The Earth has a magnetic field which is approximately aligned with its axis of rotation. A magnetic compass is a device that uses this field to determine the cardinal directions. Magnetic compasses are widely used, but only moderately accurate. The north pole of the magnetic needle points towards the geographic north pole of the earth and vice versa. This is because the geographic north pole of the earth lies very close to the magnetic south pole of the earth. This south magnetic pole of the earth located at an angle of 17 degrees to the geographic north pole attracts the north pole of the magnetic needle and vice versa.
The position of the Sun in the sky can be used for orientation if the general time of day is known. In the morning the Sun rises roughly in the east due east only on the equinoxes and tracks upwards. In the evening it sets in the west, again roughly and only due west exactly on the equinoxes.
The four cardinal directions, or cardinal points, are the directions north, east, south, and west, to South. When travelling East or West, it is only on the Equator that one can keep East or West and be going straight (without the need to steer). The conventional orders of the pairs north/south and east/west are . and final glottal stops followed by *-s, but not the other way round, i.e. no.
In the middle of the day, it is to the south for viewers in the Northern Hemisphere , who live north of the Tropic of Cancer, and the north for those in the Southern Hemisphere , who live south of the Tropic of Capricorn. This method does not work very well when closer to the equator i.
Conversely, at low latitudes in the southern hemisphere the sun may be to the south of the observer in summer.
In these locations, one needs first to determine whether the sun is moving from east to west through north or south by watching its movements—left to right means it is going through south while the right to left means it is going through north; or one can watch the sun's shadows.
If they move clockwise, the sun will be in the south at midday, and if they move anticlockwise, then the sun will be in the north at midday. Because of the Earth's axial tilt , no matter what the location of the viewer, there are only two days each year when the sun rises precisely due east. These days are the equinoxes. On all other days, depending on the time of year, the sun rises either north or south of true east and sets north or south of true west. For all locations, the sun is seen to rise north of east and set north of west from the Northward equinox to the Southward equinox , and rise south of east and set south of west from the Southward equinox to the Northward equinox.
There is a traditional method by which an analogue watch can be used to locate north and south. The Sun appears to move in the sky over a hour period while the hour hand of a hour clock dial takes twelve hours to complete one rotation. In the northern hemisphere, if the watch is rotated so that the hour hand points toward the Sun, the point halfway between the hour hand and 12 o'clock will indicate south. For this method to work in the southern hemisphere, the 12 is pointed toward the Sun and the point halfway between the hour hand and 12 o'clock will indicate north.
During daylight saving time , the same method can be employed using 1 o'clock instead of The difference between local time and zone time, the equation of time , and near the tropics the non-uniform change of the Sun's azimuth at different times of day limit the accuracy of this method. A portable sundial can be used as a more accurate instrument than a watch for determining the cardinal directions. Since the design of a sundial takes account of the latitude of the observer, it can be used at any latitude.
See: Sundial Using a sundial as a compass. Astronomy provides a method for finding direction at night. All the stars appear to lie on the imaginary Celestial sphere. Because of the rotation of the Earth, the Celestial Sphere appears to rotate around an axis passing through the North and South poles of the Earth.
This axis intersects the Celestial Sphere at the North and South Celestial poles , which appear to the observer to lie directly above due North and South respectively on the horizon. In either hemisphere, observations of the night sky show that the visible stars appear to be moving in circular paths, caused by the rotation of the Earth. This is best seen in a long exposure photograph , which is obtained by locking the shutter open for most of the intensely dark part of a moonless night. The resulting photograph reveals a multitude of concentric arcs portions of perfect circles from which the exact center can be readily derived, and which corresponds to the Celestial pole , which lies directly above the position of the true pole North or South on the horizon.
A published photograph exposed for nearly 8 hours demonstrates this effect. The Northern Celestial pole is currently but not permanently within a fraction of 1 degree of the bright star Polaris. The exact position of the pole changes over thousands of years because of the precession of the equinoxes. Polaris is also known as the North Star , and is generically called a pole star or lodestar. Polaris is only visible during fair weather at night to inhabitants of the Northern Hemisphere. The asterism " Big Dipper " may be used to find Polaris. The 2 corner stars of the "pan" those opposite from the handle point above the top of the "pan" to Polaris.
