[jeffreyH (OP)]

I just read this paragraph.

http://en.wikipedia.org/wiki/Introduction_to_general_relativity
"Paraphrasing John Wheeler, Einstein's geometric theory of gravity can be summarized thus: spacetime tells matter how to move; matter tells spacetime how to curve.[16] What this means is addressed in the following three sections, which explore the motion of so-called test particles, examine which properties of matter serve as a source for gravity, and, finally, introduce Einstein's equations, which relate these matter properties to the curvature of spacetime."

Doesn't the Higgs field determine the path of a mass.

[JP]

No.  The Higgs field explains inertial mass of fundamental particles in flat space-time.  It doesn't deal with gravity or determine the paths of things in the presence of gravity.  Right now, we don't know why the equivalence principle seems to hold: i.e. why the mass from the Higgs mechanism and the mass that interacts with gravity have the same value.

[jeffreyH (OP)]

No.  The Higgs field explains inertial mass of fundamental particles in flat space-time.  It doesn't deal with gravity or determine the paths of things in the presence of gravity.  Right now, we don't know why the equivalence principle seems to hold: i.e. why the mass from the Higgs mechanism and the mass that interacts with gravity have the same value.

Isn't the fact that "Right now, we don't know why the equivalence principle seems to hold: i.e. why the mass from the Higgs mechanism and the mass that interacts with gravity have the same value" mean that "spacetime tells matter how to move; matter tells spacetime how to curve" is an equivalence of the same type? It seems to me it is just another way of saying the exact same thing. What exactly curves? Is it vacuum or nothingness? It has to be a field.

[JP]

No.  The Higgs field explains inertial mass of fundamental particles in flat space-time.  It doesn't deal with gravity or determine the paths of things in the presence of gravity.  Right now, we don't know why the equivalence principle seems to hold: i.e. why the mass from the Higgs mechanism and the mass that interacts with gravity have the same value.

Isn't the fact that "Right now, we don't know why the equivalence principle seems to hold: i.e. why the mass from the Higgs mechanism and the mass that interacts with gravity have the same value" mean that "spacetime tells matter how to move; matter tells spacetime how to curve" is an equivalence of the same type? It seems to me it is just another way of saying the exact same thing. What exactly curves? Is it vacuum or nothingness? It has to be a field.

The Higgs mechanism deals with quantum effects on patches of space-time small enough to behave as flat.  General relativity deals with macroscopic effects and the curvature of space-time.

The relationship between them is that for some reason the mass described by the Higgs mechanism is somehow related to the masses that come into play in general relativity.  We don't know how or why, or if their equivalence is exact or just an approximation. 

[jeffreyH (OP)]

No.  The Higgs field explains inertial mass of fundamental particles in flat space-time.  It doesn't deal with gravity or determine the paths of things in the presence of gravity.  Right now, we don't know why the equivalence principle seems to hold: i.e. why the mass from the Higgs mechanism and the mass that interacts with gravity have the same value.

Isn't the fact that "Right now, we don't know why the equivalence principle seems to hold: i.e. why the mass from the Higgs mechanism and the mass that interacts with gravity have the same value" mean that "spacetime tells matter how to move; matter tells spacetime how to curve" is an equivalence of the same type? It seems to me it is just another way of saying the exact same thing. What exactly curves? Is it vacuum or nothingness? It has to be a field.

The Higgs mechanism deals with quantum effects on patches of space-time small enough to behave as flat.  General relativity deals with macroscopic effects and the curvature of space-time.

The relationship between them is that for some reason the mass described by the Higgs mechanism is somehow related to the masses that come into play in general relativity.  We don't know how or why, or if their equivalence is exact or just an approximation.

A curvature does appear flat on a large enough scale. So microscopic and macroscopic systems have this in common.

[Bill S]

Would I be right in thinking that the Higgs field determines only the masses of elementary particles, and that that is only a small part of the total mass of matter as influenced by gravity?

[JP]

No.  The Higgs field explains inertial mass of fundamental particles in flat space-time.  It doesn't deal with gravity or determine the paths of things in the presence of gravity.  Right now, we don't know why the equivalence principle seems to hold: i.e. why the mass from the Higgs mechanism and the mass that interacts with gravity have the same value.

Isn't the fact that "Right now, we don't know why the equivalence principle seems to hold: i.e. why the mass from the Higgs mechanism and the mass that interacts with gravity have the same value" mean that "spacetime tells matter how to move; matter tells spacetime how to curve" is an equivalence of the same type? It seems to me it is just another way of saying the exact same thing. What exactly curves? Is it vacuum or nothingness? It has to be a field.

