Quantum electrodynamics, commonly referred to as QED, is a quantum field theory of the electromagnetic force. Taking the example of the force between two electrons, the classical theory of electromagnetism would describe it as arising from the electric field produced by each electron at the position of the other. The force can be calculated from Coulomb's law.
The quantum field theory approach visualizes the force between the electrons as an exchange force arising from the exchange of virtual photons. It is represented by a series of Feynman diagrams.
With time proceeding upward in the diagram, this diagram describes the electron interaction in which two electrons enter, exchange a photon, and then emerge. Using a mathematical approach known as the Feynman calculus, the strength of the force can be calculated in a series of steps which assign contributions to each of the types of Feynman diagrams associated with the force.
QED applies to all electromagnetic phenomena associated with charged fundamental particles such as electrons and positrons, and the associated phenomena such as pair production, electron-positron annihilation, Compton scattering, etc. It was used to precisely model some quantum phenomena which had no classical analogs, such as the Lamb shift and the anomalous magnetic moment of the electron. QED was the first successful quantum field theory, incorporating such ideas as particle creation and annihilation into a self-consistent framework. The development of the theory was the basis of the 1965 Nobel Prize in physics, awarded to Richard Feynman, Julian Schwinger and Sin-itero Tomonaga.
Isn't it interesting? Do comment...
Tuesday, September 18, 2007
Thursday, September 13, 2007
Is Pluto A Planet Or Not?
Pluto was first refered to as Planet X by the astronomer Percival Lowell. He reasoned it existedbecause something was causing slight variations in the orbits of the planets Neptune and Uranus. He belived only another body large enough to exert a strong enough gravitational field could affectNeptune and Uranus' orbits.Unfortunatly Percival Lowell died in 1916 without having proven the exisitence of Planet X. In 1930,astronomer Clyde Tombaugh discovered "Planet X" 3.7 billion miles from our sun. He did this byusing an astronomical telescope to expose a series of photographic plates. The Plates clearly showeda small object had moved against the background of distant stars.This discovery turned out to be the result of a happy accident. The calculations that predictedthe existence of a planet beyond the orbit of Neptune later proved to be in error. The Voyager2 spacecraft was able to measure the mass of the planet Neptune more accuratly. When this new datais used the variations in the orbits of Uranus and Neptune dissappear.None the less the new planet was dubbed Pluto. Several names were suggested including Zeus,Cronus and Minerva. But in 1930 Pluto was officially labeled the ninth planet by theInternational Astronomical Union and named for the Roman god of the underworld.The axis of Pluto's poles do not point "up" and "down" out of the plane of the solar systemlike planet Earth's. Instead the point more inward toward the Sun. Pluto is usually fartherfrom the Sun than any of the other planets. But due to it's eccentric orbit, it is closer to theSun than Neptune for 20 years out of its 249 year orbit. Pluto crossed inside Neptune's orbiton January 21, 1979 and made its closest approach to the Sun on September 5, 1989. It remainedwithin the orbit of Neptune until February 11, 1999. This will not happen again until September 2226.Pluto's odd orbit has lead some to say it is a "trans-Neptunian interloper". Which means it ismore like a Kuiper belt comet than a planet.The composition of Pluto is unknown, but its density (about 2 gm/cm3) probably indicates it is a mixture of and 30% water ice and 70% rock. The bright areas of the surface appear to be covered with ices of nitrogen and smaller amounts of methane, ethane and carbon monoxide. The composition of the darker areas on Pluto's surface is not known.Pluto does have an atmosphere which probably consists mostly of nitrogen with some carbon monoxide and methane. It is extremely thin with a surface pressure of only a few microbars. Pluto's atmosphere probably exist as a gas only when Pluto is near the Sun. For the rest of Pluto's long orbit the atmospheric gases are frozen solid. Near theSun it is possible that some of the atmospheric gases escape into space. NASA mission planners hope to arrive at Pluto while the atmosphere is still in gas form. In 1978 it was discovered that pluto