Sunday, 25 May 2014
The Higgs boson or Higgs particle is an elementary particle initially theorised in 1964, whose discovery was announced at CERN on 4 July 2012. The discovery has been called "monumental" because it appears to confirm the existence of the Higgs field, which is pivotal to the Standard Model and other theories within particle physics. It would explain why some fundamental particles have mass when the symmetries controlling their interactions should require them to be massless, and why the weak force has a much shorter range than the electromagnetic force. The discovery of a Higgs boson should allow physicists to finally validate the last untested area of the Standard Model's approach to fundamental particles and forces, guide other theories and discoveries in particle physics, and potentially lead to developments in "new" physics.
This unanswered question in fundamental physics is of such importance that it led to a search of more than 40 years for the Higgs boson and finally the construction of one of the world's most expensive and complex experimental facilities to date, the Large Hadron Collider, able to create Higgs bosons and other particles for observation and study. On 4 July 2012, it was announced that a previously unknown particle with a mass between 125 and 127 GeV/c2 (134.2 and 136.3 amu) had been detected; physicists suspected at the time that it was the Higgs boson. By March 2013, the particle had been proven to behave, interact and decay in many of the ways predicted by the Standard Model, and was also tentatively confirmed to have positive parity and zero spin, two fundamental attributes of a Higgs boson. This appears to be the first elementary scalar particle discovered in nature. More data is needed to know if the discovered particle exactly matches the predictions of the Standard Model, or whether, as predicted by some theories, multiple Higgs bosons exist.
The Higgs boson is named after Peter Higgs, one of six physicists who, in 1964, proposed the mechanism that suggested the existence of such a particle. Although Higgs's name has come to be associated with this theory, several researchers between about 1960 and 1972 each independently developed different parts of it. In mainstream media the Higgs boson has often been called the "God particle", from a 1993 book on the topic; the nickname is strongly disliked by many physicists, including Higgs, who regard it as inappropriate sensationalism. In 2013 two of the original researchers, Peter Higgs and François Englert, were awarded the Nobel Prize in Physics for their work and prediction Englert's co-researcher Robert Brout had died in 2011, and except in unusual circumstances, the Nobel is not given posthumously.
In the Standard Model, the Higgs particle is a boson with no spin, electric charge, or color charge. It is also very unstable, decaying into other particles almost immediately. It is a quantum excitation of one of the four components of the Higgs field. The latter constitutes a scalar field, with two neutral and two electrically charged components, and forms a complex doublet of the weak isospin SU symmetry. The field has a "Mexican hat" shaped potential with nonzero strength everywhere (including otherwise empty space) which in its vacuum state breaks the weak isospin symmetry of the electroweak interaction. When this happens, three components of the Higgs field are "absorbed" by the SU and U gauge bosons (the "Higgs mechanism") to become the longitudinal components of the now-massive W and Z bosons of the weak force. The remaining electrically neutral component separately couples to other particles known as fermions (via Yukawa couplings), causing these to acquire mass as well. Some versions of the theory predict more than one kind of Higgs fields and bosons. Alternative "Higgsless" models would have been considered if the Higgs boson were not discovered.
Friday, 23 May 2014
Space shuttle Atlantis and its crew of seven astronauts ended an 11-day journey of nearly 4.5 million miles with a Perfect landing at NASA's Kennedy Space Center in Florida.
The mission, designated STS-129, included three spacewalks and the installation of two platforms to the International Space Station's truss, or backbone. The platforms hold large spare parts to sustain station operations after the shuttles are retired. The shuttle crew delivered about 30,000 pounds of replacement parts for systems that provide power to the station, keep it from overheating, and maintain a proper orientation in space.
The Space Shuttle Atlantis (Orbiter Vehicle Designation: OV‑104) was a Space Shuttle orbiter belonging to the National Aeronautics and Space Administration (NASA), the spaceflight and space exploration agency of the United States. Atlantis was the fourth operational (and the next-to-the-last) Space Shuttle to be constructed by the Rockwell International company in Southern California, and it was delivered to the John F. Kennedy Space Center in eastern Florida in April 1985. Atlantis was the only orbiter which lacked the ability to draw power from the International Space Station while docked there; it had to continue to provide its own power through fuel cells.
The last mission of Atlantis was STS-135, the last flight of the Shuttle program. This final flight, authorized in October 2010, brought additional supplies to the International Space Station and took advantage of the processing performed for the Launch on Need mission, which would only have been flown if Endeavour's STS-134 crew required rescue. Atlantis launched for the last time on 8 July 2011 at 16:29 UTC, landing at the John F. Kennedy Space Center on 21 July 2011 at 09:57 UTC.
By the end of its final mission, Atlantis had orbited the Earth 4,848 times, traveling nearly 126,000,000 mi (203,000,000 km) or more than 525 times the distance from the Earth to the Moon.
Atlantis was named after RV Atlantis, a two-masted sailing ship that operated as the primary research vessel for the Woods Hole Oceanographic Institution from 1930 to 1966
Stargazer Nation Facebook Group - https://www.facebook.com/groups/1441276202795886/
Thursday, 22 May 2014
If you like it, you'll find a way to justify it.
But if you don't , you'll find ways to falsify it.
Wednesday, 21 May 2014
A previously unobserved celestial event called the Camelopardalid meteor shower is set to take place for the first time on the night of 23 May.
Although skywatchers have been able to watch annual showers such as the Leonids and the Perseids, when Earth passes through debris left behind by the Comet Swift-Tuttle, for hundreds of years, next week's shower has never before graced our skies.
The spectacular show is the result of tiny pieces of rock and ice given off by Comet 209P/LINEAR, a very faint comet that was discovered in 2004 by the Lincoln Near-Earth Asteroid Research initiative. The comet completes one orbit around the Sun every five years.
