Movement?

[jajrussel]

Doesn't it seem controversial, or t least odd to say that an object of zero mass moves at c. To then turn around and say that to move an object you have to give it mass in the form of energy?

The thoughts seems backwards? Maybe it is the scale that seems backwards? Its like saying less is more, unless you want more, then you have to add more.

Does moving the object give it some negative value on a scale I am not considering?

Is it because an object of zero mass is completely at odds with something that has mass to the point that they are so different that my sudden late night thought is like comparing space to a light particle then saying that because space has zero mass it should move at c?

Still, it seems odd?

[Sensei]

In Special Relativity object with non-zero rest-mass cannot move at speed of light c. [math]\gamma[/math] is going to infinity while approaching c. [math]\gamma[/math] for v=c cannot be calculated at all (division by 0).

Object with zero rest-mass moving nearly at speed of light would have zero kinetic energy and zero momentum..

[math]KE = m_0c^2\gamma - m_0c^2[/math] , for [math]m_0=0[/math], [math]KE=0[/math]

It's true in either Special Relativity and Classical Physics math equations.

You would need to invent completely new math equations for kinetic energy and for momentum to be able solve your questions.

Edited June 3, 2018 by Sensei

[Strange]

28 minutes ago, jajrussel said:

Doesn't it seem controversial, or t least odd to say that an object of zero mass moves at c. To then turn around and say that to move an object you have to give it mass in the form of energy?

You don't need to give an object mass to make it move; you need to give it energy. The energy is to accelerate it. Massless particles never accelerate so they don't nee (extra) energy to make them move. Massless particles already have energy.

30 minutes ago, jajrussel said:

Is it because an object of zero mass is completely at odds with something that has mass

That is probably true.

[Markus Hanke]

35 minutes ago, jajrussel said:

Is it because an object of zero mass is completely at odds with something that has mass

Surprisingly, no. As a matter of fact, above a certain energy level, all particles are massless and move at exactly c. In a way, masslessness is the natural state of all particles. Mass comes about when ambient energy drops below a certain level, which triggers a process called “spontaneous symmetry breaking”. You then have something called the Higgs mechanism kicking in, which means that most (but not all) particles begin to interact with the Higgs field, which gives them mass and slows them down. So mass is actually an acquired property, it is not intrinsic to fundamental particles; the only intrinsic thing is the degree by which they interact with the Higgs field. 

What this means is that in the early universe, before a certain point in time, “mass” did not exist - all particles were naturally massless and moving at c. Only when the universe cooled down enough, did mass “happen”.

[StringJunky]

3 minutes ago, Markus Hanke said:

Surprisingly, no. As a matter of fact, above a certain energy level, all particles are massless and move at exactly c. In a way, masslessness is the natural state of all particles. Mass comes about when ambient energy drops below a certain level, which triggers a process called “spontaneous symmetry breaking”. You then have something called the Higgs mechanism kicking in, which means that most (but not all) particles begin to interact with the Higgs field, which gives them mass and slows them down. So mass is actually an acquired property, it is not intrinsic to fundamental particles; the only intrinsic thing is the degree by which they interact with the Higgs field. 

What this means is that in the early universe, before a certain point in time, “mass” did not exist - all particles were naturally massless and moving at c. Only when the universe cooled down enough, did mass “happen”.

Does this mean that when the universe was super hot there was no gravity?

[jajrussel]

25 minutes ago, Strange said:

You don't need to give an object mass to make it move; you need to give it energy. The energy is to accelerate it. Massless particles never accelerate so they don't nee (extra) energy to make them move. Massless particles already have energy.

So, the object of intent is to accelerate, not move. So accelerate = Apples, while move = Oranges?

Question? A photon never changes direction? Perhaps, from a relative point of view what we observe as a curved path is a change in the shape of space which we can see by observing the photons path?

I see I have two new replies, which I should read before I go any further.

Edited June 3, 2018 by jajrussel
wrong spelling =wrong word~sometimes

[Strange]

5 minutes ago, Markus Hanke said:

the only intrinsic thing is the degree by which they interact with the Higgs field. 

