Ask any question you want about Physics

originally posted by: ImaFungi
If your belief is true, the EM field must be some type of zipper, and when the electrons acceleration disturbs the prior relative order, the total mass and compressed nature of the EM field is focused on this one tiny break, which 'works itself out' by traveling indefinitely, unallowed to expand, by the total pressure of the orderly EM field which surrounds it.

No, infinitesimal point perturbations do not stay as point perturbations.

If something like that is the case, then I easily admit my theory is incorrect. I have not witnessed anyone attempt to explain explicitly, generally, simply, reducibly, analogously, anyway approaching confidence in understanding, how the EM field exists as an energetic phenomenon, and how it is coupled to the electron, and how when the electron is accelerated, only 1 infinitesimal point on that area of coupling, is effected, in such the way, as to ripple away from the electron, while all other EM coupled directions surrounding the electron locally, remain unaffected, in such that way, as to also, ripple away, as EM radiation.

I think you're still confused.

The "ripples" happen in all directions. The question of electromagnetic *radiation* is a bit different: radiation is a subset of what fields can do, and refers to situations where energy is propagated out effectively to large distances.
Mathematically you can separate fluctuating field components into "near field" and "far field" and it is the far field which transfers energy & momentum away permanently and is commonly called radiation.

And the direction of that propagation could be represented in some cases as a single vector pointing away which you may have confused with the fields being altered only in a single infinitesimal "straw" shooting out from the charge, which is not the right picture.

You can also use google to search for instructional videos before starting on the Feynman lectures. (You WILL do that, right?). There are tons of courses and videos online.

www.youtube.com...

Question: How many of you guys/girls have your PhD? What do you do now? If not, why didn't you go for a PhD? I take it most of you do not work as physicists even with your PhDs, seeing it as most physics PhDs end up leaving physics from what I've read.

My degree was in engineering physics (which is basically a physics degree along with the core requirements of electrical and mechanical engineering), and I've been considering going back for the PhD.

Your input is definitely appreciated.

originally posted by: Diablos
Question: How many of you guys/girls have your PhD? What do you do now? If not, why didn't you go for a PhD?

Well, for my part, I was a 'non-trad' who got started later than the rest of the kiddies, having spent right at 10 years in the military before deciding to get cracking on a family and some higher education. I got something like you, Georgia Tech didn't have a combo degree so I made my own and got a Bach in EE and another in physics, then later got my masters in both. I wanted to get my doctorate, but didn't find it that necessary in my line of work as long as we had ONE PhD in the business.

I had one of my former professors working for us at one time, he told me he would have accepted most of our projects as a doctoral thesis if I'd put in the class time, but I never seemed to have the time. I don't now. And now I'm not sure it's worth the time to spend on it. If I get Operation ITOFTS to go, I *might* go get my physics doctorate just because it's so FUN. But it's my impression if you don't go for it when you get your undergrad, you are unlikely to have the time or inclination later.

a reply to: mbkennel

Ok, so that first graphic shows the field all surrounding the charged particle being effected. Would this be EM radiation propagating away from that charged particle, in all directions surrounding the particle (at least on some 2d plane, perpendicular to direction of acceleration maybe)?

This is all I was getting at. Arb seems to think, that graphic should only show 1 field line around the charged particle waving when the particle is accelerated, as that is what he says a photon being emitted from a moment of accelerated charged particle resulting in EM radiation, is.

The electron is 3d. No such thing, essence, quanta, can exist in any way, that is not at least 3d.

Make at least one statement that supports your faith in less than 3d electron. A math paper that defines the electron as being a less than 3d object, has nothing to do with reality, that has to do with symbols on paper, that do not corroborate to reality, everything is rounded and skewed, I am after closest to truth, the electron not existing in 3d can not be a statement that is closest to truth. It is silly to even argue with you, you are absolutely wrong. One way to destroy your stance, is to ask you to state the first particle that is 3d (I am sure you will have trouble understanding what I mean for reasons obviously not obvious to you, but I mean to say, if electron is not 3d according to ignorance and idiocy, what particles moving up in dimension, is the first particle that is 3d...you are an absolute mongrel, disgusting, filthy intellect. garbage.)

a reply to: mbkennel

Ripples happen in all directions. All I was trying to suggest to arb a few pages back, and he disagreed, I suppose my case is rested as I suspected.

originally posted by: ImaFungi
a reply to: mbkennel

Ripples happen in all directions. All I was trying to suggest to arb a few pages back, and he disagreed, I suppose my case is rested as I suspected.