The Camelopardalid meteor shower will be visible for spectators in North America, as it is expected to occur on the night of 23 May and the early morning of 24 May. However, as the event will occur after sunrise, it will not be visible in the UK.
Tuesday, 20 May 2014
In 1905, Albert Einstein published the theory of special relativity, which explains how to interpret motion between different inertial frames of reference — that is, places that are moving at constant speeds relative to each other.
Einstein explained that when two objects are moving at a constant speed as the relative motion between the two objects, instead of appealing to the ether as an absolute frame of reference that defined what was going on. If you and some astronaut, Amber, are moving in different spaceships and want to compare your observations, all that matters is how fast you and Amber are moving with respect to each other.
El Niño is a band of anomalously warm ocean water temperatures that periodically develops off the Pacific coast of South America. Extreme climate change pattern oscillations fluctuate weather across the Pacific Ocean which results in fluctuating droughts, floods, and crop yields in varying regions of the world.
There is a phase of 'El Niño--Southern Oscillation' (ENSO), which refers to variations in the temperature of the surface of the tropical eastern Pacific Ocean (El Niño and La Niña) and in air surface pressure in the tropical western Pacific. The two variations are coupled: the warm oceanic phase, El Niño, accompanies high air surface pressure in the western Pacific, while the cold phase, La Niña, accompanies low air surface pressure in the western Pacific. Mechanisms that cause the oscillation remain under study.
Developing countries dependent upon agriculture and fishing, particularly those bordering the Pacific Ocean, are the most affected. El niño is Spanish for "the boy", and the capitalized term El Niño refers to the Christ child, Jesus, because periodic warming in the Pacific near South America is usually noticed around Christmas.
Most tropical cyclones form on the side of the subtropical ridge closer to the equator, then move poleward past the ridge axis before recurving into the main belt of the Westerlies. When the subtropical ridge position shifts due to El Niño, so will the preferred tropical cyclone tracks. Areas west of Japan and Korea tend to experience much fewer September--November tropical cyclone impacts during El Niño and neutral years. During El Niño years, the break in the subtropical ridge tends to lie near 130°E, which would favor the Japanese archipelago. During El Niño years, Guam's chance of a tropical cyclone impact is one-third of the long-term average. The tropical Atlantic ocean experiences depressed activity due to increased vertical wind shear across the region during El Niño years. On the flip side, however, the tropical Pacific Ocean east of the dateline has above-normal activity during El Niño years due to water temperatures well above average and decreased windshear. Most of the recorded East Pacific category 5 hurricanes occur during El Niño years in clusters.
Monday, 19 May 2014
between May 21, 2014 and August 5, 2014 the Rosetta spacecraft will perform crucial orbit correction maneuvers.
These are required to slow down the spacecraft's speed relative to comet 67P/Churyumov-Gerasimenko - from 750 meters per-second to just one meter per-second. This will reduce Rosetta's distance from the comet from one million kilometers to just under 200 kilometers.
Saturday, 17 May 2014
Yury Gagarin's 108-minute orbit around the Earth on April 12, 1961 captured the imagination of the entire world, while setting in motion many national and international projects to reach “the final frontier.”
The stunning achievements of the Soviet space program, which sparked a wave of panic in US academic and political circles, forced Americans to rethink the way they were approaching their studies.
This national navel-gazing, however, had already started before cosmonaut Yury Gagarin arrived on the scene.
Four years before Gagarin’s epic space flight, on October 4, 1957, the Soviet Union had launched Sputnik, the first Earth-orbiting artificial satellite. This successful mission provoked an avalanche of handwringing reports in the US media centered on the single question: “Why is the US educational system failing to keep pace with the Soviets?”
The Cold War story of Alexei Kutzkov versus Stephen Lapekas
The March 1958 issue of Life magazine featured a controversial article, entitled “Crisis in Education,” which scrutinized the academic achievements of two students, Alexei Kutzkov from Moscow and Stephen Lapekas from Chicago, both 16 years old.
The Life reporters doggedly followed Kutzkov and Lapekas around their respective schools (they even managed to follow Kutzkov around Moscow), putting their noses into their extracurricular activities, and noting the differences between these young representatives from opposite sides of the ideological iron curtain.
The article begins with a glowing report of the Soviet youth.
“In the austere atmosphere of Moscow’s School 49, Alexei Kutzkov spends six intensive days a week on a formidable array of subjects,” the article opens. “They include Russian literature, sixth-year English, fifth-year physics, fourth-year chemistry, electrical technique, mathematics, technical drawing, machinery and astronomy.”
“More than half of Alexei’s classroom time is given over to scientific subjects,” the article adds.
Outside of the classroom, Alexei keeps moving “at the same determined pace,” and it should come as no surprise that his “interest in girls, by U.S. teenage standards, has been slow in developing,” which goes far at explaining the tongue-in-cheek comment that “there is no sex in the Soviet Union.” The comrades were too busy hitting the books.
The assorted black-and-white photographs that accompanied the Life story, which presents Soviet Russia in a rare positive light, show Alexei participating in a wide range of cerebral activities, including working in the laboratory, reading from an English book, and contemplating his next move on the chess board.
Meanwhile, Kutzkov’s impressive list of academic exertions makes his American counterpart’s school day look ordinary and almost wasteful by comparison.
“Stephen Lapekas of Chicago starts out almost every school day by meeting his steady, Penny Donahue, and heading for Austin High,” the article continues, under a section entitled, ‘Relaxed Studies’. “Ten minutes later he gets to the Typing II class, slips behind a large electric typewriter and another pleasant school day begins.”
The Life article was intentionally designed to set off a firecracker inside the halls of America’s sleepy, self-contented school system, and it certainly succeeded on that point. Indeed, the painful limits of Lapekas’s academic life – with so much attention being given to Typing and Dancing – makes one wonder how America ever got to the Moon just one decade later .