Is this understood? Is there some parameter of the particle that quantifies this? (I’m guessing it is ... mass  )

11 minutes ago, jajrussel said:

So, the object of intent is to accelerate, not move. 

Thinking about it, it is probably both. There is energy required to change the speed of something. But there may also be energy needed to change its position  (for example, more energy is needed to move something up than down, because there is gravitational potential energy).

[jajrussel]

14 minutes ago, StringJunky said:

Does this mean that when the universe was super hot there was no gravity?

I like this question It keeps sparking thought that seems to allude me the moment I start to think about it. Eventually It will hold still long enough for me to look t it.  

[StringJunky]

Just now, jajrussel said:

I like this question It keeps sparking thought that seems to allude me the moment I start to think about it. Eventually It will hold still long enough for me to look t it.  

It's annoying when that happens... like a ghost drifting in and out of visibility.  

[Markus Hanke]

29 minutes ago, Strange said:

Is this understood? Is there some parameter of the particle that quantifies this? (I’m guessing it is ... mass  )

It is more complicated than this. Basically, you need to go back to the quantum field theoretic description - each type of particle is an excitation of a quantum field. Mathematically, such a collection of fields is described by a Lagrangian, which will have several terms in it; only terms that are quadratic in the fields correspond to mass. Initially an overall Lagrangian may be invariant under some symmetry group, and not contain such quadratic mass terms; however, if you break the symmetry, suddenly extra terms can appear in the Lagrangian, and some of them may be quadratic, corresponding to massive fields and their interactions. Each of these terms will have a constant in it that is called the coupling strength; and the mass of particles arises from the constant (through some maths). So basically, mass comes from how strongly quantum fields interact, specifically with the Higgs field.

This is very inexact and non-specific, but you might get the general idea.

32 minutes ago, StringJunky said:

Does this mean that when the universe was super hot there was no gravity?

No, because the source of gravity is energy-momentum, not just mass. There may not have been rest mass back then, but there definitely was lots of energy! Even today, light (which is massless) has a gravitational effect, due to the fact that it carries energy in the form of momentum, 

Edited June 3, 2018 by Markus Hanke

[jajrussel]

48 minutes ago, Markus Hanke said:

It is more complicated than this. Basically, you need to go back to the quantum field theoretic description - each type of particle is an excitation of a quantum field. Mathematically, such a collection of fields is described by a Lagrangian, which will have several terms in it; only terms that are quadratic in the fields correspond to mass. Initially an overall Lagrangian may be invariant under some symmetry group, and not contain such quadratic mass terms; however, if you break the symmetry, suddenly extra terms can appear in the Lagrangian, and some of them may be quadratic, corresponding to massive fields and their interactions. Each of these terms will have a constant in it that is called the coupling strength; and the mass of particles arises from the constant (through some maths). So basically, mass comes from how strongly quantum fields interact, specifically with the Higgs field.

This is very inexact and non-specific, but you might get the general idea.

 

This reminds me of a question I had a while back when watching a video. Is the particle  an excitation of a field ? Or, is the excitation more like evidence of the particles existence? Then you mention the Higgs field. Was a quantum field renamed to honer Higgs, or does the existence of the Higgs boson give rise to the fact that there must then also be a Higgs field? I'm trying to understand exactly as possible what defines a field. Excluding the term gravitational field how many different fields are there? One for every particle, or does a particle need a specific  characteristic before a field presents as  a property of the particle? These are the kind of questions you can not ask a book, and are apparently the kind of questions the ones writing the book would never think to present and answer. 

I also see now, that toward the paragraph end you have fields interacting rather than particles?

Edited June 3, 2018 by jajrussel

[StringJunky]

1 hour ago, Markus Hanke said:

No, because the source of gravity is energy-momentum, not just mass. There may not have been rest mass back then, but there definitely was lots of energy! Even today, light (which is massless) has a gravitational effect, due to the fact that it carries energy in the form of momentum, 

Of course, I forgot that.

