Archive: 12/11/2013

The rise and fall of oxygen

How long has Earth's atmosphere included oxygen? A recent paper suggests low levels of oxygen appeared in the atmosphere approximately 2.95 billion years ago. That's about 550 million years earlier than p ...

Dec 11, 2013 4.8 / 5 (4) 0

Video: The anatomy of a raindrop

When asked to picture the shape of raindrops, many of us will imagine water looking like tears that fall from our eyes, or the stretched out drip from a leaky faucet. This popular misconception is often reinforced in weather ...

Dec 11, 2013 5 / 5 (3) 0