Monday, April 26, 2010
Thursday, April 22, 2010
Castile and León
Castile and León (Spanish: Castilla y León), known formally as the Community of Castile and León, is one of the 17 autonomous communities of Spain. It was constructed from Old Castile (Spanish: Castilla la Vieja) and León, first as a preautonomía—a "pre-autonomous" region—in 1978 and then as an autonomous community in 1983. It is the largest autonomous community in Spain, covering an area of 94,223 square kilometres (36,380 sq mi) with an official population of around 2.5 million (2005).
The supreme law of Castile and León, under the Spanish Constitution of 1978, is the region's Statute of Autonomy. The statute lays out the basic laws of the region and defines a series of essential values and symbols of the inhabitants of Castile and León, such as their linguistic patrimony (the Castilian language, which English-speakers common refer to simply as "Spanish", as well as Leonese and Galician), as well as their historic, artistic, and natural patrimony. Other symbols alluded to are the coat of arms, flag, and banner; there is also allusion to a regional anthem, though as of 2009 none has been adopted. April 23 is designated Castile and León Day, commemorating the defeat of the comuneros at the Battle of Villalar during the Revolt of the Comuneros, in 1521.
The supreme law of Castile and León, under the Spanish Constitution of 1978, is the region's Statute of Autonomy. The statute lays out the basic laws of the region and defines a series of essential values and symbols of the inhabitants of Castile and León, such as their linguistic patrimony (the Castilian language, which English-speakers common refer to simply as "Spanish", as well as Leonese and Galician), as well as their historic, artistic, and natural patrimony. Other symbols alluded to are the coat of arms, flag, and banner; there is also allusion to a regional anthem, though as of 2009 none has been adopted. April 23 is designated Castile and León Day, commemorating the defeat of the comuneros at the Battle of Villalar during the Revolt of the Comuneros, in 1521.
Sunday, April 11, 2010
Can Special Relativity handle accelerations?
It is a common misconception that Special Relativity cannot handle accelerating objects or accelerating reference frames. It is claimed that general relativity is required because special relativity only applies to inertial frames. This is not true. Special relativity treats accelerating frames differently from inertial frames but can still deal with them. Accelerating objects can be dealt with without even calling upon accelerating frames.
This error often comes up in the context of the twin paradox when people claim that it can only be resolved in general relativity because of acceleration. This is not the case.
The only sense in which special relativity is an approximation when there are accelerating bodies is that gravitational effects such as generation of gravitational waves are being ignored. But of course there are larger gravitational effects being neglected even when massive bodies are not accelerating and they are small for many applications so this is not strictly relevant. Special relativity gives a completely self-consistent description of the mechanics of accelerating bodies neglecting gravitation, just as newtonian mechanics did.
The difference between general and special relativity is that in the general theory all frames of reference including spinning and accelerating frames are treated on an equal footing. In special relativity accelerating frames are different from inertial frames. Velocities are relative but acceleration is treated as absolute. In general relativity all motion is relative. To accommodate this change general relativity has to use curved space-time. In special relativity space-time is always flat.
In special relativity an accelerating particle has a worldline which is not straight. This is not difficult to handle. The 4-vector acceleration can be defined as the derivative with respect to proper time of the 4-velocity. It is possible to solve the equations of motion for a particle in electric and magnetic fields, for example.
Accelerating reference frames are a different matter. In GR the physical equations take the same form in any co-ordinate system. In SR they do not but it is still possible to use co-ordinate systems corresponding to accelerating or rotating frames of reference just as it is possible to solve ordinary mechanics problems in curvilinear co-ordinate systems. This is done by introducing a metric tensor. The formalism is very similar to that of many general relativity problems but it is still special relativity so long as the space-time is constrained to be flat and Minkowskian. Note that the speed of light is rarely constant in non-inertial frames and this has been known to cause confusion.
