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Acion without reaction !
[b]F1 = F2 = Gm*M/ R^2 ?



mass M was in past in point p1..p2..p3..
How small m is able give the same reactions to big M ???


EN https://youtu.be/tEv6GxLPJRA

PL - https://youtu.be/vMJjuYJSxDA

Orac, perhaps we should examine my earlier post a bit more closely.

1. QM indicates that zero is not a possible value of electromagnetic energy.
2. QM tells us that matter particles behave as waves.
3. This is sometimes interpreted as saying that matter might be composed of wavelike energy, with particles appearing as disturbances in the energy field.
4. This matter/energy duality accords with the concepts of relativity – E=mc2.
5. If statement 1 is correct the vacuum always has non-zero energy, which takes the form of (virtual) particles and waves.
6. Relativity indicates that space and time are linked in such a way that they cannot be thought of as individual entities.
6. This leads us towards a scenario in which a qualitative similarity appears to exist between matter/energy, on the one hand, and space/time on the other.

I agree with everything except the last statement

In general I agree with you to a points 1-5 about QM. However QM is not clear about the structure of spacetime other than Space and time are continuous. QM research has considered the possibility that space or even time are discrete but such theories are inevitably inconsistent.

In fact there are two alternate ways to deal with spacetime in QM which contrast to position space you are familiar with in classic physics.

a) Momentum space (https://en.wikipedia.org/wiki/Position_and_momentum_space)
b) Phase space (https://en.wikipedia.org/wiki/Phase_space_formulation)

So sometimes for ease of analysis spacetime is turned into something classically we would not recognize but the treatments are valid under QM.

People view this many different ways from a simply mathematical thing to it is implying something physical and I leave that as an exercise for you if interested and I am happy to answer questions.

Statement 6 directly link space and time in GR correctly.

So I can't in good faith say I agree with the last statement (which should be 7) because whether the two concepts smoothly join is not clear at least to me.

However this is not about me, if you are happy that all connects I won't strenuously object and lets see where you go next.

I wish I knew! Possibly good to get this distraction out of the way first.

QED describes the strong, weak and electromagnetic forces in terms of exchanges of messenger particles. It seems reasonable, therefore, to use the same description for gravity, although the graviton, which would be the messenger particle, has not yet been found.

A quantum theory of gravity would necessitate the reality of gravitational waves which, like gravitons, have not yet been observed. There is indirect evidence of the existence of gravitational waves, and if they exist, it is reasonable to consider the graviton as an excitation of a wave in the gravitational field.

An electron is considered as being surrounded by a retinue of virtual photons, constantly appearing and disappearing, and the energy of this combination is calculated as going to infinity in the case of each electron. In the same way, every matter particle must be considered as having a similar retinue of gravitons, the energy of which would go to infinity.

A serious consideration here is that, unlike photons, gravitons would interact with other gravitons. This means that any situation involving loops escalates into multiple loops-within-loops. The energy of each of these loops goes to infinity, so in each case infinities are multiplied - infinitely.

Is this an impediment to finding a quantum theory of gravity?

Renormalization is the standard method of dealing with infinities in these calculations, but that is nothing more than the dubious practice of dividing “both sides” by infinity. As a non-mathematician I can do no more than acknowledge that renormalization seems to work, and is valuable in making progress, but how far can that progress go?

Yes it's a Quantum field theory and so that is how it works.


Yes but nature may not care to be reasonable


Ok you are mixing up things here a gravitation wave is a ripple in spacetime metrics in GR theory.
A graviton is particle or virtual particle in a gravitational field theory.

So we have seen indirect evidence of a gravity wave but no indirect evidence of a graviton.


Yes, No, Maybe you have so many different concepts mixed up it's hard to work

Lets start with what a Field theory says, so start here
http://profmattstrassler.com/articles-and-posts/the-higgs-particle/the-higgs-faq-2-0/

The key points as Matt underlines

a) A field is present everywhere in space and time,
b) The field can be, on average, zero or not zero, and
c) Can have waves in it.
d) And if it is a quantum field, its waves are made from particles.

So a GR gravity wave is (c) while a graviton is (d) if that helps above.

