SS-BN: Is Pluto a planet?

In order to determine whether or not Pluto is a planet, a number of issues must be raised and analysed. This essay will look at the set of criteria an object must satisfy in order to be classified as a planet. They are: The object must be in orbit around the sun, The object must be massive enough to be a sphere by its own gravitational force, and it must have cleared the neighbourhood around its orbit.

  It can be argued that Pluto satisfies the first rule of classifying an object as a planet, since it is in orbit around the sun. This can be seen from official photographs and texts on the solar system, which clearly show Pluto with its own circular orbit around the sun:

Figure 1.0:  http://img684.imageshack.us/i/solarsystem.gif/

It can be seen from Figure 1.0 that Pluto has its own unique orbit around the sun, fulfilling the first of this set of criteria. However, it may be argued that Pluto’s orbit is questionable, since it regularly interferes with the running order of the planets. For example, Pluto's orbit appears to intersect Neptune's, and for a period of about 20 years Pluto is slightly closer to the sun than Neptune [1] . Therefore, it can be argued that Pluto’s status as a planet is questionable, since it does not maintain a fixed orbit around the sun. On the other hand, it may be argued that while this orbit is eccentric, it still fulfills one of the set of criteria by being in orbit around the sun. Therefore, it can be argued that Pluto can be classified as a planet under the criteria set by the International Astronomical Union (IAU).

  In addition to its orbit, Pluto may be referred to as a planet, since it also fulfills the second rule by which an object is judged to be a planet – that it must be massive enough to be a sphere by its own gravitational force. It can be argued that it does possess gravitational qualities. It does possess a gravitational pull of 0.637, compared to 1 for Earth [2]. Although it may be argued that this is an almost negligible force, it is nonetheless a gravitational pull belonging to Pluto. However, it may be argued that its miniscule gravitational pull allows it to be influenced by other planets. Malhorta supports this when he points out that Pluto’s gravitational force tends to be provided by Neptune, when Neptune’s gravitational force pulls Pluto into its own orbit [3]. Although, this is a temporary phenomenon. On the other hand, it can be argued that Pluto still satisfies the second law of the IAU planet classification by possessing its own gravitational force. Therefore, it may be argued that by these standards, Pluto is indeed a planet.

  In addition to gravitational force, an object must also satisfy the third criterion in order to be classified as a planet. This is: it must clear the neighbourhood around its orbit. This means that it must become gravitationally dominant within its own orbit and be influenced by its surrounding objects. It can be argued that Pluto does indeed satisfy this criterion, when it is seen that Pluto has three moons: Charon, Nix, and Hydra [4], which are all influenced by Pluto’s gravitational force. This can be illustrated by the following:

Figure 2.0  http://www.nasa.gov/images/content/150871main_new_moons.jpg

It can be seen from Figure 2.0 that all three of Pluto’s moons are closely within orbit of their influential planet. However, it may be argued once again that Pluto does not strictly adhere to this criterion, since its orbit is occasionally intercepted by that of Neptune, which has a greater gravitational pull, and brings Pluto into its own orbit [5]. Again this is a temporary phenomenon. It can be argued that while Pluto is only influenced by Neptune’s orbit once every twenty years [6], Pluto is still unable to be gravitationally dominant, and this does not satisfy the criterion of clearing the neighbourhood around its orbit. Overall , it may be argued that Pluto is not a planet, since it does not satisfy this IAU criterion for classifying a planet.

  In conclusion, it may be argued that while Pluto satisfies two of the three criterion for planetary classification, it still fails to meet the standards of the third and final criterion. Pluto orbits the sun, meaning that it fits the classification of a planet. In addition, it is a sphere by its own gravitational force, possessing three moons in its orbit. Therefore, Pluto could be classified as a planet for this reason. However, Pluto fails to clear the neighbourhood of its orbit, by intercepting Neptune and coming under the influence of Neptune’s gravitational pull, meaning that it fails to be gravitationally dominant. For this reason, Pluto fails to meet the criteria necessary to be classified as a planet. Therefore, Pluto is not a classified planet.

Bibliography

Malhorta, Renu, Dynamics of Pluto, http://nineplanets.org/plutodyn.html, (accessed on 16^th February, 2011), 1997.

Perez, Daniel, http://library.thinkquest.org/, Pluto: The Far Planet, (accessed on 16^th February, 2011), 2005.

Schilling, Govert, Pluto’s Twins Get Their Name, http://news.sciencemag.org/, (accessed on 16^th February, 2011), 2006.

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[1] Renu Malhorta, Dynamics of Pluto, http://nineplanets.org/plutodyn.html, (accessed on 16^th February, 2011), 1997.

[2] Daniel Perez, http://library.thinkquest.org, Pluto: The Far Planet, (accessed on 16^th February, 2011), 2005.

[3] Malhorta, 1997.

[4] Govert Schilling, Pluto’s Twins Get Their Name, http://news.sciencemag.org, (accessed on 16^th February, 2011), 2006.

[5] Malhorta, 1997.

[6] Malhorta, 1997.

