Since I live in Alabama and don't come in contact with that many Muslims, I thought I'd just ask you. When Muslims must face Mecca and pray, which way do they face? Since our planet is round, one could really face Mecca going east or west. Is there some line that is the switching point between Muslims who face east and Muslims who face west?
-- Mark Godfrey, Fairhope, Ala.
Guys like you are the reason the Saracens wanted to slay the infidels. However, you've accidentally hit upon an interesting question.
The direction Muslims must face when they pray is called the qibla. What they face, strictly speaking, is not Mecca but the revered Kaaba (spellings vary), the central shrine in Mecca's Great Mosque, which is Islam's holiest place. As one might suppose, the qibla varies from place to place, but an effort is made to enforce uniformity in any given location. In places where Muslims are accustomed to praying, it's not uncommon to see the qibla indicated by an arrow on the ceiling with the legend Makkah (Mecca). You want to make sure you get lined up right, because a prayer carelessly sent in the wrong direction is invalid, or so some believe.
I know what you're thinking, Mark: Those nutty Arabs! Listen, bubba, it's no wackier than the Jewish dietary laws or Aquinas' angels dancing on the head of a pin. Besides, determination of the qibla has had practical benefits for Islamic civilization.
In the early days of the faith, determining the local qibla was a pretty basic proposition
This may not seem like the world's most exacting standard, but don't be fooled -- it taxed the science of the day. Various methods were proposed to determine direction, such as prevailing winds, mountains, etc., but the most reliable by far was felt to be sighting on Polaris, the north star. This, along with the need to compute prayer times based on sun location, gave rise to an interest in astronomy, navigation, and related subjects that put the Muslim world centuries ahead of Europe.
As time went on and scientific understanding improved, the determination of the qibla became increasingly precise. Today you can use a personal computer to determine the qibla to within fractions of a degree of arc for most major cities on the globe. (See for example www.time palette.com/macqibla. html).
But it's still easy to get messed up. If you look at a standard flat map of the world, you notice that New York is north of the 40th parallel, while Mecca is south of the 22nd parallel. Therefore the local qibla must be approximately east by southeast, right? Wrong. The computer and most Muslim authorities agree that the qibla in North America is to the northeast, ranging from 56.3 degrees for Washington, D.C., to 23.7 degrees for Los Angeles. How can this be? Because the typical flat map uses Mercator projection, which distorts the curvature of the earth. But get a globe and stretch a thread between Mecca and any point in North America, and sure enough, you find that the shortest distance, and thus the true direction of the qibla, is northeast. The qibla and the thread follow a so-called great circle, the same route that would be followed by a nonstop jet. (To be fair, this confuses some Muslims, too -- for an opinion on the subject, see www.alislam.org/organizations/ AalimNetwork/msg00614.html.)
Having thus grasped the complexity of the issue, we are now equipped to answer your question. Since the operative principle in determining the qibla is the shortest distance, there is a unique qibla for every point on earth except two. The first is (duh) the location of the Kaaba itself. The second is the point precisely opposite it on the globe. If we ignore variations in the curvature of the earth, this point is equidistant in all directions from Mecca. Thus one could argue that the qibla is in any direction one cares to turn -- an ambiguity that the more timorous may find unsettling. But since the point is in the middle of the South Pacific, I'm not going to get too excited about it for now.