“The intellectual application of him is moderate. In English, for example, students seldom bother to read assigned books and sometimes make book reports based on comic book condensations. Stephen’s extracurricular activities [he is described as the school’s “star swimmer,” and a “leader in student affairs”]…leave him little time for hard study.”
In an article following the Kutzkov-Lapekas matchup, the novelist Sloan Wilson slammed the disastrous condition of the US public school system, yet these are criticisms would not seem out of place today.
“A surprisingly small percentage of high school students is studying what used to be considered standard subjects,” Sloan wrote. “Only 12% are taking any mathematics more advanced than algebra, and only 25% are studying physics. A foreign language is studied by fewer than 15% of the students.”
He even lamented that so many Russians were studying English, but not the other way around.
“Ten million Russians are studying English,” Wilson wrote, “but only 8,000 Americans are studying Russian.”
Then, next to an illustration of two teenagers dancing in front of a jukebox, with a teacher attempting to offer them a pile of books, Wilson wrote, quoting a junior high school teacher, “students nowadays are smothered with anxious concern, softened with lack of exercise, then flung into the morass of excessive sex interest…They are overfed and underworked. They have too much leisure and too little discipline.”
The same complaints are regularly heard today.
Space Race takes off
Although the official start of the Space Race between the two superpowers happened in 1955, when both sides announced their intention to launch satellites into Earth’s orbit, the Soviet’s no-nonsense approach to education hit a raw nerve in US academic circles.
As a result, US school curricula began to reflect the prioritization of math and scientific studies. The results of this change of academic priorities, together with advances in ballistic missile research, allowed US President John F. Kennedy to announce the goal of putting a man on the Moon “before this decade is out.”
"I believe that this nation should commit itself to achieving the goal,” Kennedy said in an address to a special joint session of Congress in May, 1961, “before this decade is out, of landing a man on the moon and returning him safely to the earth."
That ambitious goal was reached on July 20, 1969 with the Moon landing of the Apollo 11.
The US space program has witnessed its fair share of historic accomplishments, including the implementation of the Space Shuttle program, which since 1981 has had 135 launches.
This year, however, fifty years after Yury Gagarin became the first man in space, “the US space shuttle program is winding down leaving former rival Russia as the only nation able to carry astronauts into orbit,” the Associated Press reported.
NASA is now forced to rely on Russian Soyuz capsules to deliver its astronauts to the International Space Station – “to the tune of $50 million per seat until a new shuttle is ready,” the AP report continues.
Presently, the United States is facing huge budget deficits (fighting three wars will do that) and can ill afford to foot the bill for ambitious space projects. And though Washington’s Cold War rivalry with the Soviets has disappeared, China is showing tremendous promise on the space front.
Meanwhile, a fierce battle is being waged in many US states, which are attempting to balance their books by cutting back on spending on public education.
Although US president Barack Obama has promised not to let this happen, his track record of keeping his promises leaves a lot to be desired. On Sunday, the White House announced that $13 billion would be cut from the departments of Education, Labor, and Health and Human Services.
Early Tuesday morning, the House Appropriations Committee released a detailed listing of the educational agencies scheduled to take a hit, including “Literacy Through School Libraries, the National Writing Project, International Education and Foreign Language, AmeriCorps and programs to mentor the children of prisoners,” according to the Washington Times.
While the US space program has hit the skids, and is now forced to hitch a ride to the stars with Russian assistance, it is clearly not time for Russia to plant a flag and proclaim the galactic mountaintops.
Svetlana Savitskaya, who flew two space missions in 1982 and 1984 and became the first woman to make a spacewalk, criticized the government’s handling of space programs following the 1991 collapse of the Soviet Union.
"Cosmonautics in my opinion is one of the rare if not the only thing in our country today that is still left that our people can be proud of in this country,” Savitskaya told reporters at Moscow's Space Memorial Museum. “There's nothing new to be proud of [in the realm of space exploration] the last 20 years. Thank God, it has been preserved, this is a thing to be proud of, that at least it has been preserved.”
Savitskaya, however, said she was confident that “we'll create something new."
Meanwhile, Russian President Dmitry Medvedev, expressing his pride that a Soviet was the first person to travel into outer space, said he is confident man will eventually conquer other planets, in an interview with China Central Television.
“I believe it was a truly revolutionary event, a highly symbolic one. It was a tremendous achievement of Soviet cosmonautics, which divided the world into ‘before’ and ‘after the flight’, what has been termed the ‘space era’”,
the Russian leader said.
An unintended consequence of space travel
Meanwhile, there is one ironic legacy of man’s space flights that goes to often unmentioned: appreciation for the Earth.
An unintended outcome of the Cold War Space Race is that it helped introduce the modern environmental movement.
As astronauts and cosmonauts journeyed deep into outer space, they sent back to Earth first-ever photographs of the Earth as it appears from the heavens. The first remarkable pictures show a fragile blue sphere bordered by the blackness of outer space.
So perhaps the greatest lesson we may learn from Gagarin’s epic space voyage is that although space is a tempting place, it is only Earth where man can truly call his home. Thus, it would speak far better of the human species if we were to use the tremendous strides that we have made in the fields of math and science to finding ways of saving the planet, not destroying it in yet another maddening "race."
Otherwise, there will be no future generations of children to pass along the stories of our amazing accomplishments, like Yury Gargarin’s first-ever space journey, and America’s Apollo mission to the Moon.
West Michigan's infamous brush with the unknown isn't fading into the past anytime soon.
In March 1994, UFOs were reported speeding along the shoreline, leaving police and witnesses scratching their heads in wonder. The phenomenon was even caught on National Weather Service radar and recorded on a call to a 911 operator.
Now, 20 years after the headlines have faded, the phenomenon is once again about to be thrust into the national spotlight.
