How Do You Weigh Things in Space?
Astronauts need to know their mass while in orbit, but a normal scale would be free-falling around the Earth with them. So how do they measure their mass without gravity? We're conducting...
==========
On Earth, or any other body with enough gravity, we have a couple different tools to measure how much something weighs. There are balancing scales, like you might stand on at a doctor’s office, or spring scales, like the ones you might use to weigh fruit in a grocery store. Now, astronauts need to know their mass to log things like bone density, muscle loss, and other data points for human research experiments. But, in orbit, a normal scale would be free-falling around the Earth with them. So how do they measure their mass without gravity? Every accelerating object with mass exerts a force—that’s Isaac Newton's second law of motion. And weight is the force an object exerts due to gravitational acceleration, like what we feel here on Earth. It’s b...
==========
On Earth, or any other body with enough gravity, we have a couple different tools to measure how much something weighs. There are balancing scales, like you might stand on at a doctor’s office, or spring scales, like the ones you might use to weigh fruit in a grocery store. Now, astronauts need to know their mass to log things like bone density, muscle loss, and other data points for human research experiments. But, in orbit, a normal scale would be free-falling around the Earth with them. So how do they measure their mass without gravity? Every accelerating object with mass exerts a force—that’s Isaac Newton's second law of motion. And weight is the force an object exerts due to gravitational acceleration, like what we feel here on Earth. It’s b...
