Repliee is more than a humanoid robot ? it is an
     honest-to-goodness android, so lifelike that it seems like
     a real person. It has moist lips, glossy hair and vivid
     eyes that blink slowly. Seated on a stool with hands
 5    folded primly on its lap at the 2005 World Exposition in
     Japan's Aichi prefecture, it wore a bright pink blazer and
     gray slacks. For a mesmerizing few seconds from several
     meters away, Repliee was virtually indistinguishable from
     an ordinary woman in her 30s. In fact, it was a copy of
 10    one.
          Japan is proud of the most advanced humanoids in
     the world, which are expected to eventually be used as
     the workforce diminishes among the decreasing and aging
     population. But why build a robot with pigmented silicone
 15    skin, smooth gestures and even makeup? To Repliee's
     creator, Hiroshi Ishiguro, Director of Osaka University's
     Intelligent Robotics Laboratory, the answer is simple:
     "Android science."
          Besides the justification for making robots
 20    anthropomorphic and bipedal so they can work in human
     environments with architectural features such as stairs,
     Ishiguro believes that people respond better to very
     humanlike automatons. Androids can thus elicit the most
     natural communication. "Appearance is very important
 25    to have better interpersonal relationships with a robot,"
     says the 42-year-old Ishiguro. "Robots are information
     media, especially humanoid robots. Their main role in
     our future is to interact naturally with people."
          Mild colorblindness forced Ishiguro to abandon his
 30    aspirations of a career as an oil painter. Drawn to
     computer and robot vision instead, he built a guide robot
     for the blind as an undergraduate at the University of
     Yamanashi. A fan of the android character Data from the
     Star Trek franchise, he sees robots as the ideal vehicle
 35    to understand more about ourselves.
          To imitate human looks and behavior successfully,
     Ishiguro combines robotics with cognitive science. In turn,
     cognitive science research can use the robot to study
     human perception, communication and other faculties.
 40    This novel cross-fertilization is what Ishiguro describes
     as android science. In a 2005 paper, he and his
     collaborators explained it thus: "To make the android
     humanlike, we must investigate human activity from the
     standpoint of cognitive science, behavioral science and
 45    neuroscience, and to evaluate human activity, we need
     to implement processes that support it in the android."
          One key strategy in Ishiguro's approach is to model
     his artificial creations on real people. He began research
     four years ago with his then four-year-old daughter,
 50    casting a rudimentary android from her body, but its
     mechanisms resulted in strange, unnatural motion.
          Humanlike robots run the risk of compromising
     people's comfort zones. Because the android's
     appearance is very similar to that of a human, any subtle
 55    differences in motion and responses will make it seem
     strange. Repliee, though, is so lifelike that it has
     overcome the creepiness factor, partly because of the
     natural way it moves.
          Ishiguro wants his next android, a male, to be as
 60    authentic as possible. The model? Himself. The scientist
     thinks having a robot clone could ease his busy schedule:
     he could dispatch it to classes and meetings and then
     teleconference through it. "My question has always been,
     Why are we living, and what is human?" he says. An
 65    Ishiguro made of circuitry and silicone might soon be
     answering his own questions.

adapted from www.scientificamerican.com - May 2006

          What are the best energy sources? "Best" depends
     on many factors - how the energy is being used, where
     it is being used, what energy sources are available,
     which sources are most convenient and reliable, which
5   are easiest to use, what each costs, and the effects on
     public safety, health, and the environment. Making smart
     energy choices means understanding resources and their
     relative costs and benefits.
          Some energy sources have advantages for specific
10  uses or locations. For example, fuels from petroleum
     are well suited for transportation because they pack a
     lot of energy in a small space and are easily transported
     and stored. Small hydroelectric installations are a good
     solution for supplying power or mechanical energy close
15  to where it is used. Coal is widely used for power
     generation in many fast-developing countries - including
     China, India, and many others - because domestic
     supplies are readily available.
          Efficiency is an important factor in energy costs.
20  How efficiently can the energy be produced, delivered,
     and used? How much energy value is lost in that process,
     and how much ends up being transformed into useful
     work? Industries that produce or use energy continually
     look for ways to improve efficiency, since this is a key to
25  making their products more competitive.
          The ideal energy source - cheap, plentiful, and
     pollution-free - may prove unattainable in our lifetime,
     but that is the ultimate goal. The energy industry is
     continuing to improve its technologies and practices, to
30  produce and use energy more efficiently and cleanly.
          Energy resources are often categorized as
     renewable or nonrenewable.
          Renewable energy resources are those that can be
     replenished quickly - examples are solar power,
35  biomass, geothermal, hydroelectric, wind power, and
     fast-reaction nuclear power. They supply about seven
     percent of energy needs in the United States; the other
     93 percent comes from nonrenewables. The two largest
     categories of renewable energy now in use in the U.S.
40  are biomass - primarily wood wastes that are used by
     the forest products industry to generate electricity and
     heat - and hydroelectricity.
          Nonrenewable energy resources include coal, oil,
     natural gas, and uranium-235, which is used to fuel
45  slow-reaction nuclear power. Projections of how long a
     nonrenewable energy resource will last depend on many
     changeable factors. These include the growth rate of
     consumption, and estimates of how much of the remaining
     resources can be economically recovered. New exploration
50  and production technologies often increase the ability of
     producers to locate and recover resources. World
     reserves of fossil energy are projected to last for many
     more decades - and, in the case of coal, for centuries.

In: http://www.classroom-energy.org/teachers/energy_tour/pg5.html