This fall, the sighting -- witnessed by residents in Muskegon and Ottawa counties -- will be the topic of UFO Hunters, a History Channel series that gives extraterrestrial encounters a primetime TV treatment.
The show's stated mission: Separate "fact from fallacy."
There's no denying the fact that something strange, even extraordinary, happened in West Michigan that cold spring night.
And Kevin Barry, who's producing the episode, is confident the public is still hungry for details.
"Everybody loves the idea of investigating UFOs," said Barry, a Michigan native who graduated from Wayne State University with a master's degree in film. "It subverts everything (people) have been taught and everything we believe."
Some witnesses aren't sure what to believe about the lights they saw hovering in the sky.
As he sat in front of Holland High School ready to be interviewed by Barry and his crew, Lee Lamberts seemed both mystified and passive.
Lamberts, who covers sports for the Holland Sentinel, isn't forgetting the glowing object he saw near the school. But he's not wracking his brain for answers, either.
"If I'm driving home late at night from the school I look up at the sky thinking I might see something again," he said as he pointed to where he saw the UFO. "Some people think I'm making this up because I'm kind of a jokester, but this is all true."
Barry doesn't doubt Lambert's recollection.
"I believe most of these stories, that people saw something," he said. "They aren't saying they saw little green men, but they did see something."
Ever since a UFO crashed in the New Mexico desert in 1947, countless numbers of Americans have uttered the same words.
It's a topic that stirs passions, raises troubling questions and piques the curiosity of millions of Americans.
So it's easy to be skeptical. UFO sightings are often associated with the most sensational media organizations, making Barry's work all the more difficult.
But he chose Holland for a reason.
The witnesses were regular people, not UFO enthusiasts, and they all reported seeing the same thing -- a glowing circular object.
And then there's the 911 recording of the conversation between a National Weather Service Operator at Muskegon County Airport and an Ottawa County dispatcher.
The conversation -- which at one point features the weather service operator saying, "I've never seen anything like this" -- was obtained by former Muskegon Chronicle reporter Michael G. Walsh using Michigan's Freedom of Information Act.
Before he heard the tapes, Walsh was skeptical too. A quick listen changed his mind.
"You could hear it in their voices, they were mystified, they were concerned," said Walsh, now a Muskegon attorney. "I said, 'My God, this is a story.' "
He was right.
In the following week, the story was covered by major television and radio news networks as well as talk show hosts, including Larry King Live.
"Being the object of the stories was unusual," said Walsh, who wrote a series of stories on the sighting. "Here I am and my claim to fame are the UFOs."
The unexplainable phenomenon has brought other witnesses their 15 minutes of fame, too.
Cindy Pravda, who spotted the UFOs from the window of her Grand Haven Township home, was interviewed by the UFO Hunters last weekend.
The sighting didn't startle Pravda. If anything, the sight of four bright lights silently hovering above the tree line was hypnotic. She watched the object for nearly a half hour.
"I saw my horse, and she was just sitting in the backyard sleeping," Pravda said. "I thought if nothing bothered her, what do I need to worry about."
The chance to tell her story to the History channel "totally amazes" Pravda.
"I'm like a little piece of the puzzle."
Friday, 16 May 2014
Modern physics is dominated by the concepts of Quantum Mechanics. This page aims to give a brief introduction to some of these ideas.
Until the closing decades of the last century the physical world, as studied by experiment, could be explained according to the principles of classical (or Newtonian) mechanics: the physics of everyday life. By the turn of the century, however, the cracks were beginning to show and the disciplines of Relativity and Quantum Mechanics were developed to account for them. Relativity came first, and described the physics of very massive and very fast objects, then came Quantum Mechanics in the 1920's to describe the physics of very small objects.
Neither of these theories provide an easy intuitive picture of the world, since they contradict the predictions of familiar Newtonian Mechanics in the regimes for which they were developed. Nevertheless, both schemes reproduce the Newtonian results when applied to the everyday world. In seeking to understand the physics of semiconductors at an atomic level we must start from a Quantum Mechanical viewpoint, since the entities with which we will be dealing (electrons, atoms, etc) are so very small....
Waves and Particles
At the macroscopic scale we are used to two broad types of phenomena: waves and particles. Briefly, particles are localised phenomena which transport both mass and energy as they move, while waves are de-localised phenomena (that is they are spread-out in space) which carry energy but no mass as they move. Physical objects that one can touch are particle-like phenomena (e.g. cricket balls), while ripples on a lake (for example) are waves (note that there is no net transport of water: hence no net transport of mass).
In Quantum Mechanics this neat distinction is blurred. Entities which we would normally think of as particles (e.g. electrons) can behave like waves in certain situations, while entities which we would normally think of as waves (e.g. electromagnetic radiation: light) can behave like particles. Thus electrons can create wave-like diffraction patterns upon passing through narrow slits, just like water waves do as they pass through the entrance to a harbour. Conversely, the photoelectric effect (i.e. the absorption of light by electrons in solids) can only be explained if the light has a particulate nature (leading to the concept of photons).
Such ideas led DeBroglie to the conclusion that all entities had both wave and particle aspects, and that different aspects were manifested by the entity according to what type of process it was undergoing. This became known as the Principle of Wave-Particle Duality. Furthermore, DeBroglie was able to relate the momentum of a "particle" to the wavelength (i.e. the peak-to-peak distance) of the corresponding "wave". The DeBroglie relation tells us that p=h/lambda, where p is the particle's momentum, lambda is its wavelength and h is Planck's constant. Thus it is possible to calculate the quantum wavelength of a particle through knowledge of its momentum.
This was important because wave phenomena, such as diffraction, are generally only important when waves interact with objects of a size comparable to their wavelength. Fortunately for the theory, the wavelength of everyday objects moving at everyday speeds turns out to be incredibly small. So small in fact that no Quantum Mechanical effects should be noticeable at the macroscopic level, confirming that Newtonian Mechanics is perfectly acceptable for everyday applications (as required by the Correspondence Principle). Conversely, small objects like electrons have wavelengths comparable to the microscopic atomic structures they encounter in solids. Thus a Quantum Mechanical description, which includes their wave-like aspects, is essential to their understanding.
