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Jupiter60
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Why is there no West Pole and East Pole? There's a North Pole and a South Pole, but no West Pole and no East Pole.
Jupiter60 said:Why is there no West Pole and East Pole? There's a North Pole and a South Pole, but no West Pole and no East Pole.
Yes Uranus, if I'm not mistaken is tilted 98 degree. That they rotates from west to east.BWV said:There is on Uranus (groan)
Long before anyone thought that the Earth rotated, early man noticed that the North Star remained fixed, while all others rotated around it. That direction would naturally be special. When the compass was discovered, it also pointed toward the north. Defining an East/West pole would contradict all of that.Jupiter60 said:Why is there no West Pole and East Pole? There's a North Pole and a South Pole, but no West Pole and no East Pole.
But the compass does not "point" to the North Star, right. It points to magnetic compass which happens to be in the north. There is no south star. We use constellation "cross"FactChecker said:Long before anyone thought that the Earth rotated, early man noticed that the North Star remained fixed, while all others rotated around it. That direction would naturally be special. When the compass was discovered, it also pointed toward the north. Defining an East/West pole would contradict all of that.
South, "sud", Sol, means Sun.phinds said:It (the word "North") is not arbitrary, and I do not believe that it is derived from the "North Star" but rather the North Star is derived from the same older word/concept. I think I recall it came out of something having to do with the direction that the sun rises.
EDIT: I Googled it to double check and yeah, it came from some old phrase meaning more or less "to the left of the rising sun". I have no recollection of where the word "South came from". You can look that one up yourself
And the sun as well. My point was that the word North evolved out of interest in the sun.FactChecker said:I think the point is not so much what word is used for the North Pole, but why did people think there was something worth naming in the North/South but not in the East/West. The derivation of the term "North Pole" is probably a question for an English language forum. Before people thought the Earth rotated, they could see that the North Star was stationary and all other stars revolved around it. They had a lot of beliefs related to stars and their motion. It would be surprising if they did not have a word for the North Pole.
Libration changes the position of Earth a bit over time. For the same reason, we can observe nearly 60% of the surface of Moon from Earth.BobPixel said:It also has an East and a West Pole, where you could stand and watch precisely 50% of the Earth, continually rolling towards you or away from you.
In standard usage, "pole" means a point on the surface corresponding to the axis of rotation. There are only two such points on a rotating sphere, so I disagree w/ what you have said.NGNeer said:They do exist! Mathematically, any point on the surface of a sphere can be defined as the pole.
BobPixel said:On a body that is tidally locked to what it orbits, there would be a total of 6 Poles!
Consider the Earth's Moon. It has a North and South Pole. It also has an East and a West Pole, where you could stand and watch precisely 50% of the Earth, continually rolling towards you or away from you. In addition, there's a Pole with the Earth directly overhead, and another directly opposite. I've no idea what those poles would be called, however.
No matter where you would put east and west poles on Earth, for some places the sun would rise over the west pole and set over the east pole, which makes the concept pointless.NGNeer said:eople seem to like having the sun rise in the "east" and set in the "west", do not ask me why.
The magnetic North pole is close to the South pole and vice versa. The magnetic north of a magnet needle points north - towards the North pole = magnetic South pole.ebos said:There is no similarity except that the Earth's North magnetic pole just coincidentally happened to be near the Earth's north pole.
mfb said:The magnetic North pole is close to the South pole and vice versa. The magnetic north of a magnet needle points north - towards the North pole = magnetic South pole.
Nik_2213 said:In addition to the major N/S magnetic pole, aren't there additional 'minor' poles which point other ways ? AKA multipole with a dominant axis ?
IIRC, there's an uppity minor pole beneath South Atlantic, producing the deepening, drifting 'South Atlantic Anomaly'.
IIRC, a magnetic pole reversal doesn't do a 'head stand', it goes through a complex 'multipole' phase, where the winner takes all...
I stand corrected. Allow me to clarify the difference. You can rotate the sphere about any line passing through its center. This includes any line connecting any two diametrically opposed (antipodal) points. Once you do, that line becomes the axis of rotation. Given two standard usage poles that are on the axis of rotation, the rest of my statements hold true -- there is an infinite number of great circles connecting the standard usage poles, "Greenwich" narrows the list down to one, the resulting hemispheres are called "eastern" and "western" and they each have a central point. The only statement that is no longer true is that these central points qualify for the definition of a standard usage pole. In this light, the original question was really asking why the Earth cannot spin about two axes simultaneously, and the answer to that is that the Earth is a rigid body in 3D space, and Euler's rotation theorem says there can only be one rotation axis.phinds said:In standard usage, "pole" means a point on the surface corresponding to the axis of rotation. There are only two such points on a rotating sphere, so I disagree w/ what you have said.
NGNeer said:I stand corrected. Allow me to clarify the difference. You can rotate the sphere about any line passing through its center. This includes any line connecting any two diametrically opposed (antipodal) points. Once you do, that line becomes the axis of rotation. Given two standard usage poles that are on the axis of rotation, the rest of my statements hold true -- there is an infinite number of great circles connecting the standard usage poles, "Greenwich" narrows the list down to one, the resulting hemispheres are called "eastern" and "western" and they each have a central point. The only statement that is no longer true is that these central points qualify for the definition of a standard usage pole. In this light, the original question was really asking why the Earth cannot spin about two axes simultaneously, and the answer to that is that the Earth is a rigid body in 3D space, and Euler's rotation theorem says there can only be one rotation axis.
There is no West Pole and East Pole because the Earth's axis of rotation is tilted, causing the North and South Poles to be the only fixed points on the planet. The Earth rotates around this axis, creating the illusion of a West and East Pole, but they do not actually exist.
The Earth's tilt, also known as its axial tilt or obliquity, is the reason why there is no West and East Pole. This tilt causes the Earth's axis to be inclined at an angle of approximately 23.5 degrees from its orbital plane. As a result, the North and South Poles are the only two points on the Earth's surface that are always in the same position relative to the stars.
Yes, the absence of a West and East Pole has significant scientific implications. The Earth's tilt is responsible for the changing seasons, as well as the distribution of sunlight and heat around the globe. It also affects the Earth's climate and weather patterns, making it a crucial factor in understanding our planet's ecosystem.
Yes, there are other planets with a similar tilt and lack of West and East Poles. Uranus, for example, has an axial tilt of 98 degrees, causing its poles to be located near its equator. This results in extreme seasonal changes on the planet. Saturn also has a significant tilt of 27 degrees, but its poles are not fixed points due to its fast rotational speed.
No, there will never be a West and East Pole on Earth. The Earth's tilt is a fundamental aspect of its rotation and is not expected to change significantly in the future. While the Earth's axis does experience slight fluctuations, it will always remain tilted, making the North and South Poles the only two fixed points on our planet.