It's A Smaller World After All
And other recent science discoveries
by Otto Johnson
New calculations made by University of Washington scientists for Earth's mass were reported in May 2000. According to UW physicists Jens Gundlach and Stephen Merkowitaz, Earth weighs in at 5.972 sextillion (5,972 followed by 18 zeros) metric tons.
One Trillion Tons for Everyone
Recent textbooks list the weight as 5.98 sextillion metric tons. Either way, that's about one trillion metric tons for each person on Earth.
Measuring With A Torsion Balance
To make their precise measurements, the researchers used a computer-controlled device called a torsion balance that records nearly imperceptible accelerations from the gravitational effects of four 8.14-kilogram (18-pound) stainless-steel balls on a 7.62-by-3.81-centimeter (3-by-1.5-inch) gold-coated Pyrex plate just 1.5 millimeters (0.591 inches) thick.