Hopefully the foregoing discussion provides a convincing enough argument to use Quantum Mechanical ideas when dealing with electrons in solids. Next we must address the question of how exactly one describes electrons in a wave-like manner....
The Schrodinger Equation
OK, OK, I know I said I would avoid equations, but I can't write about Quantum Mechanics and not mention the biggie now can I ? What I will do is try to talk about the ideas behind the equation, and its consequences, rather than dwell on the form of the equation itself. Given the current limitations of html I'm not even going to try and write it out for you, its easy enough to find in any QM textbook. There are actually two Schrodinger equations: time-dependent and time-independent. We'll start with the time-dependent version and see what all the fuss is about....
The approach suggested by Schrodinger was to postulate a function which would vary in both time and space in a wave-like manner (the so-called wavefunction) and which would carry within it information about a particle or system. The time-dependent Schrodinger equation allows us to deterministically predict the behaviour of the wavefunction over time, once we know its environment. The information concerning environment is in the form of the potential which would be experienced by the particle according to classical mechanics (if you are unfamiliar with the classical concept of potential an explanation is available).
Whenever we make a measurement on a Quantum system, the results are dictated by the wavefunction at the time at which the measurement is made. It turns out that for each possible quantity we might want to measure (an observable) there is a set of special wavefunctions (known as eigenfunctions) which will always return the same value (an eigenvalue) for the observable. e.g.....
EIGENFUNCTION always returns EIGENVALUE
where (x,t) is standard notation to remind us that the eigenfunctions psi_n(x,t)
are dependent upon position (x) and time (t).
Even if the wavefunction happens not to be one of these eigenfunctions, it is always possible to think of it as a unique superposition of two or more of the eigenfunctions, e.g....
psi(x,t) = c_1*psi_1(x,t) + c_2*psi_2(x,t) + c_3*psi_3(x,t) + ....
where c_1, c_2,.... are coefficients which define the composition of the state.
If a measurement is made on such a state, then the following two things will happen:
The wavefunction will suddenly change into one or other of the eigenfunctions making it up. This is known as the collapse of the wavefunction and the probability of the wavefunction collapsing into a particular eigenfunction depends on how much that eigenfunction contributed to the original superposition. More precisely, the probability that a given eigenfunction will be chosen is proportional to the square of the coefficient of that eigenfunction in the superposition, normalised so that the overall probability of collapse is unity (i.e. the sum of the squares of all the coefficients is 1).
The measurement will return the eigenvalue associated with the eigenfunction into which the wavefunction has collapsed. Clearly therefore the measurement can only ever yield an eigenvalue (even though the original state was not an eigenfunction), and it will do so with a probability determined by the composition of the original superposition. There are clearly only a limited number of discrete values which the observable can take. We say that the system is quantised (which means essentially the same as discretised).
Once the wavefunction has collapsed into one particular eigenfunction it will stay in that state until it is perturbed by the outside world. The fundamental limitation of Quantum Mechanics lies in the Heisenberg Uncertainty Principle which tells us that certain quantum measurements disturb the system and push the wavefunction back into a superposed state once again.
For example, consider a measurement of the position of a particle. Before the measurement is made the particle wavefunction is a superposition of several position eigenfunctions, each corresponding to a different possible position for the particle. When the measurement is made the wavefunction collapses into one of these eigenfunctions, with a probability determined by the composition of the original superposition. One particular position will be recorded by the measurement: the one corresponding to the eigenfunction chosen by the particle.
If a further position measurement is made shortly afterwards the wavefunction will still be the same as when the first measurement was made (because nothing has happened to change it), and so the same position will be recorded. However, if a measurement of the momentum of the particle is now made, the particle wavefunction will change to one of the momentum eigenfunctions (which are not the same as the position eigenfunctions). Thus, if a still later measurement of the position is made, the particle will once again be in a superposition of possible position eigenfunctions, so the position recorded by the measurement will once again come down to probability. What all this means is that one cannot know both the position and the momentum of a particle at the same time because when you measure one quantity you randomise the value of the other. See below....
notation: x=position, p=momentum
action | wavefunction after action
start | superposition of x and/or p eigenfunctions
measure x | x eigenfunction = superposition of p eigenfunctions
measure x again | same x eigenfunction
measure p | p eigenfunction = superposition of x eigenfunctions
measure x again | x eigenfunction (not necessarily same one as before)
Precisely what constitutes a measurement and the process by which the wavefunction collapses are two issues I am not even going to touch on. Suffice to say they are still matters for vigorous debate !
At any rate, in a macroscopic system the wavefunctions of the many component particles are constantly being disturbed by measurement-like processes, so a macroscopic measurement on the system only ever yields a time- and particle- averaged value for an observable. This averaged value need not, of course, be an eigenvalue, so we do not generally observe quantisation at the macroscopic level (the correspondence principle again). If we are to investigate the microscopic behaviour of particles we would (in an ideal world) like to know the wavefunctions of any individual particles at any given instant in time....
The time-dependent Schrodinger equation allows us to calculate the wavefunctions of particles, given the potential in which they move. Importantly, all the solutions of this equation will vary over time in some kind of wave-like manner, but only certain solutions will vary in a predictable pure sinusoidal manner. These special solutions of the time-dependent Schrodinger equation turn out to be the energy eigenfunctions, and can be written as a time-independent factor multiplied by a sinusoidal time-dependent factor related to the energy (in fact the frequency of the sine wave is given by the relation E=h*frequency). Because of the simple time-dependence of these functions the time-dependent Schrodinger equation reduces to the time-independent Schrodinger equation for the time-independent part of the energy eigenfunctions. That is to say that we can find the energy eigenfunctions simply by solving the time-independent Schrodinger equation and multiplying the solutions by a simple sinusoidal factor related to the energy. It should therefore always be remembered that the solutions to the time-independent Schrodinger equation are simply the amplitudes of the solutions to the full time-dependent equation.