You said photons expand. They don't, and mbkennel didn't say that they do. You didn't say "ripples" expand, you said "photons" expand and nothing mbkennel said makes the following statement correct.

mbkennel, I know you're not confirming this, but please clarify to imafungi that you're not confirming this is correct:

originally posted by: ImaFungi
If when EM radiation is created, it looks like this: O ..... And that circle, expands in area and circumfrence. That is 1 photon, the circle as a whole expanding, anywhere along its circumference would be measured as '1 photon', and the nature of how this circles circumference increases, is that it does so as a wave.

Does 1 photon expand? no.

Does the wave function allow the probability amplitude of the photon's location to expand in space over time as Astyanax already explained? Yes, but the wave function of the photon isn't the photon; the photon itself doesn't expand.

a reply to: Arbitrageur

You are misinterpreting me, I was much more thorough than that at expressing my intent.

To correspond what you quoted with my intent, imagine that the electron is in the middle of the 'O' that you quoted. If it helps, imagine the circle is the size of your computer screen, and the electron is the size of this period . But the circle starts out around the . and then becomes a larger circle. I made the analogy of a stone metaphorically being the electron, dropped in a pond, creating a circular wave of ripple around it, as when the electron is accelerated I posit a circular wave of EM field expands its area surrounding it. I have stated this sort of concept in several different thorough ways, you failing to grasp what I was saying, is not a failure of what I was saying to be true. Now that I have presented it again, directly to you, again, super thoroughly, what say you.

a reply to: ImaFungi

The problem is you have this picture in your head about how you see these waves propagating and the picture is wrong. Wehave tried to tell you and even ponted you to places to help you change this image you have. Your stuck in a 18th century view where things traveled through this invisible jelly called an ether. The answers you seek arein QED which by the way Freeman J. Dyson, Richard P. Feynman and Julian S. Schwinger in the United States and Shinichiro Tomonaga in Japan refined and developed. The place where every physics student starts id the Feynman diagrams it gives you the basic understanding to move forward. And also gets you to understand photons are just energy carriers.And fields in reality are constructs used to help us explain an interaction.

So lets start first To answer to your questions requires that you understand how EM waves are generated. Imagine an electron which is not moving and stationary. According to Coulomb's law, a field is produced by this electron. The field will be static and not changing as long the electron isn't moving. Now key point here we wouldnt even be able to detect this field without adding another charge! Now our field will move or oscillate but it doesnt really go any where this is near field. But what it does do is create a magnetic field which creates and electric field which in turn creates magnetic field and so on. This is all an EM wave is energy causing an imbalance that creates a field to correct the imbalance which again creates an imbalance. This goes back to the basic point in physics everything in the universe is attempting to reach its ground state to do this it has to discharge energy either through heat or light.

a reply to: dragonridr

To be thorough, I will start most simply.

" Imagine an electron which is not moving and stationary. According to Coulomb's law, a field is produced by this electron."

What are the words/terms you wish to use to express to me what this field is made of, and in what physical manner the stationary electrons stationary field exists?

After you answer that, I will ask if your description of how that physical field exists, 'physically stops existing' at some point, at a distance away from the stationary electron. (you will of course have trouble answering this, so just focus on answering the first question above... and then instead of saying anything else, if you dont get what I mean by the second part, tell me what you dont understand about the second part, and I will clarify).

To clarify by my use of the term physical and/or exist, what I mean is that, for example, when you say 'a field is produced', I would say, if the field that is produced is anything except for absolute pure nothing, than I would say that field exists, and is physical. If you dont like my use of the term physical to denote 'that which in some way exists', than I will use the term exists, or non nothing.

a reply to: ImaFungi

Coulomb's law describes the force between two point charges. The electric field is derived from the law. It is a mathematical model, as is the law, and everything else in physics.

The photon is a result of the quantisation of a field, the energy and momentum transfered by the "ripples" caused by an electron happens to be in discrete units. Again this has been derived to describe observed behavior correctly.

What there is, that makes things behave the way they do, and why mathematics can be used to describe it, is more a philosophical question imho.

originally posted by: ImaFungi
a reply to: dragonridr

To be thorough, I will start most simply.

