Posted by: Rajan Sambandam in Environment on
Aug 03, 2008
Asteroids are space objects and sometimes they hit earth. Depending on their size they can cause great damage. Small asteroids can burn up when they enter the atmosphere. Larger ones can hit earth and cause damage directly and indirectly. The most popular reason for the extinction of the dinosaurs 65 million years ago is asteroid strikes and the resulting global climactic changes. Okay, nothing new so far. Everyone can agree that asteroid strikes can have no to devastating impact. The next question is how likely are such impacts? To understand how frequently asteroids have struck earth in the past the traditional research method is to look for craters. Using this method scientists have estimated that large strikes happen about once in a million years or so. Then geophysicist Dallas Abbott began wondering if that kind of calculation made sense. Since about seventy percent of the earth is covered with water, wouldn't it make sense that most asteroid strikes are likely to have been in water than land. If so isn't it likely we have been underestimating the number of asteroid strikes on earth?
Posted by: Rajan Sambandam in Environment, Books on
Jun 30, 2008
Guns, Germs and Steel: The Fates of Human Societies, by Jared Diamond
Why did history unfold differently on different continents? Rather than point the finger at racial or ethnic differences to answer this question, Diamond focuses on environmental differences and proceeds to lay out a comprehensive case. Four sets of factors, he argues, contributed to the world as we see it today.
Insightology