Looking at the history of the Earth, we can go back to a time when all the continents
we’re familiar with, and some we might not be, were joined together in one supercontinent.
This supercontinent was Pangea, which means “all the Earth” in Greek.
So obviously if they are in a different position now then they were then, they must be moving.
This is called continental drift, first proposed by German scientist Alfred Wegener in his
book “The Origin of Continents”.
But is this all just speculation?
How do we know this not some wild guess?
Firstly, just by looking at a map, you can tell that there is some sort of pattern.
The coastlines of Africa and South America line up quite well, indicating they could
have been together at one point.
But people often see things where they don’t exist like a face on the moon or a shape in
the clouds.
Clearly if something was together then pulled apart, they must share something more unique
than land itself?
Many fossils of the same species have been found across continents.
These are species that cannot swim, so they had no way of crossing any ocean.
The triassic land reptile lystrosaurus has been found in Antarctica, India, and Southern
Africa.
Lystrosaurus definitely did not know how to swim an entire ocean.
Fossils are not the only things to extend across continents, the Appalachian mountains
of the United States for example continue into Ireland and Scandinavia.
When rocks are formed, certain minerals inside the rock point to the magnetic North.
Over millions of years, the magnetic poles change significantly, which allows scientists
to compare samples and tell which way the continents were before.
All of this should be pretty convincing, but what was the accepted theory before continental
drift?
When faced with the issue of the same animal being separated by an ocean, people thought,
hey, there must have been a land bridge.
Now, there are some very real land bridges, like between India and Sri Lanka up until
1480, and the Bering Land Bridge up until almost 17 000 years ago, but these other ones
were quite wild.
Like one from Brazil to South Africa, from Central America to Japan, and many others.
These supposed land bridges must have been tall enough as the deepest part of the Ocean,
and wide enough to not collapse.
That would be quite a formation.
And according to them, these land bridges just vanished without a trace?
Wegener’s theory was first rejected by virtually everyone and he was ridiculed.
The continents have moved, are currently moving, and will continue to move.
This is why we have mountains, volcanoes, and all sorts of features.
And until next time, thanks for watching.
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