If the Earth were to be put on a scale, about how much might it weigh?

Question

If the Earth were to be put on a scale, about how much might it weigh?

Answer 1

Earth's Weight (Mass): 5.972 sextillion (1,000 trillion) metric tons. That's 5,972,000,000,000,000,000,000 tons! Actually, scientists prefer to refer to this measurement as the Earth's mass instead of weight since weight is the result of Earth's gravitational pull on another object. And the Earth cannot pull on itself! As the Earth orbits the Sun, it is weightless. If the Earth were placed on the Sun, it would weigh more than if it were placed on Jupiter, the largest planet in the solar system but much smaller than the sun. Yet, Earth (or any other object for that matter) would have the same mass regardless of where it is located.

New measurements of the weight of planet Earth have taken physicists a step closer to their holy grail: a precise value for the Newtonian gravitational constant.

Jens Gundlach and Stephen Merkowitz from the University of Washington have found that the Earth

weighs in at 5.972 sextillion (5,972,000,000,000,000,000,000) metric tons. While this is just a shade under the current textbook estimate of 5.98 sextillion metric tons, it could make all the difference to nailing down the gravitational constant, or Big G.

The researchers presented their findings this week at a meeting of the American Physical Society in Long Beach, California, and will publish after peer review.

The weight for Earth calculated by the Washington physicists is about 1 trillion metric tons for each person living on the planet, about the weight of the entire amount of plant and animal life living on the Earth's surface.

Debate over the gravitational constant has been raging for 13 years. New attempts to measure the Big G in the 1990's brought results widely different from the previously accepted figure. Indeed, the National Institute of Standards committee that establishes the accepted value noted that there was 12 times more uncertainty about the figure in 1999 than in 1987.

"Gravity is the most important large-scale interaction in the universe, there's no doubt about it," Gundlach said. "It is largely responsible for the fate of the universe. Yet it is relatively little understood."

Newton's gravitational constant tells how much gravitational force there is between two masses -- the Earth and sun, for instance -- separated by a known distance.

The gravitational constant along with the speed of light and Planck's constant (a key value in quantum mechanics) are considered the three most fundamental and universal constants in nature.

"That is a huge embarrassment for modern physics, where we think we know everything so well and other constants are defined to many, many digits," Gundlach said.

If accepted, the measurement by Gundlach and Merkowitz would reduce the uncertainty by nearly a factor of 100 from the currently accepted figure, making it far more precise than even the 1987 figure. Gundlach notes his numbers could change as additional data are analysed in preparation for submitting the work for peer review.

To make their measurements, the researchers are using a device called a torsion balance that records nearly imperceptible accelerations from the gravitational effects of four 8.14-kilogram stainless steel balls on a 3- by 1.5-inch gold-coated Pyrex plate just 1.5 millimeters thick.

The device, operating inside an old cyclotron hall in the UW nuclear physics laboratory, is similar in nature to one used 200 years ago to make the first Big G measurement. But it is computer controlled and contains numerous mechanical refinements that make the more precise measurement possible.

Gundlach acknowledged that the more precise calculation probably wouldn't mean much to the average person.

"Just because we know the value of G won't make better cell phones," he said. "But it's something mankind should know because it's such a fundamental constant."

Answer 2

It would be more proper to ask, "What is the mass of planet Earth?"1 The quick answer to that is: approximately 6,000,000,000,000,000,000,000,000 (6E+24) kilograms.

(Got it on a website) Your welcome!

Answer 3

Weight of the earth hints at Big G

Wednesday, 3 May  2000



Torsion balance used in measuring gravitational constant - image University of Washington

New measurements of the weight of planet Earth have taken physicists a step closer to their holy grail: a precise value for the Newtonian gravitational constant.

Jens Gundlach and Stephen Merkowitz from the University of Washington have found that the Earth

weighs in at 5.972 sextillion (5,972,000,000,000,000,000,000) metric tons. While this is just a shade under the current textbook estimate of 5.98 sextillion metric tons, it could make all the difference to nailing down the gravitational constant, or Big G.

The researchers presented their findings this week at a meeting of the American Physical Society in Long Beach, California, and will publish after peer review.

The weight for Earth calculated by the Washington physicists is about 1 trillion metric tons for each person living on the planet, about the weight of the entire amount of plant and animal life living on the Earth's surface.

Debate over the gravitational constant has been raging for 13 years. New attempts to measure the Big G in the 1990's brought results widely different from the previously accepted figure. Indeed, the National Institute of Standards committee that establishes the accepted value noted that there was 12 times more uncertainty about the figure in 1999 than in 1987.

"Gravity is the most important large-scale interaction in the universe, there's no doubt about it," Gundlach said. "It is largely responsible for the fate of the universe. Yet it is relatively little understood."

Newton's gravitational constant tells how much gravitational force there is between two masses -- the Earth and sun, for instance -- separated by a known distance.

Answer 4

a lot