QUES: Renewable Energy Resource Sunlight Sunlight can be used to heat homes. It can also be used to produce electricity. This conversion is made possible by solar cells. However, solar energy may not always be practical. Some areas are just too cloudy. Example Solar panels on the roof of this house generate enough electricity to supply a familys needs. Moving Water Falling water can have a lot of energy. Its energy can be converted into kinetic energy. This energy can turn a turbine and generate electricity. The water may fall naturally over a waterfall or flow through a dam. A drawback of dams is that they flood land upstream. They can also reduce water flow downstream. Either effect may harm ecosystems. Wind Wind is moving air. It has kinetic energy that can do work. Wind turbines change the kinetic energy of the wind to electrical energy. Only certain areas of the world get enough steady wind. Many people also think that wind turbines are noisy and not very nice to look at.
Do you have any questions?
MY QUESTION: What can these forms of energy be used to produce?

QUES: While this process moved along, diplomacy continued its rounds. Direct pressure on the Taliban had proved unsuccessful. As one NSC staff note put it, "Under the Taliban, Afghanistan is not so much a state sponsor of terrorism as it is a state sponsored by terrorists." In early 2000, the United States began a high-level effort to persuade Pakistan to use its influence over the Taliban. In January 2000, Assistant Secretary of State Karl Inderfurth and the State Department's counterterrorism coordinator, Michael Sheehan, met with General Musharraf in Islamabad, dangling before him the possibility of a presidential visit in March as a reward for Pakistani cooperation. Such a visit was coveted by Musharraf, partly as a sign of his government's legitimacy. He told the two envoys that he would meet with Mullah Omar and press him on Bin Laden. They left, however, reporting to Washington that Pakistan was unlikely in fact to do anything," given what it sees as the benefits of Taliban control of Afghanistan." President Clinton was scheduled to travel to India. The State Department felt that he should not visit India without also visiting Pakistan. The Secret Service and the CIA, however, warned in the strongest terms that visiting Pakistan would risk the President's life. Counterterrorism officials also argued that Pakistan had not done enough to merit a presidential visit. But President Clinton insisted on including Pakistan in the itinerary for his trip to South Asia. His one-day stopover on March 25, 2000, was the first time a U.S. president had been there since 1969. At his meeting with Musharraf and others, President Clinton concentrated on tensions between Pakistan and India and the dangers of nuclear proliferation, but also discussed Bin Laden. President Clinton told us that when he pulled Musharraf aside for a brief, one-on-one meeting, he pleaded with the general for help regarding Bin Laden." I offered him the moon when I went to see him, in terms of better relations with the United States, if he'd help us get Bin Laden and deal with another issue or two." The U.S. effort continued.
Do you have any questions?
MY QUESTION: What did the high-level effort to persuade Pakistan include?

QUES: Shelly wanted a puppy. She asked her mommy and daddy every day for one. She told them that she would help take care of the puppy, if she could have one. Her mommy and daddy talked it over and said that they would get Shelly a new puppy. Her mommy took her to the dog pound so that she could choose one that she wanted. All the puppies at the dog pound need a loving home. Shelly went to every cage and looked each puppy in the eyes and talked to each one. After each one, she told her mommy, "No, this isn't the one for me." Finally, she saw a black and white spotted one that she fell in love with. She screamed, "Mommy, this is the one!" Her mommy asked the worker to take the puppy out so that Shelly could make sure. Shelly and the puppy fell in love with each other right away. Shelly and her mommy took the black and white spotted puppy home with them. Shelly was so excited that she talked all the way home. After thinking hard, Shelly had a name for her new puppy, Spot. Now, Shelly has a new best friend and they play together every day when Shelly gets home from school.
Do you have any questions?
MY QUESTION: How did Shelly decide which puppy was the right one for her?

QUES: 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.
Do you have any questions?
MY QUESTION:
Did Landau use dynamical spacetime in his theory, if not, what?