Gravity never zero

[OnlyMe]

Keep in mind the following is highly speculative.

The fact that it gets harder and harder to accelerate an object as it approaches relativistic velocities is this due to the relativistic mass increasing, so you are no longer accelerating the rest mass but any mass acquired through the input of the energy prior to that?
Would it be at slower speeds the relativistic effect being too insignificant to measure?

In my youth I was never a fan of quantum mechanics. I was most interested in gravity and inertia.., and I approached those initially from Mach's principle and general relativity. From that perspective it would seem so... That as the inertial mass of an object increases it requires more force to further increase its velocity.

One issue that comes up with that is that, in the rest frame of the object, its mass never changes. So from its own frame of reference it should never require more force to gain one more increment of velocity, than it did or does at any other time.

As I said, I was not a fan of QM, but over the past few years I have come to believe that inertia may not be Machian in nature. Instead there seems reason to believe that it is an emergent phenomena of QM.

Though it is a crude example, it could be that just as we have come to confirm that frame-dragging occurs, where space or spacetime is distorted and drug along by the angular and even linear momentum of mass.., so it may also be that as any object moves through space, space resists that motion.., and that resistance is proportional the the object's velocity and mass, such that the resistance has an additive effect and the speed of light becomes a limiting velocity.

Currently I have been considering the DCE (dynamical Casimir effect) as a potential mechanism, for this inertial resistance. That as an object moves through the vacuum energy of space, virtual particles — photons, interact with the object at an ever increase rate. Perhaps even under the right conditions, being converted into real photons at relativistic velocities. Two things can occur during this process. For one photons carry momentum and some portion of that momentum could oppose the motion of the object. And in the second case, as photons interact with matter, they may be absorbed and add mass to it. This second aspect should remain insignificantly trivial, but never the less...

There are other models and suggestions. None have been fully explored or experimentally confirmed, as far as I am aware. In any case, if inertial resistance to motion does originate from something along these lines, it would be undetectable at the classical velocities, to which we are currently limited.

I do believe that it is likely the answers will one day be discovered within some related context and both inertia and gravitation will be found to be emergent QM phenomena.

So I would say that is not the object's inertial mass, which is really a pseudomass, rather it is something more fundamental about inertia, yet to be nailed down, so to speak.

 

[Robittybob1]

@OnlyMe - thanks for sharing your insight. I hope you get a chance to expiment and find out the answer to the problem. I would never have considered the problem of going through space itself.

 

[hansda]

Hansda, I don't know where on Wiki you got that reference, but I believe it is misleading.

Follow this link : http://en.wikipedia.org/wiki/Equivalence_principle .

I dont know if this wiki explanation is misleading .

 

[hansda]

Keep in mind the following is highly speculative.



In my youth I was never a fan of quantum mechanics. I was most interested in gravity and inertia.., and I approached those initially from Mach's principle and general relativity. From that perspective it would seem so... That as the inertial mass of an object increases it requires more force to further increase its velocity.

One issue that comes up with that is that, in the rest frame of the object, its mass never changes. So from its own frame of reference it should never require more force to gain one more increment of velocity, than it did or does at any other time.

As I said, I was not a fan of QM, but over the past few years I have come to believe that inertia may not be Machian in nature. Instead there seems reason to believe that it is an emergent phenomena of QM.

Though it is a crude example, it could be that just as we have come to confirm that frame-dragging occurs, where space or spacetime is distorted and drug along by the angular and even linear momentum of mass.., so it may also be that as any object moves through space, space resists that motion.., and that resistance is proportional the the object's velocity and mass, such that the resistance has an additive effect and the speed of light becomes a limiting velocity.

Currently I have been considering the DCE (dynamical Casimir effect) as a potential mechanism, for this inertial resistance. That as an object moves through the vacuum energy of space, virtual particles — photons, interact with the object at an ever increase rate. Perhaps even under the right conditions, being converted into real photons at relativistic velocities. Two things can occur during this process. For one photons carry momentum and some portion of that momentum could oppose the motion of the object. And in the second case, as photons interact with matter, they may be absorbed and add mass to it. This second aspect should remain insignificantly trivial, but never the less...

Photon is massless ( m = 0 ) .

