<story><title>Billion-year-old air reveals surprise about oxygen on ancient Earth</title><url>http://www.cbc.ca/news/technology/ancient-air-oxygen-life-1.3698842</url></story><parent_chain></parent_chain><comment><author>rebelde</author><text>I see articles like this one every once in a while.&lt;p&gt;A chemistry professor once told my class that due to the rate of diffusion, that we had just learned, the test of the &amp;quot;old air&amp;quot; would be wrong.&lt;p&gt;I don&amp;#x27;t know chemistry well. My question is if the salt completely stopped all diffusion over the last billion years. Maybe somebody here can answer.</text></comment>
<story><title>Billion-year-old air reveals surprise about oxygen on ancient Earth</title><url>http://www.cbc.ca/news/technology/ancient-air-oxygen-life-1.3698842</url></story><parent_chain></parent_chain><comment><author>TimGremalm</author><text>&amp;quot;What they found may have implications for the origin of complex life.&lt;p&gt;The air, which has been preserved, undisturbed, in tiny pockets in the crystals for about 815 million years, appears to contain 10.9 per cent oxygen — just half the amount in the atmosphere today.&lt;p&gt;But it&amp;#x27;s about five times more than scientists expected for that time period, which is about 200 million years before the first known multicellular fossils.&amp;quot;</text></comment>