When you wake up, you’re about 1 cm taller than you were the night before. This happens because, while you sleep, gravity isn’t compressing your spine, allowing the cartilage in your joints to expand slightly.
Throughout the day, as you move and stand, gravity pushes down on your spine, making you slightly shorter by bedtime.
This effect is small, but astronauts experience a more extreme version—growing up to 2 inches taller in space due to the lack of gravity. Even though the height difference disappears daily, it’s a cool reminder of how our bodies respond to physics.
