Circumnavigating the Earth

Is there any course that a ship can follow that would allow it to circumnavigate the full circumference of the earth without bumping into any land while travelling the whole time in a straight line? Assume that your ship has perfect ice-cutting capacity and can cut through any mass of ice, but cannot, of course, cut through land.

First Answer:

No. It is not possible for any ship to travel in a straight line, since they all follow the curvature of the earth.

So, the question becomes: Is there any course that a ship can follow that would allow it to circumnavigate the full circumference of the earth without bumping into any land while travelling the whole time in a straight line as looked at from above?

Answer:

No.

Explanation: First, it should be clear that any ship that is circumnavigating the earth along its full circumference would as some point have to cross the equator, with one exception: if the ship were travelling along the equator. Any ship travelling along the equator would obviously, from looking at any map of the world bump into South America, Africa and parts of Indonesia, so this path will not work. Any ship crossing the equator at a right angle ("square") would have to also pass through both the north and south poles, and since the south pole is located on land, Antarctica, this will also not work. So any successful path would have to cross the equator at an angle either in the Atlantic, Pacific, or Indian Ocean.

The Indian Ocean can be cast out of consideration at a glance of the map. Any ship crossing the equator at any angle in the Indian Ocean would have to pass through either the continent of Africa, Asia or Australia or through Indonesia. Although it might be conceivable that a ship could slip between two of the Indonesian islands and continue without running into another land mass, such as the Philippines, it would then encounter the same problem that we will encounter in discussing the Pacific Ocean.

Any ship crossing the equator in the Pacific Ocean and continuing "straight" would eventually hit the land mass of North America or Asia, unless it passed through the relatively narrow constriction of the Bering Strait. A look at a north polar projection of the earth shows that a ship passing through the Bering Strait could possibly hug close to the island of Greenland and thereby avoid running into Scandinavia, but it would then continue on to run into the mainland of Europe, so there is no path through the Arctic that will suffice.

Any ship crossing the equator in the Atlantic would run into the land mass of North America, Africa or Europe, unless it passed through the also relatively narrow Norwegian or Greenland Sea to get through the Arctic. We have already determined, however, that there is no path through the Arctic that will work (such a ship would run into Siberia), so this is also not possible.

There is one other possibility that we overlooked: that a ship in the Pacific Ocean might pass through the Panama Canal and continue onward. However, a line straight through the Panama Canal runs into both North and South America, and, even if this were not so, we would still run into the problem of trying to get through the Arctic from the Atlantic Ocean.