Q: How do you measure the height of a peak?
As far back as the early 1800s, surveyors had a reasonably accurate method: stand below a peak with a telescopic instrument called a theodolite, measure the angle from your position to the summit, perform some trigonometry, andvoiláyou had an elevation. The first official measurement of Everest, published in 1856, proposed a remarkably accurate figure of 29,002 feet. But even as techniques improve, the key to determining elevation ultimately rests upon correctly pinpointing the "zero" from which to begin counting up. Sea level has always been the base line, but the sea is often too far away to be measured reliablyand its level varies with the tides and with location. So to figure out mean sea level anywhere on Earth, scientists examine the planet's varying gravitational field and its distribution of mass to arrive at a theoretical model called a geoid. A climber standing on the summit can then use a GPS device to calculate the vertical distance separating him from the established geoid. In the remote Himalaya, the local geoid has been calculated only to within about three feet, so even Everest's latest height of 29,035 feet has a built-in margin of error of plus or minus six and a half feet. No one knows with total precision how many feet above sea level the actual rock summit lies (though Italian geophysicist Giorgio Poretti plans to measure it exactly with ground-penetrating radar next year). Why would anyone go to such trouble to eliminate such relatively tiny uncertainties? In the words of Colorado geoscience professor Roger Bilham: "Because they are there."
Q: How much does it cost to climb Everest?
A standard guiding fee will set you back about $65,000. Sounds steep, until you consider the costs factored into the pricesuch as climbing Sherpas (seven per six-person party, at $5,000 a head), yaks ($5,000), and oxygen ($23,000) [click here for a complete tally]. On top of the fee, airfare to Kathmandu is about $1,500 (from the U.S.), gear another $8,000. Says Ted Wheeler, who summited Everest last year, "If you're starting from scratch, it will cost a fortune. But I'd be nervous if someone going to Everest has to buy climbing boots." The real burdens, he says, are the car and mortgage payments you still have to cover during your two and a half months at the top of the world. Moreover, Wheeler adds, "Every year before I go to the Himalaya, I meet with my lawyer and go through my will" ($2,000 to be drawn up; $300 to $500 for each codicil).
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