has a moon. Officially named Charon after the mythologicalfigure who ferried the dead across the River Acheron into the underworld. Charon was discoveredby Jim Christy and may have been named in honor of his wife Charlene. Before the discovery ofCharon it was believed Pluto was much larger since the images of the two were blurred together.Pluto and Charon are unique in that they rotate synchronously with each other. Which means theyboth keep the same face toward one another. It has been suggested that Charon was formed by agiant impact against Pluto similar to the one that formed Earth's Moon. In 2005 a team usingthe Hubble Space Telescope discovered two tiny moons orbiting around both Pluto and Charon.They have been named Nix and Hydra. They are very small with diameters between 40 and 60 kilometers.Recently there has been considerable debate about the classification of Pluto. It was classified as the aplanet just after its discovery and remained so for 75 years. But on 2006 Aug 24 the InternationalAstronomical Union decided to change the definition of a "planet". The new definition does not include Pluto.Instead Pluto is now classified as a "dwarf planet". Personally I don't agree with taking away Pluto'sstatus as a planet. Maybe I am being superstitious, but as any sailor worth his salt will tell you it isgenerally considered bad luck to change the name of a ship once she was been christend.As of the writing of this article Pluto has not yet been explored by a space probe. On January 19, 2006NASA launched New Horizons which will be the first spacecraft to visit Pluto in July 2015. New Horizonsis equiped with remote sensing devices that include imaging instruments, a radio science tool, aspectroscopic sensor and other experiments. The tiny moons Nix and Hydra may present a certaindanger as their presence indicates the possibility of ring system similiar to the one around saturn,though much smaller. Any ring system poses the threat of micrometeorite damage to the New Horizonsspacecraft as it flys past.I hope very much that all goes well and the New Horizons spaceprobe sends back a wealth of information about"Planet X" or Pluto as it is known. Perhaps then we will be able to settle the debate as to whetherPluto is really a planet or not.
what should i do?
well, now i'm studying here, in upmkb, and this is not my first time of falling in love with someone. i admit that now i like someone in a very special way, which i can say that i'm in love with her. she, the girl, and this is just like a dream for me, well she likes me back and we have expressed our feelings to each other and discussed about what kind af a relationship that we are having now. we've made a good decision to ourselves that we are working on it, i mean the relationship since we are still studying and not very serious into it but we knew that we like each other and love each other but the good thing is, we've decided to start everything from the beginning and slowly we will see what will happen to our relationship - whether we can really make it or not. i prefer the way she decided what should we do to each other and for me, this is a good way of having a good relationship between a boy and a girl. so far, she needs time and what i need to do is waiting for her and this is quite tough as it is needs loyalty and patience. for me, it's kinda a small matter but who knows, sometimes patience has its limit and there would be problems and things like that. but anyway, i'm enjoying it - having a special relationship with someone and i hope everything will be fine as it is expected.
Wednesday, September 12, 2007
The Necklaces Of The Middle Ages
The European era of necklaces this article covers is from 1300’s to 1600’s. During the middle ages it was customary for men, women, and children to all wear jewelry. This era had two main themes for jewelry: religion and romantic love.
Very popular were busts and portraits of saints, altars, or ornaments worn on necklaces. Mythical creatures such as mermaids and dragons were very popular along with animals, such as dolphins and lions. European towns each developed their own unique design style, such as Venice which was influenced by the imports of precious gems and other items from the orient bringing forth oriental approaches to the designs. Engraving ranged from having ones initials to lengths of scriptures or poetry. A popular religious pendant was the Tau Cross, which was worn by itself or with many on the chain, sometimes just one tiny bell was worn with it. It was also popular to wear a necklace with just a tiny bell attached only.
