ajdad's Blog

September 30, 2008

Albert Einstein (German: IPA: [ˈalbɐt ˈaɪ̯nʃtaɪ̯n] (Audio file) (help·info); English: IPA: /ˈælbɝt ˈaɪnstaɪn/) (14 March 1879 – 18 April 1955) was a German-born theoretical physicist. He is best known for his theory of relativity and specifically mass–energy equivalence, E = mc 2. Einstein received the 1921 Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect."

Einstein's many contributions to physics include his special theory of relativity, which reconciled mechanics with electromagnetism, and his general theory of relativity, which was intended to extend the principle of relativity to non-uniform motion and to provide a new theory of gravitation. His other contributions include relativistic cosmology, capillary action, critical opalescence, classical problems of statistical mechanics and their application to quantum theory, an explanation of the Brownian movement of molecules, atomic transition probabilities, the quantum theory of a monatomic gas, thermal properties of light with low radiation density (which laid the foundation for the photon theory), a theory of radiation including stimulated emission, the conception of a unified field theory, and the geometrization of physics.

Einstein published over 300 scientific works and over 150 non-scientific works.[2][3] Einstein is revered by the physics community,[4] and in 1999 Time magazine named him the "Person of the Century". In wider culture the name "Einstein" has become synonymous with genius.

Youth and schooling

Albert Einstein was born into a Jewish family in Ulm, Württemberg, Germany on 14 March 1879. His father was Hermann Einstein, a salesman and engineer. His mother was Pauline Einstein (née Koch). In 1880, the family moved to Munich, where his father and his uncle founded a company, Elektrotechnische Fabrik J. Einstein & Cie, that manufactured electrical equipment.

The Einsteins were not observant of Jewish religious practices, and Albert attended a Catholic elementary school. Although Einstein had early speech difficulties, he was a top student in elementary school.

When Einstein was five, his father showed him a pocket compass. Einstein realized that there must be something in the space, previously thought to be empty, that was moving the needle and later stated that this experience made "a deep and lasting impression".[7] At his mother's insistence, he took violin lessons starting at age six, and although he disliked them and eventually quit, he later took great pleasure in Mozart's violin sonatas. As he grew, Einstein built models and mechanical devices for fun, and began to show a talent for mathematics.

In 1889, family friend Max Talmud, a medical student, introduced the ten-year-old Einstein to key science, mathematics, and philosophy texts, including Kant's Critique of Pure Reason and Euclid's Elements (Einstein called it the "holy little geometry book"). From Euclid, Einstein began to understand deductive reasoning, and by the age of twelve, he had learned Euclidean geometry. Soon thereafter he began to investigate calculus.

In his early teens, Einstein attended the progressive Luitpold Gymnasium. His father intended for him to pursue electrical engineering, but Einstein clashed with authorities and resented the school regimen. He later wrote that the spirit of learning and creative thought were lost in strict rote learning.

In 1894, when Einstein was fifteen, his father's business failed, and the Einstein family moved to Italy, first to Milan and then, after a few months, to Pavia. During this time, Einstein wrote his first scientific work, "The Investigation of the State of Aether in Magnetic Fields". Einstein had been left behind in Munich to finish high school, but in the spring of 1895, he withdrew to join his family in Pavia, convincing the school to let him go by using a doctor's note.

Rather than completing high school, Einstein decided to apply directly to the ETH Zurich, the Swiss Federal Institute of Technology in Zürich, Switzerland. Lacking a school certificate, he was required to take an entrance examination, which he did not pass, although he got exceptional marks in mathematics and physics.Einstein wrote that it was in that same year, at age 16, that he first performed his famous thought experiment visualizing traveling alongside a beam of light (Einstein 1979).

Following graduation, Einstein could not find a teaching post. After almost two years of searching, a former classmate's father helped him get a job in Berne, at the Federal Office for Intellectual Property,[14] the patent office, as an assistant examiner. His responsibility was evaluating patent applications for electromagnetic devices. In 1903, Einstein's position at the Swiss Patent Office was made permanent, although he was passed over for promotion until he "fully mastered machine technology".[15]

With friends he met in Berne, Einstein formed a weekly discussion club on science and philosophy, jokingly named "The Olympia Academy". Their readings included Poincaré, Mach, and Hume, who influenced Einstein's scientific and philosophical outlook.[16]

During this period Einstein had almost no personal contact with the physics community.[17] Much of his work at the patent office related to questions about transmission of electric signals and electrical-mechanical synchronization of time: two technical problems that show up conspicuously in the thought experiments that eventually led Einstein to his radical conclusions about the nature of light and the fundamental connection between space and time.[15][16]

Marriage and family life

Einstein and Mileva Marić had a daughter, Lieserl Einstein, born in early 1902.[18] Her fate is unknown.

