A Timely Remembrance of Chester A. Arthur

It's time to say a few timely words about President Chester A. Arthur.

We don't think about time zones much when we are at home in the US.  We all know that California is three time zones away from the East Coast, but for the most part we don't give them much thought.

President Chester A. Arthur

It's a different story for me in Astana.  Even after getting over the jet lag of my arrival, I find that time has acquired a greater significance.  The East Coast is ten hours away from Kazakhstan in the summer and eleven time zones away during the winter months when the US -- well, Arizona and a few other jurisdictions excluded -- go off daylight saving time and return to standard time.  Those time zones are in the way when I want to talk by Skype with a friend or loved one at home.  

The imposition is all that much greater when one flies home or returns to Central Asia.  The human body just wasn't designed to absorb a 10-11 hour time difference in the blink of an eye unless, of course, it takes a week or ten days to blink that eye. 

It wasn't always this way, you know.   Two hundred years ago there were no time zones.  Each major city maintained its own time based on the daily passage of the Sun across the meridian, the line that connects due North with due South that passes through the zenith. Life was easy.  When the Sun was on the meridian, it was noon.   It's what we would call today local apparent time.  The time it took to travel from one city to another in Europe or the American colonies was so great that the local definition of time in any one city was not an issue. 

Things began to change in the early nineteenth century.  By then local mean time had begun to replace local apparent time.   Instead of the actual, physical Sun, the mean Sun's passage through the meridian is what determined the noon hour.  It had long been noted that the physical Sun sometimes took more than 24 hours between meridian crossings, sometimes less, with the deviation reaching as much as 16 minutes. 

 “The reason?” 

 “Why, it's elementary, dear Newton!” 

This discrepancy is caused first of all by the 23.44-deg obliquity of the ecliptic, the angle between the Earth's equator and the plane of the Earth's orbital motion around the Sun.  Secondly, the Earth's orbit is not exactly circular but is, rather, an ellipse, which means that the Earth's orbital motion around the Sun is faster at the time of perihelion -- closest approach to the Sun -- than it is six months later at aphelion. 

Now enter the railroads.  The first transcontinental railroad in the US was completed in 1869.  Each major city through which this and later railroads passed maintained its own time.  Roughly speaking, the time difference between two cities separated by 1-deg of longitude was four minutes.   If we complain of jet lag today, we should also pity the designers of the first railroad schedules.  Not only was it a pain to try to keep track of independent time systems maintained by hundreds of U.S. cities.  It was also a safety problem that could lead to head-on collisions of trains heading in opposite directions where one train engineer was using one time system and the other was using a different one. 
  
The U.S. experience in the mid-ninteenth century was quickly being replicated in much of the industrialized world.   It was compounded by the circumstance that different countries were using different prime meridians relative to which to measure longtitude and time. France used the Paris meridian.   Russia used the Pulkovo meridian.   Great Britain measured longtitude from Greenwich.  The US at times used the meridian of the U.S. Naval Observatory.   Several meetings and conferences were held beginning in the mid-nineteenth century to try to resolve the joint problem of standardized time and longitude.  In 1870, U.S. educator Charles F. Dowd proposed a system of U.S. time zones.  He was followed a few years later by Canadian railroad engineer Sanford Fleming who proposed that there be a worldwide system of time zones.  

Delegates to the International Meridian Conference

The Third International Geographical Congress in Venice in 1881 proposed adoption of a universal prime meridian.  Another conference in 1883 began to work through the details, and the U.S. Contress passed an Act in 1882 authorizing President Chester A. Arthur to call an international conference to fix the prime meridian for measuring time and longitude.  The International Meridian Conference convened in Washington in October 1884.  By a vote of 22-1, the Greenwich Meridian was adopted as the prime meridian for use by all nations. (Santo Domingo voted against; France and Brazil abstained with France only giving up on the Paris Meridian in 1911.)  A year earlier, in November 1883, U.S. and Canadian railroads instituted standard time in time zones in the US and Canada.  Between the Meridian Conference and the action taken by the railroads, the stage was set for the entire world to be divided up into standard time zones that were nominally 1-hour or 15-deg in width.  The Calder Act of 1918 made standard time in time zones the law in the US.  At the same time, the concept of Greenwich Mean Time, the time as determined by the mean Sun at the Greenwich meridian, had taken hold with each time zone measured in number of hours east or west of Greenwich.  

The Greenwich Meridian

And so, dear readers, you get some of the picture of how we got to where we are today.  Some countries and even U.S. states have chosen to bend time zone boundaries for their own convenience.   Some time zones, Newfoundland is a good example, differ by a half hour rather than an hour from their neighbors.  All in all, however, it's a system that works for commerce even as the physical human body groans under the the strain of jet lag.  The adoption of standard time and a prime meridian was also a triumph of international nineteenth century diplomacy when the needs of commerce and government brought all parties to the table to find a common solution to the common problem of longitude and time measurement. 

Is it all over?  Has time been resolved for all civil purposes?  Well, not really.   For the answer to that and more, look for a possible future entry on atomic time, Coordinated Universal Time, and leap seconds.  The story is just beginning.   

(Dramatic foreshadowing:   Greenwich Mean Time has not existed as an intenational time standard since Richard Nixon was President of the US.)