45 minutes ago, jajrussel said:

 

This reminds me of a question I had a while back when watching a video. Is the particle  an excitation of a field ? Or, is the excitation more like evidence of the particles existence? Then you mention the Higgs field. Was a quantum field renamed to honer Higgs, or does the existence of the Higgs boson give rise to the fact that there must then also be a Higgs field? I'm trying to understand exactly as possible what defines a field. Excluding the term gravitational field how many different fields are there? One for every particle, or does a particle need a specific  characteristic before a field presents as  a property of the particle? These are the kind of questions you can not ask a book, and are apparently the kind of questions the ones writing the book would never think to present and answer. 

I also see now, that toward the paragraph end you have fields interacting rather than particles?

Have you seen Sean Carroll's lecture "Particles, fields and the future of physics"?. It's good primer. Basically, there are no particles, only fields.

 

Edited June 3, 2018 by StringJunky

[jajrussel]

 

19 minutes ago, StringJunky said:

Of course, I forgot that.

I don't remember ever knowing that. Now I'm tying to figure out why I've never heard that the source of gravity is energy momentum? I am admitting to being a senile old man. Well, at least senile, but I would think that being senile I would not realize that I am confused... but, I do?

23 minutes ago, StringJunky said:

Of course, I forgot that.

Have you seen Sean Carroll's lecture "Particles, fields and the future of physics"?. It's good primer. Basically, there are no particles, only fields.

 

No I haven't seen this. Thanks I'll check it out....

[Markus Hanke]

1 hour ago, jajrussel said:

Is the particle  an excitation of a field ? Or, is the excitation more like evidence of the particles existence?

The quantum field is the more fundamental entity here, so a particle is the excitation of a field - like a wave is an excitation of a body of water. You can have a field without any excitations, but you can’t have an excitation (i.e. a particle) without the field. 

1 hour ago, jajrussel said:

Was a quantum field renamed to honer Higgs, or does the existence of the Higgs boson give rise to the fact that there must then also be a Higgs field?

The entire thing - symmetry breaking, the Higgs mechanism, the Higgs field, and its excitation being the Higgs boson - were theoretical predictions made by Prof Higgs long before the particle itself was experimentally found. So basically, he suggested this mechanism based on the question of how fundamental particles in the Standard Model obtain their different masses, and the detection of the Higgs boson later showed that this model was indeed a good one.

1 hour ago, jajrussel said:

I'm trying to understand exactly as possible what defines a field

A field is a mathematical object that assigns some quantity to each point in spacetime. For example, you could decide to assign a single number - such as temperature - to each point on earth’s surface; that would be an example of a scalar field. Or you could decide to assign a force vector to every point in some region of space (maybe outside a magnet etc); that would be an example of vector field. And so on. Quantum fields assign mathematical objects called “operators” to each point in space and time.

1 hour ago, jajrussel said:

Excluding the term gravitational field how many different fields are there?

It depends on exactly how you count them (not as trivial a task as it may naively seem!), but most commonly we are counting 37 quantum fields in the Standard Model as it stands today. That is after symmetry breaking, i.e. when all particles have obtained their respective masses and interactions.

1 hour ago, jajrussel said:

One for every particle

It’s essentially one for every fundamental particle, whereby particles and their antiparticles are counted as separate fields. Like I said, the exact number depends on exactly what you consider a single field. Gravity does not fit into this, because it cannot be meaningfully described as a quantum field (well, actually it can, but the model you get is physically meaningless, so we are disregarding this).

1 hour ago, jajrussel said:

I also see now, that toward the paragraph end you have fields interacting rather than particles?

Yes. In quantum field theory (QFT), everything is described in terms of the fields - they are taken as the fundamental objects.

Edited June 3, 2018 by Markus Hanke

[studiot]

3 hours ago, jajrussel said:

Doesn't it seem controversial, or t least odd to say that an object of zero mass moves at c. To then turn around and say that to move an object you have to give it mass in the form of energy?

 

Moving in whose frame of reference?

Time 'stands still' for an object moving at lightspeed.
That is from the point of view of its own frame of reference
This means it takes zero time to get from A to B
or that the object is at every point along its track at once.