Einstein married Mileva on 6 January 1903, although Einstein's mother had objected to the match because she had a prejudice against Serbs and thought Marić "too old" and "physically defective."[19] [20] Their relationship was for a time a personal and intellectual partnership. In a letter to her, Einstein called Marić "a creature who is my equal and who is as strong and independent as I am."[21] There has been debate about whether Marić influenced Einstein's work; however, most historians do not think she made major contributions.[22][23][24] On 14 May 1904, Albert and Mileva's first son, Hans Albert Einstein, was born in Berne, Switzerland. Their second son, Eduard, was born in Munich on 28 July 1910.

Einstein and Marić divorced on 14 February 1919, having lived apart for five years. On 2 June of that year, Einstein married Elsa Löwenthal, who had nursed him through an illness. Elsa was Albert's first cousin maternally and his second cousin paternally. Together the Einsteins raised Margot and Ilse, Elsa's daughters from her first marriage.[25] Their union produced no children.

Annus Mirabilis

In 1905, while he was working in the patent office, Einstein had four papers published in the Annalen der Physik, the leading German physics journal. These are the papers that history has come to call the Annus Mirabilis Papers:

His paper on the particulate nature of light put forward the idea that certain experimental results, notably the photoelectric effect, could be simply understood from the postulate that light interacts with matter as discrete "packets" (quanta) of energy, an idea that had been introduced by Max Planck in 1900 as a purely mathematical manipulation, and which seemed to contradict contemporary wave theories of light (Einstein 1905a). This was the only work of Einstein's that he himself called "revolutionary."
His paper on Brownian motion explained the random movement of very small objects as direct evidence of molecular action, thus supporting the atomic theory. (Einstein 1905c)
His paper on the electrodynamics of moving bodies introduced the radical theory of special relativity, which showed that the observed independence of the speed of light on the observer's state of motion required fundamental changes to the notion of simultaneity. Consequences of this include the time-space frame of a moving body slowing down and contracting (in the direction of motion) relative to the frame of the observer. This paper also argued that the idea of a luminiferous aether—one of the leading theoretical entities in physics at the time—was superfluous. (Einstein 1905d)
In his paper on mass–energy equivalence (previously considered to be distinct concepts), Einstein deduced from his equations of special relativity what later became the well-known expression: $E = m c 2$ , suggesting that tiny amounts of mass could be converted into huge amounts of energy. (Einstein 1905e)

All four papers are today recognized as tremendous achievements—and hence 1905 is known as Einstein's "Wonderful Year". At the time, however, they were not noticed by most physicists as being important, and many of those who did notice them rejected them outright. Some of this work—such as the theory of light quanta—remained controversial for years.[26][27]

At the age of 26, having studied under Alfred Kleiner, Professor of Experimental Physics, Einstein was awarded a PhD by the University of Zurich. His dissertation was entitled A New Determination of Molecular Dimensions. (Einstein 1905b)

Light and general relativity

In 1906, the patent office promoted Einstein to Technical Examiner Second Class, but he had not given up on academia. In 1908, he became a privatdozent at the University of Bern.[28] In 1910, he wrote a paper on critical opalescence that described the cumulative effect of light scattered by individual molecules in the atmosphere, i.e., why the sky is blue.[29]

During 1909, Einstein published "Über die Entwicklung unserer Anschauungen über das Wesen und die Konstitution der Strahlung" ("The Development of Our Views on the Composition and Essence of Radiation"), on the quantization of light. In this and in an earlier 1909 paper, Einstein showed that Max Planck's energy quanta must have well-defined momenta and act in some respects as independent, point-like particles. This paper introduced the photon concept (although the term itself was introduced by Gilbert N. Lewis in 1926) and inspired the notion of wave–particle duality in quantum mechanics.