The leading workshops were in, Paris, Limoges, Meuse, Belgian-Lorraine, Siena, Florence, and Venice. The main precious metals used in jewelry making were gold and silver with the main gemstones being sapphires, rubies, and pearls. During the early part of this era (14th century) gemstones were finished with the en cabochon method which is highly polishing smooth the stone and not cutting it into faceted angular cuts until later when cutting was more perfected. Other types of neck jewelry were glass beads of various colors combined with precious gems mounted in silver or gold. Covering certain areas of the piece with enamel was also a common practice. Niello was also used which was a mixture of silver, sulphur, and lead. Fashioning jewelry necklaces was often done with molten metal poured into molds. Germany was well known for using milled wire instead of pouring to make them.
The en cabochon method gave way to a new method during the 15th century which was the forerunner of the diamond facet cutting we know today. The Dutchman Louis de Berken, was the first to discover in Brussels that a diamond could be polished with pulverized diamond moistened with oil. In 1476 he was able to perform facet cutting to diamonds, which had previously been used for rock crystal. Charles the Bold employed Louis de Berken at his court for his newly discovered amazing ability.
Cloisonne\’ enameling was where the enamel was applied and fired in raised cells which would sometimes be done with soldered wire. Champleve\’ took over in popularity which is the carving out of areas and filing these areas with enamel and then leveling down (usually sanding) the surrounding metal with the level of the enamel. The copper champleve\’ work was a technique which allowed colorful jewelry to be produced from inexpensive material and was opaque with clearly outlined areas of color,. Paris goldsmiths have been credited with inventing translucent silver enameling. With this technique the goldsmith pours the opaque enamel into a bas-relief carved into the silver. The silver backing produces a delicate and diffused shimmer when the light hits it due to light colored enamel. The gold enameling technique en ronde bosse also developed by Paris goldsmiths in the late 14th century . This technique utilized various colors of glass flux which were melted over a gold core, and combined with beads and precious stones, including red rubies and blue sapphires being the most popular. In Hungary, which from the 13th to the 15th century was the European country richest in gold., wire enameling was taken over from Italy. This method consisted of twisted gold wire forming the contours of the design and the hollows were filled with an opaque enamel.
Gothic style came about during this era which were religious scenes portrayed similar to Gothic church cathedral art. The effect was a straight forward type of approach which started to change into a more elaborate free flowing style later on.
Short chokers were worn and light to heavy chains were worn on the neck. Necklace chains were of all manner of thicknesses and lengths, some had large round links with others having tightly woven type of braiding. Long thin chain necklaces were often weighed down with heavy pendants. Italian women were known for wearing a crown like brooch attached to a hair ribbon.
The middle ages may be one of the most famed in history for adventures and artifacts of this fantastic period including the unique jewelry. This era lives on in many of todays artist\’s designs as they have studied this amazing period in history.
Very popular were busts and portraits of saints, altars, or ornaments worn on necklaces. Mythical creatures such as mermaids and dragons were very popular along with animals, such as dolphins and lions. European towns each developed their own unique design style, such as Venice which was influenced by the imports of precious gems and other items from the orient bringing forth oriental approaches to the designs. Engraving ranged from having ones initials to lengths of scriptures or poetry. A popular religious pendant was the Tau Cross, which was worn by itself or with many on the chain, sometimes just one tiny bell was worn with it. It was also popular to wear a necklace with just a tiny bell attached only.
The leading workshops were in, Paris, Limoges, Meuse, Belgian-Lorraine, Siena, Florence, and Venice. The main precious metals used in jewelry making were gold and silver with the main gemstones being sapphires, rubies, and pearls. During the early part of this era (14th century) gemstones were finished with the en cabochon method which is highly polishing smooth the stone and not cutting it into faceted angular cuts until later when cutting was more perfected. Other types of neck jewelry were glass beads of various colors combined with precious gems mounted in silver or gold. Covering certain areas of the piece with enamel was also a common practice. Niello was also used which was a mixture of silver, sulphur, and lead. Fashioning jewelry necklaces was often done with molten metal poured into molds. Germany was well known for using milled wire instead of pouring to make them.
