Natural Order and Science

[Alex K]

But I sense from this post from you that you seem to be not in any mood to dialogue. So I will terminate this conversation.

Too bad. Can you give me a textbook source or similar where this definition as you use it is introduced and elaborated?

[little_monkey]

But I sense from this post from you that you seem to be not in any mood to dialogue. So I will terminate this conversation.

Too bad. Can you give me a textbook source or similar where this definition as you use it is introduced and elaborated?

This will be of no good as I do not argue with an appeal to authority to support my posts. I either convince you with the strength of my arguments or I don't. Since it is the latter rather than the former, there is no reason for me to continue.

[Alex K]

Too bad. Can you give me a textbook source or similar where this definition as you use it is introduced and elaborated?

This will be of no good as I do not argue with an appeal to authority to support my posts. I either convince you with the strength of my arguments or I don't. Since it is the latter rather than the former, there is no reason for me to continue.

You so far just seem to keep shouting the same thing at me and don't respond to questions or comments except by telling me how I apparently don't know anything, how is that supposed to convince me of anything.

So is the distinction you make above between virtual and real particles your entire definition or just one aspect of it?

[little_monkey]

This will be of no good as I do not argue with an appeal to authority to support my posts. I either convince you with the strength of my arguments or I don't. Since it is the latter rather than the former, there is no reason for me to continue.

You so far just seem to keep shouting

I don't recall shouting at you, but if I did, it was unintentionally, and I apologize for it. 

the same thing at me

 

It's a definition, and there are only a limited number of ways to explain a definition before one ends up repeating oneself.

and don't respond to questions or comments except by telling me how I apparently don't know anything,

I don't think I said you know nothing, but I did point out that you've failed to understand the basic definition. What was I supposed to say? 

how is that supposed to convince me of anything.

I believe I've made an honest effort to clear out things, but it didn't work. I'm not going to repeat myself on and on. So right now I have no tools in my kit to clear up things for you. This is about a basic definition that is used commonly throughout the physics community. I doubt that they will change their definition of virtual particle just because some people don't understand it. 

So is the distinction you make above between virtual and real particles your entire definition or just one aspect of it?

Well, I'm not sure what you have in mind. One aspect is to look at how the idea of virtual particles came about, from its origin due to Yukawa to how Feynman used them in his development of the path integral. Another very interesting aspect is how it affected gauge theory, and led to postulate the Higgs bosons, proposed first in the 1960's and was only confirmed in 2012. Another aspect is how Hawking used that concept to derive that Black Holes have entropy, that they will necessarily radiate and eventually evaporate. Another aspect is that virtual particles are used to predict the Casimir force, which was subsequently confirmed in the lab. There are so many topics in QFT in which the use of virtual particles are part of the discussion. And most likely a surprise for you, not only do we use the concept of "virtual" particles, but also the concept of "ghost" particles. They're cool but a lot harder to explain.

[Alex K]

I know how all of these things work, I just thought your definition of what a virtual particle is sounded nonstandard and so I wanted to know where you got it from or how you arrived at it.

[Neo-Scholastic]

Chad, an honest question –

Your preface is not necessary. I consider all your questions genuine. You’ve consistently demonstrated your sincerity.

...while I acknowledge that the efficacy of reason is not obviously a given and more like a working assumption which appears to yield consistent results, I still wonder, is there a coherent notion of the alternative? Could reality be unintelligible or might such a sentence be meaningless.

This is an idea I’ve been toying with lately. There seem to be two notions at play: 1) the efficacy of reason and 2) the intelligibility of reality. The first has to do with the capacity of the knowing subject. The second concerns the nature of external reality.

Just because human reason works doesn’t mean the object of inquiry (reality) is actually intelligible. Perhaps it is absurd. Perhaps it is just so. Either way, it is as it is for no reason at all. Alternatively, even if reality were intelligible that doesn’t mean the mental toolkit (reason) is valid. Reasoning could be a linguistic trick or compelling illusion. Self-evident truths only appear so to a brain functions evolved for see patterns even where none exist.

Now, I personally do not believe either of these. I believe that human reason reflects a reality that is as it is for discernable (but not necessarily obvious) reasons.

