It’s not a problem that most people have cause to think about, but weighing stuff in micro-gravity can be a real delicate matter. When you go into space, of course, your mass stays the same, but your weight depends on gravity and that is suddenly almost gone. Traditional scales won’t work, so how do you measure how much something weighs?
The traditional method involves a stool connected to oscillating springs, allowing them to measure the velocity of the object being weighed after applying an accurate, known force. The new method using the Kinect creates a 3D model of the object’s (or person’s) body, and then estimates the mass based on volume estimates.
It doesn’t sound terribly accurate to me, but practical trials have shown the margin of error to be within about 6 lbs or 2.7 kg, which is comparable to the traditional method.
As the Kinect improves, one would hope that the estimates would improve in accuracy as well. This could have important implications for people’s lives in space. It’ll help doctors keep track of patient weight, an important consideration since two of the drawbacks of extended time in low gravity is loss of both muscle mass and bone density.