The Higgs mechanism deals with quantum effects on patches of space-time small enough to behave as flat.  General relativity deals with macroscopic effects and the curvature of space-time.

The relationship between them is that for some reason the mass described by the Higgs mechanism is somehow related to the masses that come into play in general relativity.  We don't know how or why, or if their equivalence is exact or just an approximation.

A curvature does appear flat on a large enough scale. So microscopic and macroscopic systems have this in common.

No, a curvature does not necessarily appear flat on a large enough scale.  An infinitely long cylinder will always appear curved.  On tiny scales, the curved surface is approximately flat, however. 

[JP]

Would I be right in thinking that the Higgs field determines only the masses of elementary particles, and that that is only a small part of the total mass of matter as influenced by gravity?

Yes.  From E=mc² (and you can throw in the momentum part, too, if you want), the binding energies and kinetic energies of the quarks and gluons making up a proton contribute significantly to the mass of the proton and its interaction with gravity. 

More significantly for this question, the Higgs mechanism describe the fundamental (to date) process by which elementary particles gain inertial mass, i.e. how they resist the push and pull of all the fundamental forces.  It says nothing about the process by which this inertial mass is also the gravitational mass or how gravity acts on these particles.

[jeffreyH (OP)]

Would I be right in thinking that the Higgs field determines only the masses of elementary particles, and that that is only a small part of the total mass of matter as influenced by gravity?

Yes.  From E=mc² (and you can throw in the momentum part, too, if you want), the binding energies and kinetic energies of the quarks and gluons making up a proton contribute significantly to the mass of the proton and its interaction with gravity. 

More significantly for this question, the Higgs mechanism describe the fundamental (to date) process by which elementary particles gain inertial mass, i.e. how they resist the push and pull of all the fundamental forces.  It says nothing about the process by which this inertial mass is also the gravitational mass or how gravity acts on these particles.

You could say that the Higgs field is like treacle and the kinetic energy of the mass mass provides the power to move through it.

[JP]

Would I be right in thinking that the Higgs field determines only the masses of elementary particles, and that that is only a small part of the total mass of matter as influenced by gravity?

Yes.  From E=mc² (and you can throw in the momentum part, too, if you want), the binding energies and kinetic energies of the quarks and gluons making up a proton contribute significantly to the mass of the proton and its interaction with gravity. 

More significantly for this question, the Higgs mechanism describe the fundamental (to date) process by which elementary particles gain inertial mass, i.e. how they resist the push and pull of all the fundamental forces.  It says nothing about the process by which this inertial mass is also the gravitational mass or how gravity acts on these particles.

You could say that the Higgs field is like treacle and the kinetic energy of the mass mass provides the power to move through it.

Kind of, except treacle (or molasses for those of us from the states where treacle isn't widely known) exerts a drag force which slows down a moving object.  The Higgs field just gives an object inertia, but once it's moving it keeps moving without slowing down.

[Bill S]

If I have said this on this forum before, I apologise.  Perhaps, at my age I should not be on more than one forum, to avoid confusion.

Pop Sci books and articles, even those that don’t actually reproduce the “Waldgrave” analogy, still perpetrate the “molasses heresy” in which the field somehow impedes the progress of particles, as though it were molasses, thus adding to their inertial mass.  In this way the impression is maintained that motion through the Higgs field is necessary so that mass can be conferred on particles.  In fact, in the same way that it makes no real sense to talk of motion through empty space, so it makes no sense to talk of motion relative to the Higgs field.  The Higgs field permeates space, and alters space; it does not fill space in the same way that air fills a room. 

[jeffreyH (OP)]

If I have said this on this forum before, I apologise.  Perhaps, at my age I should not be on more than one forum, to avoid confusion.

Pop Sci books and articles, even those that don’t actually reproduce the “Waldgrave” analogy, still perpetrate the “molasses heresy” in which the field somehow impedes the progress of particles, as though it were molasses, thus adding to their inertial mass.  In this way the impression is maintained that motion through the Higgs field is necessary so that mass can be conferred on particles.  In fact, in the same way that it makes no real sense to talk of motion through empty space, so it makes no sense to talk of motion relative to the Higgs field.  The Higgs field permeates space, and alters space; it does not fill space in the same way that air fills a room.

This is something I personally need to get a better handle on. It was all hypothetical until recently and I didn't take much notice to be honest. Always something new to learn.

[JP]

Pop Sci books and articles, even those that don’t actually reproduce the “Waldgrave” analogy . . .

From my limited expertise in the Higgs mechanism, the "Waldgrave" analogy seems to be one of the better pop-sci analogies out there.  When you get into general relativity, analogies have more serious issues because you're dealing with curvature of 4D space-time in terms of analogies that usually involve curving 2D surfaces in 3D space.