In 1911, Einstein became an associate professor at the University of Zurich. However, shortly afterward, he accepted a full professorship at the Charles University of Prague. While in Prague, Einstein published a paper about the effects of gravity on light, specifically the gravitational redshift and the gravitational deflection of light. The paper appealed to astronomers to find ways of detecting the deflection during a solar eclipse.[30] German astronomer Erwin Finlay-Freundlich publicized Einstein's challenge to scientists around the world.[31]

In 1912, Einstein returned to Switzerland to accept a professorship at his alma mater, the ETH. There he met mathematician Marcel Grossmann who introduced him to Riemannian geometry and more generally differential geometry, and at the recommendation of Italian mathematician Tullio Levi-Civita, Einstein began exploring the usefulness of general covariance (essentially the use of tensors) for his gravitational theory. Although for a while Einstein thought that there were problems with that approach, he later returned to it and by late 1915 had published his general theory of relativity in the form that is still used today (Einstein 1915). This theory explains gravitation as distortion of the structure of spacetime by matter, affecting the inertial motion of other matter.

After many relocations, Mileva established a permanent home with the children in Zurich in 1914, just before the start of World War I. Einstein continued on alone to Berlin, where he became a member of the Prussian Academy of Sciences. As part of the arrangements for his new position, he also became a professor at the Humboldt University of Berlin, although with a special clause freeing him from most teaching obligations. From 1914 to 1932 he was also director of the Kaiser Wilhelm Institute for Physics.[32]

During World War I, the speeches and writings of Central Powers scientists were available only to Central Powers academics, for national security reasons. Some of Einstein's work did reach the United Kingdom and the United States through the efforts of the Austrian Paul Ehrenfest and physicists in the Netherlands, especially 1902 Nobel Prize-winner Hendrik Lorentz and Willem de Sitter of the Leiden University. After the war ended, Einstein maintained his relationship with the Leiden University, accepting a contract as an Extraordinary Professor; he travelled to Holland regularly to lecture there between 1920 and 1930.[33]

Nobel Prize

In 1922 Einstein was awarded the 1921 Nobel Prize in Physics[42], "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect". This refers to his 1905 paper on the photoelectric effect: "On a Heuristic Viewpoint Concerning the Production and Transformation of Light", which was well supported by the experimental evidence by that time. The presentation speech began by mentioning "his theory of relativity [which had] been the subject of lively debate in philosophical circles [and] also has astrophysical implications which are being rigorously examined at the present time." (Einstein 1923) As stipulated in their 1919 divorce settlement, Einstein gave the Nobel prize money to his first wife, Mileva Marić.

Einstein traveled to New York City in the United States for the first time on 2 April 1921. When asked where he got his scientific ideas, Einstein explained that he believed scientific work best proceeds from an examination of physical reality and a search for underlying axioms, with consistent explanations that apply in all instances and avoid contradicting each other. He also recommended theories with visualizable results (Einstein 1954).

Unified field theory

Einstein's research after general relativity consisted primarily of a long series of attempts to generalize his theory of gravitation in order to unify and simplify the fundamental laws of physics, particularly gravitation and electromagnetism. In 1950, he described this "unified field theory" in a Scientific American article entitled "On the Generalized Theory of Gravitation" (Einstein 1950).

Although he continued to be lauded for his work in theoretical physics, Einstein became increasingly isolated in his research, and his attempts were ultimately unsuccessful. In his pursuit of a unification of the fundamental forces, he ignored some mainstream developments in physics (and vice versa), most notably the strong and weak nuclear forces, which were not well understood until many years after Einstein's death. Einstein's goal of unifying the laws of physics under a single model survives in the current drive for the grand unification theory.

Death

On 17 April 1955, Albert Einstein experienced internal bleeding caused by the rupture of an aortic aneurysm, which had previously been diagnosed and reinforced.[96] He took a draft of a speech he was preparing for a television appearance commemorating the State of Israel's seventh anniversary with him to the hospital, but he did not live long enough to complete it.[97] He died in Princeton Hospital early the next morning at the age of 76, having continued to work until near the end. Einstein's remains were cremated and his ashes were scattered.[98][99]

Before the cremation, Princeton Hospital pathologist Thomas Stoltz Harvey removed Einstein's brain for preservation, without the permission of his family, in hope that the neuroscience of the future would be able to discover what made Einstein so intelligent.

A.Einstein

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Mysteries of the universe

September 30, 2008

Mysteries of the universe

Five billion years ago, a dark, vast cloud of gas and dust stretched across hundreds of light-years of space. Inside the cloud, temperatures hovered just a few degrees above absolute zero. In one small region nestled deep within the cloud, the turbulent bulk motions of gas molecules bunched enough mass together that gravity could exert its inexorable force, causing part of the cloud to collapse. Millions of years later, gravity squeezed the densest regions of the shrinking cloud to temperatures and pressures high enough to ignite thermonuclear fires, forming thousands of newborn stars.

