Justin Studebaker, age 14, of Sand Springs, Oklahoma, for his question:

Exactly how high is Mount Everest?

Most authorities give the height of Mount Everest as 29,028 feet above sea level. This is the exact figure that most people accept. It is the result of a survey made by the Indian Government in 1954. A British survey made in the 1800s gives the lofty peak a height of 29,002 feet and still another survey gave the figure as 29,141 feet above sea level. In any case, all geological surveyors agree that Mount Everest, the world's tallest peak, is at least 29,000 feet high.

People who know the lofty peak well often say that it is impossible to give its exact height. The job of measuring it is tricky and there is no sure way to do a perfect job. What's more, the high Himalayas are restless, still shifting and growing. A peak may grow a few inches or lose a few inches in an avalanche or rockfall. So even if we found the exact height today, it might not agree with the exact height , of yesterday or tomorrow.