By Harry T. Cook
6/14/13
The writer of this essay is as close to being a theoretical physicist as the dog just now walking down the sidewalk in front his house is to being a short-order cook. As such, he (the writer, not the dog) probably has no business reading excerpts from a book entitled Time Reborn: From the Crisis in Physics to the Future of the Universe.
A review of the book cites this quotation from Isaac Newton: It may be that there is no such thing as an equable motion whereby time may be accurately measured. All motions may be accelerated and retarded, but the flowing of absolute time is not liable to any change. Oh, yes, right, of course. There follow comments having to do with the space-time continuum, one or two questioning whether or not human beings' sense of the passage of time is anything but illusion or if measurable space even exists.
Isn't it time for lunch?
In fact, the concepts of time and space fascinated me well before the world began to pay attention to space as we now conceive of it, thanks to Star Trek. I learned as a youngster about those dimensions and the critical roles they play by observing how a railroad operated its trains.
When I began to hang around the village depot, the trains that ran to it and through it were controlled by timetable rules and written train orders -- by the latter when deviations from the former needed to be made.
The essential thing was that the train -- especially one transporting passengers and the U.S. mail -- had to meet its timetable schedule, and not only for expediting the mail but to make certain passengers got where they needed to go when they needed to get there. That was especially important when changing trains at a junction was concerned.
Since multiple trains occupied the same line running in both directions over 226 miles, the dispatcher and the telegraph operators under his direction kept the engineers and conductors of each train posted on where along the right-of-way other trains were in relation to their own. When delays occurred, the dispatcher via wayside telegraphers would issue orders to trainmen that, if understood and followed, would avoid collisions. It was a one-dimensional version of air traffic control that had to be at work.
Times of arrival and departure of regular trains were determined by 1) the time it took to proceed safely from the initial station to the terminal station with all the scheduled stops between figured in; 2) the speeds that were determined to be safe given grades, tangents, and curves along the right-of-way; 3) the movements of other opposing and following trains; and 4) the normal seasonable weather variables.
Each day at noon, a central office relayed by telegraph a signal sent out from the Naval Observatory in Washington, D.C., to which all clocks at stations were set and all trainmen's watches had to conform. That way, everybody involved in the movement of trains or who needed to clear the tracks for their safe passage knew exactly what time it was when.
"Standard" clocks, as they were called, as well as employees' watches, had to be inspected regularly to assure that they kept time accurately. Locomotive engineers and conductors were required to compare watches at the beginning of a run, each knowing that the other's timepiece was no more than a second or two earlier or later than one's own. Even a mere 10-second difference was seldom tolerated.
Look at your own watch now and, as the second hand moves round, count out 10 seconds, noticing that it is a longer time that you might think. Even with objects weighing hundreds of tons hurtling at 50 mph toward one another, 10 seconds can be crucial. In that time, a switch can be thrown or a brake valve applied that can save lives and property from death and destruction.
It was not until the advent of the diesel-powered variety that locomotives were regularly equipped with speedometers. However, in the timetable, a copy of which every trainman was required to carry while on duty, there appeared a speed chart laying out in minutes and seconds the speed-time factor. For example, 45 seconds a mile equals 80 miles an hour, and so on down to five minutes and zero seconds equaling 12 miles an hour.
In order to maintain the required speed and schedule, the engineer had to keep one eye on his watch, paying especial attention to the second hand, and the other on markers that stood along the right-of-way at one-mile intervals. Then, in addition to observing the aspects of trackside signals, he had also to mind the various speed restrictions placed on certain portions of trackage and to know which restrictions were permanent and which temporary due to construction or repairs. The engineer's job was highly skilled labor, not unlike that of a pilot flying a 747.
The fundamental principle of the operation rested on the reality that two objects cannot occupy the same particular space at the same particular time, except if they run into each other and in the wreckage become indistinguishable.
In observing and working around railroad operations, I came to appreciate the relationship between time and space -- both the measured passage of the former and the linear dimension of the latter.
That relationship is evident in this way: One of our sons and his family live some 600 miles and 10 hours driving time west of us. Our daughter and husband live 500 miles and at least eight hours driving time in the opposite direction. Another son and his family live 60 miles and one hour away -- better, but we wish all of our kids and their kids lived on our street.
Travel by automobile, save to the family just an hour a way, is difficult as I am temperamentally disposed neither to long car rides nor to the manifest lack of courtesy on the part of too many fellow motorists. Air travel is both expensive and trying as the TSA and many airlines seem to have made it a central purpose to treat passengers like cattle when they're not treating them like POWs.
Most unfortunately, travel by rail is next to impossible when Gaithersburg, Md., is one destination and Iowa City, Iowa, is another. You can't get to either city by rail unless in the former case you change trains at least three times over nearly 24 hours. In the latter, detraining in a hamlet at some distance from Iowa City after a nearly 12-hour trip requires rousing the sole car rental guy from his bed or calling him away from his job at the local feed store.
Just as I am anything but a theoretical physicist, so also I am not exactly at home in the universe of cyber communication. Yet, thanks to my wife and her iPad, we now are able to visit with our far-flung loved ones in real time via a nifty thing called FaceTime. At least in one dimension, we have conquered space. And with two of the senses -- sight and hearing -- we can be one with those we love.
When last autumn one of my sisters had a six-week stay in a hospital 250 miles from us, we were able to do the FaceTime thing with her when we could not make the drive. It made a big difference to our family ties.
The time factor remains important because, while our Maryland daughter and we are on Eastern time, our Iowa son is on Central time and one of my sisters-in-law on Pacific time. Yet the great distances that separate us can be reduced spatially to a few inches and temporally to the blink of an eye. Each of us can look into the little cameras on our respective iPads and behold the others as if we all were seated in the same room.
So this non-physicist will make bold to say that both time and space are definitely real and measurable. Six hundred miles or 60 miles: It makes no difference. We cannot be home and at the same time in our families' homes, at least not bodily. But with FaceTime, we are there and they are here. Most of what is important is in place, except, of course, the hugs.
I wonder what would Newton and Einstein have to say about that.
