The Earth's rocky outer crust solidified billions of
years ago, soon after the Earth formed. This crust is not a solid
shell; it is broken up into huge, thick plates that drift atop the soft,
underlying mantle.
The plates are made of rock and drift all over the globe; they move both
horizontally (sideways) and vertically (up and down). Over long
periods of time, the plates also change in size as their margins are
added to, crushed together, or pushed back into the Earth's mantle. These plates are from 50 to 250 miles (80 to 400 km) thick.
The difference between a hypothesis and theory is that the hypothesis is based on observations, but doesn't have a solid proof, while the theory is based on solid proof.
So in order for the scientist to make his hypothesis into theory about the connection of all the Earth's oceans, will need to provide a proof. This proof can be obtained by a sea traveling that will be well documented, and during the travel the scientist to manage to sail through all of the Earth's oceans without having any physical obstacle between any of them.
The rio grande river
hope it helped
