Para responder à questão, leia a pergunta feita por leitor à revista Popular Science (outubro de 1999), bem como a resposta dada a ele pela revista.

Why are we taller in the morning than we are at night?

ngogna@hotmail.com

WE ARE in fact taller in the morning, but only slightly. It’s because the horizontal position most of us sleep in relieves gravity’s pressure on our spines, so the soft cartilage between our 26 vertebral bones expands. Throughout the day, as we move in an upright position, these doughnut-shaped discs of cartilage compress under the weight of gravity. So we’re a bit taller in the morning than we are at night.

”Vertebral discs are composed of a fairly high percentage of water”, says Jerome McAndrews of the American Chiropratic Association. ”When you lie down you take the weight bearing off, and the discs expand. When your weight’s on them, they squeeze."

Such differences are more pronounced in young people. As we age we shrink less throughout the day because there’s less resilience or flexibility in our tissues.

Popular Science, 1999.

O fenômeno em questão se manifesta igualmente em toda a população? Por quê?