While observers in the Northern hemisphere can use the star Polaris to determine the Northern celestial pole, the Octans constellation's South Star is hardly visible enough to use for navigation. For this reason, the preferred alternative is to use the constellation Crux The Southern Cross. The southern celestial pole lies at the intersection of a the line along the long axis of crux i.
At the very end of the 19th century, in response to the development of battleships with large traversable guns that affected magnetic compasses, and possibly to avoid the need to wait for fair weather at night to precisely verify one's alignment with true north , the gyrocompass was developed for shipboard use. Since it finds true, rather than magnetic, north, it is immune to interference by local or shipboard magnetic fields. Its major disadvantage is that it depends on technology that many individuals might find too expensive to justify outside the context of a large commercial or military operation.
It also requires a continuous power supply for its motors, and that it can be allowed to sit in one location for a period of time while it properly aligns itself. Near the end of the 20th century, the advent of satellite-based Global Positioning Systems GPS provided yet another means for any individual to determine true north accurately.
We all know that the planets revolve around the Sun horizontally, but what would happen if the planets orbited the Sun vertically? Books Explore our library and use wonderful books in your lessons! This is conjectured to be a reference to the shining dawn; but see 'south'. If we give the Chinese cardinal points numbers in the same way i. The location of sunrise and sunset only provide an approximate idea of direction days of the year, because the sun rises due east and sets due west only on the vernal and autumnal equinoxes the first day of spring and fall. To learn how to make a shadow dial or compass to tell directions, read on! Share to Facebook.
The government agencies responsible for the satellites continuously monitor and adjust them to maintain their accurate alignment with the Earth. There are consumer versions of the receivers that are attractively priced. Since there are no periodic access fees, or other licensing charges, they have become widely used.
GPSR functionality is becoming more commonly added to other consumer devices such as mobile phones. Handheld GPSRs have modest power requirements, can be shut down as needed, and re calibrate within a couple of minutes of being restarted. In contrast with the gyrocompass which is most accurate when stationary, the GPS receiver, if it has only one antenna, must be moving, typically at more than 0.
On ships and aircraft, GPS receivers are often equipped with two or more antennas, separately attached to the vehicle. The exact latitudes and longitudes of the antennas are determined, which allows the cardinal directions to be calculated relative to the structure of the vehicle. Within these limitations GPSRs are considered both accurate and reliable. The GPSR has thus become the fastest and most convenient way to obtain a verifiable alignment with the cardinal directions. The four cardinal directions correspond to the following degrees of a compass:.
The intercardinal intermediate, or, historically, ordinal  directions are the four intermediate compass directions located halfway between each pair of cardinal directions. Let's work together to keep the conversation civil. Open in app.
Notification Center. Directions play an important role in Vastu. Right knowledge of direction is very important to make a building structure according to vaastu. In the olden days people who needed to check the directions very minutely, used to see the shadow of sun. In the modern technical world the instrument called magnetic compass is used to check the directions. In the total there are 10 directions but to check with compass only 8 directions are available.
Compass has degrees in total with its radius. The rules of mahjongg are, from this perspective, a clue to origins of the counterclockwise! In the previous century, I purchased a compass in Riyadh, Saudi Arabia. In the shop I couldn't tell which point of the needle pointed north or south.
I asked the shop keeper, "Which way is north. I went ahead and bought it and out in the bright sunlight I could see that one end of the needle was a little darker than the other. Re maidhc's early point, the "spectacles testicles" etc. While mildly irreverent, it doesn't seem so strongly taboo to plausibly be the sort of thing that was in common oral use for decades upon decades before turning up in print.
Heck, if it was an old enough Catholic schoolboy usage, James Joyce would probably have worked it into some scene involving the young Stephen Dedalus.