The en cabochon method gave way to a new method during the 15th century which was the forerunner of the diamond facet cutting we know today. The Dutchman Louis de Berken, was the first to discover in Brussels that a diamond could be polished with pulverized diamond moistened with oil. In 1476 he was able to perform facet cutting to diamonds, which had previously been used for rock crystal. Charles the Bold employed Louis de Berken at his court for his newly discovered amazing ability.
Cloisonne\’ enameling was where the enamel was applied and fired in raised cells which would sometimes be done with soldered wire. Champleve\’ took over in popularity which is the carving out of areas and filing these areas with enamel and then leveling down (usually sanding) the surrounding metal with the level of the enamel. The copper champleve\’ work was a technique which allowed colorful jewelry to be produced from inexpensive material and was opaque with clearly outlined areas of color,. Paris goldsmiths have been credited with inventing translucent silver enameling. With this technique the goldsmith pours the opaque enamel into a bas-relief carved into the silver. The silver backing produces a delicate and diffused shimmer when the light hits it due to light colored enamel. The gold enameling technique en ronde bosse also developed by Paris goldsmiths in the late 14th century . This technique utilized various colors of glass flux which were melted over a gold core, and combined with beads and precious stones, including red rubies and blue sapphires being the most popular. In Hungary, which from the 13th to the 15th century was the European country richest in gold., wire enameling was taken over from Italy. This method consisted of twisted gold wire forming the contours of the design and the hollows were filled with an opaque enamel.
Gothic style came about during this era which were religious scenes portrayed similar to Gothic church cathedral art. The effect was a straight forward type of approach which started to change into a more elaborate free flowing style later on.
Short chokers were worn and light to heavy chains were worn on the neck. Necklace chains were of all manner of thicknesses and lengths, some had large round links with others having tightly woven type of braiding. Long thin chain necklaces were often weighed down with heavy pendants. Italian women were known for wearing a crown like brooch attached to a hair ribbon.
The middle ages may be one of the most famed in history for adventures and artifacts of this fantastic period including the unique jewelry. This era lives on in many of todays artist\’s designs as they have studied this amazing period in history.
What is Quantum Phyics?
Does the thought of quantum physics send a chill down your spine, just like the words calculus, differential equations, and -gasp- organic chemistry? You may not even think that quantum physics is a serious science, like the more familiar Newtonian physics. Just relax! I'm sure you're comfortable with regular physics, which describes the way that matter interacts with other matter, i.e. gravity, velocity, etc. If not, maybe you should check out my regular Interactive Physics site. Anyway, quantum physics is just the physics of the incredibly small. While Newtonian physics can suitably describe the orbit of the planets or the energy transformations during a game of pool, quantum physics describes how electrons surround the nucleus of the atom and other subatomic actions. At this point, you may be thinking that there's not that big of a difference between these two sciences. Hey, both explain how matter interacts with other matter, so what's the big deal? The difference is that the common laws of physics begin to deteriorate on small scales. For example, Nippendenso (Japan Electric) built a car that's only half a millimeters long. One could easily mistake it for a grain of rice if not for its gold color. At the scale of 1 to 1000, physics is already changing. Oil would now gum up the engine, and the tires wouldn't have enough traction to move the car.
