Physics
Weight vs. Mass
Quick fact
An astronaut orbiting Earth is weightless (apparent weight near zero) but still has the same mass as on the ground. If they pushed off a wall, they would float—demonstrating their inertia depends on mass, not weight.
Why this is interesting
You step on a bathroom scale and read 70 kg—but if you take the same scale to the Moon, you'd weigh only about 12 kg. Yet you haven't lost any 'stuff'. How can the same object give a different number?