The Energy of mass and Gravitational Potantial Energy

In summary, the conversation discusses the concept of the total energy of the universe being zero due to the combination of matter energy and gravitational potential energy. However, this idea is not universally accepted among physicists and there are concerns about the validity of the equations used to calculate this energy. The conversation ends with the conclusion that this discussion is based on mistaken assumptions and can be closed.
  • #1
Quarlep
257
4
I know the total energy of universe is zero cause of matter energy (E=mc2) and gravitational potantial energy.
But If I try to calculate it gets crazy things:
Lets think universe made up only two particles and their mass call m and equal than

2mc2=m2G/r
2c2=mG/r
r=mG/2c2
so there must be a certain distance between these objects to make zero energy universe. Am I wrong
 
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  • #2
Quarlep said:
I know the total energy of universe is zero cause of matter energy (E=mc2) and gravitational potantial energy.

Where did you hear this? It is certainly not something that is seen as universally true among physicists. In particular as the definition of energy (and potential energy in particular) is not all that clear in general relativity.
 
  • #3
Everywhere If you search total energy of universe is zero you can look at it.
 
  • #4
This is definitely not an accepted fact in physics, please stick to mainstream science and do not quote hypotheses as facts.
 
  • #5
This is a formal approach to the problem. By its order of magnitude this radius is close to the gravitational radius of the mass (m). If the total energy of the Universe is zero, this Universe is in dynamically unstable state. The accelerated Universe, as we know today, can't have zero total energy. Also pay attention that the right side of your equation is relativistically invariant while the right side is not.
 
  • #6
This thread started with two mistaken assumptions: First, that it might be an accepted fact that the total energy of the universe is zero; and second, that an equation in which one side is a relativistic invariant and the other is not could possibly make sense.

As both of these misconceptions have been pointed out, we can close the thread now.
 

What is the difference between the energy of mass and gravitational potential energy?

The energy of mass refers to the energy that an object possesses by virtue of its mass and velocity. This energy is also known as kinetic energy. On the other hand, gravitational potential energy is the energy an object possesses due to its position in a gravitational field. This energy is dependent on the object's mass, the acceleration due to gravity, and its height above a reference point.

How is the energy of mass converted into gravitational potential energy?

When an object is lifted to a higher position, its kinetic energy decreases and its gravitational potential energy increases. This is because the object's mass and velocity remain constant, but its position in the gravitational field changes. The conversion of energy from kinetic to gravitational potential occurs due to the work done by the lifting force against the force of gravity.

Why is gravitational potential energy important?

Gravitational potential energy is important because it allows us to understand and predict the behavior of objects in a gravitational field. It is also a crucial component in many natural phenomena, such as tides, planetary orbits, and the formation of stars and galaxies.

How is the formula for calculating gravitational potential energy derived?

The formula for gravitational potential energy, U = mgh, is derived from the law of conservation of energy. This law states that energy cannot be created or destroyed, only transformed from one form to another. By considering the work done against gravity, we can derive the relationship between an object's mass, its height, and its gravitational potential energy.

How does the concept of gravitational potential energy relate to Einstein's theory of general relativity?

In Einstein's theory of general relativity, mass and energy are interchangeable, and gravity is seen as a curvature of spacetime. This means that the concept of gravitational potential energy is closely related to the concept of mass-energy equivalence. In other words, mass and gravitational potential energy can be seen as two different forms of the same underlying energy. This theory has been confirmed through various experiments, such as the bending of light around massive objects like stars.

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