APOD: Total Solar Eclipse Below the Bottom... (2021 Dec 05)

[APOD Robot]

Total Solar Eclipse Below the Bottom of the World

Explanation: Yesterday there was a total solar eclipse visible only at the end of the Earth. To capture the unusual phenomenon, airplanes took flight below the clouded seascape of Southern Ocean. The featured image shows one relatively spectacular capture where the bright spot is the outer corona of the Sun and the eclipsing Moon is seen as the dark spot in the center. A wing and engine of the airplane are visible across the left and bottom of the image, while another airplane observing the eclipse is visible on the far left. The dark area of the sky surrounding the eclipsed Sun is called a shadow cone. It is dark because you are looking down a long corridor of air shadowed by the Moon. A careful inspection of the eclipsed Sun will reveal the planet Mercury just to the right. The next total solar eclipse shadow will cross parts of Australia and Indonesia in April of 2023, while the one after that will cross North America in April of 2024.

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[Dave.denize@gmail.com]

Eah. Bottom of the world? Who orreintates this planet. It floats happily in the galaxy which is neither up or down. Anyway, it's cloudy at the moment, so won't be able to see this wonderful event. Life goes on in Aotearoa.

[Sa Ji Tario]

On a world map, where is the north and where is the south? North is up and south is down and what is down is the bottom (eg a hole)

[heehaw]

"...from the bottom of the world." That of course is Northern Hemisphere Chauvinism: https://en.wikipedia.org/wiki/South-up_map_orientation

[orin stepanek]

Very nice photo!

Kitty busy; Do Not Disturb!

[Chris Peterson]

Eah. Bottom of the world? Who orreintates this planet. It floats happily in the galaxy which is neither up or down. Anyway, it's cloudy at the moment, so won't be able to see this wonderful event. Life goes on in Aotearoa.

It has a natural orientation defined by physics: its spin axis. And it's completely rational (and necessary) to define a "top" (north) and "bottom" (south) convention, based on the direction of spin. So yes... Antarctica is very reasonably described as the "bottom of the world".

[More carbon!]

The photos are beautiful, but come on, tell me again how you worry about climate change. Not one, but two 5.5-hour flights by large airliners (plus a dozen cruise vessels, according to Space.com). Is there any scientific mystery left in eclipses that justifies this extravagance? Assuming there is, supposing that this one was anything special, and granting that stamp collecting is a honorable pursuit, are there no good photographers in the Antarctic bases who could supply equally nice pictures? And let me guess, did the organizers demonstrate their concern for the environment by making the in-flight meals plastic-free?

[Chris Peterson]

The photos are beautiful, but come on, tell me again how you worry about climate change. Not one, but two 5.5-hour flights by large airliners (plus a dozen cruise vessels, according to Space.com). Is there any scientific mystery left in eclipses that justifies this extravagance? Assuming there is, supposing that this one was anything special, and granting that stamp collecting is a honorable pursuit, are there no good photographers in the Antarctic bases who could supply equally nice pictures? And let me guess, did the organizers demonstrate their concern for the environment by making the in-flight meals plastic-free?

Reducing one's personal carbon footprint is about finding the most efficient way to do things, not about ceasing to do those things.

[neufer]

Eah. Bottom of the world? Who orreintates this planet. It floats happily in the galaxy which is neither up or down. Anyway, it's cloudy at the moment, so won't be able to see this wonderful event. Life goes on in Aotearoa.

It has a natural orientation defined by physics: its spin axis. And it's completely rational (and necessary) to define a "top" (north) and "bottom" (south) convention, based on the direction of spin. So yes... Antarctica is very reasonably described as the "bottom of the world".

PHYSICS ...You mean Ampère's right-hand grip rule based upon electric currents
which get the moving charged particles in wires and other conductors going the wrong way

Finding direction of magnetic field (B) for an electrical coil

---

Finding direction of magnetic field (B) for an electrical coil

---

<<Ampère's right-hand grip rule (also called right-hand screw rule, coffee-mug rule or the corkscrew-rule) is used either when a vector (such as the Euler vector) must be defined to represent the rotation of a body, a magnetic field, or a fluid, or vice versa, when it is necessary to define a rotation vector to understand how rotation occurs. André-Marie Ampère was inspired by Hans Christian Ørsted, another physicist who experimented with magnet needles. Ørsted observed that the needles swirled when in the proximity of an electric current-carrying wire, and concluded that electricity could create magnetic fields.