An example would be a rotating frame of reference used to deal with a rotating object. The transformation of the metric into the rotating frame would lead to "fictitious" forces such as Coriolis forces and centrifugal forces. It is not very different from ordinary mechanics.
A simple problem is to solve the motion of a body which accelerates constantly. What does this mean? We don't mean that its acceleration as measured by an inertial observer is constant. We mean that it is moving so that the acceleration measured in an inertial frame travelling at the same instantaneous velocity as the object is the same at any moment. If it was a rocket and you were on board you would experience a constant G force. This problem can be solved in a number of ways. One is to use four-vector acceleration along its worldline which must have constant magnitude. Alternatively, the object is passing constantly from one inertial frame to another in such a way that its change of speed in a fixed time interval seen as a Lorentz boost is always the same. From our understanding of adding velocities we can see that the rapidity r of the object must be increasing at a constant rate a with respect to the proper time of the object T. The rapidity is related to velocity v by the equation
This error often comes up in the context of the twin paradox when people claim that it can only be resolved in general relativity because of acceleration. This is not the case.
The only sense in which special relativity is an approximation when there are accelerating bodies is that gravitational effects such as generation of gravitational waves are being ignored. But of course there are larger gravitational effects being neglected even when massive bodies are not accelerating and they are small for many applications so this is not strictly relevant. Special relativity gives a completely self-consistent description of the mechanics of accelerating bodies neglecting gravitation, just as newtonian mechanics did.
The difference between general and special relativity is that in the general theory all frames of reference including spinning and accelerating frames are treated on an equal footing. In special relativity accelerating frames are different from inertial frames. Velocities are relative but acceleration is treated as absolute. In general relativity all motion is relative. To accommodate this change general relativity has to use curved space-time. In special relativity space-time is always flat.
In special relativity an accelerating particle has a worldline which is not straight. This is not difficult to handle. The 4-vector acceleration can be defined as the derivative with respect to proper time of the 4-velocity. It is possible to solve the equations of motion for a particle in electric and magnetic fields, for example.
Accelerating reference frames are a different matter. In GR the physical equations take the same form in any co-ordinate system. In SR they do not but it is still possible to use co-ordinate systems corresponding to accelerating or rotating frames of reference just as it is possible to solve ordinary mechanics problems in curvilinear co-ordinate systems. This is done by introducing a metric tensor. The formalism is very similar to that of many general relativity problems but it is still special relativity so long as the space-time is constrained to be flat and Minkowskian. Note that the speed of light is rarely constant in non-inertial frames and this has been known to cause confusion.
An example would be a rotating frame of reference used to deal with a rotating object. The transformation of the metric into the rotating frame would lead to "fictitious" forces such as Coriolis forces and centrifugal forces. It is not very different from ordinary mechanics.
A simple problem is to solve the motion of a body which accelerates constantly. What does this mean? We don't mean that its acceleration as measured by an inertial observer is constant. We mean that it is moving so that the acceleration measured in an inertial frame travelling at the same instantaneous velocity as the object is the same at any moment. If it was a rocket and you were on board you would experience a constant G force. This problem can be solved in a number of ways. One is to use four-vector acceleration along its worldline which must have constant magnitude. Alternatively, the object is passing constantly from one inertial frame to another in such a way that its change of speed in a fixed time interval seen as a Lorentz boost is always the same. From our understanding of adding velocities we can see that the rapidity r of the object must be increasing at a constant rate a with respect to the proper time of the object T. The rapidity is related to velocity v by the equation
v = c tanh(r/c)
From this we derive the equation
v = c tanh(aT/c)
For other acceleration equations see the relativity FAQ article on the relativistic rocket.
Friday, April 9, 2010
Reaction to Justice John Paul Stevens' retirement
Quotes on the retirement of Supreme Court Justice John Paul Stevens:
___
"He has worn the judicial robe with honor and humility. He has applied the Constitution and the laws of the land with fidelity and restraint. He will soon turn 90 this month, but he leaves his position at the top of his game." _President Barack Obama.
