As you begin to descend in an elevator, you suddenly feel lighter for a moment. As the elevator reaches a constant speed, you feel normal again. As it stops, you feel heavier for an instant. If you were standing on a scale, it would verify this sensation of an apparent change in weight. What you are feeling is the result of acceleration—speeding up and slowing down—not an actual change in weight. But that woozy feeling you get as an elevator starts to descend does give you a brief sense of what it’s like to feel weightless.