So , how photon can have momentum to oppose the motion of the object or add mass to the matter ?

There are other models and suggestions. None have been fully explored or experimentally confirmed, as far as I am aware. In any case, if inertial resistance to motion does originate from something along these lines, it would be undetectable at the classical velocities, to which we are currently limited.

I do believe that it is likely the answers will one day be discovered within some related context and both inertia and gravitation will be found to be emergent QM phenomena.

So I would say that is not the object's inertial mass, which is really a pseudomass, rather it is something more fundamental about inertia, yet to be nailed down, so to speak.

 

[OnlyMe]

Follow this link : http://en.wikipedia.org/wiki/Equivalence_principle .

I dont know if this wiki explanation is misleading .

Hansda, some of the confusion is that I am almost always projecting these discussions in practical terms. How do they fit with experience in the world. Keeping that in mind the following is a rather long post. I rarely reference Wiki except to check on a link someone has supplied. Most of the time I post as a matter of my own thoughts and interpretations, of whatever topic is being discussed. Because the confusion has come up between the Wiki reference you linked and my own understanding of things, the following post includes a number of quotes from Wiki, with links to the full Wiki references.

To begin a quote from the link in your above quoted post.

Wiki on Equivalence Principle
In the physics of general relativity, the equivalence principle is any of several related concepts dealing with the equivalence of gravitational and inertial mass, and to Albert Einstein's assertion that the gravitational "force" as experienced locally while standing on a massive body (such as the Earth) is actually the same as the pseudo-force experienced by an observer in a non-inertial (accelerated) frame of reference. ​

Then from just after the index to that section, the quote from Einstein
A little reflection will show that the law of the equality of the inertial and gravitational mass is equivalent to the assertion that the acceleration imparted to a body by a gravitational field is independent of the nature of the body. For Newton's equation of motion in a gravitational field, written out in full, it is:

(Inertial mass) (Acceleration) = (Intensity of the gravitational field) (Gravitational mass).​

It is only when there is numerical equality between the inertial and gravitational mass that the acceleration is independent of the nature of the body.​

As described above, an inertial mass is under acceleration and outside of the influence of all other forces, including gravitational. It assumes that the accelerating mass is in the essentially flat spacetime of special relativity and also locally consistent with Newtonian flat space. There is no consideration or inclusion, of the special relativistic effect that the constantly increasing instantaneous velocity associated with the acceleration has on, the concept of inertial mass.

To better understand the distinction consider the following links from that first section to both gravitational and inertial mass.

Wiki on Gravitational mass
Active gravitational mass is a property of the mass of an object that produces a gravitational field in the space surrounding the object,...​

Here gravitational mass, is the same as an object's rest mass, or its mass as defined from its own at rest frame of reference. It does not change when the object is in motion or at rest.

Wiki on Inertial mass
Inertial mass is found by applying a known net force to an unknown mass, measuring the resulting acceleration, and applying Newton's Second Law, $$m_i = F/a$$. This gives an accurate value for mass, limited only by the accuracy of the measurements.

Since Einstein used inertial mass to describe special relativity, inertial mass is closely related to relativistic mass and is therefore different from rest mass.​

Note: the subscript in $$m_i$$ above was added by myself for consistency with later formulations and denotes inertial mass.

If we restrict the definition of inertial mass to the first sentence in the above reference, there is no issue. In that case inertial mass and gravitational mass are the same thing.., and equivalent. Keep in mind, that part of the Wiki reference is describing inertial mass, from the at rest frame of reference of the involved mass. It holds in both the case of Newtonian dynamics and locally, for the flat spacetime of special relativity.