The bottom line is that we can use the time-dependent Schrodinger equation (or often the simpler time-independent version) to tell us what the wavefunctions of a quantum system are, entirely deterministically. That is, we do not have to resort to the language of probability. Once we try to apply this knowledge to the real world (i.e. to predict the outcome of measurements, etc) then we have to speak in terms of probabilities.
As a last point, it is important to realise that there is no real physical interpretation for the wavefunction. It simply contains information regarding the system to which it refers. However, one of the most important characteristics of a wavefunction is that the square of its magnitude is a measure of the probability of finding a particle described by the wavefunction at a given point in space. That is, in regions where the square of the magnitude of the wavefunction is large, the probability of finding the particle in that region is also large, and vice versa
Thursday, 15 May 2014
A new meteor shower spawned by a comet is due to light up the sky next week, with some forecasters predicting up to 200 "shooting stars" per hour — a potentially spectacular opening act for the meteor display.
Comet 209P/LINEARPin It Comet 209P/LINEAR appears as a dim, dusty object at the center of this photo taken by NASA astronauts at the Marshall Space Flight Center in Huntsville, Ala. in May 2014. Dust from the comet is expected to create a meteor shower that will be first seen on Earth in May 2014.
Credit: NASA Marshall Space Flight CenterView full size image
If it performs as expected, the never-before-seen Camelopardalid meteor shower is due to peak overnight on May 23 and 24 as the Earth passes through a debris stream left by the Comet 209P/LINEAR nearly 200 years ago. The new meteor display could rival the brilliance of the annual Perseid meteor shower that graces the night sky each August.
The prospect of a brand-new meteor shower has scientists understandably excited.
"There could be a new meteor shower, and I want to see it with my own eyes," said NASA meteor expert Bill Cooke, head of the Meteoroid EnvironmentOffice at the Marshall Space Flight Center in Huntsville, Ala., in a statement. [New Meteor Shower from Comet 209P/LINEAR
Please +1 Guys..
Please +1 Guys..
Wednesday, 14 May 2014
Scientist John Dorelli explains the MMS mission's orbit and why the four spacecraft fly in a tetrahedron formation. This complex arrangement enables scientists to gather data about magnetic reconnection in 3D.
On its journey, MMS will observe a little-understood, but universal phenomenon called magnetic reconnection, responsible for dramatic re-shaping of the magnetic environment near Earth, often sending intense amounts of energy and fast-moving particles off in a new direction. Not only is this a fundamental physical process that occurs throughout the universe, it is also one of the drivers of space weather events at Earth. To truly understand the process, requires four identical spacecraft to track how such re-connection events move across and through any given space.
Tuesday, 13 May 2014
A massive glacier system has started collapsing in West Antarctica due to global warming, and studies by two different teams of scientists claim the collapse will result in a significant rise in sea levels worldwide.
A slow-motion disaster may be unfolding according to two different teams of scientists. The scientists reported earlier this week that the Thwaites Glacier, which acts as a keystone holding back the massive West Antarctic Ice Sheet is starting to collapse. According to the reports, the entire ice sheet is doomed to collapse, raising sea levels worldwide by as much as four feet or more.
In an article published online today in Science, one team combined recent data on the receding 182,000-square-kilometer Thwaites Glacier with computer modeling of the glacier’s dynamics to forecast future movement.
The rapidly melting West Antarctic Ice Sheet is in an irreversible state of decline according to the latest NASA study. As a result, the ‘ice-dam’ preventing glaciers in the area melting into the sea will ultimately disappear.
The rapidly melting West Antarctic Ice Sheet is in an irreversible state of decline according to the latest NASA study. As a result, the ‘ice-dam’ preventing glaciers in the area melting into the sea will ultimately disappear.
West Antarctic glaciers already contribute significantly to sea level rise. They release as much ice into the ocean annually as the entire Greenland Ice Sheet and contain enough ice to increase global sea levels by 4 feet (1.2 meters). The West Antarctic Ice Sheet is melting faster than most scientists had expected, meaning that current predictions of sea level rise will need to be revised upward.
Researchers from NASA and the University of California, Irvine used 40 years of observations in their study published Monday. Lead author Eric Rignot, of UC Irvine and NASA’s Jet Propulsion Laboratory, Pasadena said the multiple lines of evidence considered by the researchers lead them to conclude that glaciers in the Amundsen Sea sector of West Antarctica “have passed the point of no return.”
Saturday, 10 May 2014
In order to awaken to our true self of infinite Divine consciousness, we must relinquish the conditioning of the disharmonic frequencies of our consciousness that is the operation of mind as thought and emotion. This is the thinking mind and emotional energy system that is within both the conscious and unconscious levels of mind. We open to heart consciousness when we directly resonate the Light within.
The awareness within is the way that we experience and express our nonlocal unity. The moment we look without for the resolution of our true nature, we fragment our consciousness in a veil of separation. Ideas, thoughts, people, places, etc., cannot provide our unity that is only from the pure awareness of our heart consciousness. Our fear-based conditioning has directed us to look outside for an answer to our wholeness, success, or evolution. If we are looking outside for an answer, we will reinforce the neural circuitry and emotional encoding of conflict, control, and separation. The resonance of our love, peace, and creativity is solely an inner choice. Any external experience in this dimension can only serve as a reminder of our response to receive, generate, and transmit our frequency.
