Gravity never zero

[hansda]

Okun's paper is based on Einstein's paper . Okun did mention about a Thought Experiment , where a photon is absorbed to become mass m as E/c^2 . But this is only a Thought-Experiment and not a real experiment .



So, Einstein's paper and Okun's paper are not conclusive to make a conclusion that , " mass of an electron increases by absorbing a photon " .

 

[OnlyMe]

Einstein mentioned radium salts as an example in his paper .

Now I am able to get Okun's paper .

Most of your questions may be answered better by Okun than I could. I will wait until you have had time to read and think it over.

On the radium salts issue, as I said at that time... In that same year Einstein published his papers on both Brownian motion and the photoelectrice effect.

The paper on Brownian motion did not prove there were atoms but it rallied science and scientists, essentially ending a centuries old debate and beginning a search for better proof.

The paper on the photoelectric effect, though it would take another 20+ years, is considered by many to have been the catalyst for quantum mechamics.

In 1905 Einstein wrote those two papers which in their own ways played a role in the search that would lead to a better understanding of the atom. They did know about radium and radioactivity, but did not know exactly what was happening. As it turns out radium decay involves alpha particle emission. Alpha particles are essentially helium nuclei, two protons and two neutrons. So the radium salts reference is not an example of what he was describing in the E = mc^2 paper. Something he could not have known at the time, but for which the ideas presented in those two papers, would lead to the proof later. Photons can be called energy while protons and neutrons both have rest mass of their own.

Einstein was wrong in thinking that radium would prove the E = mc^2 issue. On the other hand, it was and is an example of the fact that atom's are made of even smaller parts..., protons, neutrons and electrons.

 

[OnlyMe]

Okun's paper is based on Einstein's paper . Okun did mention about a Thought Experiment , where a photon is absorbed to become mass m as E/c^2 . But this is only a Thought-Experiment and not a real experiment .

So, Einstein's paper and Okun's paper are not conclusive to make a conclusion that , " mass of an electron increases by absorbing a photon " .

You are correct ofcorse. Neither paper is proof of the idea. Einstein's paper introduced the idea in 1905 and Lev Okun's describes the consensus view of science and the scientists involved some 100 years later, in 2006.

Emil, I am not a particle physicists. I did not even like QM when I was in school and have only begun to read papers in that area in the last several years. Far to late in my case to expect I will ever be an expert in the area.

That said, I can see the logic of many of the arguments I struggle through, and I accept many of the conclusions that those who have spent the time to really understand the subject, have come to. And yes it still seems there are differences of opinion, which I am unqualified to umpire or explain. The fact that there remain differences of perspective, opinion and conclusion, does not mean there is no truth to the underlying science.

There are some things I can know from personal experience, some I may suspect and some I must accept on the experience and conclussions of others, with more specific knowledge than my own. This is really how we, human beings.., have gathered the knowledge and understanding of the world we currently have, by standing on the shoulders of the giants who have gone before us. (Though in its original form, I believe Newton meant that as an insult, to a rival Robert Hooke, who was short, not an admission of his own humility.)

 

[hansda]

The fact that there remain differences of perspective, opinion and conclusion, does not mean there is no truth to the underlying science.

If mass of an electron , increases by absorbing a photon particle ; then we can very well make a conclusion that , " photon is constituent of electron " .

 

[OnlyMe]

If mass of an electron , increases by absorbing a photon particle ; then we can very well make a conclusion that , " photon is constituent of electron " .

I have thought about the underlying implications of both, the photon contributing to an increase in the mass of an electron bound within an atomic structure and the idea that rather than increasing the electron's mass it changes the total energy of the atom in some way that is reflected in an increase in mass for the atom as a whole.

In the first case it requires the we accept that while a free electron seems to have a fixed mass and is "a fundamental" particle on its own, when bound in or to an atom, its mass may not be fixed and it may not be as fundamental as we think.

In the second case the discussion leads to an assumption that kinetic energy of any kind may be equivalent to mass. An argument that leads to the idea that an object's intrinsic heat contributes to its mass, while we have independent evidence that gravity which we can connect directly to mass, is not affected by an object's kinetic energy associated with velocity.

That discussion runs like a revolving door. I have been moving more toward the opinion.., and it is only an opinion, that the answer to this question lies within understanding the relationship between QM or QFT and GR. There seems to be something going on at a fundamental level we have yet to fully describe and understand.

The question you ask above, is reasonable.., and it challenges significant fundamental assumptions and conclusions, currently represented by existing theory. The question suggests that an electron may not be a fixed fundamental particle, as described by the standard model. I do not know the answer. All I can say is that I ponder some of these same issues. Perhaps, this is a reflection of the limitations of my knowledge in some of the involved areas. Perhaps it represents aspects of those theories that require further clarification. I don't know for certain which.

