[sciconoclast]

Feynman diagrams usually produce a large number of probable out comes for particle collision of which only a small amount actually occur. Several scientist working in collaboration at the Hadron Collider found that they could reduce the possible outcomes to only those that actually occurred by removing the virtual particles from the process. I think this will ultimately lead to revisions in Standard Theory which will allow the transfer of force through space without virtual particles. Easy reading: Loops, Trees and the Search for New Physics; Scientific American, page 38, May 2012.  More detailed reading: Precise Predictions for w+4 Jet Production at the Large Hadron Collider. Physical Review Letters.       

[yor_on]

thanks for that one Scico.

"It turns out that the Feynman method is really an elaborate way for essentially brute-forcing a solution.  If what you're treying to calculate, the metaphor goes, is the ways that a person could get from one given station on the London Underground to another, it calculates not only the valid methods of movement through the system, but also all of the impossible ones, throuhg the solid rock or earth beneath London.  Most of the possibilities that end up being calculated end up canceling out with each other, or simplifying down, but you still need them for the intermediary Feynman calculations.  The three gentlemen who wrote this article, however, have resurrected an old idea from the '60s, and developed it into a theory that they call the "unitarity" method 

What it does, is it assumes that the total probability of every possibility will equal 100%, and it calculates things by breaking them down into smaller steps, essentially finding the probabilities that a person riding the London Underground will go through a given turnstyle next, rather than trying to calculate their entire route at once.  Not only has this method been used to refine the LHC results recently, but they've also resurrected Supergravity theory with it.  It was previously thought that Supergravity theory entailed too many ever-spiraling infinities in the quantum foam to possibly be correct, but it turns out that, upon refinement with the unitarity theory, these infinities cancel out.  They are able to calculate particle collisions that would traditionally require the calculation of 10^30 terms by only calculating a few dozen terms. They have already won several bottles of wine as bets from other physicists that they won't be able to correctly calculate things with their theory are proven wrong time and time again.  They conclude by commenting that they are on the verge of solving 7 gluon interaction, and that, if this works, supergravity may be seen as alive and well, and well on the road to finding a quantum theory of gravity.  They comment also that gravitons, under their model, are predicted to interact simply like a pair of three-gluon conglomerates." from
Advanced Science Study.

[yor_on]

So what both methods presume is causality chains existing, although they have two ways to get there from probability. And that is the question.

What makes causality chains?

[JP]

I think Yor_on's post sums it up well: they haven't thrown out Feynman's path integral method, but they've figured out ways to refine it and to make approximations to allow the computations to be done quickly and accurately.

I don't think the theory in itself will change anything about the way forces are transmitted, since it doesn't disagree with Feynman's predictions, but it might allow new techniques to be developed because it allows us to do previously intractable computations.

[yor_on]

This one should be read too. It's about 'super gravity' becoming a outgrowth/principle of 'super symmetry'. The idea that everything has a 'partner' of sorts, for fermions as 'matter' becoming some 'boson' etc. So for each new particle found at LHC it then should mean that there is some balance, a 'opposite mirror' that must exist according to super symmetry, all as I interpret it. And if you combine (Einsteins) 'symmetries' with GR you get to 'super gravity' as a hypothesis. But what it is as a 'field' I'm not sure, it doesn't seem to fit our descriptions of 'forces' at least, as something resembling a EM-field? Then again, it's all seems observer dependent if you go by Einstein. Take a look at  Viewpoint: Vanquishing infinity.

[wolfekeeper]

To be perfectly frank, I don't recognize yor_on's claims about virtual particles at all.

He seems to be basically saying that virtual particles don't exist, but both electrostatic and magnetic fields basically consist of virtual particles; so it's not like virtual particles don't have massive real-world effects, because they definitely do.

Virtual particles 100% definitely do exist.

[yor_on]

You can call it 'virtual particles' if you like Wolf. I think of it otherwise though. To me it has to do with a arrow, assuming a 'virtual particle' inside a arrow makes it real to me. Then it is a particle, not anything virtual. Assuming it outside a arrow is to me something else. Then i find 'particles' a bad choice of words, and think of it in terms of outcomes, governed by the probability of them becoming. What that probability then should be seen as is another matter

[Bill S]

Does this help?

http://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/

[yor_on]

I really like the way he thinks of 'virtual particles' Bill, as 'ripples in a field' more or less, if I get it right. But then you have relativity in where a EM field becomes observer dependent. What kind of 'fields' would this be, assuming a existent arrow? Observer dependent too? And would they then be the 'background' from which SpaceTime becomes? Could there be something from where 'fields' come to be? Or, is there no background at all? The fields creating it all?

