E=mc^2, Gravitational Potential & Energy Balance

In summary, the concept of mass energy equivalence from relativity and gravitational potential from classical mechanics are two separate concepts that cannot be mixed together. In order to understand the relationship between them, one must apply general relativity, which states that energy, not just mass, can be a source of gravity. This means that any type of energy can create a gravitational potential, rather than just mass.
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CaptainSlog
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If two masses that are separated by a distance are created from pure energy using the equation E=mc^2, where did the gravitational potential energy between them come from? Does this mean the speed of light isn't really constant, and must be changed very slightly to accommodate it? Could it be that gravity itself is necessary to balance energy?
 
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You are mixing two concepts that do not really go together, namely gravitational potential, which is a concept from classical mechanics, and mass energy equivalence, which is a concept from relativity.

In order to make sense of this, you need to apply general relativity. In GR, mass is not the source of gravitation. Instead, the energy-momentum tensor is and any type of energy is therefore a gravitational source. It is not that you can simply create a new gravitational source out of nothing.
 
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OK, thanks. I had always assumed gravity was due to mass, but if mass and energy are equivalent then that makes sense.
 

1. What does the equation E=mc^2 mean?

The equation E=mc^2 is one of the most famous equations in physics, and it states that energy (E) is equal to mass (m) multiplied by the speed of light squared (c^2). This equation, also known as the mass-energy equivalence equation, shows that mass and energy are two forms of the same physical quantity and can be converted into one another.

2. How does this equation relate to gravitational potential?

The equation E=mc^2 is a fundamental principle in understanding the concept of gravitational potential. According to Einstein's theory of general relativity, mass and energy are not separate entities but rather different forms of the same thing. Therefore, the mass of an object affects its gravitational potential, and the energy of an object also contributes to its gravitational potential.

3. What is gravitational potential energy?

Gravitational potential energy is the energy stored in an object due to its position in a gravitational field. It is directly related to the mass and height of the object and is given by the equation U = mgh, where m is the mass, g is the acceleration due to gravity, and h is the height.

4. How is energy conserved in a system with gravitational potential?

According to the law of conservation of energy, energy can neither be created nor destroyed, only transformed from one form to another. In a system with gravitational potential, the total energy remains constant as potential energy is converted into kinetic energy or vice versa. This balance between potential and kinetic energy is crucial in understanding the motion and stability of objects in a gravitational field.

5. How is the energy balance equation used in practical applications?

The energy balance equation, which takes into account both the mass-energy equivalence and the gravitational potential energy, has many practical applications. For example, it is used in nuclear power plants to calculate the energy released from nuclear reactions, and it is also crucial in understanding the behavior of celestial bodies, such as stars and planets, in our universe.

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