Conceptually I understand that mass is a measure of the amount of stuff present in an object, while weight is a measure of the force of gravity applied to that object. An object of a given mass will have a bigger weight on Earth than on the moon because Earth’s gravity is stronger. But… mass is determined by weighing an object on a scale. And there is a simple mathematical conversion between grams (mass) and pounds (weight), implying that they’re just different units for the same concept. So what gives? (Also this is a question that applies to so many fields, I had no idea which flair to apply.)
In: 53
>But… mass is determined by weighing an object on a scale.
In the circumstances you’re familiar with, sure. But you can also measure an object’s mass by applying a known amount of force to it and observing its acceleration, or in some astronomical cases, measuring its gravitational effect on other objects (which objects, in a cool way, you don’t even have to observe directly, sometimes).
>And there is a simple mathematical conversion between grams (mass) and pounds (weight)
Again, *under familiar conditions.* Objects in freefall (ie, orbit) have zero weight, but positive mass: that usual conversion doesn’t work in space.
Latest Answers