Bill Bryson - The Earth Moves

This chapter is about how different scientists throughout the century thought about how continents were formed and how they ended up in the positions that they are now.  The reason that this became a topic of interest was the fact that the same types of rocks and plant fossils were found in countries on opposite sides of the oceans.  Also, some scientists had observed that continents like Africa and South America looked like they fitted together.  one early theory by Austrian Eduard Suess said that the earth had cooled and become weaker in the manner of a baked apple pie, creating ocean basins and mountain ranges.  Another theory was that there used to be land bridges between continents, which allowed animals and plants to travel between these land masses.  Finally, scientists decided that the continents did move, and this was called ‘Continental Drift’.  One theory stated that there were convection currents underneath the earth that moved the continents around.  The continents were found to be sitting on large plates that were first called ‘crustal blocks’ or ‘paving stones’.  Finally they agreed to call them ‘plates’.

Connor McKenzie