For over 125 years, the world's clocks have been set to Greenwich Mean Time. But that could soon change, if Saudi Arabia gets its way. The Islamic kingdom hopes a massive new clock being built in Islam's holy city of Mecca could soon establish "Mecca Time" as the world's defining time zone. Upon completion, The Royal Mecca Clock Tower, which began ticking during this week's commencement of Ramadan, will be the largest clock tower ever built. Could the influence of this soaring timepiece spread beyond the Muslim world? (See the clock tower)

Why are they building a clock?
A group of Islamic scholars hope the clock can establish Mecca, where millions of the world's 1.5 billion Muslims make pilgrimage each year, as the "true center of earth." According to Egyptian cleric Yusuf al-Qaradawi, Mecca is more suitable for the role of prime meridian than the observatory in Greenwich, England, because it is "in perfect alignment with the magnetic north," making it a "zero-magnetism zone."

Is that a legitimate claim?
Not according to Western scientists. They say that the Magnetic North Pole is actually atop a line of longitude that passes through North and Central America. The North Pole is currently calculated to be in Ellesmere Island, Canada — though its exact location shifts around each year. 

Why do we set our clocks to Greenwich Mean Time (GMT), then?
Actually, we don't. Greenwich Mean Time "was set rather arbitrarily" in 1884, says PZ Meyers in Science Blogs, because the British Empire was the leading maritime force at the time and "used solar observations relative to Greenwich to determine the longitude of ships at sea." Since 1972, however, clocks have been set to Coordinated Universal Time (UTC), a system dictated by 300 atomic clocks, that more accurately tracks the position of the sun. The fact that the prime meridian is at Greenwich is an "arbitrary standard."

Just how big is the clock?
Not only is it by far the world's biggest clock tower — six times larger than London's Big Ben — but at a height of 1,970 feet, it is also the second tallest building in the world. The clock's four faces stretch 151 feet in diameter, and are each inscribed with huge Arabic words reading: "God is greatest." Five times a day, 21,000 green and white LED bulbs flash as a reminder to pray, and its spire is topped with a 75-foot wide golden crescent moon. The surrounding complex is set to have seven towers in total, which will house hotels, shopping malls, and conference centers.

Who is responsible for it?
The $800 million project has been funded by the Saudi royal family and was designed by a team of German engineers. It was built by the Saudi Binladen Group, a construction corporation originally founded by Osama bin Laden's father and now run by his half-brother Bakr. The Al Qaeda leader himself is estranged from his family, whom he has criticized for their wealth and privileged status. 

Is anyone taking the "Mecca Time" bid seriously?
While many Muslims reportedly support use of the clock to set global time zones, American commentators remain decidedly skeptical. "It is easy to dismiss Mecca Mean Time as a stunt," says The Washington Times in an editorial. But still, "it is another example of the ways in which the Muslim world seeks to impose a new global orthodoxy." I wouldn't be too concerned, says David Kenner in Foreign Policy. "Greenwich has performed its job as international timekeeper admirably since 1884, so many people are going to be hard-pressed to think of a reason to change the prime meridian now." 

Sources: Telegraph (2), AOL News, NPR, Washington Times, Foreign Policy, Arab News, Science Blogs