When the second sentence in the above reference and the association with relativistic mass is considered, it is not as clear. To better understand what I am getting at consider the following,

Wiki on Mass and energy in special relativity - near the end of the section
The term relativistic mass is also used, and this is the total quantity of energy in a body or system (divided by c2). The relativistic mass (of a body or system of bodies) includes a contribution from the kinetic energy of the body, and is larger the faster the body moves, so unlike the invariant mass, the relativistic mass depends on the observer's frame of reference.​

This is where the term inertial mass becomes confusing. When in special relativity it is associated with relativistic mass, inertial mass itself takes on a component of its velocity and it is no longer always equivalent to either rest mass or gravitational mass. The $$m_i = F/a$$ which was introduced earlier and is valid for Newtonian dynamics and locally within the flat spacetime of special relativity, becomes, $$m_i = \frac{m_o}{\sqrt{1-v^2/c^2}} = F/a$$, which is only equivalent to the object's rest mass and gravitational mass when it is at rest. Whenever an object is in motion, its inertial mass includes a component of the kinetic energy associated with its velocity. The greater its velocity the larger its inertial mass becomes. This distinction is generally considered to be trivially insignificant, except where the velocity approaches or becomes relativistic. Outside of particle accelerators velocities consistent with experience do not contribute measurably to any significant change in an object's inertial mass.

note: $$m_o$$ is rest mass and $$m_i$$ is inertial mass.

As far as we can determine at present, gravitational mass is the same as rest mass, and it does not change with an object's inertial or non-inertial velocity. Though non-inertial velocities can affect the shape and direction of force of a gravitational field. An object's gravitational mass is frame independent, at least within the context of the classical inertial frames of reference, consistent with experience. Meaning, as long as the object's motion does not involve linear acceleration and does not involve relativistic velocities, any gravitational interaction, at a defined location within the field, is uniformly constant, assuming the absence of other outside forces, acting on the involved system.

The definition of inertial mass, cannot be interpreted as equivalent, with gravitational mass, as described above, in an unambiguous manner, except within the object's at rest frame of reference. While mass itself is defined as a body's resistance to a change in motion, this is a reflection of the object's at rest or gravitational mass.., only as measured when the object is at rest, relative to the measurement, of its mass.

 

[OnlyMe]

Photon is massless ( m = 0 ) .

So , how photon can have momentum to oppose the motion of the object or add mass to the matter ?

Here is one reference from Wiki on momentum and photons. There are others on the same Wiki page...

Wiki on Photon, Physical Properties
In empty space, the photon moves at c (the speed of light) and its energy and momentum are related by E = pc,
where p is the magnitude of the momentum vector p.​

However, I was actually adding some interpretation to the following from Einstein's 1905 paper that introduced the equation, $$E = mc^2$$.

DOES THE INERTIA OF A BODY DEPEND UPON ITS ENERGY-CONTENT?
If a body gives off the energy L in the form of radiation, its mass diminishes by L/c2. The fact that the energy withdrawn from the body becomes energy of radiation evidently makes no difference, so that we are led to the more general conclusion that

The mass of a body is a measure of its energy-content; if the energy changes by L, the mass changes in the same sense by L/9 × 1020, the energy being measured in ergs, and the mass in grammes...

If the theory corresponds to the facts, radiation conveys inertia between the emitting and absorbing bodies.​

In the above quote Einstein refers to energy with the symbol L rather than E, as it has come to be known. While I believe, in that paper Einstein was referring to radioactive decay, the same should apply to the emission and absorption of photons. When a photon is emitted an electron moves from a high energy state to a lower energy state. When an atom absorbs an electron the reverse occurs. In either case the total energy of the atom is increased and/or decreased.

While the photon has no mass, it does carry momentum and does add and subtract from the total mass of the atom. In agreement with, $$E = mc^2$$ that change in energy represents a corresponding change in mass.

While this is trivially insignificant under most conditions, in the case of the DCE where I raised the idea and relativistic velocities, the rate of interaction would become significant.

Consider the idea of solar sails.

Or the radiometer (or light mill).. The last paragraph of the following link is the only part that has any direct application application to this issue.

How does a light mill work?
On a last note, it is possible to measure radiation pressure using a more refined apparatus. One needs to use a much better vacuum, suspend the vanes from fine fibers and coat the vanes with an inert glass to prevent out-gassing. When this is done, the vanes are deflected the other way — as predicted by Maxwell. The experiment is very difficult; it was first done successfully in 1901 by Pyotr Lebedev and also by Ernest Nichols and Gordon Hull.​

In the variation described above the light mill or radiometer turns in a direction consistent with a transfer of momentum from light — photons, to the reflective surface of the radiometer vanes...