It is only moving relative to another object with mass

That is in the frame of reference of the particle with mass.

[geordief]

15 minutes ago, Markus Hanke said:

The quantum field is the more fundamental entity here, so a particle is the excitation of a field - like a wave is an excitation of a body of water. You can have a field without any excitations, but you can’t have an excitation (i.e. a particle) without the field. 

Just an analogy? But should I be thinking of the waves as passing through the interior of the body of water  as well as on the surface?

[Markus Hanke]

1 hour ago, geordief said:

Just an analogy? But should I be thinking of the waves as passing through the interior of the body of water  as well as on the surface?

This was just really meant as an analogy.

[jajrussel]

1 hour ago, studiot said:

 

Moving in whose frame of reference?

Time 'stands still' for an object moving at lightspeed.
That is from the point of view of its own frame of reference
This means it takes zero time to get from A to B
or that the object is at every point along its track at once.

It is only moving relative to another object with mass

That is in the frame of reference of the particle with mass.

Doesn't this allow that the photon is not changing direction even tough we see its path as curved? Doesn't relativity allow this phenomenon to show us the shape of the space the photon exist in from our perspective which allows movement, and direction to be noted? Isn't it kind of like the ripple in a field that defines the existence of a particle? My reference says the photon is moving. Can I apply the same intellect to the observed curve as is applied to the ripple in a field and conclude that perhaps it shows the shape of the space the Photon exist in?

Your  very correct statement,  though prompting me to much thought, does not seem to allow any movement for a photon from my perspective, so how do i define what I see from my perspective if I limit the definition to the photons perspective?  Oh, after a re-read I do see that you say that the the photon is only moving relative to another object with mass. Which I assume can be me as the observer... Hmm? Okay scratch all the perplexing corners of what I thought you were saying I had to be painted into... New question, Why is "with mass" in bold? Is there anything that does not display mass?

Truly, I am not trying to be argumentative. I am just trying to understand why you made this statement.

Edited June 3, 2018 by jajrussel

[studiot]

11 minutes ago, jajrussel said:

Why is "with mass" in bold? Is there anything that does not display mass?

Truly, I am not trying to be argumentative. I am just trying to understand why you made this statement.

No problem.

 

The with mass ensures that the second frame is an inertial frame and not, for instance the frame of another photon.

[swansont]

4 hours ago, jajrussel said:

Doesn't it seem controversial, or t least odd to say that an object of zero mass moves at c. To then turn around and say that to move an object you have to give it mass in the form of energy?

But that's not what is being said.

In your first statement you have spoken about massless particles, which have energy. That zero mass is rest mass. In the next, you speak of giving mass to objects by moving them. That's relativistic mass. You aren't comparing the same things. Relativistic mass is a concept that seems enticing but ends up causing lots of confusion, as shown here. You can't mix and match the terminology.

 

4 hours ago, jajrussel said:

So, the object of intent is to accelerate, not move. So accelerate = Apples, while move = Oranges?

If you are not accelerating, then you can't say who is moving. It only depends on your choice of reference frame. Motion is not absolute, and can't be assigned to any massive particle. Motion is relative.

 

 

[jajrussel]

4 hours ago, Sensei said:

In Special Relativity object with non-zero rest-mass cannot move at speed of light c. γ is going to infinity while approaching c. γ for v=c cannot be calculated at all (division by 0).

Object with zero rest-mass moving nearly at speed of light would have zero kinetic energy and zero momentum..

KE=m0c2γ−m0c2 , for m0=0 , KE=0

It's true in either Special Relativity and Classical Physics math equations.

You would need to invent completely new math equations for kinetic energy and for momentum to be able solve your questions.

basically aren't you saying I would have to invent a whole new way of looking at things, since there is no way the maths  can change? What I would need to do is come up with new ways of application? Okay, maybe this is not what you are saying, but it might be easier for someone like me to do. 

note: some of your quote seems to have disappeared. I'm assuming that the part that disappeared does not transfer well when quoted.

