This is an excerpt from Cosmic Journeys "Cold Sparks & Black Holes." It's the start of a journey through the incredible continuum of cosmic energy that produced us. Today, energy is very much on our minds, as we search for ways to power our civilization and serve the needs of our citizens. But what is energy? Where does it come from? And where do we stand within the great power streams that shape time and space? Energy comes from a Greek word for activity or working. In physics, it is simply the... View MoreThis is an excerpt from Cosmic Journeys "Cold Sparks & Black Holes." It's the start of a journey through the incredible continuum of cosmic energy that produced us. Today, energy is very much on our minds, as we search for ways to power our civilization and serve the needs of our citizens. But what is energy? Where does it come from? And where do we stand within the great power streams that shape time and space? Energy comes from a Greek word for activity or working. In physics, it is simply the property or the state of anything in our universe that allows it to do work. Whether it is thermal, kinetic, electro-magnetic, chemical, or gravitational. The 19th century German scientist Hermann von Helmholtz found that all forms of energy are equivalent, that one form can be transformed into any other. The laws of physics say that in a closed system - such as our universe - energy is conserved. It may be converted, concentrated, or dissipated, but it is never lost. James Prescott Joule built an apparatus that demonstrated this principle. It had a weight that descended into water and caused a paddle to rotate. He showed that the gravitational energy lost by the weight is equivalent to heat gained by the water from friction with the paddle. That led to one of several basic energy yardsticks, called a joule. Its the amount needed to lift an apple weighing 100 grams one meter against the pull of Earth's gravity. In case you were wondering, it takes about one hundred joules to send ...
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