AA-E1: Plato and the Elements

The four classical elements of fire, air, earth and water were not only known Greece but ornamented models have been found all that date back to way before Plato or any other Greek philosopher. However, Plato seems to be the first one to refer to them with the word “elements” and he is the one that assigned his Platonic solids to each of them, even though the discovery of these solids is disputed and some authors credit Pythagoras for their discovery.

The Platonic solids were mainly used by Plato and are therefore named after him. The shapes he used were the tetrahedron, the hexahedron or simply cube, the octahedron, the dodecahedron and the icosahedron. These five are the only Platonic solids that exist, which has been explained by mathematical analysis of these solids. The basic principle of a Platonic solid is that all sides are the same shape, i.e. triangles, pentagons, squares, and that the interior angles of the vertexes where the shapes meet add up to less than 360 degrees. There are other shapes, i.e. the Kepler solids or Archimedean solids, however their sides are not uniform as in the Platonic solids.

So why did Plato assign which elements to a certain shape and how did he explain it?
Well the first thing that has to be said is that Plato did come up with another “element” to fit his fifth shape, since there were only four classical elements. He described this fifth element as the element "the god used for arranging the constellations on the whole heaven" (Timaeus 55). Other names from other writers for this element were for example quintessence or aether.

The other four elements were assigned as follows:
Water, the icosahedron: the smoothest and most spherical of all these shapes was to describe the flowing nature of water.
Fire, the tetrahedron:, the sharp edges of this shape were to represent the feeling of touching a fire.
Earth, the hexahedron or cube: this shape is the least smooth of all shapes and describes the brittle and crumbling nature of the dirt that is made of it.
Air, the octahedron: the shape of the octahedron allows movement into any direction without interference and therefore represented air.
And lastly the dodecahedron, the element of the universe as already described above.

There were also many other models of the classical elements in other cultures but in terms of our western world the Greek model did have the biggest influence.

In the 16th century the German astronomer Johannes Kepler tried to find a connection between the five Platonic solids and the other five known planets known at that time.
He then published a paper in which he presented a model in which the five solids were enclosed in one another only divided by a number of spheres which represented the six known planets of that time. The order of the solids was as follow, going from inside to outside: octahedron, icosahedron, dodecahedron, tetrahedron and cube.
This way the solids represented the distance between the different planets inside the solar system. However, Kepler eventually had to abandon this model which however resulted in the model that the orbits of the planets were ellipses, his two laws of orbitals and in the discovery of the Kepler solids.

Besides Keplers discoveries through the Platonic solids these solids have still persisted up until today as the only five solids that meet all the requirements for being such. Therefore, they have an essential value in mathematics. Eventually there have also been viruses which have been discovered which had the exact shape of a regular octahedron for example. Even though this has nothing to do with Plato it is still remarkable that was the one who came up with these essential shapes. Besides that the Platonic solids also have a vital role in modern engineering and architecture for being esthetic but also offering a high stability.
And of course the whole

of the classical elements eventually evolved into Alchemy which added Sulphur, Mercury and Salt to the classical elements and which then finally evolved into modern chemistry with the discovery of more and more elements.

Sources:

http://www.math.utah.edu/~alfeld/math/polyhedra/polyhedra.html

http://www.iep.utm.edu/plato/

http://en.wikipedia.org/wiki/Platonic_solid

http://en.wikipedia.org/wiki/Plato

http://en.wikipedia.org/wiki/Natural_philosophy

http://en.wikipedia.org/wiki/Classical_element#Classical_elements_in_Greece

http://classics.mit.edu/Plato/theatu.html

http://en.wikipedia.org/wiki/Kepler-Poinsot_polyhedron

http://en.wikipedia.org/wiki/Archimedean_solid

AA-I1: Alchemy in Harry Potter

Harry Potter, possibly one of the most praised and award winning series of children’s books, contains many detailed links and historically accurate information concerning alchemy.

Alchemy in Harry Potter is a magical science. The best known goals of the alchemists were the transmutation of common metals into Gold or Silver, the creation of a Panacea, a remedy that would cure all diseases and prolong life indefinitely and the discovery of a universal solvent. The Philosopher's Stone, a substance created by Nicolas Flamel that can turn ordinary metal into pure gold, and produce the immortality-granting Elixir of Life beat two of these goals. Alchemy is covered on Advanced Potion-Making and is part of the sixth-year Potions curriculum at Hogwarts School of Witchcraft and Wizardry.

A witch or wizard who studies alchemy is called an alchemist. According to the textbook Advanced Potion-Making, alchemists' greatest prestige came not from their trademark mystic and philosophical speculation, but from their more mundane contributions to various chemical industries, such as metalworking, glass manufacture and cosmetics[1].

Within the first book the evil Lord… You Know Who attempts to steal the infamous Philosophers stone or elixir of life from Harry who in turn had come upon it counter intuitively through the Mirror of Erised and thus make himself immortal. The power of the stone is respected by Dumbledore and Nicholas Flamel and consequently destroyed by the end of the book, ending its creator’s life.  Nicholas Flamel was in fact a successful French scribe who was falsely purported to have achieved the manufacture of both the Elixir of Life and the Philosophers Stone. This life granting substance may seem like a fanciful myth to children these days, however in mediaeval times the panacea was lucratively sought after by well respected, sometimes barmy alchemists.