" Imagine an electron which is not moving and stationary. According to Coulomb's law, a field is produced by this electron."

What are the words/terms you wish to use to express to me what this field is made of, and in what physical manner the stationary electrons stationary field exists?

After you answer that, I will ask if your description of how that physical field exists, 'physically stops existing' at some point, at a distance away from the stationary electron. (you will of course have trouble answering this, so just focus on answering the first question above... and then instead of saying anything else, if you dont get what I mean by the second part, tell me what you dont understand about the second part, and I will clarify).

To clarify by my use of the term physical and/or exist, what I mean is that, for example, when you say 'a field is produced', I would say, if the field that is produced is anything except for absolute pure nothing, than I would say that field exists, and is physical. If you dont like my use of the term physical to denote 'that which in some way exists', than I will use the term exists, or non nothing.

Fields are not made of anything i keep trying to tell you that! A field is nothing more than a mathematical description we use because a particle has force when it interact with another particle. These interactions we plot on fields Really basic QED lesson is all photons in the universe are described by a single vector field A this also gives us E through H as well. All electrons and positrons in the universe are described by a single spinor field we call psi The behavior of the two fields is governed by an equation which contains terms in A describing the propagation of free photons in our spinor field psi. When we have a positive charge it exerts a "force" on another charged particle.Now because they dont actually touch each other we explain this by saying the first charge creates a "field" around itself. And our second particle being in that field feels a "force". The interactions between the two are actual virtual like using photons as a force carrier for example. So when fields interact or disturbed if you will things happen since they are our way of describing interactions.

So the first idea you need to expel is a field is some magic circle around a particle its its points with energy plotted on a graph. In order to understand the inter actions that occur you need to understand QED and well i think we have told you how to do that at least in its basic form. Keep in mind you want the first two semesters of physics summed up in a paragraph without the work your understanding will always be rudimentary at best.

originally posted by: Bedlam
Well, for my part, I was a 'non-trad' who got started later than the rest of the kiddies, having spent right at 10 years in the military before deciding to get cracking on a family and some higher education. I got something like you, Georgia Tech didn't have a combo degree so I made my own and got a Bach in EE and another in physics, then later got my masters in both. I wanted to get my doctorate, but didn't find it that necessary in my line of work as long as we had ONE PhD in the business.

I had one of my former professors working for us at one time, he told me he would have accepted most of our projects as a doctoral thesis if I'd put in the class time, but I never seemed to have the time. I don't now. And now I'm not sure it's worth the time to spend on it. If I get Operation ITOFTS to go, I *might* go get my physics doctorate just because it's so FUN. But it's my impression if you don't go for it when you get your undergrad, you are unlikely to have the time or inclination later.

Interesting post, thanks. If you don't mind me asking, Bedlam, what kind of physics work do you do (i.e specialty, research areas, etc)? It actually sounds like you're doing good work in physics, and that's pretty surprising to me given that you only have a master's. From what I've read (on mainly other "professional" physics forums and from talking with grad students back at my school), I've come to know that most physics PhDs don't even get a chance to work in physics and either have to begin the retraining process in something completely different or use their quantitative skills in completely unrelated fields (i.e finance). I think this applies more to people with backgrounds in HEP and astrophysics, rather than those in condensed matter and optics given how relevant the latter fields are to practical applications and that the former being far removed from any modern applications and technologies.

a reply to: dragonridr

False. You do not know something about reality, you know something about fantasy.

originally posted by: ImaFungi
I made the analogy of a stone metaphorically being the electron, dropped in a pond, creating a circular wave of ripple around it, as when the electron is accelerated I posit a circular wave of EM field expands its area surrounding it. I have stated this sort of concept in several different thorough ways, you failing to grasp what I was saying, is not a failure of what I was saying to be true. Now that I have presented it again, directly to you, again, super thoroughly, what say you.

Analogies are analogies, but no analogy is a perfect representation of reality (nor is any model for that matter).

"What say you"?

