2002-04-24|Sunatori's Altitude from Earth's Centre
Potential Discovery or Invention
To measure the height of a mountain, "altitude above sea level" is measured from the "mean sea level" (MSL), which is not constant in time because of ocean, climate and geological changes. Thus, the "mean value" is determined only for a particular epoch. In fact, global-average sea level is believed to have risen by between 100 and 200 millimetre during the past century due to global warming.
Even though planet Earth is not completely spherical but oblate ellipsoidal, I believe that the absolute altitude from an origin at the centre of planet Earth is better than a relative reference which changes over time.