One of the main reasons why many scientists did not accept continental drift was because there was no known mechanism to explain how continents could move across the Earth's surface. The theory of plate tectonics, which provides the modern explanation for continental drift, was not developed until the 1960s. Before that, scientists struggled to come up with a plausible explanation for how continents could move over such vast distances.

2. Apparent fit:

Another reason why continental drift was not widely accepted was because of the apparent fit of the continents. When looking at a world map, it seems as though the continents could be fitted together like puzzle pieces. This led many scientists to believe that the continents had once been joined together, but had not actually drifted apart. However, it was later discovered that the fit of the continents is not as perfect as it seems, and that there are significant gaps and overlaps when the continents are placed together.

3. Fossil record:

The fossil record also provided some challenges to the hypothesis of continental drift. In the early 20th century, scientists were aware of the distribution of certain fossils, such as the presence of similar fossils on different continents that are now widely separated. This led some scientists to argue that continental drift could not be true, as it would require these organisms to have crossed vast oceans to spread between the continents. However, it was later discovered that many of these fossils could be explained by other mechanisms, such as land bridges or the migration of organisms over long distances.

4. Lack of supporting evidence:

Another reason why continental drift was not accepted by many scientists was the lack of supporting evidence. At the time, there was limited evidence to support the idea of continental drift, such as the distribution of certain rocks and minerals. It was not until the development of new technologies and the collection of more data in the mid-20th century that the hypothesis of continental drift began to gain wider acceptance.

Overall, the lack of a known mechanism, the apparent fit of the continents, challenges from the fossil record, and the limited supporting evidence were some of the main reasons why many scientists did not accept the hypothesis of continental drift until the mid-20th century.