I can say that I do believe there is a relationship between mass and energy, that cannot be described in a completely equivalent manner. Does the mass of an electron increase as it absorbs a photon or does the dynamics of the atom change in some way that represents an increase in mass? I don't know which is the true answer, or if they both have some merit.

After all of this I can say that I do accept the equation E = mc^2, does represent a fumdametal association between mass and energy, where the mass we are discussing is an invariant rest mass equivalent to both inertial and gravitational mass, and the energy involved does not include "all" energy that may be associated with mass at macroscopic scales. IOW E =mc^2 does not include kinetic energy associated with velocity. My opinion, as I have no credentials to lend greater merit to the discussion that that of opinion.

 

[Robittybob1]

I think I have the answer but probably will struggle to express it in one go.
So we are discussing kinetic energy in another thread the "mythbuster" one http://www.sciforums.com/showpost.php?p=2922655&postcount=48 . In there I found a quote that said KE becomes mass when it can longer be reduced by looking for a common moving frame.

You then accept that on absorption of photons the kinetic energy of the material is so random you can't assign the energy to a common direction of motion, therefore that randomised KE of the molecules which has come from the mass-less photons is part of the invariant mass of the object.

"I thought this was interesting where the kinetic contributes to the invariant mass.
from Wikipedia :
“ In any other case the total kinetic energy has a non-zero minimum, as no inertial reference frame can be chosen in which all the objects are stationary. This minimum kinetic energy contributes to the system's invariant mass, which is independent of the reference frame. ” " From;
http://en.wikipedia.org/wiki/Kinetic_energy

This means when an electron absorbs a photon this creates part of the rest mass as the molecular motion created can't be assigned to a common moving frame.
Whether you can point that right back to the electron's mass going up is not so clear, for you could say the electron just gained KE. But as I understand the electron actually looses KE in the classical model. But the energy is absorbed by the material and when the electron releases the photon its direction is randomised so the net impulse is randomised. The KE of the molecules can't be given a constant direction so the energy shows up as part of the invariant mass.

 

[hansda]

I have thought about the underlying implications of both, the photon contributing to an increase in the mass of an electron bound within an atomic structure and the idea that rather than increasing the electron's mass it changes the total energy of the atom in some way that is reflected in an increase in mass for the atom as a whole.

In the first case it requires the we accept that while a free electron seems to have a fixed mass and is "a fundamental" particle on its own, when bound in or to an atom, its mass may not be fixed and it may not be as fundamental as we think.

In the second case the discussion leads to an assumption that kinetic energy of any kind may be equivalent to mass. An argument that leads to the idea that an object's intrinsic heat contributes to its mass, while we have independent evidence that gravity which we can connect directly to mass, is not affected by an object's kinetic energy associated with velocity.

That discussion runs like a revolving door. I have been moving more toward the opinion.., and it is only an opinion, that the answer to this question lies within understanding the relationship between QM or QFT and GR. There seems to be something going on at a fundamental level we have yet to fully describe and understand.

The question you ask above, is reasonable.., and it challenges significant fundamental assumptions and conclusions, currently represented by existing theory. The question suggests that an electron may not be a fixed fundamental particle, as described by the standard model. I do not know the answer. All I can say is that I ponder some of these same issues. Perhaps, this is a reflection of the limitations of my knowledge in some of the involved areas. Perhaps it represents aspects of those theories that require further clarification. I don't know for certain which.

I can say that I do believe there is a relationship between mass and energy, that cannot be described in a completely equivalent manner. Does the mass of an electron increase as it absorbs a photon or does the dynamics of the atom change in some way that represents an increase in mass? I don't know which is the true answer, or if they both have some merit.

After all of this I can say that I do accept the equation E = mc^2, does represent a fumdametal association between mass and energy, where the mass we are discussing is an invariant rest mass equivalent to both inertial and gravitational mass, and the energy involved does not include "all" energy that may be associated with mass at macroscopic scales. IOW E =mc^2 does not include kinetic energy associated with velocity. My opinion, as I have no credentials to lend greater merit to the discussion that that of opinion.

We know that , an electron can emit and absorb a photon . We know the total energy of an electron(E(e)) . Energy of a photon(E(p)) can be calculated from its wavelength and Planck's Constant .

Can we say that , an electron is consisting of 'E(e)/E(p)' number of photons ?

 

[Robittybob1]

We know that , an electron can emit and absorb a photon . We know the total energy of an electron(E(e)) . Energy of a photon(E(p)) can be calculated from its wavelength and Planck's Constant .

Can we say that , an electron is consisting of 'E(e)/E(p)' number of photons ?

I am tending to think that the photon is not absorbed strictly by the electron alone but by the atom. It is in the energy and momentum of the whole atom.

