Why You Lose Weight While You Sleep

Here's a simple question: Why do you weigh more when you go to sleep than when you wake up? Because you do... You can check this yourself. Somehow, while doing absolutely nothing all night but sleep, you will wake up lighter. [...] All night long, every time you breathe out, a bunch of carbon atoms, formerly inside your body, leave your insides and take off into the night air. You breathe in oxygen, O2. You breathe out carbon dioxide, (two oxygen atoms with a carbon atom attached), so there...

 Trees are Made of Air

By blending water and minerals from below with sunlight and CO2 from above, green plants link the earth to the sky. We tend to believe that plants grow out of the soil, but in fact most of their substance comes from the air. The bulk of the cellulose and the other organic compounds produced through photosynthesis consists of heavy carbon and oxygen atoms, which plants take directly from the air in the form of CO2. Thus the weight of a wooden log comes almost entirely from the air. When we bur...

 The Science on the Path

A weed plucked at the side of the path might have found its way to the New World in a seventeenth century sailing ship. Scratches on a rocky ledge evoke colossal mountain-building events on the other side of the world millions of years ago that modified the planet's climate and caused glaciers to creep across New England. The oxygen atoms I suck into my lungs were forged in stars that lived and died long before the Earth was born. It is something of a cliche to say that everything is connecte...

 We Exaggerate the Magnitude of Ice Ages

The history of Earth's climate is one of the more compelling arguments in favour of Gaia's existence. We know from the record of the sedimentary rocks that for the pst three and a half aeons the climate has never been, even for a short period, wholly unfavorable for life. Because of the unbroken record of life, we also know that the oceans can never have either frozen or boiled. Indeed, subtle evidence from the ratio of the different forms of oxygen atoms laid down in the rocks over the cours...