If it isn't precisely balanced, the weather vane will topple and shift or even stop moving. Seated just beneath the pointer are the fixed directional markers, pointing toward the north, south, east and west.
Over time, you will get to know your local weather, and may even get fairly experienced in predicting coming storms. In addition to writing for Demand Studios, Jordan currently provides content for several promotional business blogs, herbal and alternative health guides, and is a certified Childhood Obesity Specialist, Core Training Specialist, Personal Trainer and Aerobics Instructor.
Although partly functional, weather vanes are generally decorative, often featuring the traditional cockerel design with letters indicating the points of the compass. Other common motifs include ships, arrows and horses.
The weather vane was independently invented in ancient China and Greece around the same time during the 2nd century BCE. The oldest textual reference to a weather vane comes from the ancient Chinese text Hainan dating from around 139 BC, which describes a wind -observing fan” (you fend shan't, ).
The Tower of the Winds on the ancient Greek Agora in Athens once bore on its roof a weather vane in the form of a bronze Triton holding a rod in his outstretched hand, rotating as the wind changed direction. Military documents from the Three Kingdoms period of China (220–280) refer to the weather vane as “five ounces” (WU Liang, ), named after the weight of its materials.
The Snafu Huang (), a 3rd-century book written by Mao Hangman about the palaces at Chang'an, describes a bird-shaped weather vane situated on a tower roof, which was possibly also an anemometer : It was called 'Ling Tai' because it was originally intended for observations of the Yin and the Yang and the changes occurring in the celestial bodies, but in the Han it began to be called Qing Tai.
Go Quashing, in his SHU Zheng Hi (Records of Military Expeditions), says that south of the palaces there was a Ling Tai, fifteen rens (120 feet) high, upon the top of which was the artillery sphere made by Zhang Hung. Pope Gregory I said that the cock (rooster) “was the most suitable emblem of Christianity”, being “the emblem of St Peter”, a reference to Luke 22:34 in which Jesus predicts that Peter will deny him three times before the rooster crows.
As a result of this, the cock gradually began to be used as a weather vane on church steeples, and in the 9th century Pope Nicholas I ordered the figure to be placed on every church steeple. One alternative theory about the origin of weathercocks on church steeples is that it was an emblem of the vigilance of the clergy calling the people to prayer.
Another theory says that the cock was not a Christian symbol but an emblem of the sun derived from the Goths. Early weather vanes had very ornamental pointers, but modern weather vanes are usually simple arrows that dispense with the directional because the instrument is connected to a remote reading station.
A challenger for the title of world's largest weather vane is located in Whitehorse, Yukon. The weather vane is a retired Douglas DC-3 Copy atop a swiveling support.
Located at the Yukon Transportation Museum beside Whitehorse International Airport, the weather vane is used by pilots to determine wind direction, used as a landmark by tourists and enjoyed by locals. A challenger for the world's tallest weather vane is located in West lock, Alberta.
The classic weather vane that reaches to 50 feet is topped by a 1942 Case Model D Tractor. The term “weather vane” is also a slang word for a politician who has frequent changes of opinion.
A dipole being used to install a weather vane atop the 200-foot steeple of a church in Kingston, New York. ^ a b c d Needham, Joseph; Ling, Wang (1959), Science and Civilization in China: Mathematics and the Sciences of the Heavens and the Earth, 3, Cambridge University Press, p. 478 ^ Noble, Joseph V.; Price, Derek J. DE Sulla (October 1968).
^ Thomas Ignatius M. Forster, Circle of the Seasons, p. 18 ^ William White, Notes and Queries ^ Hargrove Jennings, Phallic ism, p. 72 ^ William Shepard Walsh, A Handy Book of Curious Information ^ “History of London: Vanity and Wind ". Bishop, Robert; Koblenz, Patricia (1981), A Gallery of American Weather Vanes and Whirligigs, New York: Button, ISBN 9780525931515 Burn ell, Marcia (1991), Heritage Above: a tribute to Maine's tradition of weather vanes, Camden, ME: Down East Books, ISBN 9780892722785 Repeat, Pierre; Portland, Pauline (1990), Pointing at the Wind : the weather-vane collection of the Canadian Museum of Civilization, Hull, Quebec: Canadian Museum of Civilization, ISBN 9780660129044 Fitzgerald, Ken (1967).
Kaye, Myrna (1975), Yankee Weather vanes, New York: Button, ISBN 9780525238591 Lambkin, Charles (1973), Weather Vanes: The history, design and manufacture of an American folk art, New York: Hawthorn Books, CLC 756017 Lane Arts Council (Or.) (1994), Whirligigs & Weather vanes, Eugene, OR: Visual Arts Resources, CLC 33052846 Lynch, Kenneth; Crowell, Andrew Durfee (1971), Weather vanes, Architectural Handbook series, Canterbury, CN: Canterbury Publishing Company, CLC 1945107 Mes sent, Claude John Wilson (1937), The Weather Vanes of Norfolk & Norwich, Norwich: Fletcher & Son Limited, CLC 5318669 Miller, Steve (1984), The Art of the Weather vane, Eaton, PA: Stiffer Pub., ISBN 9780887400056 Mock ridge, Patricia; Mock ridge, Philip (1990), Weather Vanes of Great Britain, London: Hale, ISBN 9780709037224 Needham, Albert (1953), English Weather Vanes, their stories and legends from medieval to modern times, Hayward's Heath, Sussex: C. Clarke, CLC 1472757 Despite, Else Bu chert; Despite, Alexander (1970), Weathercocks and Weather creatures; some examples of early American folk art from the collection of the Melbourne Museum, Vermont, Newport, RI: Third & Elm Press, CLC 155708 Again, W. E. (1949).