Ampère's right-hand grip rule is used in two different applications of Ampère's circuital law:

1) An electric current passes through a straight wire. When the thumb is pointed in the direction of conventional current (from positive to negative), the curled fingers will then point in the direction of the magnetic flux lines around the conductor. The direction of the magnetic field (counterclockwise instead of clockwise when viewing the tip of the thumb) is a result of this convention and not an underlying physical phenomenon.

2) An electric current passes through a solenoid, resulting in a magnetic field. When wrapping the right hand around the solenoid with the fingers in the direction of the conventional current, the thumb points in the direction of the magnetic north pole.>>

[Chris Peterson]

Eah. Bottom of the world? Who orreintates this planet. It floats happily in the galaxy which is neither up or down. Anyway, it's cloudy at the moment, so won't be able to see this wonderful event. Life goes on in Aotearoa.

It has a natural orientation defined by physics: its spin axis. And it's completely rational (and necessary) to define a "top" (north) and "bottom" (south) convention, based on the direction of spin. So yes... Antarctica is very reasonably described as the "bottom of the world".

PHYSICS :?: ...You mean Ampère's right-hand grip rule based upon electric currents
which get the moving charged particles in wires and other conductors going the wrong way :?:

Finding direction of magnetic field (B) for an electrical coil

---

Finding direction of magnetic field (B) for an electrical coil

---

<<Ampère's right-hand grip rule (also called right-hand screw rule, coffee-mug rule or the corkscrew-rule) is used either when a vector (such as the Euler vector) must be defined to represent the rotation of a body, a magnetic field, or a fluid, or vice versa, when it is necessary to define a rotation vector to understand how rotation occurs. André-Marie Ampère was inspired by Hans Christian Ørsted, another physicist who experimented with magnet needles. Ørsted observed that the needles swirled when in the proximity of an electric current-carrying wire, and concluded that electricity could create magnetic fields.

Ampère's right-hand grip rule is used in two different applications of Ampère's circuital law:

1) An electric current passes through a straight wire. When the thumb is pointed in the direction of conventional current (from positive to negative), the curled fingers will then point in the direction of the magnetic flux lines around the conductor. The direction of the magnetic field (counterclockwise instead of clockwise when viewing the tip of the thumb) is a result of this convention and not an underlying physical phenomenon.

2) An electric current passes through a solenoid, resulting in a magnetic field. When wrapping the right hand around the solenoid with the fingers in the direction of the conventional current, the thumb points in the direction of the magnetic north pole.>>

Of course, depending on whether you learn about this in an electronics class or a physics class determines whether you view the relationship between "current flow" and "particle movement" as being the right or the wrong way!

[alter-ego]

It has a natural orientation defined by physics: its spin axis. And it's completely rational (and necessary) to define a "top" (north) and "bottom" (south) convention, based on the direction of spin. So yes... Antarctica is very reasonably described as the "bottom of the world".

PHYSICS ...You mean Ampère's right-hand grip rule based upon electric currents
which get the moving charged particles in wires and other conductors going the wrong way

Finding direction of magnetic field (B) for an electrical coil

---

Finding direction of magnetic field (B) for an electrical coil

---

<<Ampère's right-hand grip rule (also called right-hand screw rule, coffee-mug rule or the corkscrew-rule) is used either when a vector (such as the Euler vector) must be defined to represent the rotation of a body, a magnetic field, or a fluid, or vice versa, when it is necessary to define a rotation vector to understand how rotation occurs. André-Marie Ampère was inspired by Hans Christian Ørsted, another physicist who experimented with magnet needles. Ørsted observed that the needles swirled when in the proximity of an electric current-carrying wire, and concluded that electricity could create magnetic fields.

Ampère's right-hand grip rule is used in two different applications of Ampère's circuital law:

1) An electric current passes through a straight wire. When the thumb is pointed in the direction of conventional current (from positive to negative), the curled fingers will then point in the direction of the magnetic flux lines around the conductor. The direction of the magnetic field (counterclockwise instead of clockwise when viewing the tip of the thumb) is a result of this convention and not an underlying physical phenomenon.

2) An electric current passes through a solenoid, resulting in a magnetic field. When wrapping the right hand around the solenoid with the fingers in the direction of the conventional current, the thumb points in the direction of the magnetic north pole.>>

Of course, depending on whether you learn about this in an electronics class or a physics class determines whether you view the relationship between "current flow" and "particle movement" as being the right or the wrong way!

