jupitersterrain four

Katyia

2 October 2012 4:01AM

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The total energy contained in an object is identified with its mass, and energy cannot be created or destroyed. When matter (ordinary material particles) is changed into energy (such as energy of motion, or into radiation), the mass of the system does not change through the transformation process. However, there may be mechanistic limits as to how much of the matter in an object may be changed into other types of energy and thus into work, on other systems. Energy, like mass, is a scalar physical quantity. In the International System of Units (SI), energy is measured in joules, but in many fields other units, such as kilowatt-hours and kilocalories, are customary. All of these units translate to units of work, which is always defined in terms of forces and the distances that the forces act through

Energy may be stored in systems without being present as matter, or as kinetic or electromagnetic energy. Stored energy is created whenever a particle has been moved through a field it interacts with (requiring a force to do so), but the energy to accomplish this is stored as a new position of the particles in the field?a configuration that must be "held" or fixed by a different type of force (otherwise, the new configuration would resolve itself by the field pushing or pulling the particle back toward its previous position). This type of energy "stored" by force-fields and particles that have been pushed into a new physical configuration in the field by doing work on them by another system, is referred to as potential energy. A simple example of potential energy is the work needed to lift an object in a gravity field. Each of the basic forces of nature is associated with a different type of potential energy, and all types of potential energy (like all other types of energy) appears as system mass, whenever present. For example, a compressed spring will be slightly more massive than before it was compressed

In physics, energy energeia?"activity, operation" is an indirectly observed quantity that is often understood as the ability of a physical system to do work on other physical systems. Since work is defined as a force acting through a distance (a length of space), energy is always equivalent to the ability to exert pulls or pushes against the basic forces of nature, along a path of a certain length

Wikipedia

Katyia

2 October 2012 3:05AM

Response to memtitude, 1 October 2012 5:59PM

The problem, as he saw it, was that private-sector consumption and investment plans are formed in the face of expectations about the future economic environment that are inherently uncertain and subject to shifts that have more to do with emotions than with the rational calculations postulated in neoclassical economics. The associated Lucas critique argues that private-sector agents have rational expectations that take into account all the relevant information contained in a model of their behavior then forming their (usually differing) expectations. Their behavior is thus not invariant with regard to the policy interventions of governments or their agencies

theories of unemployment seem rather limited in view of animal spirit - - -

Full employment cannot be achieved because workers would shirk if they were not threatened with the possibility of unemployment. The curve for the no-shirking condition (labeled NSC) goes to infinity at full employment as a result. The inflation-fighting benefits to the entire economy arising from a presumed optimum level of unemployment has been studied extensively. The Shapiro-Stiglitz model suggests that wages are not bid down sufficiently to ever reach 0% unemployment. This occurs because employers know that when wages decrease, workers will shirk and expend less effort. Employers avoid shirking by preventing wages from decreasing so low that workers give up and become unproductive. These higher wages perpetuate unemployment while the threat of unemployment reduces shirking

While economists from the Classical school believe that the economy will tend to return to an equilibrium position whenever it is pushed away, and thus favor the concept of a "natural" rate, other economists question whether an economy is really a stable system at all. Some economists, including John Maynard Keynes and Joseph Schumpeter (1883 –1950) envisioned economies as more dynamic and evolving. While Keynes is often associated with a rather pro-government political stance, and Schumpeter with the more libertarian, small-government views held by adherents of the Austrian School of economics, both Keynes and Schumpeter stressed the inherent instability of economic systems. To them, factors such as uncertainty, innovation, institutions, and technological advance made economies quite unpredictable

Wikipedia

It's called hydraulic fracturing or fracking, and some herald it as the future of clean, safe energy from natural gas. But from Pennsylvania to West Virginia to Arkansas, residents are seeing earthquakes, poisoned water courses and contaminated drinking water. So as this massively expanding industry gears up to pump out gas, from deeply buried muds and shales, those local concerns have states, such as New York's, introducing moratoriums. But beyond those immediate problems looms a larger issue - is fracking just a way for us to continue with our fossil-fuel fix, and so dodge the rapid switch to renewables that the planet's climate needs so badly?

http://www.earthtimes.org/energy/dangers-hydraulic-fracturing-poisoned-water-supplies-earthquakes/552/