___
"Justice Stevens' unique and enduring perspective is irreplaceable; his stalwart adherence to the rule of law is unparalleled. The federal judiciary, and indeed the entire nation, will miss his principled jurisprudence." _Sen. Patrick Leahy, D-Vt., chairman of the Senate Judiciary Committee.
___
"It is important for us to recognize the long and historic role that Justice Stevens has played on the Supreme Court, and to thank him for his lifelong service to his country. He is a tireless worker and a historic figure in America's legal system, and we wish him only the best during his retirement from the court." _Sen. Jeff Sessions of Alabama, senior Republican on the Senate Judiciary Committee.
___
"Justice Stevens has been a strong presence on the court for almost 35 years and worked to build consensus and protect the rule of law. I honor his service to America and wish him well in his retirement." _Senate Majority Leader Harry Reid, D-Nev.
___
"Even if Justice Stevens' liberalism has led to many decisions I oppose, I respect his devotion to the institution and the gentlemanly manner in which he always carried out his work." _Senate Republican Leader Mitch McConnell, R-Ky.
___
"While Justice Stevens' retirement is not unexpected, the loss of such a great leader at a time of great change for America and the court is worrisome. Justice Stevens' greatness is marked not only by the length of his service, but the enduring quality of his jurisprudence. His leadership will affect America for much longer than the 35 years he served on the court." _Sen. Charles Schumer, D-N.Y. and a Senate Judiciary Committee member.
___
"Justice Stevens' commitment to expanding freedom, safeguarding our rights and liberties and understanding the challenges faced by ordinary Americans will be his legal legacy. He has had no judicial agenda other than fidelity to the law and the Constitution." _Majority Whip Dick Durbin, D-Ill., a Senate Judiciary Committee member.
___
"Stevens is among the strongest supporters of the right to choose currently serving on the Supreme Court, and his retirement serves as yet another stark reminder of the important role the court plays in our everyday lives." _Nancy Keenan, president of abortion rights group NARAL Pro-Choice America.
___
"Justice Stevens has had a profound impact on the judiciary and the law. He is a remarkably dedicated public servant and a profoundly decent human being." _Sen. Orrin Hatch, R-Utah, a member and former chairman of the Senate Judiciary Committee.
___
"In recent years, the court has given extraordinary preference to powerful interests at the expense of ordinary Americans. Justice Stevens was a bulwark against that trend." _Michael Keegan, president of the liberal interest group People for the American Way.
"Justice Stevens devoted his career to our nation's judicial system, participating in some of the most important cases in our history. While he and I may have different judicial philosophies, I thank Justice Stevens for his service." _Sen. John Cornyn, R-Texas, a Senate Judiciary Committee member.
___
"He has worn the judicial robe with honor and humility. He has applied the Constitution and the laws of the land with fidelity and restraint. He will soon turn 90 this month, but he leaves his position at the top of his game." _President Barack Obama.
___
"Justice Stevens' unique and enduring perspective is irreplaceable; his stalwart adherence to the rule of law is unparalleled. The federal judiciary, and indeed the entire nation, will miss his principled jurisprudence." _Sen. Patrick Leahy, D-Vt., chairman of the Senate Judiciary Committee.
___
"It is important for us to recognize the long and historic role that Justice Stevens has played on the Supreme Court, and to thank him for his lifelong service to his country. He is a tireless worker and a historic figure in America's legal system, and we wish him only the best during his retirement from the court." _Sen. Jeff Sessions of Alabama, senior Republican on the Senate Judiciary Committee.
___
"Justice Stevens has been a strong presence on the court for almost 35 years and worked to build consensus and protect the rule of law. I honor his service to America and wish him well in his retirement." _Senate Majority Leader Harry Reid, D-Nev.
___
"Even if Justice Stevens' liberalism has led to many decisions I oppose, I respect his devotion to the institution and the gentlemanly manner in which he always carried out his work." _Senate Republican Leader Mitch McConnell, R-Ky.
