I live on the side of a hill at about 500 feet above sea level. I weigh about 11 stone. would I weigh less at 5000 feet, 10,000 feet, 20,000 and 30,000 feet? Thanks, ODM.
yes. but don't confuse mass and weight. your mass is 11 stone. that is constant. however, weight is a force applied to your mass by gravity. it is equal to your mass multiplied by the acceleration due to gravity, g. your mass remains constant but g decreases with altitude so your weight decreases.
in space you are not subject to gravity, so g is virtually zero, you are weightless. but you don't disappear, you still have a mass of 11 stone.