 

[Robittybob1]

Well referenced but I would like to see some of those ideas tested experimentally.
Experiment 1.
Is relativistic mass affected by gravity?
What could be done?
Method?

For as I looked at it if a rocket was to travel near light speed to catch up with a stars that is receding at 0.5 speed of light away form us. The rocket lands but is still retaining it's RELATIVE SPEED WHEN COMPARED TO ITS ORIGINAL FRAME.
Will it loose that relativistic mass?

Results
Nil so far.

 

[OnlyMe]

Well referenced but I would like to see some of those ideas tested experimentally.
Experiment 1.
Is relativistic mass affected by gravity?
What could be done?
Method?

For as I looked at it if a rocket was to travel near light speed to catch up with a stars that is receding at 0.5 speed of light away form us. The rocket lands but is still retaining it's RELATIVE SPEED WHEN COMPARED TO ITS ORIGINAL FRAME.
Will it loose that relativistic mass?

Results
Nil so far.

The term, "relativistic mass" should be discarded and just treated as momentum and an inertial factor that scales with velocity. As you go faster your inertial residence to further acceleration grows, limiting velocities to <= c.

Relativistic and inertial mass in that respect are already frame dependent. ... With the exception that limits an object's velocity to <= c.

 

[Robittybob1]

The term, "relativistic mass" should be discarded and just treated as momentum and an inertial factor that scales with velocity. As you go faster your inertial residence to further acceleration grows, limiting velocities to <= c.

Relativistic and inertial mass in that respect are already frame dependent. ... With the exception that limits an object's velocity to <= c.

Like a rocket is broken down so they decide to send up a part. They have to travel near light speed to catch it up. Its velocity never drops below 0.5 C.
The people in the repaired craft, do they recieve the part with the relativistic mass or does it revert to its rest mass once on board?
Remembering they themselves have relativistic mass as well.

 

[Farsight]

As far as they can tell it has the same mass as it would have had if they'd received it when they were in a low-earth orbit. It's a bit like me handing you a cannonball when we're in a plane. The plane is going at 500mph, so the cannonball is too. But so are you.

OnlyMe: rest mass is just the flip side of momentum. If a photon hits you, it imparts momentum. Think of yourself as being the electron in Compton scattering. The photon exhibits resistance to change in motion. It doesn't have any rest mass because it's moving at c. But when you trap it in a mirror-box, it's effectively at rest, even though it's going round and round at c, so it adds rest mass to that system. When you hit the box, the photon inside still exhibits resistance to change in motion, only now you call it inertia. If you open the box the photon escapes, and you've got a radiating body that loses mass.

 

[hansda]

Hansda, some of the confusion is that I am almost always projecting these discussions in practical terms. How do they fit with experience in the world. Keeping that in mind the following is a rather long post. I rarely reference Wiki except to check on a link someone has supplied. Most of the time I post as a matter of my own thoughts and interpretations, of whatever topic is being discussed. Because the confusion has come up between the Wiki reference you linked and my own understanding of things, the following post includes a number of quotes from Wiki, with links to the full Wiki references.

To begin a quote from the link in your above quoted post.

Wiki on Equivalence Principle
In the physics of general relativity, the equivalence principle is any of several related concepts dealing with the equivalence of gravitational and inertial mass, and to Albert Einstein's assertion that the gravitational "force" as experienced locally while standing on a massive body (such as the Earth) is actually the same as the pseudo-force experienced by an observer in a non-inertial (accelerated) frame of reference. ​

Then from just after the index to that section, the quote from Einstein
A little reflection will show that the law of the equality of the inertial and gravitational mass is equivalent to the assertion that the acceleration imparted to a body by a gravitational field is independent of the nature of the body. For Newton's equation of motion in a gravitational field, written out in full, it is:

(Inertial mass) (Acceleration) = (Intensity of the gravitational field) (Gravitational mass).​

It is only when there is numerical equality between the inertial and gravitational mass that the acceleration is independent of the nature of the body.​

As described above, an inertial mass is under acceleration and outside of the influence of all other forces, including gravitational. It assumes that the accelerating mass is in the essentially flat spacetime of special relativity and also locally consistent with Newtonian flat space. There is no consideration or inclusion, of the special relativistic effect that the constantly increasing instantaneous velocity associated with the acceleration has on, the concept of inertial mass.