The philosophers' stone, said to be capable of turning base metals, especially lead, into gold it was also sometimes believed to be an elixir of life, used for rejuvenation and possibly achieving immortality. For hundreds of years it was the most sought-after goal in Western alchemy, meditated upon by alchemists such as Sir Isaac Newton, Nicolas Flamel, and Frater Albertus. The Stone was the central symbol of the mystical terminology of alchemy, symbolizing perfection, enlightenment, and heavenly bliss. The discovery of the philosopher's stone was known as the Great Work.

In Harry Potter, Potions taught at Hogwarts School of Witchcraft and Wizardry. This is where students learn how to brew potions, following specific recipes and using various magical ingredients to create their potions, starting with simple ones first and moving to more advanced ones as they progress in knowledge. A standard potions kit includes plant ingredients such as Belladonna and supplies such as glass phials and weighing scales[2]. This seems to mirror the romanticized image of the basement alcamest brewing bubbling potions in beakers and other glassware.

Examples of these potions in Harry Potter are the Elixir to Induce Euphoria is a sunshine-yellow potion that induces a strong sense of happiness upon the drinker. The Draught of Living Death is an extremely powerful sleeping potion. It sends the drinker into a deep trance that mimics the state of death.

In the Classroom: professor-snape.tumblr.com

References

www.harrypotterforseekers.com/.../liberatingalchemy.php

en.wikipedia.org/wiki/Alchemy

harrypotter.wikia.com/wiki/Alchemy

http://harrypotter.wikia.com/wiki/Advanced Potion-Making

[1] http://harrypotter.wikia.com/wiki/Alchemy

[2] http://harrypotter.wikia.com/wiki/Advanced Potion-Making

AA-K2: The Question is Phlogiston

Phlogiston was believed to be the substance that was given off by a flammable object when it was burned. For example, when wood was burned, its mass would decrease so in 1669 a scientist called Johann Becher, believed this to be a colourless, odourless, weightless fire element that was lost during combustion. Only things that contained phlogiston would burn and would be dephlogisticated when all phlogiston had left the item and had become ash or residue which was known as true material or ‘calx’. If something was burned to nothing it was thought to be completely composed of phlogiston. Nowadays, phlogiston is known to be the process called oxidation in chemistry.

The idea of Phlogiston was created at this time as a form of trying to determine what caused rusting in metals. This was invented in England just after the time of Oliver Cromwell’s leadership of the country. He had enforced strong laws and work which was of a very high priority at this time. Metal work was essential for the country, thus creating a greater need to find out why over time metals rust so that a theory could be resolved to prevent rusting.

Phlogiston is that theory, it was used to explain many experiments which at the time weren’t understood or could be proven by scientists. The theory at the time was very simple and was used by scientists who tested different types of materials; once the materials had been burnt the dephlogisticated remains would be left. In 1772 the Phlogiston theory was used to prove Nitrogen.

The phlogiston theory was connected with ideas to do with alchemy where it was thought the four elements earth, air, fire and water were all contained within a substance which is shown in the diagram below. Substances which burned in the air were said to be rich in phlogiston, with the fact that combustion after a while stopped in an enclosed space this was taken as evidence that air couldn’t absorb more phlogiston.

The surrounding air that was saturated in phlogiston was said to be ‘phlogisticated air’. When oxygen was discovered it was thought to be "dephlogisticated air" which was able to take in more phlogiston and supported the theory of combustion.

The theory was believed for 100 years where problems in the theory were patched up by philologists who strongly believed in the theory. It wasn’t until 1753 that it was disproved by the discovery of oxygen as a separate element. Also a Russian chemist called Mikhail Lomonsov discovered that if magnesium was weighed,placed in a sealed bottle, and burned then the overall mass would not be reduced and weighed the same. Since phlogiston was supposed to pass through glass and so forth he concluded that the theory was wrong. 
 
Oxygen was discovered in the early 1770s by two different people One was Carl Scheele in Sweden and the other Joseph Priestley in England. A few experiments were completed showed that oxygen supported the combustion a lot better than air even though oxygen is present in air. Lavoisier decided that this was the basis and main reason of combustion, thus disproving phlogiston.

Lavoisier's had done similar experiments to Lomonsov which involved weighing of metal before and after combustion in an enclosed bottle and finding the weight stayed the same. But he took it further and opened the bottle, noting some gas went in. After reweighing it, he found the extra weight of the gas was the same as the increase in the weight of the metal plus the burnt metal. He therefore concluded that the metal had absorbed something from the air in the bottle that turned out to be oxygen therefore going against the idea of the phlogiston theory which was later dismissed as just a hypothesis in the 18^th century and better theories were made.

Bibliography

http://www.bbc.co.uk/dna/h2g2/A471278

http://www.britannica.com/EBchecked/topic/456974/phlogiston

http://en.wikipedia.org/wiki/Phlogiston_theory

http://www.answerbag.com/q_view/1817155