special Theory of Relativity states that there is no such thing as absolute time or speed. Everything is relative -- it depends on the observer. While it is no longer necessary to provide evidence of the truth of this theory (long since established as fact), still I was able to provide more data from my visits to Tanzania.
My colleagues there have very different ideas about distance and time than we Americans do. On several occasions, while on the way to a visit or a meeting, I will ask one of them, "How far is it?" Inevitably the answer is, "Not far." It doesn't matter whether we are walking or driving -- "not far" is the distance we have yet to travel.
On a recent trip to Tanzania, we were driving to visit a village which was 15 kilometers from the nearest health facility and our host wanted to show us this place and how long villagers had to travel for health services. "Not far" turned out to be a 40-minute ride along dirt tracks, through overgrown thorn bushes and through some slippery muddy spots. At one point, my cellphone rang with a message saying "Welcome to Uganda Telecom. We offer you good rates." We had nearly crossed into another country on our "not far" journey.
On another occasion, my team was to make a house call on a terminally AIDS patient to verify the impact of our Community Health Workers. I asked the Lutheran pastor who would accompany us, how far it was to the patient's home. "Not far."
We trudged about two kilometers along goat trails, avoiding thorn bushes, and through muddy spots from yesterday's showers. We ended up at the foot of a hill and I asked the pastor. "Where is the home of the patient?" He pointed upwards and said, "Up there," indicating another goat path at the end of which, was a mud brick residence of the patient. The patient was pleased to see us and asked his daughter and caretaker to make us some tea.
My friends from Texas tell me that distance between points is measured by the number of cans of beer you can drink between Dallas and Houston, for example.
This same dependence on the observer applies to time. Tanzanians are habitually late for meetings and appointments. Mainly this is because the transportation infrastructure is so limited, it is tough to get around. The other reason is that Tanzania survives through relationships that focus on regular communication. So, when you meet a friend on the street, it is common for you to stop and exchange all the news since the last time you met. Inevitably we are late to meetings and not surprisingly, our hosts have no problem with us arriving half an hour to two hours late since they have been doing the same thing. The only time a meeting starts at the stated time is when it is advertised as "American time."
These differences in distance and time between Tanzanians and Americans are instructive. They are learning that time is valuable and should not be wasted. We learn patience and come to understand that there are many ways to perceive time and distance. It is a humbling moment for us as we learn that ours is not the only way.
We have now come to understand Einstein's contribution without the math