Quantum physics tries to explain the behavior of even smaller particles. These particles are things like electrons, protons, and neutrons. Quantum physics even describes the particles which make these particles! That's right; the model of an atom that you were taught in high-school is wrong. The electrons don't orbit like planets; they form blurred clouds of probabilities around the nucleus. Protons and neutrons? They're each made of three quarks, each with its own 'flavor' and one of three 'colors'. Lets not forget the gluons, the even smaller particles that hold this mess together when they collect and form glueballs (not a very original name). Why weren't you told about this already? Were you fluent in calculus when you took general chemistry? The quantum model of the atom is much more complex than the traditional model, so most teachers save that stuff for college. (But this doesn't mean that you can't have a basic understanding and impress your friends!) The reason that quantum physics needs complex math to explain the behaviors and properties of small particles is that the world of these subatomic particles is a very bizarre one, filled with quantum probabilities and organized chaos. For example, the exact position and velocity of an electron is very hard to find because attempts to "see" it involve bouncing other particles off of it. By doing this, you've just changed the electron's velocity, so your data is useless. What quantum physics does is give us the statistical probability of the electron's location at any one moment. By learning how these particles act, scientists can better understand the matter which makes up the universe, and the way it behaves (or misbehaves). Quantum physics even plays a part in blackholes, where regular physics is thrown out the window and then some! This is one of my favourite subject of studying science but then unfortunately now I'm into agriculture but I think this doesn't mean that I have to stop studying physics. I just reall admire my cousin, a physicist in UKM and uring holidays when we spend time together, quantum physics is one of the most favourite topic that we like to talk about and sometimes we argue with each other. Anyway, the most expert wins... and obviously it is not me!
Quantum physics tries to explain the behavior of even smaller particles. These particles are things like electrons, protons, and neutrons. Quantum physics even describes the particles which make these particles! That's right; the model of an atom that you were taught in high-school is wrong. The electrons don't orbit like planets; they form blurred clouds of probabilities around the nucleus. Protons and neutrons? They're each made of three quarks, each with its own 'flavor' and one of three 'colors'. Lets not forget the gluons, the even smaller particles that hold this mess together when they collect and form glueballs (not a very original name). Why weren't you told about this already? Were you fluent in calculus when you took general chemistry? The quantum model of the atom is much more complex than the traditional model, so most teachers save that stuff for college. (But this doesn't mean that you can't have a basic understanding and impress your friends!) The reason that quantum physics needs complex math to explain the behaviors and properties of small particles is that the world of these subatomic particles is a very bizarre one, filled with quantum probabilities and organized chaos. For example, the exact position and velocity of an electron is very hard to find because attempts to "see" it involve bouncing other particles off of it. By doing this, you've just changed the electron's velocity, so your data is useless. What quantum physics does is give us the statistical probability of the electron's location at any one moment. By learning how these particles act, scientists can better understand the matter which makes up the universe, and the way it behaves (or misbehaves). Quantum physics even plays a part in blackholes, where regular physics is thrown out the window and then some! This is one of my favourite subject of studying science but then unfortunately now I'm into agriculture but I think this doesn't mean that I have to stop studying physics. I just reall admire my cousin, a physicist in UKM and uring holidays when we spend time together, quantum physics is one of the most favourite topic that we like to talk about and sometimes we argue with each other. Anyway, the most expert wins... and obviously it is not me!
Wilson's Disease
Wilson's disease causes the body to retain copper. The liver of a person who has Wilson's disease does not release copper into bile as it should. Bile is a liquid produced by the liver that helps with digestion. As the intestines absorb copper from food, the copper builds up in the liver and injures liver tissue. Eventually, the damage causes the liver to release the copper directly into the bloodstream, which carries the copper throughout the body. The copper buildup leads to damage in the kidneys, brain, and eyes. If not treated, Wilson's disease can cause severe brain damage, liver failure, and death.
Wilson's disease is hereditary. Symptoms usually appear between the ages of 6 and 20 years, but can begin as late as age 40. The most characteristic sign is the Kayser-Fleischer ring—a rusty brown ring around the cornea of the eye that can be seen only through an eye exam. Other signs depend on whether the damage occurs in the liver, blood, central nervous system, urinary system, or musculoskeletal system. Many signs can be detected only by a doctor, like swelling of the liver and spleen; fluid buildup in the lining of the abdomen; anemia; low platelet and white blood cell count in the blood; high levels of amino acids, protein, uric acid, and carbohydrates in urine; and softening of the bones. Some symptoms are more obvious, like jaundice, which appears as yellowing of the eyes and skin; vomiting blood; speech and language problems; tremors in the arms and hands; and rigid muscles.