___
"While Justice Stevens' retirement is not unexpected, the loss of such a great leader at a time of great change for America and the court is worrisome. Justice Stevens' greatness is marked not only by the length of his service, but the enduring quality of his jurisprudence. His leadership will affect America for much longer than the 35 years he served on the court." _Sen. Charles Schumer, D-N.Y. and a Senate Judiciary Committee member.
___
"Justice Stevens' commitment to expanding freedom, safeguarding our rights and liberties and understanding the challenges faced by ordinary Americans will be his legal legacy. He has had no judicial agenda other than fidelity to the law and the Constitution." _Majority Whip Dick Durbin, D-Ill., a Senate Judiciary Committee member.
___
"Stevens is among the strongest supporters of the right to choose currently serving on the Supreme Court, and his retirement serves as yet another stark reminder of the important role the court plays in our everyday lives." _Nancy Keenan, president of abortion rights group NARAL Pro-Choice America.
___
"Justice Stevens has had a profound impact on the judiciary and the law. He is a remarkably dedicated public servant and a profoundly decent human being." _Sen. Orrin Hatch, R-Utah, a member and former chairman of the Senate Judiciary Committee.
___
"In recent years, the court has given extraordinary preference to powerful interests at the expense of ordinary Americans. Justice Stevens was a bulwark against that trend." _Michael Keegan, president of the liberal interest group People for the American Way.
"Justice Stevens devoted his career to our nation's judicial system, participating in some of the most important cases in our history. While he and I may have different judicial philosophies, I thank Justice Stevens for his service." _Sen. John Cornyn, R-Texas, a Senate Judiciary Committee member.
The Masters Golf Tournament 2010
The Master TV Schedule and Live Games Coverage
Masters Golf Tournament 2010: The Master TV Schedule and Live Games Coverage – The much awaited Masters Golf Tournament 2010 event is now on its second day that currently held in Augusta National Golf Club Augusta, Georgia. Masters Golf Tournament 2010 will be aired live by ESPN and CBS channels in US and BBC for UK.
The Masters Golf Tournament started yesterday, April 8, 2010. ESPN will provide the coverage of the event from 4:00 PM – 7:30 PM ET and 8:00 PM – 11:00 PM ET for this day. For the third and fourth round, CBS channel will provide the Masters Golf Tournament coverage at 3:30 PM – 7:00 PM ET on Saturday and 2:00 PM – 7:00 PM ET on Sunday.
Watch the Masters Golf Tournament live stream at Masters official website. You can also catch the game updates and leader board of the game on their official website.
Tuesday, April 6, 2010
West Virginia mine explosion
Twelve miners died Monday and more than a dozen were unaccounted for after an explosion erupted inside an underground mine in Raleigh County, West Virginia, the mine's parent company said.
Another 21 miners were injured in the blast at the Upper Big Branch Mine, according to Michael Mayhorn, emergency dispatcher for Boone County, which was called in to assist in the response.
The explosion apparently occurred during an afternoon shift change, witnesses and officials said.
At least 20 ambulances and three helicopters were dispatched from surrounding counties, and the state medical examiner was heading to the scene, Mayhorn said. At least one miner was evacuated by helicopter, according to Mayhorn.
Don Blankenship, the chief executive officer of Massey Energy Co., which oversees the mine, said in a statement that the company is "working diligently on rescue efforts."
"Our prayers go out to the families of the miners," he said. "We want to assure the families of all the miners we are taking every action possible to locate and rescue those still missing."
The explosion happened about 4:30 p.m. at Massey Energy's Performance Coal Co. mine in Whitesville, West Virginia, 30 miles south of Charleston, West Virginia, CNN affiliate WCHS reported.