He further distinguishes by referring back to earlier articles that a "virtual particle" is simply a disturbance in the field, a "real particle" is a resonant wave that persists in the field. There are other tricky things about virtual particles that they do not have to precisely obey particle behaviour because they are short lived
http://profmattstrassler.com/articles-an...-what-are-they/

So under a Quantum field theory your whole statement is misguided and/or wrong the correct field version he expresses as


In itself the statement won't cause you any issue as a layman, until I point out you and your entire classical universe is therefore nothing more than resonant waves in the fields in spacetime. At which point you usually run for the door, you saw the movie Matrix and didn't like it .

So no quantum field theories dispose of classic physics and are very different to the concept of considering virtual particles as real (classical objects) and popping in and out of existence. You do that and then try to borrow calculations from QM field theory, and put simply you can't. You either accept your classical world is gone (IE we have a quantum universe) or rework your theory/ideas from scratch with classical objects and new classical calculations. You are not alone Bill G/Rede struggle a lot with the same issue.


That is not what renormalization is but it probably isn't important if you get the message above about mixing different ideas.

Sorry for length I tried to shorten responses up as much as possible.

I debated whether to discuss real vs virtual particles in QFT so I will put this bit as a new post, it may interest you.

In a practical sense deciding if a particle is real or not is very problematic especially to try and do it classically.
Wikipedia does a terrible job, there is some discussions going to try and clean it up and it ends up at this statement

https://en.wikipedia.org/wiki/Virtual_particle

They have done what you did combined many different ideas and tried to join them into an encompassing statement.

Under Quantum Field Theory that statement is blatantly wrong there is a clear definition like so

You can actually prove the statement by a rather long calculation.

So QFT puts a clear definition under the decision, you find a particle violating SR and it is virtual or just a disturbance in the field using Matt's terminology.

In this regard QFT is unique in that is explains why and what Virtual Particles are.

In order to move towards a QT of gravity, would we not have to consider what Strassler refers to as “quantum waves” in a gravitational field?
How else would we explain gravitons, which would seem to be essential to quantum gravity?

I saw all the Matrix films, and enjoyed them.

The idea that the “classical universe is therefore nothing more than resonant waves in the fields in spacetime” certainly doesn’t cause me to run for the door. It fits beautifully into my ideas about infinity, but let’s not go there! :P

BTW, I’ve read Matt Strassler’s article about virtual particles a couple of times; it’s probably time to read it again.

I'm very happy with long posts, as long as they say something, which (in this thread) yours do.

Yes everyone has tried but there are some very obvious problems and the reasons.
I will offer a general view on the underlying issues, consider it personal not a science consensus view.

QM mathematics and formulation is very exact and there is only one solution you saw that in above discussion.
However the issue is the solution doesn't resemble the classic world so it cause interpretation issues with the classical world.
You just ran thru that above where the world under QFT looks very different to our perceived world.

GR unfortunately is not so exact there are actually many solutions to it's equations.
I would strongly recommend you looking at exact solutions to GR article
(https://en.wikipedia.org/wiki/Exact_solutions_in_general_relativity)
The point is that GR may be considered a kind of compatibility condition not a specific solution.

I was trying to get you to look at the stress-energy-tensor because it shows you the problem of multiple solutions.
It isn't well covered in science media and the same with dark energy, I think largely due to resistance to GR in the past.
You can have fun with those who rely on Science magazines and don't know the background if you are mean
I was hard on Bill G/Rede because they made out what they said was scientific and it simply wasn't, it was more like Marosz.
I may have been brutal to someone else over infinity

If you want a comparison here is a list of the current wiki exact solutions in QM
https://en.wikipedia.org/wiki/List_of_quantum-mechanical_systems_with_analytical_solutions
There are probably many more in literature and on the internet.

QM can not be refined it gives just one answer, GR gives many and in a nutshell that is the problem to me.
So to me we are only going to progress by finding the exact solution to GR or some observation pops up to show us the way.
QM science can and does construct many theories that are compatible with GR but it would come down to luck in finding the right one.
I think string theory is an expression of that and why it offers seeming limitless candidates.

It's up to you but armed with that background it might be interesting to look at traditional GR gravity waves under different stress-energy tensors.