[Alex K]

@Chad
Interesting, the thought to treat the two separately never really occurred to me before. In one direction I feel it might be justified not to, because, if reason does not work, does the concept of intelligibility even survive? Isn't that a stopping point where nothing further can even be said?
In the other direction, I kind of unwittingly assumed the mind to come from the brain, and that to be part of the outside world. Thus under these conditions, in an unintelligible world I find it doubtful that reason can be generated. But I haven't given much thought to that - of course if the mind(s) are a separate thing not dependent on worldly order for their operation, there could plausibly be reason without intelligibility of the outside world. The mind would then form a small intelligible (maybe not, but an orderly and consistent one) patch of the world on its own, which communicates with the remainder somehow.
If I, as you do in an aside in your response, entertain the idea that the mind came about through evolution, my knee jerk conclusion would be that it needs a "logical" world in order to produce reliable reason.

I also wonder what it would mean for the world to be unintelligible. If quantum uncertainty is actually non-deterministic (it might be), wouldn't "unintelligibility" already creep in there? In the same vein, the perception of the arrow of time seems to be a statistical phenomenon that becomes fuzzy when looking at small subsystems such as one or two particles. What criteria does the universe have to fulfil to you for the label to be justified?

[Harris]

I had depicted a general view on how logic works. It always starts from intelligible objects however it may end in other observable object or in some metaphysical concept. It all depends upon what you are trying to explore by the use of logic.

IOW, you have no evidence. With your point of view, anyone can start with logic and then develop any  metaphysical concept. But how would you decide which metaphysical concept is true, since you have no evidence to differentiate those that are true from those that false?

Simply keep in mind that life is too short and it would not let us comprehend every single truth through scientific explorations or philosophical methods. However, our beings encompass a huge amount of data stored in our conscience, a gift of nature, which gives us the sense of right and wrong. Therefore, use logic to refine those feelings by developing logic with the help of science, philosophy, history, and any true information about the nature that you have.

The biggest hurdle in all that process of searching the truth is our ego, self-centric attitude, pleasure seeking behaviour, etc. If you are honest in searching the truth, then you should keep yourself refrain from these hurdles and I assure you that you will reach the ultimate truth within a very short time.

[Harris]

In the Quantum Field Theory view, actual particles are viewed as being detectable excitations of underlying Quantum Fields. Virtual Particles are also viewed as excitations of the underlying fields, but appear only as forces, not as detectable particles. They are "temporary" in the sense that they appear in calculations, but are not detected as single particles. Thus, in mathematical terms, they never appear as indices to the scattering matrix, which is to say, they never appear as the observable inputs and outputs of the physical process being modelled.

I would like to come back to this statement, in which you seem to trace back the reason why particles and virtual particles have a different "ontological status" (one really exists, the other is an artefact of calculational method) to the fact that one appears as scattering matrix-elements, whereas the others don't. Since you are eager to discuss S-matrix theory, you must be aware that this distinction is problematic because

1. S-Matrix elements are infra-red divergent due to soft emission, and only lead to physically meaningful results if they are combined with virtual corrections in scattering cross-sections. From this it appears to me that real emission of particles alone isn't even defined, and that the distinction between the two classes of particles based on arguments from S-Matrix theory is problematic. What's your perspective?

2. The S-Matrix is a somewhat artificial construct obtained by assuming that ingoing and outgoing particles stop interacting, and then taking the time to +/- infinity and using the resulting asymptotic free states as "external particles". This works great when describing scattering processes in which isolated, massive and stable particles meet and part again, but if you depart from this idealized scenario, things like 1.) happen. Also, if you just look at the unitary time evolution operator without  taking it to asymptotic times, the distinction between what's an S-Matrix index and what isn't surely isn't as clear-cut any more.

Do you disagree? Or do you subscribe to an axiomatic S-Matrix approach to particle physics in which there is no local Lagrangian and no time evolution? Because that worked out so well?

Moderator Notice
Unbelievable. Content of post removed due to plagiarism, only one day after your previous warning.

Continue on this path and it will end terribly for you.

Pandæmonium

[robvalue]

No comment on the plagiarism Harris?

Should I go through this latest post to see if you've done it again?