Somehow it all feels as a question of hidden variables, our observables being what we can measure.

[yor_on]

and the next step, if I presume something not measurable for us, is the question how we ever will be able to validate what we can't measure. Where do we draw the limits? Are 'photon paths' observables or are they assumptions? I prefer observables myself, when I want to make a assumption, but how far can I go from them? You can turn it around and make a presumption in where what we can measure is the tip of a iceberg, mostly hidden below water. Then you can from there question if what we measure should decide what we can't. I like the idea of symmetry breaks myself, and think of SpaceTime as one.
==

If you think of SpaceTime as a symmetry break, then the arrow and other degrees of freedom we find is a expression of that 'wound', if I may. From that you also can wonder about how SpaceTime is seen from whatever 'place' it breaks free from. And there you have the question of what those degrees of freedom really mean, if they also are shown to observer dependent, which they are according to relativity..

[JP]

Yor_on, I'm not sure what you're getting at exactly, but as long as you believe the Standard Model is correct, virtual particles are a part of the model by their very definition.  They're manifested in the mathematics of the model and can often be used to simplify computations.  Now, what we can debate without throwing out the Standard Model is whether or not "virtual particle" is the best term for the physical processes/mathematics they represent.

[yor_on]

Just explaining why I personally doubt 'virtual particles' as being 'particles' But as you say, that has to do with what one may mean by using it. We have a geometry, that we measure. But if relativity is correct that geometry can be seen as 'shrinking/disappearing' coming close to lights speed.

Why? And what would that mean if locality, meaning yourself measuring locally, can be the only first hand description of a universe? If we believe in direct measurements being the correct approach to the universe then the theoretical counterpart, our conceptualization of the same into a 'indivisibly same' universe for us all together becomes a contradiction in terms. Because our direct measurements are always done locally, and even if we can translate them to each others descriptions, it doesn't change that my measurements will define my existence, as yours will you.

I like fields too, but I'm not sure what they are.

[JP]

Fields are things that exist and have energy at every point in space-time.  As space-time geometry changes, fields warp along with it.  They don't have to be quantum and by thinking of them as quantum you're making things harder. 

Would you agree that we know how light and electromagnetic forces classically exist and travel around the universe?  Those are due to fields.  We can model gravitational lensing and red/blue shifts as due to the geometry of space-time.  If we take that classical field and lower the energy so much that we need to worry about quantum effects, we still have a field.  It just has slightly different rules, but it still lives over space-time and bends along with space-time.

[yor_on]

A very nice description JP, and I see how you think there. As for radiation (light if you like) propagating I'm not sure how it works. Whatever way it express itself as 'propagating' it still seems the simplest explanation to assume it moving as some corpuscles or excitation from 'a to b'. But I can't ignore the 'warping' of SpaceTime, because according to locality it's no 'warping' at all. It's just as true measuring as it will be for someone not having that 'speed' finding another 'warping'.

If it was so that no matter your uniform motion, you and SpaceTime would express itself the same relative some observers then we would have a common nominator from where we might define a warping. But as far as I understand it isn't so, with different uniform motions you will find different time dilations & LorentzFitzGerald contractions. Without that there is no warping anywhere, because a warping actually assumes that common nominator from where you can measure one. But I would love to see one defining what a warping should be.

[yor_on]

what this reasoning is trying to lead to is the question what is more 'real'? If you have three observers, describing and measuring the same field. Each one finding it to be different, is it still the same 'field' for them? In a way you can argue that it is, conceptually and logically finding rules for how it change with the observers.

In another, if we discuss it as your 'local truth', yours is not 'the same' as the other observers, and the difference you find will define your universe. Accepting that locality is the definition of what can be 'true', which i find, it becomes very hard to argue for a 'indivisibly same universe' for us all. And that will, if we look at SpaceTime as 'fields', be just as true there. Your measurement is not mine, and your field is not mine either, even though we can translate them to each other. Could you state that as all languages can be translated into each other, they all must be the 'indivisibly same'? I don't think so myself. A translation is a expression of it existing some principle, aka logic, making it possible to communicate/translate changes, as perceived locally, in a logically understandable way for all.

And without that principle all communication would fall. But I don't see it as a guarantee for anything, more than there is a logic to SpaceTime.
==

One may see it as two versions of Relativity. One is a 'conceptual SpaceTime' in where we try to find principles guaranteeing that what I see is translatable to what you see, and so find a 'indivisibly same' although strictly conceptual 'reality'. The other goes out from who and where you are, using local measurements. That 'reality' is in fact the one you will live, and die, in. And your measurements there must define the limits of what you can do, whilst living.