I'm not sure why electromagnetics was brought into this. A more direct basis for the right-hand rule is within rotational kinematics that defines the angular momentum vector.

[neufer]

Of course, depending on whether you learn about this in an electronics class or a physics class determines whether you view the relationship between "current flow" and "particle movement" as being the right or the wrong way!

I'm not sure why electromagnetics was brought into this. A more direct basis for the right-hand rule is within rotational kinematics that defines the angular momentum vector.

It's all agreed upon convention...NOT BASIC PHYSICS...
(like the definition of the magnetic B/H field direction.)

The most common double helical structure found in nature (i.e., B-DNA) is right-handed and all antineutrinos are right-handed. However, globes have Antarctica at the bottom because few people live there (or anywhere near there) and:

• 1) For most people & major civilizations: the North Star is "up"
  2) and most people are both right-handed & right-footed

<<In human biology, handedness is an individual's preferential use of one hand, known as the dominant hand, due to it being stronger, faster or better in dexterity. The other hand, comparatively often the weaker, less dextrous or simply less subjectively preferred, is called the non-dominant hand. Right-handedness is by far more common; about 90% of the human population are right hand dominant.

Left-handed people are more likely to have several specific physical and mental disorders and health problems. As handedness is a highly heritable trait associated with various medical conditions, and because many of these conditions could have presented a Darwinian fitness challenge in ancestral populations, this indicates left-handedness may have previously been rarer than it currently is, due to natural selection.>>

[neufer]

The photos are beautiful, but come on, tell me again how you worry about climate change. Not one, but two 5.5-hour flights by large airliners (plus a dozen cruise vessels, according to Space.com). Is there any scientific mystery left in eclipses that justifies this extravagance? Assuming there is, supposing that this one was anything special, and granting that stamp collecting is a honorable pursuit, are there no good photographers in the Antarctic bases who could supply equally nice pictures? And let me guess, did the organizers demonstrate their concern for the environment by making the in-flight meals plastic-free?

Reducing one's personal carbon footprint is about finding the most efficient way to do things, not about ceasing to do those things.

Eclipse chasers are primarily private citizens going after personal private experiences.

Scientific "routine" research is almost always cost effective.

<<The discovery of the Antarctic "ozone hole" by British Antarctic Survey scientists Farman, Gardiner and Shanklin (first reported in a paper in Nature in May 1985) came as a shock to the scientific community, because the observed decline in polar ozone was far larger than anyone had anticipated. Satellite measurements (TOMS onboard Nimbus 7) showing massive depletion of ozone around the south pole were becoming available at the same time. However, these were initially rejected as unreasonable by data quality control algorithms (they were filtered out as errors since the values were unexpectedly low); the ozone hole was detected only in satellite data when the raw data was reprocessed following evidence of ozone depletion in in situ observations. When the software was rerun without the flags, the ozone hole was seen as far back as 1976.>>

<<Charles David Keeling (April 20, 1928 – June 20, 2005) was an American scientist whose recording of carbon dioxide at the Mauna Loa Observatory confirmed Svante Arrhenius's proposition (1896) of the possibility of anthropogenic contribution to the "greenhouse effect" and global warming, by documenting the steadily rising carbon dioxide levels.

Atmospheric CO2 concentrations measured at Mauna Loa Observatory: The Keeling Curve.

---

Keeling worked at the Scripps Institution for 43 years during which time he published many influential papers. Roger Revelle, the Director of Scripps Institution of Oceanography, based at La Jolla, California, persuaded Keeling to continue his work there. Revelle was also one of the founders of the International Geophysical Year (IGY) in 1957–58 and Keeling received IGY funding to establish a base on Mauna Loa in Hawaii.

Keeling started collecting carbon dioxide samples at the base in 1958. By 1960, he had established that there are strong seasonal variations in carbon dioxide levels with peak levels reached in the late northern hemisphere winter. A reduction in carbon dioxide followed during spring and early summer each year as plant growth increased in the land-rich northern hemisphere. In 1961, Keeling produced data showing that carbon dioxide levels were rising steadily in what later became known as the "Keeling Curve".

In the early 1960.s, the National Science Foundation stopped supporting his research, calling the outcome "routine"Despite this lack of interest, the Foundation used Keeling's research in its warning in 1963 of rapidly increasing amounts of heat-trapping gases. A 1965 report from President Johnson's Science Advisory Committee similarly warned of the dangers of extra heat-trapping gases, which cause the temperature of the Earth to rise.