Wilson's disease is diagnosed through tests that measure the amount of copper in the blood, urine, and liver. An eye exam would detect the Kayser-Fleischer ring.
The disease is treated with lifelong use of D-penicillamine or trientine hydrochloride, drugs that help remove copper from tissue, or zinc acetate, which stops the intestines from absorbing copper and promotes copper excretion. Patients will also need to take vitamin B6 and follow a low-copper diet, which means avoiding mushrooms, nuts, chocolate, dried fruit, liver, and shellfish.
Wilson's disease requires lifelong treatment. If the disorder is detected early and treated correctly, a person with Wilson's disease can enjoy completely normal health. The last sentence of this article makes me feel relief. Why? I have the disease, I mean I'm having it. That is why I need to go for the medical check up every three months and on low-cooper diet which means that I cannot take the food that is mentioned above.
Wilson's disease is hereditary. Symptoms usually appear between the ages of 6 and 20 years, but can begin as late as age 40. The most characteristic sign is the Kayser-Fleischer ring—a rusty brown ring around the cornea of the eye that can be seen only through an eye exam. Other signs depend on whether the damage occurs in the liver, blood, central nervous system, urinary system, or musculoskeletal system. Many signs can be detected only by a doctor, like swelling of the liver and spleen; fluid buildup in the lining of the abdomen; anemia; low platelet and white blood cell count in the blood; high levels of amino acids, protein, uric acid, and carbohydrates in urine; and softening of the bones. Some symptoms are more obvious, like jaundice, which appears as yellowing of the eyes and skin; vomiting blood; speech and language problems; tremors in the arms and hands; and rigid muscles.
Wilson's disease is diagnosed through tests that measure the amount of copper in the blood, urine, and liver. An eye exam would detect the Kayser-Fleischer ring.
The disease is treated with lifelong use of D-penicillamine or trientine hydrochloride, drugs that help remove copper from tissue, or zinc acetate, which stops the intestines from absorbing copper and promotes copper excretion. Patients will also need to take vitamin B6 and follow a low-copper diet, which means avoiding mushrooms, nuts, chocolate, dried fruit, liver, and shellfish.
Wilson's disease requires lifelong treatment. If the disorder is detected early and treated correctly, a person with Wilson's disease can enjoy completely normal health. The last sentence of this article makes me feel relief. Why? I have the disease, I mean I'm having it. That is why I need to go for the medical check up every three months and on low-cooper diet which means that I cannot take the food that is mentioned above.
Thursday, August 16, 2007
my first blog...
actually this is not my first time of writing a blog... i used to write few blogs in my friendster... since by doing this i'll get bonus mark for english assignment so here it is... i need to create a new google account and some other things that are necessary... huhu... sometimes the connectivity is not good so i must always be patient especially in doing references in particular subjects such as mathematics and biology plus english... and even i can't check my e-mail and friendster sometimes... i need to go to the town and find cybercafe if i want to do so... well, being a student... again... for me is a best moment in life... as i never get bored studying... that's why my parents allow me to study again... i was given two choices... either to get a job, freshly after finished secondary school (form 5) or study again either form 6 or diploma (ipta's)... thank god... my parents are very understanding and they knew that i was very interested in furthering my studies... diploma in agriculture which is offered in universiti putra malaysia kampus bintulu is my forth choice and it is one of my interests... my ambition actually is to become a doctor... which is mean that i am mainly into medicine an health sciences... since i was not offered in universiti teknologi mara in shah alam, what can i do?... besides, it is good enough to have a chance to study here... uniputra is cool... cool lecturers (mr. peter especially), cool students, cool facilities, cool library, and cool cleaner... hehe... everything is just very fine...
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