To better understand the distinction consider the following links from that first section to both gravitational and inertial mass.

Wiki on Gravitational mass
Active gravitational mass is a property of the mass of an object that produces a gravitational field in the space surrounding the object,...​

Here gravitational mass, is the same as an object's rest mass, or its mass as defined from its own at rest frame of reference. It does not change when the object is in motion or at rest.

Wiki on Inertial mass
Inertial mass is found by applying a known net force to an unknown mass, measuring the resulting acceleration, and applying Newton's Second Law, $$m_i = F/a$$. This gives an accurate value for mass, limited only by the accuracy of the measurements.

Since Einstein used inertial mass to describe special relativity, inertial mass is closely related to relativistic mass and is therefore different from rest mass.​

Note: the subscript in $$m_i$$ above was added by myself for consistency with later formulations and denotes inertial mass.

If we restrict the definition of inertial mass to the first sentence in the above reference, there is no issue. In that case inertial mass and gravitational mass are the same thing.., and equivalent. Keep in mind, that part of the Wiki reference is describing inertial mass, from the at rest frame of reference of the involved mass. It holds in both the case of Newtonian dynamics and locally, for the flat spacetime of special relativity.

When the second sentence in the above reference and the association with relativistic mass is considered, it is not as clear. To better understand what I am getting at consider the following,

Wiki on Mass and energy in special relativity - near the end of the section
The term relativistic mass is also used, and this is the total quantity of energy in a body or system (divided by c2). The relativistic mass (of a body or system of bodies) includes a contribution from the kinetic energy of the body, and is larger the faster the body moves, so unlike the invariant mass, the relativistic mass depends on the observer's frame of reference.​

This is where the term inertial mass becomes confusing. When in special relativity it is associated with relativistic mass, inertial mass itself takes on a component of its velocity and it is no longer always equivalent to either rest mass or gravitational mass. The $$m_i = F/a$$ which was introduced earlier and is valid for Newtonian dynamics and locally within the flat spacetime of special relativity, becomes, $$m_i = \frac{m_o}{\sqrt{1-v^2/c^2}} = F/a$$, which is only equivalent to the object's rest mass and gravitational mass when it is at rest. Whenever an object is in motion, its inertial mass includes a component of the kinetic energy associated with its velocity. The greater its velocity the larger its inertial mass becomes. This distinction is generally considered to be trivially insignificant, except where the velocity approaches or becomes relativistic. Outside of particle accelerators velocities consistent with experience do not contribute measurably to any significant change in an object's inertial mass.

note: $$m_o$$ is rest mass and $$m_i$$ is inertial mass.

As far as we can determine at present, gravitational mass is the same as rest mass, and it does not change with an object's inertial or non-inertial velocity. Though non-inertial velocities can affect the shape and direction of force of a gravitational field. An object's gravitational mass is frame independent, at least within the context of the classical inertial frames of reference, consistent with experience. Meaning, as long as the object's motion does not involve linear acceleration and does not involve relativistic velocities, any gravitational interaction, at a defined location within the field, is uniformly constant, assuming the absence of other outside forces, acting on the involved system.

The definition of inertial mass, cannot be interpreted as equivalent, with gravitational mass, as described above, in an unambiguous manner, except within the object's at rest frame of reference. While mass itself is defined as a body's resistance to a change in motion, this is a reflection of the object's at rest or gravitational mass.., only as measured when the object is at rest, relative to the measurement, of its mass.

What i understand is that : inertial-mass of a body(matter) increases from its gravitaional-mass ( or rest-mass ) as its speed becomes relativistic and inceases further .

My understanding is that : this fact is again due to the effect of frame-dragging .

 

[hansda]

Well referenced but I would like to see some of those ideas tested experimentally.
Experiment 1.

Is relativistic mass affected by gravity?

My understanding is that : relativistic mass is due relativistic speed .

What could be done?
Method?

For as I looked at it if a rocket was to travel near light speed to catch up with a stars that is receding at 0.5 speed of light away form us. The rocket lands but is still retaining it's RELATIVE SPEED WHEN COMPARED TO ITS ORIGINAL FRAME.
Will it loose that relativistic mass?

