Question:
General relativity includes a dynamical spacetime, so it is difficult to see how to identify the conserved energy and momentum. Noether's theorem allows these quantities to be determined from a Lagrangian with translation invariance, but general covariance makes translation invariance into something of a gauge symmetry. The energy and momentum derived within general relativity by Noether's presecriptions do not make a real tensor for this reason. Einstein argued that this is true for fundamental reasons, because the gravitational field could be made to vanish by a choice of coordinates. He maintained that the non-covariant energy momentum pseudotensor was in fact the best description of the energy momentum distribution in a gravitational field. This approach has been echoed by Lev Landau and Evgeny Lifshitz, and others, and has become standard. The use of non-covariant objects like pseudotensors was heavily criticized in 1917 by Erwin Schrodinger and others. After reading the above, is "Noether's theory" the correct answer to the question "Who's theory did not have a more precise symmetry for conserved energy and momentum?"?

Answer:
yes

Question:
Clarifying the Record The defense of U.S. airspace on 9/11 was not conducted in accord with preexisting training and protocols. It was improvised by civilians who had never handled a hijacked aircraft that attempted to disappear, and by a military unprepared for the transformation of commercial aircraft into weapons of mass destruction. As it turned out, the NEADS air defenders had nine minutes' notice on the first hijacked plane, no advance notice on the second, no advance notice on the third, and no advance notice on the fourth. We do not believe that the true picture of that morning reflects discredit on the operational personnel at NEADS or FAA facilities. NEADS commanders and officers actively sought out information, and made the best judgments they could on the basis of what they knew. Individual FAA controllers, facility managers, and Command Center managers thought outside the box in recommending a nationwide alert, in ground-stopping local traffic, and, ultimately, in deciding to land all aircraft and executing that unprecedented order flawlessly. More than the actual events, inaccurate government accounts of those events made it appear that the military was notified in time to respond to two of the hijackings, raising questions about the adequacy of the response. Those accounts had the effect of deflecting questions about the military's capacity to obtain timely and accurate information from its own sources. In addition, they overstated the FAA's ability to provide the military with timely and useful information that morning. In public testimony before this Commission in May 2003, NORAD officials stated that at 9:16, NEADS received hijack notification of United 93 from the FAA. This statement was incorrect. There was no hijack to report at 9:16. United 93 was proceeding normally at that time. In this same public testimony, NORAD officials stated that at 9:24, NEADS received notification of the hijacking of American 77. This statement was also incorrect. The notice NEADS received at 9:24 was that American 11 had not hit the World Trade Center and was heading for Washington, D.C. In their testimony and in other public accounts, NORAD officials also stated that the Langley fighters were scrambled to respond to the notifications about American 77,178 United 93, or both. These statements were incorrect as well. The fighters were scrambled because of the report that American 11 was heading south, as is clear not just from taped conversations at NEADS but also from taped conversations at FAA centers; contemporaneous logs compiled at NEADS, Continental Region headquarters, and NORAD; and other records. After reading the above, is "FAA" the correct answer to the question "Who needed to clarify the record of the U.S. defense of 9/11?"?

Answer:
no

Question:
We do not know exactly how the hijackers gained access to the cockpit; FAA rules required that the doors remain closed and locked during flight. Ong speculated that they had "jammed their way" in. Perhaps the terrorists stabbed the flight attendants to get a cockpit key, to force one of them to open the cockpit door, or to lure the captain or first officer out of the cockpit. Or the flight attendants may just have been in their way. At the same time or shortly thereafter, Atta-the only terrorist on board trained to fly a jet-would have moved to the cockpit from his business-class seat, possibly accompanied by Omari. As this was happening, passenger Daniel Lewin, who was seated in the row just behind Atta and Omari, was stabbed by one of the hijackers-probably Satam al Suqami, who was seated directly behind Lewin. Lewin had served four years as an officer in the Israeli military. He may have made an attempt to stop the hijackers in front of him, not realizing that another was sitting behind him. The hijackers quickly gained control and sprayed Mace, pepper spray, or some other irritant in the first-class cabin, in order to force the passengers and flight attendants toward the rear of the plane. They claimed they had a bomb. About five minutes after the hijacking began, Betty Ong contacted the American Airlines Southeastern Reservations Office in Cary, North Carolina, via an AT&T airphone to report an emergency aboard the flight. This was the first of several occasions on 9/11 when flight attendants took action outside the scope of their training, which emphasized that in a hijacking, they were to communicate with the cockpit crew. The emergency call lasted approximately 25 minutes, as Ong calmly and professionally relayed information about events taking place aboard the airplane to authorities on the ground. At 8:19, Ong reported:"The cockpit is not answering, somebody's stabbed in business class-and I think there's Mace-that we can't breathe-I don't know, I think we're getting hijacked." She then told of the stabbings of the two flight attendants. At 8:21, one of the American employees receiving Ong's call in North Carolina, Nydia Gonzalez, alerted the American Airlines operations center in Fort Worth, Texas, reaching Craig Marquis, the manager on duty. Marquis soon realized this was an emergency and instructed the airline's dispatcher responsible for the flight to contact the cockpit. At 8:23, the dispatcher tried unsuccessfully to contact the aircraft. After reading the above, is "The passengers" the correct answer to the question "Who claimed there was a bomb on the plane?"?

Answer:
no