The Light is harmonic, fluid, frictionless, and with no opposition, conflict, or resistance. In the incarnate dimensions of the universe, the full embodiment of Divine consciousness is a pure movement of frequencies of matter that pulse in a synchronous expansive and contractive movement. There is not the constant inertia, friction, resistance, and struggle that has been the experience in a 3D/4D experience of the movement of matter. Divine infinite consciousness experienced through the Light mind in the heart is a whole new experience of the frequencies of consciousness as physical matter. These harmonic frequencies do not operate on the reactionary friction based energies of thought and emotion.
The thinking mind and emotions are based on accumulated past programming. This conditioning system of mind and emotional signaling system is a restrictive protective system of conflict in a survival based consciousness. The experience of hurtful actions of conflict is a result of the inharmonic dense level of consciousness that has infiltrated the human mind and body over thousands of years
Thursday, 8 May 2014
William Harvey "Bill" Dana (November 3, 1930 -- May 6, 2014) was a NASA test pilot and astronaut.
Dana was born in Pasadena, California on November 3, 1930. He received a Bachelor of Science degree from the United States Military Academy in 1952 and served four years as a pilot in the United States Air Force. He joined NASA after receiving a Master of Science degree in Aeronautical Engineering from the University of Southern California in 1958.
Dana was Chief Engineer at NASA's Dryden Flight Research Center, Edwards Air Force Base, California, from 1993 until 1998, when he retired after almost 40 years of distinguished service to NASA. Formerly an aerospace research pilot, Dana flew the F-100 variable stability research aircraft and the Advanced Fighter Technology Integration/F-16 aircraft as well as many others.
Before his assignment as Chief Engineer, he was Assistant Chief of the Flight Operations Division, a position he assumed after serving since 1986 as Chief Pilot. He was also a project pilot on the F-15 HIDEC (Highly Integrated Digital Electronic Control) research program, and a co-project pilot on the F-18 High Angle of Attack research program.
As a research pilot, Dana was involved in some of the most significant aeronautical programs carried out at Dryden. For his service as a flight research pilot, he received NASA Distinguished Service Medal in 1997. In 2000 he was awarded the Milton O. Thompson Lifetime Achievement Award by the Dryden Flight Research Center.
From 1960 through 1962 he was a pilot astronaut in the U.S. Air Force X-20 Dyna-Soar program.
Dana was a project pilot on the hypersonic North American X-15 research aircraft and flew the rocket-powered vehicle 16 times, reaching a top speed of 3,897 mph. His peak altitude of 307,000 feet (nearly 59 miles high) technically qualified him for the Astronaut Badge, although he was not formally recognized as an astronaut until 2005. He was the pilot on the final (199th) flight of the 10-year program.
In the late 1960s and in the 1970s, Dana was a project pilot on the manned lifting body program, which flew several versions of the wingless vehicles and produced data that helped in development of the Space Shuttle. He completed one NASA M2-F1, nine Northrop HL-10, nineteen Northrop M2-F3 and two Martin Marietta X-24B flights, for a total of 31 lifting body missions.
Dana was married to Judi Dana since 1962. Together, they raised four children: Sidney, Matt, Janet (Jan), and Leslie (Cricket). Dana died on May 5, 2014.
For his contributions to the lifting body program, Dana received the NASA Exceptional Service Medal. In 1976 he received the Haley Space Flight Award from the American Institute of Aeronautics and Astronautics (AIAA) for his research work on the M2-F3 lifting body control systems.
A member of the Society of Experimental Test Pilots, Dana is the author of several technical papers. In 1993, he was inducted into the Aerospace Walk of Honor.
Sunday, 4 May 2014
The more precisely the position is determined, the less precisely the momentum is known in this instant, and vice versa.
--Heisenberg, uncertainty paper, 1927
This is a succinct statement of the "uncertainty relation" between the position and the momentum (mass times velocity) of a subatomic particle, such as an electron. This relation has profound implications for such fundamental notions as causality and the determination of the future behavior of an atomic particle.
Because of the scientific and philosophical implications of the seemingly harmless sounding uncertainty relations, physicists speak of an uncertainty principle, which is often called more descriptively the "principle of indeterminacy." This page focuses on the origins of Heisenberg's uncertainty relations and principle.
Erwin Schrödinger, the founder of wave mechanics
The origins of uncertainty entail almost as much personality as they do physics. Heisenberg's route to uncertainty lies in a debate that began in early 1926 between Heisenberg and his closest colleagues on the one hand, who espoused the "matrix" form of quantum mechanics, and Erwin Schrödinger and his colleagues on the other, who espoused the new "wave mechanics."
I knew of [Heisenberg's] theory, of course, but I felt discouraged, not to say repelled, by the methods of transcendental algebra, which appeared difficult to me, and by the lack of visualizability.
-Schrödinger in 1926
Louis de Broglie, who discovered the theoretical existence of matter waves
Most physicists were slow to accept "matrix mechanics" because of its abstract nature and its unfamiliar mathematics. They gladly welcomed Schrödinger's alternative wave mechanics when it appeared in early 1926, since it entailed more familiar concepts and equations, and it seemed to do away with quantum jumps and discontinuities. French physicist Louis de Broglie had suggested that not only light but also matter might behave like a wave. Drawing on this idea, to which Einstein had lent his support, Schrödinger attributed the quantum energies of the electron orbits in the old quantum theory of the atom to the vibration frequencies of electron "matter waves" around the atom's nucleus. Just as a piano string has a fixed tone, so an electron-wave would have a fixed quantum of energy. This led to much easier calculations and more familiar visualizations of atomic events than did Heisenberg's matrix mechanics, where the energy was found in an abstruse calculation.
I had no faith in a theory that ran completely counter to our Copenhagen conception.
In May 1926 Schrödinger published a proof that matrix and wave mechanics gave equivalent results: mathematically they were the same theory. He also argued for the superiority of wave mechanics over matrix mechanics. This provoked an angry reaction, especially from Heisenberg, who insisted on the existence of discontinuous quantum jumps rather than a theory based on continuous waves.
