Final answer:
The mnemonic 'Never Eat Sour Watermelons' stands for North, East, South, West and is used to remember the cardinal directions on a compass. A compass aligns itself with Earth's magnetic field and points to magnetic north, which is different from true north. Despite Earth's rotation, the compass needle's orientation does not change when moving along the equator and facing west if the magnetic and geographic north poles are assumed to coincide.
Step-by-step explanation:
The mnemonic 'Never Eat Sour Watermelons,' which stands for North, East, South, West, belongs to a category known as directional or compass point mnemonics. These are used to remember the order of the cardinal directions on a compass. The compass is a navigational tool that has been crucial for direction-finding throughout history. It has a magnetized needle that aligns itself with the Earth's magnetic field and points towards the magnetic poles. The Earth can be thought of as having a giant bar magnet within it, where the magnetic field lines extend from what we consider the magnetic north pole to the magnetic south pole. It is interesting to note that the magnetic north pole is actually a magnetic south pole if we think of Earth as a bar magnet.
Understanding the Earth's rotation, which is from west to east, is also integral to comprehending navigational principles. Moreover, while using a compass, it's important to note that there is a difference between magnetic north and true north, and this can affect navigation accuracy. When flying in an airplane along the equator and facing west, the compass will always show the needle pointing to the north no matter the location, given that we assume the Earth's magnetic north pole and geographic north pole coincide for simplicity. Therefore, the orientation of the needle will not change if we continue flying due west along the equator.