The cause of the explosion was not immediately known, but methane gas has been blamed in several deadly mining accidents in recent years, including the 2006 explosion at the Sago mine, also in West Virginia, that killed 12 people. Five miners in Harlan County, Kentucky, were killed five months later in a methane gas explosion in Kentucky Darby Mine No. 1.
West Virginia Gov. Joe Manchin, however, said spring is an unusual time of year to see such explosions, which typically occur in winter as barometric pressure changes occur inside mines.
Manchin said he had spoken to Blankenship, who told him that the mine was equipped with rescue chambers, a safety measure put in place following several deadly accidents in 2006. The chambers are stocked with such supplies as first-aid kits and oxygen tanks in the event of an emergency.
"We're very hopeful that the miners who are missing were able to make it to those rescue chambers," said Manchin, who was on his way to the site.
Manchin also spoke to President Barack Obama, who offered his condolences and federal government assistance in the rescue effort.
Miners paced outside the mine shaft, trying to help emergency responders treating their injured colleagues, said Shawn Kline, a reporter for CNN affiliate WVVA.
"The look of worry is on just about everyone's faces," Kline said as dozens of fire trucks, ambulances and police cars streamed into and out of the site.
Eric Martin, who works the day shift at the mine, told WVVA that his father is one of the missing.
"It's like I got hit in the gut right there real hard (and) I just keep getting hit," he said.
At least one miner was evacuated by helicopter and two others by ambulance, officials said.
CAMC spokeswoman Elizabeth Pellegrin said the hospital received one person from the mine via a helicopter at 6 p.m. That patient is getting treatment in the hospital's intensive care unit, she said, declining to elaborate on the person's injuries.
Sen. Jay Rockefeller, D-West Virginia, said in a statement Monday that he is "working with state and federal officials to get as much information as possible and ... doing all I can to help make sure all resources are made available for this rescue effort."
Massey Energy Co., based in Richmond, Virginia, has operations in West Virginia, Kentucky and Virginia. It is the largest coal producer in Central Appalachia, it said in a statement.
Three other deaths have happened in the Upper Big Branch Mine in the past 12 years, according to federal records.
In 1998, a man was killed when a beam he was constructing collapsed; in 2001, a worker died after a rock fell on him; and in 2003, an electrician who was repairing a shuttle car was found dead, according to the Mine Safety and Health Administration.
Monday's explosion is the latest in a string of problems for Massey Energy, which operates 44 underground and surface mines and controls 2.2 billion tons of coal reserves in West Virginia, Kentucky, Virginia and Tennessee, according to the Environmental Protection Agency and Massey's Web site.
The company has been fined for several incidents, some fatal, at its facilities in recent years, including a 2006 fire that killed two miners in Aracoma Coal Company's Alma Mine No. 1. Aracoma is a division of Massey. The company pleaded guilty to 10 criminal charges in connection with the fire and was fined $2.5 million in 2009.
In 2000, a coal sludge impoundment owned by Massey Energy broke into an abandoned underground mine, oozing more than 300 million gallons of coal waste into tributaries in eastern Kentucky.
Also in 2000, a series of accidents at Massey facilities killed eight miners during the course of the year, according to Davitt McAteer, former director of the Mine Safety and Health Administration during the Clinton administration.
"Massey has had difficulty with their accident records and their numbers of citations and penalties that have been issued against them," McAteer said. "There is a problem here, and it's a problem that we hoped had gone away."
A post on the Massey Web site touts the company's 2009 safety record, saying it "marked the sixth consecutive year and the 17th year out of the past 20 years in which Massey's safety performance was stronger than the industry average."
The U.S. mining industry in 2009 saw its safest year in the history of American mining with 18 deaths. Prior to Monday's explosion, two deaths had been recorded for 2010.
Yusuf Was A Kazab According To Islamic Shariah
This is a response to Zaid Hamid who states that Yusuf can not be called a Kazab, because Shariah rules for calling someone a Kazab were not fulfilled. Watch the video and find out if Shariah rules were fulfilled or not.
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