And 4.6 billion years after that, one of the small chunks of debris left over from the formation of one of those stars, intelligent beings emerged who could ask questions about their origin. Our Sun, our solar system, our planet, everyone we know, everything we love, everything we ever cared about — all of these owe their existence to a collapsing gas cloud some five billion years ago.

Our lives are intimately linked to the stars. Thermonuclear reactions deep inside the Sun provide the sustenance for life on Earth. The carbon in our cells, the oxygen we breathe, the calcium in our bones, and the iron in our blood were forged inside stars that expired billions of years ago. So, you see that virtually everything is made from star dust, we are star dust.

Feature
BLACK HOLES
(Mg,Fe)3Si2O5(OH)4
(Hydrous magnesium iron silicates)

Black holes are bodies so massive and dense that their theoretical escape velocity is greater than the speed of light itself, due to the exceptionally strong gravitational field. This means that not even light can escape from such bodies, effectively rendering them invisible — hence the name.

At one time black holes were entirely theoretical. The black hole theory began in 1783 when Rev. John Michell used Newton’s theory of gravity to predict the possibility of "dark stars". In 1915, Einstein’s General Theory of Relativity predicted so-called "Schwartzschild singularities" (non-rotating black holes). And in 1963 the "Kerr" or rotating black hole solution was found. This was especially important, since most stars are rotating, and the rotation rate is expected to increase when such stars collapse. They were renamed "black holes" in 1967. Today their existence has been confirmed, both in our own galaxy and elsewhere in the universe, bringing the total known to 33 (the closest being at the center of the Andromeda galaxy, and the largest at the center of galaxy M106). We can infer the presence and location of a black hole by monitoring the gravitational effects that it has on surrounding objects like companion stars. They are also evidenced by the emission of x-rays, which are easily detectable.

A black hole is formed when a very large star (at least 30 times the mass of our Sun) dies or runs out of hydrogen, and collapses or implodes under its own weight. It shrinks down to an infinitely dense point known as a singularity (the point at which the star’s mass is centered), and it is at this point that conventional mathematics can no longer cope. Around the singularity, at the opening of the black hole, there is a doughnut-shaped ring called the event horizon. It is the black hole’s gravitational boundary beyond which nothing, including light, can escape. And once this boundary is crossed, there is no return. Einstein has proven that gravity can not only capture light, but can also distort time and space. Inside the event horizon, the entire concept of time and space completely breaks down.

Black holes have a reputation for sucking in everything around them. Thankfully, the black holes we know about are of no danger to Earth. The closest stellar-sized black hole, V404 Cygni, is at least 15 light years away, and super massive black holes are confined to the centers of distant galaxies, so they pose no conceivable threat. Black holes are no more deadly than any other objects of the same mass — if you keep your distance. A black hole could suck in only enough material to equal its own mass, and no more.

There are other implications of other phenomena concerning black holes. Einstein’s equations suggest that black holes theoretically should lead to parallel universes; i.e., one that is separate from our own. There may be multiple universes, each slightly different to the one we are presently existing in. There is also the possibly of time travel into the past and future. And the possibility of using a wormhole (where two black holes connect), to travel instantly to far places within the universe.

If you were standing on the edge of the event horizon and you fell feet first into a black hole, the difference between the gravitational pull on your head and your feet would be so powerful that it would instantly stretch you out like spaghetti. If you could look back as you fell, you would see the future history of the universe flash before your eyes. But once inside the event horizon, you would be unable to communicate anything you saw back to anyone outside it. As you neared the singularity at the center, you would have felt yourself being torn apart, atom by atom. Space and time would be so distorted at this point, everything we have ever known about the universe has broken down. Some say at this point, only a primordial froth exists.

Black holes could actually be beneficial. Mathematician Roger Penrose of Oxford University has calculated that a technologically advanced civilization could extract enough energy from a black hole to supply all of its power requirements.

Penrose’s idea requires the civilization to build a structure encircling the black hole, from which a stream of fuel can be "fed" into it. At the event horizon, each particle in the fuel stream is then split into two fragments — perhaps using suitably placed explosive charges. Penrose has calculated that at the very moment one of these fragments falls over the black hole’s event horizon, the other fragment will throw out a kick of pure energy supplied by the annihilation of its partner. This is something like the boost you get after jumping from a carousel.

The theory goes on to suggest that the "energy kicks" could be collected by the structure around the black hole, but energy extracted in this way would not be limitless. Calculations by Demetrios Christodoulou, a researcher at Princeton University, New Jersey, show that a black hole’s rate of spin is steadily reduced by the Penrose process. There would come a point when the black hole stops spinning, and its energy-producing properties would vanish.