[Markus Hanke]

10 minutes ago, jajrussel said:

I would have to invent a whole new way of looking at things

And this, my friend, is how advancements in our understanding of the world are made - by looking at things in whole new ways  

[jajrussel]

11 minutes ago, swansont said:

But that's not what is being said.

In your first statement you have spoken about massless particles, which have energy. That zero mass is rest mass. In the next, you speak of giving mass to objects by moving them. That's relativistic mass. You aren't comparing the same things. Relativistic mass is a concept that seems enticing but ends up causing lots of confusion, as shown here. You can't mix and match the terminology.

 

 

 

5 hours ago, jajrussel said:

Doesn't it seem controversial, or t least odd to say that an object of zero mass moves at c. To then turn around and say that to move an object you have to give it mass in the form of energy?

The thoughts seems backwards? Maybe it is the scale that seems backwards? Its like saying less is more, unless you want more, then you have to add more.

Does moving the object give it some negative value on a scale I am not considering?

Is it because an object of zero mass is completely at odds with something that has mass to the point that they are so different that my sudden late night thought is like comparing space to a light particle then saying that because space has zero mass it should move at c?

Still, it seems odd?

I was just repeating what is said about mass-less particles. Parroting isn't specifying a condition, but now that I think about it if I understand your point.  To say that a mass-less particle moves at C. is an oxymoron, but not of my creation.

Now for the sake of consideration does a photon gain mass through acceleration? Wait! It has been pointed out and partially accepted by me that a photon does not accelerate. See  Stranges initial responses.... Now is it correct to say that kinetic energy does not add mass to the photon. If the photon does gain mass in the form of kinetic energy would it be correct to say that the Photon needs to present mass at C. in order to be called a photon? Would it be correct to say that a Photon displays mass anytime it interacts with something else.

I was trying to use relativity to justify for my own sake of clarity Stranges statement that Photons do not accelerate when from my perspective it appears that they do when using the full meaning of the word accelerate. As in, I don't mean to just speedup. 

[swansont]

3 hours ago, jajrussel said:

 To say that a mass-less particle moves at C. is an oxymoron, but not of my creation.

I don't see that.

Quote

Now for the sake of consideration does a photon gain mass through acceleration? Wait! It has been pointed out and partially accepted by me that a photon does not accelerate. See  Stranges initial responses.... Now is it correct to say that kinetic energy does not add mass to the photon. If the photon does gain mass in the form of kinetic energy would it be correct to say that the Photon needs to present mass at C. in order to be called a photon? Would it be correct to say that a Photon displays mass anytime it interacts with something else.

Photons are massless. Mass means rest mass (and we junk the irresponsible concept of relativistic mass, which is just a proxy for total energy)

Massless particles move at c.

Total energy is given by E^2 = p^2c^2 + m^2c^4

If you have a massive particle and add energy it changes the momentum, not the mass. Massless particles only have the momentum term. E = pc in that case.

Quote

I was trying to use relativity to justify for my own sake of clarity Stranges statement that Photons do not accelerate when from my perspective it appears that they do when using the full meaning of the word accelerate. As in, I don't mean to just speedup. 

A geodesic is a straight line in the nonlinear coordinate system of GR. If you think they have accelerated then you are not in the proper frame of reference, similar to how you get fictitious forces in Newtonian physics when you are in a rotating frame of reference.

[Sensei]

3 minutes ago, swansont said:

If you have a massive particle and add energy it changes the momentum, not the mass.

I would rephrase it to "If you have a massive particle and add energy it changes the relativistic-mass and relativistic-momentum, not the rest-mass (as it's invariant)."

This way it's absolute clear to either scientists and non-scientists.

3 hours ago, jajrussel said:

it be correct to say that the Photon needs to present mass at C. in order to be called a photon? Would it be correct to say that a Photon displays mass anytime it interacts with something else.

When some scientists like swansont says about mass they really mean rest-mass (aka "invariant-mass")..

Rest-mass of particle is measured in particle's frame-of-reference. You don't have frame-of-reference in which photon is at rest to be able to measure photon's rest-mass ("invariant-mass"). At least in current laboratory experiments.