Results
Nil so far.

 

[OnlyMe]

What i understand is that : inertial-mass of a body(matter) increases from its gravitaional-mass ( or rest-mass ) as its speed becomes relativistic and inceases further .

My understanding is that : this fact is again due to the effect of frame-dragging .

My understanding is that : relativistic mass is due relativistic speed .

This is where some of the confusion comes from when using the term "relativistic mass" and then, "inertial mass" as it is associated with the former.

Relativistic mass — is mass only, in that mass contributes to "it", and as far as inertial mass is associated with relativistic mass, the same applies.

The problem is that there is more than one way to project the definition of inertia. It not only is a measure of an object's resistance to a change in motion, it is also descriptive of the object's momentum. It is within this aspect that relativistic mass and inertial mass become confusing. To the extent that an object's velocity contributes to either its inertial or relativistic mass, what is being described is the object's momentum.

But this is not the only issue once relativistic velocities are involved. As that same object's velocity approaches relativistic magnitudes, the object's inertial resistance increases exponentially. It takes more to accelerate an object that is already in motion than it does one that is at rest. The increased force required is just insignificant until relativistic velocities are involved.

From the above it becomes clear that relativistic mass is not really mass, but momentum and to the extent that inertial mass is similarly defined, it also represents an object's momentum, rather than any absolute definition of the object's mass.

The reason that either case is associated with mass, stems from the increasing force required to further accelerate an object already in motion. Both relativistic and inertial mass, in this sense are pseudo or ficticiuos mass terms. Since we already define mass as an object's resistance to a change in motion, it becomes easy to explain the increasing resitance to acceleration, as an increase in inertial or relativistic mass. However, once again.., since even at relativistic velocities an object's gravitational mass remains constant, as does its gravitational field, its mass does not actually increase with velocity.

The rest and gravitational mass of an object, does not change with any inertial or non-inertial (accelerating) motion. And so long as an object's inertial mass is measured from, the object's own at rest frame of reference, it is the same — equvalent to both its gravitational and rest mass.

This is one of the reasons, I have become interested in some of the attempts to explain inertia as emergent from the interaction of an object, as it moves through the vacuum energy of empty space. That interaction would be proportional to the object's velocity and would not require reference to relativistic or inertial mass.

 

[hansda]

This is where some of the confusion comes from when using the term "relativistic mass" and then, "inertial mass" as it is associated with the former.

Relativistic mass — is mass only, in that mass contributes to "it", and as far as inertial mass is associated with relativistic mass, the same applies.

The problem is that there is more than one way to project the definition of inertia. It not only is a measure of an object's resistance to a change in motion, it is also descriptive of the object's momentum. It is within this aspect that relativistic mass and inertial mass become confusing. To the extent that an object's velocity contributes to either its inertial or relativistic mass, what is being described is the object's momentum.

But this is not the only issue once relativistic velocities are involved. As that same object's velocity approaches relativistic magnitudes, the object's inertial resistance increases exponentially. It takes more to accelerate an object that is already in motion than it does one that is at rest. The increased force required is just insignificant until relativistic velocities are involved.

From the above it becomes clear that relativistic mass is not really mass, but momentum and to the extent that inertial mass is similarly defined, it also represents an object's momentum, rather than any absolute definition of the object's mass.

The reason that either case is associated with mass, stems from the increasing force required to further accelerate an object already in motion. Both relativistic and inertial mass, in this sense are pseudo or ficticiuos mass terms. Since we already define mass as an object's resistance to a change in motion, it becomes easy to explain the increasing resitance to acceleration, as an increase in inertial or relativistic mass. However, once again.., since even at relativistic velocities an object's gravitational mass remains constant, as does its gravitational field, its mass does not actually increase with velocity.

Consider this case :


" A gravitaional-mass ( or rest-mass ) is being accelerated to the relativistic speed . "


In this case , at the relativistic speed ; the mass will cause frame-dragging .


This frame-dragging effect will distort spacetime . So, some additional energy or force will be required to restore back the distorted spacetime .


This additional energy or force , accounts for the additional inertial-mass ( or relativistic-mass ) .