I say that there is a lot of experimental evidence you need to familiarize yourself with. To explain this evidence we've come up with models. Let's put all this evidence and these models "in the box". Now, if you want to think "outside the box" and say there's something wrong with this evidence, or these models, I would admit that may be possible. However, the only way you can make a convincing argument that I know of is to first learn what's inside the box, then explain to other physicists or better yet prove in a paper how you have determined what's "inside the box" is wrong (if it is). If your supporting arguments are not based in observation and experiment but in "logic", your work won't be taken seriously as the universe has failed to behave as logically as we would expect in experiment, which is why we rely on experiment and observation rather than logic.

originally posted by: ImaFungi
What are the words/terms you wish to use to express to me what this field is made of, and in what physical manner the stationary electrons stationary field exists?

originally posted by: dragonridr
Fields are not made of anything i keep trying to tell you that! A field is nothing more than a mathematical description we use because a particle has force when it interact with another particle.

Yes, we are getting redundant here, but as I already explained the word "fundamental" in physics as in "fundamental interactions" like electromagnetism means that we don't have a deeper explanation. Maybe there is a deeper reason why electric charges interact with other electric charges the way that they do, but we call that "fundamental" because we don't understand the deeper reason, if there is one. There may be no deeper explanation, we just don't know. I agree with dragonridr that we make observations on how charged particles interact, and we make a model with fields to describe the interaction but we call the interaction "fundamental" because we don't have a deeper understanding.

originally posted by: ImaFungi
After you answer that, I will ask if your description of how that physical field exists, 'physically stops existing' at some point

When spy66 asked a question about photons and related it to a space-time diagram, I didn't see the relevance of the space-time diagram to his question, but it turns out to be somewhat relevant to your question:
www.abovetopsecret.com...

The space time diagram puts limits on how far an electromagnetic field can have an effect at some point in the future, so the flashlight you shine today can reach a star 10,000 light years away 10,000 years from now, but at that time a star 11,000 light years away would be beyond the future light cone of your flashlight's em radiation.

originally posted by: ImaFungi
The electron is 3d. No such thing, essence, quanta, can exist in any way, that is not at least 3d.

The electric field certainly is 3D. There are different methods of calculating the size of the electron but it's apparently too small to confirm any of those calculations, and too small to talk about its surface versus its interior based on any measurements we can currently make. That could change in the future.

originally posted by: ImaFungi
a reply to: mbkennel (I am sure you will have trouble understanding what I mean for reasons obviously not obvious to you, but I mean to say, if electron is not 3d according to ignorance and idiocy, what particles moving up in dimension, is the first particle that is 3d...you are an absolute mongrel, disgusting, filthy intellect. garbage.)

This thread is for friendly discussions, and name-calling is discouraged in this thread and on ATS in general. If we lack instruments to determine the actual size of the electron because it's so darn small, that doesn't make anybody "an absolute mongrel, disgusting, filthy intellect. garbage.", though it may suggest perhaps we can strive to improve our measurement methods in the future, and it's pretty much a given that we are always trying to do this.

originally posted by: ImaFungi
a reply to: dragonridr

False. You do not know something about reality, you know something about fantasy.

He made a fairly good sized post. What specifically do you think is "false", and is your statement based on observation and experiment, or some kind of "logic"?

originally posted by: Diablos
Question: How many of you guys/girls have your PhD? What do you do now? If not, why didn't you go for a PhD? I take it most of you do not work as physicists even with your PhDs, seeing it as most physics PhDs end up leaving physics from what I've read.

My degree was in engineering physics (which is basically a physics degree along with the core requirements of electrical and mechanical engineering), and I've been considering going back for the PhD.

Your input is definitely appreciated.

If you want a job, get a computer science PhD and work on something quantitative (i.e. not just software).

originally posted by: Arbitrageur

originally posted by: ImaFungi
a reply to: mbkennel

Ripples happen in all directions. All I was trying to suggest to arb a few pages back, and he disagreed, I suppose my case is rested as I suspected.

You said photons expand. They don't, and mbkennel didn't say that they do. You didn't say "ripples" expand, you said "photons" expand and nothing mbkennel said makes the following statement correct.

mbkennel, I know you're not confirming this, but please clarify to imafungi that you're not confirming this is correct:

originally posted by: ImaFungi
If when EM radiation is created, it looks like this: O ..... And that circle, expands in area and circumfrence. That is 1 photon, the circle as a whole expanding, anywhere along its circumference would be measured as '1 photon', and the nature of how this circles circumference increases, is that it does so as a wave.

Does 1 photon expand? no.

