In physics and other sciences, energy (from the Greek ενεργός, energos, "active, working")[1] is a scalar physical quantity that is a property of objects and systems of objects which is conserved by nature. Several different forms, such as kinetic, potential, thermal, electromagnetic, chemical, nuclear, and mass have been defined to explain all known natural phenomena.

Energy is converted from one form to another, but it is never created or destroyed. This principle, the conservation of energy, was first postulated in the early 19th century, and applies to any isolated system. According to Noether's theorem, the conservation of energy is a consequence of the fact that the laws of physics do not change over time.[2]

Although the total energy of a system does not change with time, its value may depend on the frame of reference. For example, a passenger in an airplane has zero kinetic energy relative to the airplane, but nonzero kinetic energy relative to the earth.

Your Comments, Thoughts, Questions, Ideas

Florina's picture
Florina says:

its amazing news and i got many answers for it and thank u ............Florina!
i had a fun time reading it and pls viewers read it!

posted on Mon, 11/05/2007 - 10:22am
Florina's picture
Florina says:

thanx flora!
i loved this artiocle!
lovely!
bye bye
!!!!!!!!!!!!!!!

posted on Mon, 11/05/2007 - 10:23am
Joe's picture
Joe says:

Hey Florina, I think you just copied your article from Wikipedia - the original is here, footnotes and all. It is way cool that you are participating on the Buzz, though I would encourage you to remember that when you are quoting information from another source to provide a link to the original content.

Check out our Community Guidelines.

We welcome all perspectives, but offensive or inappropriate comments/stories will not be posted.

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Buzz Blog entries should relate to recently published science, or to current phenomena (leaves changing color, floods, animal migrations, etc.)

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If your story or comment doesn't relate to current science or one of the blog entries, or to the website itself, we won't allow it.

Thanks again for participating.

posted on Mon, 11/05/2007 - 11:54am

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