When a photon is emitted an electron may change valence levels, but in some cases there is no change in valence levels but a change in the molecular vibrations.
A free electron is the one that can be measured, but they don't emit or absorb electrons in this state, so even if you rearranged your equation, it wouldn't work for E(p) has an endless number of values.

 

[hansda]

I am tending to think that the photon is not absorbed strictly by the electron alone but by the atom. It is in the energy and momentum of the whole atom.

When a photon is emitted an electron may change valence levels, but in some cases there is no change in valence levels but a change in the molecular vibrations.
A free electron is the one that can be measured, but they don't emit or absorb electrons in this state, so even if you rearranged your equation, it wouldn't work for E(p) has an endless number of values.

Suppose an electron is converted into Light Energy . So, all the energy of the particle electron will be carried by many photon particles . Consider energy of electron is E(e) and energy of a photon particle is E(p) . So, an electron of energy E(e) will generate E(e)/E(p) number of photons .

 

[Robittybob1]

Suppose an electron is converted into Light Energy . So, all the energy of the particle electron will be carried by many photon particles . Consider energy of electron is E(e) and energy of a photon particle is E(p) . So, an electron of energy E(e) will generate E(e)/E(p) number of photons .

This still has no meaning to me sorry.
An electron is negative and when it gets near a positive charged atom there is attraction. Is that right? When the electron gets close enough it can emit a photon and become a valence electron. Once it has become a valence electron it is in an orbital (or something like that) but it is no longer free.
It doesn't fall further so it is not possible to turn completely into light energy (photons).

 

[hansda]

This still has no meaning to me sorry.
An electron is negative and when it gets near a positive charged atom there is attraction. Is that right? When the electron gets close enough it can emit a photon and become a valence electron. Once it has become a valence electron it is in an orbital (or something like that) but it is no longer free.
It doesn't fall further so it is not possible to turn completely into light energy (photons).

If you have followed Einstein's paper or Einstein's Equation , any mass which has kinetic energy can be converted into Light Energy or Photon Particles . This mass can be either mass of Electron, Proton , Neutron or any other massive particle which has kinetic energy . Einstein did not mention anything about the charge of a particle in his paper or equation .

Consider energies of an electron , neutron , proton and photon particles are E(e) , E(n) , E(pr) and E(p) respectively .

As per Einstein's Equation ,

An electron will generate E(e)/E(p) number of photons .

A neutron will generate E(n)/E(p) number of photons .

A proton will generate E(pr)/E(p) number of photons .

So , there can be some co-relation between mass(inertia) of a particle and number of photon particles or photon . Though individually a photon particle is mass-less .

 

[OnlyMe]

If you have followed Einstein's paper or Einstein's Equation , any mass which has kinetic energy can be converted into Light Energy or Photon Particles . This mass can be either mass of Electron, Proton , Neutron or any other massive particle which has kinetic energy . Einstein did not mention anything about the charge of a particle in his paper or equation .

Consider energies of an electron , neutron , proton and photon particles are E(e) , E(n) , E(pr) and E(p) respectively .

As per Einstein's Equation ,

An electron will generate E(e)/E(p) number of photons .

A neutron will generate E(n)/E(p) number of photons .

A proton will generate E(pr)/E(p) number of photons .

So , there can be some co-relation between mass(inertia) of a particle and number of photon particles or photon . Though individually a photon particle is mass-less .

This is not entirely accurate. Einstein first published several papers in 1905, among them was the E = mc^2 paper. In that year he first made an argument for both Brownian motion, largely ending the debate as to whether atoms exist and a paper on the photoelectric effect, quantifying light, and introducing the origin of photons. There were no protons or neutrons at the time. Quantum mechanics followed some 20 years later.

All Einstein presented is that when an electron is associated with an atom, emission and absorption of photons, involves a change in the mass of the atom. There is speculation as to whether that is a direct change in the mass of the electron or a dynamic change in the atom that represents a change in mass. But it only seems to involve atoms, not individual free electrons

Nowhere, that I am aware of, is there any suggestion that a free electron's mass is variable. The electron is considered to be a fundamental particle. No smaller parts.

For most of what you are saying to be accurate the standard model of particle physics would have to be wrong. It (your suggestion) just does not represent the way things, atoms and subatomic particles breakdown.

 

[hansda]

This is not entirely accurate. Einstein first published several papers in 1905, among them was the E = mc^2 paper. In that year he first made an argument for both Brownian motion, largely ending the debate as to whether atoms exist and a paper on the photoelectric effect, quantifying light, and introducing the origin of photons. There were no protons or neutrons at the time. Quantum mechanics followed some 20 years later.

All Einstein presented is that when an electron is associated with an atom, emission and absorption of photons, involves a change in the mass of the atom. There is speculation as to whether that is a direct change in the mass of the electron or a dynamic change in the atom that represents a change in mass. But it only seems to involve atoms, not individual free electrons

Nowhere, that I am aware of, is there any suggestion that a free electron's mass is variable. The electron is considered to be a fundamental particle. No smaller parts.