So which one is truer? The conceptual or the one you live in?
The one you live in.

And it's deeper than that. What do 'you' think your life is? A conceptual exercise, or a reality. According to relativity it can only be real for you locally, as soon as you in-cooperate a 'whole indivisibly SpaceTime for all' you have moved from measuring locally to 'translating' observer dependencies conceptually. All of that would be good if it wasn't so that what you measure locally is your 'destiny', it will be what defines you until you die.

[yor_on]

But you're right JP

I do have a tendency to put it all to quantum (energy), including relativity. And that's also what 'locality' implies to me. That locality should be what 'reality' can be traced too, and there I prefer it to be Planck scale that defines when something becomes 'real', including ones arrow.

This one is really cool. Observation of the Dynamical Casimir Effect in a Superconducting Circuit. If one like one can call it a 'field of energy' with 'virtual particles' becoming 'real' as measurable inside a arrow I suppose. But if one does, one also must admit that this 'field' will be observer dependent, and so always locally defined.

[yor_on]

The weirdest thing with such a reasoning, accepting light (radiation) to be what binds those 'frames of reference' together (communicate changes). The weirdest, yep, absolutely strangest idea I get is that when we discuss 'multiverses' of any kind, we actually already have them, here and now. Each frame of reference can be seen as its own representation of a universe.

Also assuming some sort of 'observer'. If one accept that a observer is needed, and then accept this as an weird idea we get to the question what a observer would need to be, to make this one work. If so a consciousness isn't needed, as I think, at least not one inside a arrow, because those 'frames' exist even without us macroscopically. although if we go down in scale?

And I'm not that thrilled over multiverses myself It gets confoundedly complicated if we have both those and then assume that our 'frames of reference' also would represent something similar. Or maybe it makes it simpler? I don't know
==

The point here is that when we go down in scale, consciousness might have something to do with what we will observe. But assuming that you measure a planets motion through space, not observing the moon, or not even knowing that there is a moon involved, you will still be able to 'reason forward' that moon, or at least something with mass. And that one we've already done in astronomy, finding things due to other suns motion through space. So the question if the moon is there even when you don't look I find to be moot. It's there, macroscopically at least. But from a quantum perspective? QM is seriously weiird

[JP]

The weirdest, yep, absolutely strangest idea I get is that when we discuss 'multiverses' of any kind, we actually already have them, here and now. Each frame of reference can be seen as its own representation of a universe.

Just because frames are different representations of the universe doesn't mean they're different universes, though.  It's still the same universe, and the representations are just different ways of looking at it.

The only reason you need a multiverse is if you think there are other universes, each with lots of reference frames.  There's no need to assume multiverses in the Standard Model.

[yor_on]

That's what I mean by the conceptual model of relativity JP. Assuming that 'reality' is best described conceptually you can get a 'indivisible universe' same for us all, expressed through Lorentz transformations. Assuming locality you instead get frames of reference, mediated through radiations constant, or 'lights speed in a vacuum' as we describe it. That's one reason why I'm still holding out on lights 'propagation', because in a thought up relativistic 'multi verse', described through lights propagation, and always relative your local frame of reference that 'propagation' becomes weird.

[yor_on]

Eh, not that it isn't weird as it is already Disprove light as a constant and relativity should fall as I expect, but as it is it seems to fit the experiments we've done? But in a thought up mosaic of local frames it seems quite difficult to see how light would be thought to 'propagate' between them. In such a scenario you need some other mechanism for what we observe to be a propagation, and keeping light as a constant it must have to do with those local representations of our four dimensions, and then something more, as we do communicate between them. This one is really more fitting for 'new theories' though As I said, it's one of the strangest consequences I've imagined, if it now would be that way.
=

My point here is that all local representations/observers each will see 'one undivided universe', consisting of all frames of reference, relative their local measurements. But they won't 'fit' together if somehow being able to take in all observers measurements simultaneously, except conceptually through logical transformations. And the 'conceptual point of view' can then, as I see it, just as easily be described as begetting the 'eyes of a God', and view one 'coherent universe' from it.

For each transformation you do relative a local description the difficulties to see them all (simultaneously) must rise. And how many representations can there be? A countless number, or a finite? In a way it very much reminds me of how to imagine looking at something through five dimensions, or more. Not a human way of thinking.