地球有多重?这是个有趣的问题。有人试图用公式“质量=密度×体积”来计算它。已知地球的体积是1.08×10~(21)立方米,可是构成地球各部分物质的密度不同,无法知道密度的平均值,仍然没法求出地球的重量。于是,17世纪的权威人士断言:人类永远也不会知道地球的重量。牛顿发现了万有引力定律, How heavy is the earth? This is an interesting question. Someone tried to calculate it using the formula “mass = density x volume”. It is known that the volume of the Earth is 1.08 × 10-21 cubic meters. However, the density of the materials that make up the Earth is not the same. Therefore, the weight of the earth can not be calculated yet. As a result, the 17th century authorities asserted that mankind will never know the weight of the earth. Newton discovered the law of gravity,