The data collection started by Keeling and continued at Mauna Loa is the longest continuous record of atmospheric carbon dioxide in the world and is considered a reliable indicator of the global trend in the mid-level troposphere. Keeling's research showed that the atmospheric concentration of carbon dioxide grew from 315 parts per million (ppm) in 1958 to 380 (ppm) in 2005, with increases correlated to fossil fuel emissions. There has also been an increase in seasonal variation in samples from the late 20th century and early 21st century.>>

[alter-ego]

Of course, depending on whether you learn about this in an electronics class or a physics class determines whether you view the relationship between "current flow" and "particle movement" as being the right or the wrong way!

I'm not sure why electromagnetics was brought into this. A more direct basis for the right-hand rule is within rotational kinematics that defines the angular momentum vector.

It's all agreed upon convention...NOT BASIC PHYSICS...
(like the definition of the magnetic B/H field direction.)

The most common double helical structure found in nature (i.e., B-DNA) is right-handed and all antineutrinos are right-handed. However, globes have Antarctica at the bottom because few people live there (or anywhere near there) and:

• 1) For most people & major civilizations: the North Star is "up"
  2) and most people are both right-handed & right-footed

<<In human biology, handedness is an individual's preferential use of one hand, known as the dominant hand, due to it being stronger, faster or better in dexterity. The other hand, comparatively often the weaker, less dextrous or simply less subjectively preferred, is called the non-dominant hand. Right-handedness is by far more common; about 90% of the human population are right hand dominant.

Left-handed people are more likely to have several specific physical and mental disorders and health problems. As handedness is a highly heritable trait associated with various medical conditions, and because many of these conditions could have presented a Darwinian fitness challenge in ancestral populations, this indicates left-handedness may have previously been rarer than it currently is, due to natural selection.>>

---

---

A legacy origin predating any consideration of physics is the only answer. I fell prey to the convenient coincidence, and an apparent setup

...
It is only within the last few hundred years that north has been consistently at the top
...
Given that each culture has a very different idea of who, or what, they should look up to it’s perhaps not surprising that there is very little consistency in which way early maps pointed. In ancient Egyptian times the top of the world was east, the position of sunrise. Early Islamic maps favoured south at the top because most of the early Muslim cultures were north of Mecca, so they imagined looking up (south) towards it. Christian maps from the same era (called Mappa Mundi) put east at the top, towards the Garden of Eden and with Jerusalem in the centre.

So when did everyone get together and decide that north was the top? It’s tempting to put it down to European explorers like Christopher Columbus and Ferdinand Megellan, who were navigating by the North Star. But Brotton argues that these early explorers didn’t think of the world like that at all. “When Columbus describes the world it is in accordance with east being at the top,” he says. “Columbus says he is going towards paradise, so his mentality is from a medieval mappa mundi.” We’ve got to remember, adds Brotton, that at the time, “no one knows what they are doing and where they are going”.
Mercator’s world map, from 1569, was almost certainly a defining moment in north-up map-making. His map was famously the first to take into account the curvature of the Earth, so that sailors could cross long distances without overshooting the mark.
...
So, the answer to the question of which way up is the Earth is simple: it is not any particular way up and there is no good reason other than a historical superiority complex to think of north as being the top of the world.
...

Specifically, within the discipline of astronomy, it's possible that a world-wide committee of astronomers could agree to define an official "up" direction that could align right-hand rule to the coincidental north-up view. (Similarly, Pluto was "demoted" to a dwarf planet by a collective agreement). However, the only reason to define an 'up' direction is to officially formalize a standard, but I don't think this would ever make it to that level of importance.

[Ann]

Math idiot observes:

I like the shadow cone of the eclipse.

Ann

[neufer]

I like the shadow cone of the eclipse.

The intersection of the umbra shadow cone with our atmosphere is an eclipse ellipse.

[Chris Peterson]

I like the shadow cone of the eclipse.

The intersection of the umbra shadow cone with our atmosphere is an eclipse ellipse.

You missed a very Neuferish opportunity by failing to end that comment with "..."

[neufer]

I like the shadow cone of the eclipse.

The intersection of the umbra shadow cone with our atmosphere is an eclipse ellipse.

You missed a very Neuferish opportunity by failing to end that comment with "..."

• I must be getting a bit dotty.

