Review Sheet - The REAL Symposium

In 1926, a symposium on continental drift was held in New York City.  All the top geologists of the time came together to debate the merits of Wegener’s new theory.  The geologists were split in their opinions of the theory at the start, but at the end, most were in agreement:  Continental drift seemed like a good idea, with some evidence that the continents had once been in different positions on the Earth.  However, because nobody had any good idea about what would cause continents to drift, the scientists were hesitant to accept the idea as a theory.  (Wegener did have one idea, that was not accepted - he thought that maybe the continents would drift because the Earth spins, flinging the continents apart like children on a playground merry-go-round.) By 1930, most geologists did not support the idea of continental drift, and the idea seemed doomed to disappear forever.

This historical lesson teaches us that theories are not easily accepted.  Remember that Wegener wasn’t even a geologist - he was a meteorologist and he developed the theory of continental drift based on what he read of others’ research.  Wegener used the following pieces of evidence to argue for his idea:

• The continents on either side of the Atlantic fit together as if they were puzzle pieces.
• Mountain ranges on either side of the Atlantic line right up with each other, and contain similar geological features.
• The remains of fossils, such as Glossopteris,, are found on separate continents, separated by thousands of miles of ocean.  This is true in spite of the fact that Glossopteris is a land plant..
• In the past, glaciers have occurred in the equator and swamp-produced coal was produced in Antarctica.

As you know, experiments are important in science.  Firsthand observations are necessary to collect the evidence to build scientific ideas.  Hopefully, you are also learning that scientists do not work in isolation from each other.  They communicate extensively, and that is how the big ideas of science (theories) are developed.  You might be surprised to know that many scientists spend more time reading journals about other scientists’ work than they do conducting experiments!