So, increase of inertial or relativistic mass is due to the frame-dragging effect .

The rest and gravitational mass of an object, does not change with any inertial or non-inertial (accelerating) motion. And so long as an object's inertial mass is measured from, the object's own at rest frame of reference, it is the same — equvalent to both its gravitational and rest mass.

This is one of the reasons, I have become interested in some of the attempts to explain inertia as emergent from the interaction of an object, as it moves through the vacuum energy of empty space. That interaction would be proportional to the object's velocity and would not require reference to relativistic or inertial mass.

 

[hansda]

I think Newton did not consider frame-dragging effect in his definition of inertia .

Perhaps this is also causing some confusion about understanding inertia .

 

[Robittybob1]

I think Newton did not consider frame-dragging effect in his definition of inertia .

Perhaps this is also causing some confusion about understanding inertia .

That would seem logical as the concept of General Relativity was from the early 1900's, where as Newton lived in the 1600's.

(Sir Isaac Newton Sir Isaac Newton (December 1642 – March 1727) was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian. )

In the most simplistic way what are the effects attributable to Space Time frame dragging (STFD)?

 

[Robittybob1]

Consider this case :


" A gravitaional-mass ( or rest-mass ) is being accelerated to the relativistic speed . "

In this case , at the relativistic speed ; the mass will cause frame-dragging.

This frame-dragging effect will distort spacetime . So, some additional energy or force will be required to restore back the distorted spacetime .

This additional energy or force , accounts for the additional inertial-mass (or relativistic-mass ).

So, increase of inertial or relativistic mass is due to the frame-dragging effect .

There is no particular speed that is "relativistic speed". All velocities contributes a part to the relativistic mass of an object. It primarily that this component is so small at everyday velocities it is not added in.
"This frame-dragging effect will distort spacetime (ST)", same thing. Really it is the mass moving in ST that distorts ST.
If you accelerate a mass sideways at 9.8 m/sec^2 you experience its inertial mass being the same as its weight.
So when an object is not moving because it is resting on a hard surface the gravitational force is always constantly "Pulling (pushing?) it down".

 

[arfa brane]

Relativistic mass is related to "rest" mass. In Minkowski spacetime, rest mass is a magnitude corresponding to the length of a four-momentum which points inside the lightcone.

Relativistic speed is just a speed which is comparable to the speed of light.

 

[Robittybob1]

Relativistic mass is related to "rest" mass. In Minkowski spacetime, rest mass is a magnitude corresponding to the length of a four-momentum which points inside the lightcone.

Relativistic speed is just a speed which is comparable to the speed of light.

Relativistic speed as defined by Wikipedia this means that significant relativistic mass would kick in at the same speed.

http://en.wikipedia.org/wiki/Relativistic_speed
Relativistic speed
From Wikipedia, the free encyclopedia
A Relativistic speed is a speed which is a significant proportion of the speed of light. Therefore scientific analysis must take the consequences of special relativity into account. A relativistic particle is a subatomic particle moving at relativistic speed.
The boundary for when a particle becomes relativistic is difficult to define, but a particle can generally be said to be relativistic when Newtonian Mechanics no longer provide an accurate description which, within a margin of error of 1%, is 10% of the speed of light.

 

[hansda]

There is no particular speed that is "relativistic speed". All velocities contributes a part to the relativistic mass of an object. It primarily that this component is so small at everyday velocities it is not added in.

An experiment can be performed to find out , at what speed frame-dragging is starting to take place . Speeds greater than this speed can be considered as "relativistic speed" .

"This frame-dragging effect will distort spacetime (ST)", same thing. Really it is the mass moving in ST that distorts ST.

Consider Newton's First Law of Motion , which explains inertia .

As per this law , a body(mass) in motion will remain in its state of uniform motion ; unless acted upon by some external force .

This Law holds true for a speed below relativistic speed . At relativistic speed this Law does not hold true , because frame-dragging effect will change that speed .

If you accelerate a mass sideways at 9.8 m/sec^2 you experience its inertial mass being the same as its weight.

This is equivalence-principle .

So when an object is not moving because it is resting on a hard surface the gravitational force is always constantly "Pulling (pushing?) it down".