Does the wave function allow the probability amplitude of the photon's location to expand in space over time as Astyanax already explained? Yes, but the wave function of the photon isn't the photon; the photon itself doesn't expand.

That's correct. Quantum field theory is about functionals: quantum wavefunctions of functions (the fields).
Photon are the names of the 'basis set' in which to expand solutions, and there are choices depending on the problem and desired application---this is the field of quantum optics. For instance a strong monochromatic sinewave, (i.e. classical plane wave or a laser) is not a pure state of photon number necessarily. What a 'photon' 'is' might even depend on the boundary conditions, but a photon is, in my opinion, that elementary basis function for which you get a clear 'number' basis which supports creation & annihilation operators with the conventional result. It doesn't really have an obvious physical picture at this level. Remember than in QM you can look at different representations and coordinate transforms in the functional space to make the superficial equations look different but in the end, all physically real & observable quantities come out with the same value. (Not really different from Langrangian or Hamiltonian mechanics in this way).

The area over which you can get nonzero field/occupation (in expectation over quantum states) is expanding.

originally posted by: ImaFungi
a reply to: dragonridr

False. You do not know something about reality, you know something about fantasy.

Science is the sort of magic that actually works.

a reply to: mbkennel

When an electron is accelerated does EM radiation propagate in, the electrons frame of reference what would be, more than one direction away from the electron?

In the electrons frame of reference is there EM field In 3 dimensions surrounding it (up down, left right, front to back...and all inbetween).

If you do not know truth, these sorts of questions will bother you. I have been asking this same question for the past 10 pages or so, this simple question, simple not in knowledge and truth, but simple in thorough and obvious presentation. Everything I have written makes sense and I meant to say, it is specific and for a reason, that reason being, wanting to gain a comprehension of truth, greater than I have now. If you can not answer my question, I do not want to waste my time learning all the neat ways you are unable to answer my question. If you cannot answer my questions, just say so.

originally posted by: ImaFungi
a reply to: mbkennel

When an electron is accelerated does EM radiation propagate in, the electrons frame of reference what would be, more than one direction away from the electron?

Yes.

www.tapir.caltech.edu...

In the electrons frame of reference is there EM field In 3 dimensions surrounding it (up down, left right, front to back...and all inbetween).

Yes, that's what a "field" means means, and the field is defined over x,y,z,t. This is 1st day of class electromagnetism 101. Classical Maxwell theory: there are two 3-d vectors, E(x,y,z,t) and B(x,y,z,t) (meaning that each one evaluates to a 3-vector with length and direction in 3-d space) so that in every point in space and time there are 6 numbers whose values defined the values of the field.

The Maxwell equations are partial differential equations which describe the time evolution of these. You then add in charges (which have a nonzero mass) which move by Newton (at slow speeds) or Einstein (at arbitrary speeds) mechanical equations of motion, a force law from fields to charges (Lorentz force) and the coupled system of charges and fields forms the domain of classical electrodynamics. If the charges are mobile as they often are then it's called plasma physics.

If you do not know truth, these sorts of questions will bother you. I have been asking this same question for the past 10 pages or so, this simple question, simple not in knowledge and truth, but simple in thorough and obvious presentation.

Yes it's true. Google the demos on youtube. Take in evidence from outside your own thinking.

There are books that teach this thing which you still haven't bothered to read. Another book is Ed Purcell's introductory textbook which I used as a freshman.

www.scribd.com...

originally posted by: Diablos
Interesting post, thanks. If you don't mind me asking, Bedlam, what kind of physics work do you do (i.e specialty, research areas, etc)? It actually sounds like you're doing good work in physics, and that's pretty surprising to me given that you only have a master's.

Well, I work for the military-industrial complex. In times past, I *mostly* did comm related stuff - radar, radios, some light crypto and the like, plus the odd bit of laser physics. And for a while I worked for a national lab and did something totally off-the-wall for DOE, and still like to gig them by dropping the occasional patent their way, not that any of that has been used, unless they're just neglecting to inform me.

We have done some really wild radio and radar work. As long as you've got one legit PhD 'on the project', no matter how rarely, you can get grants and contracts.

The last few years, it's been non-stop systems integration work and acting as an interpreter between the physics guys and the engineering guys on a never-ending project, when I'm not just being a "mechanic" on one particularly fragile and complex system.