This term originally meant the division of the circle of the horizon into 32 points.

Tropics, Zones, and Meridian Line?'
So the Bellman would cry; and the crew would reply,
"They are merely conventional signs!"

—Lewis Carroll: "The Hunting of the Snark"

Nocturnals, or nocturlabes as they were sometimes called, are devices for calculating latitude and telling the time of night for navigators. First described in 1272, the nocturnal was phased out in the late fifteenth century. Their operation applies the fact that the stars, while remaining fixed relative to one another, appear to rotate about the pole star (currently Polaris). Actually the Earth is rotating and the pole star remains fixed because it lies along the Earth's axis of rotation. The other stars seemingly rotate around the pole star. Their positions at any moment indicate the time.

The art and science of navigating by the stars, sun, moon, and planets.

See Secrets of Ancient Navigation

See also The Seaman's Secrets" from 1594

Refer to the star compass

From The Seaman's Secrets by John Davis (1594)

The Solstical Colure is a great circle paseing by the Poles of the world, and the Poles of the Zodiac, and the Solstical points or first minute of Capricorn and Cancer, cutting the Equinoctical at right spheric angles, in his 90 and his 270 degrees.

The Equinoctial Colure is likewise a great Circle passing by the Poles of the world, and the Equinoctial point of Aries and Libra, and crosseth the Equator in his 1 and 18 degrees.

These colours do intersect each other in the poles of the world to the right Spherick angles.

What is the use of these Colures? Their use is to distinguish the four principal seasons of the year,

All living creatures have a strong affinity for the magnetic aspects of Earth. Bacteria and algae follow magnetic lines of force. Sea turtles use a two-way coordinate system based on magnetic dip and intensity. Birds use the Earth's magnetic field as a compass (magnetism geography).

Magnetite is found in the brains of dolphins, whales, certain fish (including salmon), green turtles and homing pigeons, and it seems to interact with their brains. Bees rely on the magnetic field to find their way from flowers to the hive. Honey bee dances are tuned to the sun and the local magnetic field direction, as are salmon migrations.

An explanation of magnetism based on knowledge that the universe knows its right from its left — it is not symmetrical, as the ancient Greeks had people believing for a long time. This "handedness" is the concept of chirality.

Opposites are built into the universe. Yin and yang — one of the earliest concepts of opposites — relate to an early understaninding of chemistry and the function of DNA.

The universe is left-handed. In Chinese science the left hand is yang. All amino acids (what life is built from) are left-handed. Horgan. The Sinister Cosmos (May 1997). Scientific American.