Revelry, Mabel E.; Unheard, Priscilla (1984), Weather vane Secrets, Dublin, NH: W. L. Batman, ISBN 9780872330757 Westerly, A. That day at dinner when we were discussing the weather, my older kids suggested we make a weather vane (or a wind vane) for him.
My kids decided on a Darth Vader wind vane this year. We will find out below after we make a wind vane and test it outside.
This Darth Vader is part of a pack I bought a few years ago and used in a multitude of projects. Lucky for you, the set came with a full license so that I can share it with my readers.
I placed the template in our subscribers-only library of resources, so leave your email below, and I will send you a password. Cut out 2 or 3 triangles that are about half the size of Darth Vader and glue them all together.
If kids are interested in a measurement lesson, then they can use the ruler to make the calculations more precise. The weather vane works due to two factors: (1) an equal mass on each side, and (2) an unequal area.
Make sure it’s centered and there is an equal space below and above the drinking straw for easy rotation. Go outside on a windy day and ask the kids which direction they think the wind is blowing from.
Then stick your wind vane into the ground and observe carefully to confirm or refute their guess. Our wind vane is now in a flower pot that we can see out of our kitchen window.
We already know cardinal points in our neighborhood, so we didn’t take any special steps to figure it out. Print out our chart that marks not only cardinal points but also intercardinal points (i.e., northeast, northwest …) Put it on the ground in correspondence with compass readings.
To help kids remember the points of a compass, you can use a mnemonic device like N ever E at Sweet W heat. “Turn east at the corner.” “ We are walking north now.” “The bakery is south from here.” This will develop your kids’ spatial thinking.
According to a National Geographic article, I read recently, experts believe that even in the world of GPS, the ability to make sense in our world without special devices is very important. Spatial thinking plays an active role in a wide range of activities from understanding metaphors to making sense of molecules and geometry.
You might remember the concept of a path of the least resistance from your high school physics class. However, the area of the ornaments on the opposite sides of the vane must be unequal, forcing the point of the least resistance to face into the wind.
The word “vane” comes from the Old English word “flag” because original vanes were fabric banners attached to medieval towers to show the direction of the wind. As long as there were farmers and fleets, fishermen and armies, there was a need to know where the wind is coming from.
Ask the kids how knowing the direction of the wind could help farmers and sailors. Wind vanes make for the best lesson on weight, area, balance, and Medieval history.
In addition, they are a great introduction to physics and the kids actually will be begging you for more. We still haven’t made a cat and a mouse wind vane (bigger cat at the tail chasing the small mouse in the front).
$\begingroup$It seems that a weather vane will rotate in order to minimize energy and thus orient itself parallel to the wind. What I do not understand is why it is implied that the weather vane arrow should point in the direction of the wind.
I do not understand why the arrow pointing in the opposite direction of the wind is also not a minimum energy solution. In the example that you included, this is implemented by the flag at the back providing a broader cross-section than the arrow head and also by the rooster standing slightly to the back half of the arrow.
You are correct that if the vane became perfectly anti-aligned to the wind, it might stay there for a bit. If the wind shifts even a little, assuming the vane is well-designed, it should snap around to the proper direction for the reasons above.
Any area of the wind vane that is exactly on the fulcrum will result in no rotation. In designing your wind vane therefore, the part that you desire to be pointing away from the direction from which the wind is blowing should have the greatest product of (surface area) X (distance from the fulcrum).
In the image posted with your question, the rooster and the arrow head at their positions and sizes are merely decorative. A wind vane with only a tail of similar shape to that in your image, attached to the fulcrum would work just fine.
Users would need to understand that it is pointing in the direction in which the wind is going, not where it is coming from. It also follows that if the arrowhead were large enough in area and far enough from the fulcrum, then it would point away from the direction from which the wind is coming.
The wind does work on the weather vane, which then causes friction, converting the energy to heat. Suppose the weather vane starts out perpendicular to the wind and rotating.
Work is force times distance, and the distance a rotating object travels is proportional to the radius, so the wind will be doing net work on the vane if the side moving in the same direction as the wind has a larger mass×radius (i.e. moment of inertia) than the other side. This means it moves towards pointing to the side the wind is blowing.
BTW, systems don't always move to the configuration with the lowest energy. For instance, if you put a ball on the top of a hill perfectly balanced, it will stay there.
Note that the tail of the vane has a much larger square, compared to the triangle. Generally speaking, this means the center of pressure will be closer to the tail.
If the vane points its head to the left of the wind, the tail is kicked out to the right. This means the tail is now a square that isn't perfectly in line with the wind.
Thus, the airflow will push the tail a bit to the left, “trying” to straighten it out. Now, even if the wind returns to being perfectly from the south, the weather vane is no longer pointed directly north.
The instability will cause the vane to swing around so that there's no longer that metastable point from the south. The pointed end of the arrow offers the least resistance to wind.