There was more at stake than personal preferences, for jobs were now in the balance for the creators of matrix mechanics. Most of the young men who created matrix mechanics were ready to move into teaching positions as professors, and the older generation of theoretical physicists was beginning to vacate positions at German universities. Heisenberg's family was exerting pressure on the young man to capture one of the vacancies at the same time that his best work, matrix mechanics, seemed to be overshadowed by wave mechanics.
The more I think about the physical portion of Schrödinger's theory, the more repulsive I find it...What Schrödinger writes about the visualizability of his theory 'is probably not quite right,' in other words it's crap.
--Heisenberg, writing to Pauli, 1926
Heisenberg had just begun his job as Niels Bohr's assistant in Copenhagen when Schrödinger came to town in October 1926 to debate the alternative theories with Bohr. The intense debates in Copenhagen proved inconclusive. They showed only that neither interpretation of atomic events could be considered satisfactory. Both sides began searching for a satisfactory physical interpretation of the quantum mechanics equations in line with their own preferences
|After Schrödinger showed the equivalence of the matrix and wave versions of quantum mechanics, and Born presented a statistical interpretation of the wave function, Jordan in Göttingen and Paul Dirac in Cambridge, England, created unified equations known as "transformation theory." These formed the basis of what is now regarded as quantum mechanics. The task then became a search for the physical meaning of these equations in actual situations showing the nature of physical objects in terms of waves or particles, or both. As Bohr later explained it, events in tiny atoms are subject to quantum mechanics, yet people deal with larger objects in the laboratory, where the "classical" physics of Newton prevails. What was needed was an "interpretation" of the Dirac-Jordan quantum equations that would allow physicists to connect observations in the everyday world of the laboratory with events and processes in the quantum world of the atom.|
|Studying the papers of Dirac and Jordan, while in frequent correspondence with Wolfgang Pauli, Heisenberg discovered a problem in the way one could measure basic physical variables appearing in the equations. His analysis showed that uncertainties, or imprecisions, always turned up if one tried to measure the position and the momentum of a particle at the same time. (Similar uncertainties occurred when measuring the energy and the time variables of the particle simultaneously.) These uncertainties or imprecisions in the measurements were not the fault of the experimenter, said Heisenberg, they were inherent in quantum mechanics. Heisenberg presented his discovery and its consequences in a 14-page letter to Pauli in February 1927. The letter evolved into a published paper in which Heisenberg presented to the world for the first time what became known as the uncertainty principle|
Saturday, 3 May 2014
Quantum mechanics (QM -- also known as quantum physics, or quantum theory) is a branch of physics which deals with physical phenomena at nanoscopic scales where the action is on the order of the Planck constant. It departs from classical mechanics primarily at the quantum realm of atomic and subatomic length scales. Quantum mechanics provides a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. Quantum mechanics provides a substantially useful framework for many features of the modern periodic table of elements including the behavior of atoms during chemical bonding and has played a significant role in the development of many modern technologies.
In advanced topics of quantum mechanics, some of these behaviors are macroscopic (see macroscopic quantum phenomena) and emerge at only extreme (i.e., very low or very high) energies or temperatures (such as in the use of superconducting magnets). For example, the angular momentum of an electron bound to an atom or molecule is quantized. In contrast, the angular momentum of an unbound electron is not quantized. In the context of quantum mechanics, the wave--particle duality of energy and matter and the uncertainty principle provide a unified view of the behavior of photons, electrons, and other atomic-scale objects.
The mathematical formulations of quantum mechanics are abstract. A mathematical function, the wavefunction, provides information about the probability amplitude of position, momentum, and other physical properties of a particle. Mathematical manipulations of the wavefunction usually involve bra--ket notation which requires an understanding of complex numbers and linear functionals. The wavefunction formulation treats the particle as a quantum harmonic oscillator, and the mathematics is akin to that describing acoustic resonance. Many of the results of quantum mechanics are not easily visualized in terms of classical mechanics. For instance, in a quantum mechanical model the lowest energy state of a system, the ground state, is non-zero as opposed to a more "traditional" ground state with zero kinetic energy (all particles at rest). Instead of a traditional static, unchanging zero energy state, quantum mechanics allows for far more dynamic, chaotic possibilities, according to John Wheeler.
The earliest versions of quantum mechanics were formulated in the first decade of the 20th century. About this time, the atomic theory and the corpuscular theory of light (as updated by Einstein) first came to be widely accepted as scientific fact; these latter theories can be viewed as quantum theories of matter and electromagnetic radiation, respectively. Early quantum theory was significantly reformulated in the mid-1920s by Werner Heisenberg, Max Born and Pascual Jordan, (matrix mechanics); Louis de Broglie and Erwin Schrödinger (wave mechanics); and Wolfgang Pauli and Satyendra Nath Bose (statistics of subatomic particles). Moreover, the Copenhagen interpretation of Niels Bohr became widely accepted. By 1930, quantum mechanics had been further unified and formalized by the work of David Hilbert, Paul Dirac and John von Neumann with a greater emphasis placed on measurement in quantum mechanics, the statistical nature of our knowledge of reality, and philosophical speculation about the role of the observer. Quantum mechanics has since permeated throughout many aspects of 20th-century physics and other disciplines including quantum chemistry, quantum electronics, quantum optics, and quantum information science. Much 19th-century physics has been re-evaluated as the "classical limit" of quantum mechanics and its more advanced developments in terms of quantum field theory, string theory, and speculative quantum gravity theories.
The name quantum mechanics derives from the observation that some physical quantities can change only in discrete amounts (Latin quanta), and not in a continuousway.
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"The Gift of Mental power comes from God, Divine Being.If we Concentrate our minds on that truth, we become in tune with this great power" - Nikola Tesla
Thursday, 1 May 2014
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