地球上的物体,都受到重力作用。重力是地球对物体的吸引力。根据万有引力定律可知,距离地心愈远,地球的吸引力就愈小。在大气层外运行的人造卫星和宇宙飞船上,由于还有惯性离心力的作用,宇航员的重量就更小了,轻飘飘的,有时还悬浮起来。这就是“微重力状态”。大量空间实验表明,微重力是一种很有价值的资 Objects on Earth are affected by gravity. Gravity is the Earth’s attraction to objects. According to the law of universal gravitation, the farther away from the earth’s center, the less attractive the earth is. On satellites and spacecraft that operate outside the atmosphere, astronauts also weigh less, frivolously, and sometimes float because of inertial centrifugal forces. This is “microgravity state ”. A large number of space experiments show that microgravity is a valuable resource