Why doesn't gravity violate LoCE?

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Discussion Overview

The discussion revolves around the question of whether gravity violates the Law of Conservation of Energy (LoCE). Participants explore the nature of gravity, its relationship to energy, and the implications for conservation laws in various scenarios.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants question how gravity could be seen as energy that "comes out of nowhere," suggesting a need for clarification on the conservation law.
  • One participant argues that gravity manifests as a force rather than energy, using the example of a book on a table to illustrate that no energy is expended in this scenario.
  • Another participant states that gravitational energy originates from potential energy, implying a connection between the two concepts.
  • A later reply elaborates on the conservation of energy by explaining that if the energy calculated in a given situation remains constant as it evolves, then energy is conserved, emphasizing the importance of understanding the law's implications.
  • One participant presents a perspective that the work done by gravity is independent of the path taken between two points, suggesting a method to define gravitational energy and asserting that energy conservation holds when considering gravitational energy.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between gravity and energy, with no consensus reached on whether gravity violates the Law of Conservation of Energy. Multiple competing perspectives remain throughout the discussion.

Contextual Notes

Some discussions involve assumptions about the definitions of energy and potential energy, as well as the conditions under which energy conservation is evaluated. The implications of gravitational work and its independence from the path taken are also points of contention.

Crazy Tosser
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Why doesn't it violate Law of Conservation of Energy?
Isn't it energy that comes out of nowhere?
 
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Crazy Tosser said:
Why doesn't it violate Law of Conservation of Energy?
Isn't it energy that comes out of nowhere?

How so?
 
Gravity manifests as a force, not an energy. Ie, a book sitting on a table experiences a constant force from gravity (and the table), but no energy is being expended.
 
It comes from potential energy.
 
Crazy Tosser said:
Why doesn't it violate Law of Conservation of Energy?
Isn't it energy that comes out of nowhere?

You should understand exactly what the law of conservation of energy tells us. It tells us that *if we have a certain situation* and we calculate a quantity, called energy, for that situation, and then the situation evolves, and somewhat later, and we calculate the same quantity again, we find the same number.

If the interactions that make the situation evolve from the first to the second state are such that we do indeed find the same number, we say that those interactions "conserve energy".
 
Crazy Tosser said:
Why doesn't it violate Law of Conservation of Energy?
Isn't it energy that comes out of nowhere?
It can be shown that if you move an object from a position A to B, then the work done by gravity will be independent of the path: it depends only on the points A and B. So we can define gravitational energy in general point B as work done by gravity when the object moves from A to B (we can chose any A, this just affect a constant in the energy). Consequently energy will be conserved once we add gravitational energy.
 

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