<<ellipse (n.) 1753, from French ellipse (17c.), from Latin ellipsis "ellipse," also, "a falling short, deficit," from Greek elleipsis (see ellipsis). So called because the conic section of the cutting plane makes a smaller angle with the base than does the side of the cone, hence, a "falling short." The Greek word was first applied by Apollonius of Perga (3c. B.C.E.). to the curve which previously had been called the section of the acute-angled cone, but the word earlier had been technically applied to a rectangle one of whose sides coincides with a part of a given line (Euclid, VI. 27).>>

<<The ellipsis ..., . . ., or (as a single glyph) …, also known informally as dot-dot-dot, is a series of (usually three) dots that indicates an intentional omission of a word, sentence, or whole section from a text without altering its original meaning. The word (plural ellipses) originates from the Ancient Greek: ἔλλειψις, élleipsis meaning 'leave out'. Occasionally, it would be used in pulp fiction and other works of early 20th-century fiction to denote expletives that would otherwise have been censored. An ellipsis may also imply an unstated alternative indicated by context. For example, when Sue says "I never drink wine . . . ", the implication is that she does drink something else—such as vodka.

In her book _Ellipsis in English Literature: Signs of Omission_ (Cambridge University Press, 2015), Anne Toner suggests that the first use of the punctuation in the English language dates to a 1588 translation of Terence's Andria, by Maurice Kyffin. In this case, however, the ellipsis consists not of dots but of short dashes. "Subpuncting" of medieval manuscripts also denotes omitted meaning and may be related.>>

<<Andria (English: The Woman from Andros) is a Roman comedy adapted by Terence from two Greek plays by Menander the first being Samia and the other being Perinthia. It was the first play by Terence to be presented publicly, and was performed in 166 BC during the Ludi Megalenses. It became the first of Terence's plays to be performed post-antiquity, in Florence in 1476. It was adapted by Machiavelli, whose Andria was likewise the author's first venture into playwriting, and was the first of Terence's plays to be translated into English ca. 1520. The second English translation was by the Welsh writer Morris Kyffin in 1588. Thornton Wilder, an American writer, wrote The Woman of Andros, a novel based on Terence's Andria, which presents a fable about the emptiness of the classical world on the brink of profound changes provoked by the birth of Jesus.>>

[Fred the Cat]

Aren’t we all “ above” in the sense of the Milky Way? In that, we can all claim to be above the bottom of our larger home.

In our closer surroundings, the shadow of the moon is still awe-mazing!

[neufer]

Aren’t we all “ above” in the sense of the Milky Way?
In that, we can all claim to be above the bottom of our larger home.

Only by relying upon the right-handed convention again

https://en.wikipedia.org/wiki/Galactic_ ... ate_system

<<The galactic coordinate system is a celestial coordinate system in spherical coordinates, with the Sun as its center, the primary direction aligned with the approximate center of the Milky Way Galaxy, and the fundamental plane parallel to an approximation of the galactic plane but offset to its north. It uses the right-handed convention, meaning that coordinates are positive toward the north and toward the east in the fundamental plane.>>

Click to play embedded YouTube video.

Click to play embedded YouTube video.

<<The Leftorium was a store in the Springfield Mall that specialized in products for left-handed people. The store was owned by Ned Flanders, who first started the Leftorium in the episode "When Flanders Failed". At first, business at the store was going very poorly. Irritated with Flanders, Homer wished that the store would go out of business after Homer received the larger half of a wishbone. Homer got his wish and the Flanders family were forced to sell many of their possessions, much of which Homer purchased at a meager price of $75. The bank repossessed the Flanders' home and the Leftorium was to be the next asset repossessed. Homer then regretted making this wish and the fact that he never told any of his friends who were in need of left-handed items about the Leftorium. As a result, he managed to get everyone he knew in town to shop at Ned's store, saving it from closure.


The Leftorium continued to thrive over the following years. However, Flanders mentioned in several episodes that the store does not do that well, such as in the season 10 episode "Thirty Minutes over Tokyo", where Ned mentions that he purchased most of his possessions cheaply, and that the business moved way downhill since "Leftopolis" moved in next door to it. In the episode "Home Away from Homer", Ned mentions that a recently opened, left-hand megastore, called "Left-Mart" is threatening his business. The season 25 episode "White Christmas Blues" reveals that competition from the Southpaw Superstore forced Flanders to downsize the business to a mall cart, the "Leftorium Express", which he splits with a cosmetic saleswoman. In the season 29 episode "Left Behind", the Leftorium closes for good, leaving Flanders unemployed until he finds a new job as Bart Simpson's new teacher.>>