<blockquote><font class="small">In reply to:</font><hr /><p>Would the earth be constantly growing concidering the human population dies in mass...which means that they decay and cant leave earth...which means every human body that has died is still on earth...which means i just asnswered my own question but since i typed this all out i shall post it anyways for the mass to respond to the obvious. thanks<p><hr /></p></p></blockquote><br /><br />The serious answer is conservation of matter. Humans are made up of bits of the Earth, therefore, when we die (assuming we stay on Earth instead of being blasted into space on a Celestis capsule -- which comes back to Earth eventually anyway), those bits go right back to the Earth. No net mass change.<br /><br />However, the Earth <i>does</i> gain material. Accretion never really stops. There is a constant rain of interplanetary and interstellar dust, as well as micrometeoroids and meteors. Most of these are vaporized on reentry, but their mass does stay with the Earth once added. Meteorites also exist; these are meteoroids which survived reentry (at least partially) and have struck the Earth. Their mass is added to the Earth's mass.<br /><br />The Earth also loses mass, though. Atmospheric particles are lost to space through a variety of processes (the lighter ones can acheive escape velocity on their own if they get up high enough, and the solar wind can knock heavier ones free). Really big meteorites can kick up debris at escape velocity, although since the meteorite itself is contributing material, it could be a net gain <i>or</i> a net loss, depending on the circumstances. (Random factoid: one popular theory for the formation of the Moon holds that an exceptionally big meteorite, probably the size of Mars, struck the Earth so hard that a huge blob of molten Earth came away and formed the Moon.) And of course Mankind is now sending bits of the Earth away into space in the form of spacecraft, rockets, rocket stages, and rocket pro <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em> -- The Tenth Doctor, "Blink"</font></p> </div>