For most of what you are saying to be accurate the standard model of particle physics would have to be wrong. It (your suggestion) just does not represent the way things, atoms and subatomic particles breakdown.

I mean to say some co-relation can be found between inertia and photon . This was also predicted by Einstein in his paper .

 

[OnlyMe]

I mean to say some co-relation can be found between inertia and photon . This was also predicted by Einstein in his paper .

I don't think so. The photon travels at c and only at c. As far as we can tell within the context of SR photons experience no resistance to motion. Inertia is defined as an object's, or particle's resistance to a change in motion.

C is constant for all observers and within the context of SR, it is always measured to be the same for all observers. There is an argument within the context of GR, when gravity is involved, where two observers may not agree on the value of c, but that is a separate issue and only in as much as gravity and inertia seem to be associated, would inertia be even remotely involved where photons are concerned.

It just does not appear from what we currently know that light or photon's are subject to the limitations associated with massive particles, which are subject to the laws of inertia.

 

[Robittybob1]

I don't think so. The photon travels at c and only at c. As far as we can tell within the context of SR photons experience no resistance to motion. Inertia is defined as an object's, or particle's resistance to a change in motion.
.... and only in as much as gravity and inertia seem to be associated, would inertia be even remotely involved where photons are concerned.

It just does not appear from what we currently know that light or photon's are subject to the limitations associated with massive particles, which are subject to the laws of inertia.

Haven't got time right now but light is affected by gravity but the change of direction is minimal, so I'd imagine the degree of change in direction relates to its inertia. If there was no resistance to change in motion it would turn into the gravitational field.

 

[James R]

Consider energies of an electron , neutron , proton and photon particles are E(e) , E(n) , E(pr) and E(p) respectively .

As per Einstein's Equation ,

An electron will generate E(e)/E(p) number of photons .

A neutron will generate E(n)/E(p) number of photons .

A proton will generate E(pr)/E(p) number of photons .

So , there can be some co-relation between mass(inertia) of a particle and number of photon particles or photon.

Einstein's equation is a statement of energy conservation, but that isn't the only thing that needs to be satisfied in particle interactions. Other quantities are also conserved, such as momentum, charge, lepton number, isospin etc.

For example, when an electron and a positron interact, two photons are always produced - never one or three or seven.

 

[hansda]

I don't think so. The photon travels at c and only at c. As far as we can tell within the context of SR photons experience no resistance to motion. Inertia is defined as an object's, or particle's resistance to a change in motion.

C is constant for all observers and within the context of SR, it is always measured to be the same for all observers. There is an argument within the context of GR, when gravity is involved, where two observers may not agree on the value of c, but that is a separate issue and only in as much as gravity and inertia seem to be associated, would inertia be even remotely involved where photons are concerned.

It just does not appear from what we currently know that light or photon's are subject to the limitations associated with massive particles, which are subject to the laws of inertia.

It seems that photon doesnt interact with the gravity of our Earth , because gravity is the weakest of all the four forces . But when the gravity is very strong , photon interacts with the very strong gravity as in the case of gravitational-lensing and with Black-Hole .

 

[AlphaNumeric]

For example, when an electron and a positron interact, two photons are always produced - never one or three or seven.

This isn't entirely true. In QED there is only one photon made by the combination of electron and positron directly, it's the QED interaction vertex. However, machines like a PET scanner rely on the fact there's a non-zero chance for an additional photon to be made by one of the charged particles before annihilation. When you then consider momentum conservation you end up with the photons typically going in opposite directions (but with some slight perturbation), which is what the scanner relies on. The double photon decay channel isn't the only one but it is significant enough to make the scanner viable.

 

[hansda]

Einstein's equation is a statement of energy conservation, but that isn't the only thing that needs to be satisfied in particle interactions. Other quantities are also conserved, such as momentum, charge, lepton number, isospin etc.

That is true . I am not denying the conservation of other quantities in particle interactions . But what i am trying to say is that , as per Einstein's Equation some co-relation can be found between inertia(mass) and 'number of photon particles generated from the mass(inertia)' .

For example, when an electron and a positron interact, two photons are always produced - never one or three or seven.

In this case , consider energies of an electron , a positron and a photon respectively as E(e) , E(pos) and E(p) .

Here E(e) = E(pos) = E(p) .

So, E(e)/E(p) = E(pos)/E(p) = 1 ; or ( E(e) + E(pos) )/E(p) = 2 .



Thats why in this case only two photons are generated .

 

[Robittybob1]

That is true . I am not denying the conservation of other quantities in particle interactions . But what i am trying to say is that , as per Einstein's Equation some co-relation can be found between inertia(mass) and 'number of photon particles generated from the mass(inertia)' .

Could you show us a few more examples and we might get to understand your maths.