If the same civilization could build a craft capable of withstanding the enormous forces that apply in and around a black hole, scientists have speculated that it might be possible to cross the event horizon into a new region of space-time, through what is known as a wormhole. So living next to a black hole could not only save on utilities, it could also provide the ultimate ticket to the rest of the universe — past, present and future.

mysteries, of, the, universe

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Programming Courses: Computer Programming Training

September 30, 2008

A computer programming degree allows students to work in a diverse industry within the information technology environments. Computer programmers are in high demand in today's technologically advancing industries, and students enrolling in the computer programming school will receive formal, hands-on computer programming training that is necessary for today's growing market. Each programming language course requires strong mathematical abilities and understanding technical concepts, with direct application for a variety of software and computer programs. Students who wish to learn programming can do so by enrolling in computer programming training, online, at a technical college, or pursuing a bachelors or Masters degree program at a university.

Job Description and Responsibilities After Completion of a Programming Course

After achieving certification and skills through various computer programming courses, a computer programmer is often involved with projects such as:

Writing, testing, and maintaining detailed instructions to run computer programs
Testing logical structures to solve computer-related problems
Writing programs according to computer programming specifications determined by software analysts
Designing logical series of instructions for computers to follow
Developing scientific and business applications
Learning a variety of computer programming languages
Group working with software development firms to develop packaged software

Computer programming school allows students to explore a variety of computer programming courses and opportunities in information technology. A programming course can be specialized within a specific computer programming field such as Java, C++, or Visual Basic. A computer programming degree generally involves studying a variety of programming languages, and students may choose to specialize in specific language. By developing skills in a particular division.

Skills Obtained through Computer Programming School

Most students who wish to learn programming turn to a computer programming school for in-class instruction, and it's the skills and knowledge to complete certification. Computer programming certification is the best way to prove experience and provide credentials for prospective employers. The most marketable areas include C++, Java, and object oriented programming. The most attractive programming language course is object oriented programming, as well as Java in some specializations.

Programming school and programming courses may also supplement a degree program that focuses on computer database administration, engineering, or statistics. Each programming course provides specific skills and techniques for application in understanding programming language.

Career Options after Computer Programming Training

Computer programming training lays the foundation for a variety of career options for prospective computer programmers, research analysts, and database administrators. The most common career tracks for qualified students include:

Computer Software Engineer
Computer System Analyst
Computer Operator
Applications Programmer
Systems Programmer
Computer Instructor
Software Administrator

Applications programmers helped to write programs that it's track and handle a specific job or task. They are often involved with revising existing software, and adapting technology and computer group programs to suit the specific business or industry. Systems programmers work on operating systems instead, and must learn computer programming that provides instructions for creating networks, communicating with hardware, and other database administration tasks. Enrollment in an additional programming language course of study may be required for programmers who need to extend their skills in particular areas.

Common Programming Courses Taken at Programming School

The most common programming courses taken at programming school include:

.NET Programming Courses
Visual Basic
C# Training
CSS Training
Introduction to C++ Programming
Visual Studio Training
Office VBA Development
HTML Training
Java Essentials
Visual FoxPro
Crystal Reports
Action Scripting

Computer Programming Degree Requirements and Options at Programming School

Many students who wish to learn programming choose to enroll in a programming school in order to obtain a computer programming degree. Since the industry is so competitive, it has become even more important for students to obtain certification and specialization in specific fields of study. Programming school allows students to find their match, and this burned credits and credentials for certification and licensing.

Formal computer programming training allows students to become successful computer programmers, Independent trainers, instructors, or consultants in furthering their career. Gaining experience is especially important within this technical profession, and applying skills and keeping up with development trends is an important part of many positions within the industry.

Employment Prospects after Computer Programming School

the demand for qualified and professional computer programmers is constantly rising, and employment for graduates of computer programming schools is expected to rise as fast as average through 2012. After completing computer programming training, certification is a valuable addition to any education received. Median salaries of the majority of computer programming jobs range between $60,000 to upward of $100,000. The average median salary was $62,890 in May 2004 for computer programmers.

Staying up-to-date with the latest technology offers the most prospects for advancement within the field. After gaining experience through formal computer programming school, many graduates choose to specialized knowledge and experience to pursue research, development, Internet marketing, or open up their own website developments business. Gaining expertise in the specific area is an advantage to this competitive industry. Related occupations include: