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leobiologo leobiologo
wrote...
Posts: 38
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11 years ago
Here's the question - actually 2 essential questions.

If e=mc², then what portion of that total energy can be attributed to the former gravity of the mass particle prior to the conversion and where does that gravity go afterwards?

On the other hand, when massless energy particles interact to form matter from pure energy, what portion of that energy becomes the gravitational energy of the resulting mass particles and where does that gravity originate?

The equation e=mc² seems to imply that all the resulting energy is purely electromagnetic, but electromagnetic energy and gravity seem to have entirely different properties and have so far eluded any effort to unify them.

Somewhere during this interconversion process gravity disappears into nowhere or appears from nowhere as the result of an entirely electromagnetic process that in no way addresses where gravity goes or originates.

Where's Stephen Hawking when I need him ?
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wrote...
11 years ago
That's a nice ques. But I think mass cannot b attributed 2 gravity only weight can. I might b wrong though.
Another thing, acc. 2 Quantum Phy., gravity is a curve in space-time & light carries it 2 earth(thr u have the relation btwn electromagnetic light & gravity); though acc. 2 classical phy., gravity is produced due 2 the xchange of graviton.
This is all i know.U surely need Steven Hawkin.
smn
wrote...
11 years ago
All energy is the result of a distortion of the all prevailing medium. In the case of gravity it is seen as a gravitational distortion of space. In the same manner charge also distorts space. The difference between the distortion of mass space and charge space is due to the nature of dimensions. Mass force is the result of a dynamic change in a dimension that is perpendicular to the force that produces charge force. A similar effect can be seen when working with electromagnetism. Electromagnetic forces have no effect on each other if they are perpendicular to each other. This allows for three different dimensional alignments that are independent from each other.

When mass is converted to energy the only thing that changes is the dimensional direction of the distortion.
wrote...
11 years ago
I'll answer part of this. Gravity is always there, it's just that the speed on light can escape it's grasp because gravitational pull is based on the object and it's relative closeness as well as the  size and density of the object. The reason why let's say light can't escape a black holes grasp is because they are constantly getting bigger and more dense and there gravitational pull increases. Therefore they bend light and as a result we can't detect them. Good question
wrote...
11 years ago
Your question is not silly and does raise real issues that I have never seen addressed.  If I may rephrase it:  mass and energy are equivalent according to the equation E=mc^2.  Associated with any mass is a gravitational field that contains energy and therefore has an equivalent mass.  We usually ignore the mass of the gravitational energy because it is so small, but the mass equivalent of the gravitational energy should be added to the physical mass for any computations (including momentum computations).
I do know that one of the difficulties in obtaining solutions to Einstein's General Relativity field equations results from the fact that the gravitational field is determined by the mass-energy tensor, which also includes the energy of that gravitational field.  So you have a complicated recursive situation.

So I would think that to be 100% accurate, if a mass is coverted to energy, you would have to add gravitational energy to what comes from the mass itself in the formula E=mc^2.  This latter formula is derived from Special Relativity which does not consider gravitation, so it could not include the energy from the gravitational field.

Quote: "..when massless energy particles interact to form matter from pure energy, what portion of that energy becomes the gravitational energy of the resulting mass particles and where does that gravity originate?"

Some of the energy of the massless particles must go into the gravitationl field produced by the resulting mass.  The amount can be determined from General Relativity,

This doesn't have anything to do with field unification.

These are just my opinions in this area; I would sure like to hear the views of Stephen Hawking or Brian Green on this.  It is not addressed in their books.
wrote...
11 years ago
Responder gp4rts is close.  The gravitational energy of the mass is negligibly small, so need not be taken into account in computation.  If you wish to account for it, simply take the mass corresponding to the gravitational energy as a correction to the rest mass.  Since the gravitational mass is only 10^-40 of the rest mass, it can be ignored for practical purposes.
wrote...
11 years ago
ok, first of all, E=mc^2 just tells you the total energy due to the mass of an object, it doesn't include the energy due to position or motion. Also, there is no implication in this equation that the energy must be electromagnetic.

Total energy is given by E = gamma*m*c^2 where gamma is 1/sqrt{1-(v/c)^2}.  v is the speed (magnitude of velocity). This takes kinetic energy into account.  If you enter a frame of reference in which the mass is not moving, then this reduces to E=mc^2

The gravitational potential energy of the massive particles is just that:  potential.  It's energy that *could* be available.  The photons created in a particle-antiparticle annihilation are also subject to that gravitational potential energy.  The photons lose energy as they recede from a mass (gravitational red shift) and they gain energy as they approach a mass (gravitational blue shift).  You can define any position to have zero potential energy, --only *Changes* in potential energy are important.

hope that clears things up
wrote...
11 years ago
All I can give is a possible plug in to this equation.

  (Time + Space = Dimension)

 Interesting huh!
wrote...
11 years ago
The Gravity goes right along with the portion
of energy that was equivelant to the mass/energy.

Einstein Fretted over this problem.

I believe everything occupies space and therefore
must have Gravity. Granted, it is so small it is
considered to have no mass but if you keep
"Pecking" away at the mass until it's all gone and
all that is left is Energy, then the Energy must have
brought the Gravity along with itself. The process is reversible. Matter can neither be created nor destroyed.
It doesn't seem possible that Gravity can come and go.
It either is, or it isnt. If Gravity can disappear, then
I think I would have to believe that some "Matter" has
disappeared.

By the way, scientists say Negligible Mass.
wrote...
11 years ago
e=mc² is one of the most famous yet misunderstood equations in physics. This equation actually just refers to the "rest mass" of a particle, which is derived from the special theory of relativity. This theory deals purely with uniform motion and does not involve gravity.

Furthermore, e=mc² is simply just part of the total energy of a particle in motion in a reference frame where the only variable is velocity.

Finally, gravitational energy is not due to the particle itself, but from its relative position in space to another particle
wrote...
11 years ago
The best way to answer this question is to break down and define each variable of the equation concerned. The variable 'E' in this problem represents Energy and not any particular Energy like Electromagnetic Energy; it means all Energy. After that is 'M' which means Mass of matter, and that is any form of matter and in any phase from frozen solid at absolute zero to plasma at over a million degrees centigrade. Then finally is the variable 'C' which stands for the velocity of light. When you put it all together: Energy equals Mass of matter multiplied by the Velocity of Light Squared. Gravity has nothing to do with the equation itself. Gravity is its own force and you can input the equation for Matter and Energy to make it more accurate however the matter/energy equation stands alone without help of gravity as an influence.                                                Brian
 P.S. How do you type E=MC^2 to the way it looks all cool like you got it?
Leo
wrote...
11 years ago
None.

Considering gravity a form of energy is a common misconception. It is a FORCE, not ENERGY. The thing is, a FORCE is always a force, and can't be converted to energy. The gravity disappears with mass.

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