I can't imagine who that would have been. If he even noticed he probably thought "What does he know about infinity?"

I would probably need some very basic background on tensors before I could do much with that.

You are over thinking it .. start where we all started including Einstein

You have a perfect fluid consider the pressure on an individual molecule in the fluid.

http://www.zweigmedia.com/diff_geom/Sec12.html

You don't even have to really follow the mathematics just follow they are describing the pressure at a specific point and trust there mathematics.

The key point here is it is a calculation in general you can never actually measure but it doesn't mean it's useless

In the real world the fluid would be less than ideal so it may compress, change viscosity etc which is the reason the calculation was first done.
Do you remember the post I calculated the pressure at the centre of the earth ... very similar
I smile because good luck ever measuring it.

To make electomagnetism relativistic you give it the same treatment
https://en.wikipedia.org/wiki/Electromagnetic_stress-energy_tensor

You will see it ends up having the same properties

What we are dealing with has a scientific name called a body force.
https://en.wikipedia.org/wiki/Body_force


It's that issue that leads to most of the complications from what many did with contact forces at school.
When you throw the frame of reference stuff in on top it gets very complicated.

As we have strayed into fields and particles, I think this would be a good point at which to check some of my thoughts/questions on that subject.

1. So far, what I think I have is that fields permeate the cosmos. (Is this theory, or is there any way in which it has been/could be established?)
2. On average, fields may be measured as zero or non-zero, at any point in space. (Is that their energy?)
3. We detect fields by observing disturbances in them.
4. I assume this also applies to the gravitational field, because, although gravity waves have not yet been observed directly, we can detect it only because it is disturbed by the presence of matter and/or energy.
5. The normal form taken by disturbances is that of waves.
6. In quantum field theory the waves are [also] particles. (Are there any fields that cannot be described as quantum fields?)
7. All particles are associated with fields, but only at quantum level is this of significance in the present state of our knowledge.

That is all pretty much spot on what science says, I will expand a couple of points.

1. So far, what I think I have is that fields permeate the cosmos. (Is this theory, or is there any way in which it has been/could be established?)

QFT goes a little further and says fields make spacetime and consider it to be a physical entity.
GR doesn't go that path because it is based on a classic field in it's inception.


Do you see the subtlety you can expand/contract spacetime, and there is an outside spacetime.
So QFT definitely takes an approach some other areas of science might not agree with.
You may want to consider your favourite infinity under that.

2. On average, fields may be measured as zero or non-zero, at any point in space. (Is that their energy?)
Agreed

3. We detect fields by observing disturbances in them.
Agree and science detected the higgs field in exactly that way.
If you produce a certain collision it reacts with the field and you see the disturbance as a
short lived virtual particle we call the Higgs boson.

4. I assume this also applies to the gravitational field, because, although gravity waves have not yet been observed directly, we can detect it only because it is disturbed by the presence of matter and/or energy.
Agreed and science is uncertain yet if gravity is a quantum field or a classic field.

5. The normal form taken by disturbances is that of waves.
Agree and extend.
The waves are the exchange of energy and the maximum speed of the waves is the speed of light.

6. In quantum field theory the waves are [also] particles. (Are there any fields that cannot be described as quantum fields?)
Agree and gravity may not be a quantum field.
Our current best theory to described gravity is a classic field theory.
Ultimately if gravity is quantum it would follow the normal QFT transformation done on other fields.

7. All particles are associated with fields, but only at quantum level is this of significance in the present state of our knowledge.
[/quote]
Disagree even in a classic sense you have a problem of the chicken and egg scenario, I sort of bought this up with the electron.
So an isolated electron produces and has a field around it at school you may have drawn it like this



See the problem is the electron producing the field or merely visible because of the field.

Classic physics assumes the electron is producing the field and it radiates out to infinity.
QFT says the field was always there you just made it visible by putting a particle at a point.
QFT also says it is correct because of the discovery of the higgs you can't see or even deduce that field in classic physics.
So science answered the chicken and egg question conclusively .. classic physics lost

However definitions on "the universe" got a little more interesting didn't they
You may care to think of a particle moving vast distances without losing energy in that scheme
Which scheme does QM entanglement make more sense in

If you ever wanted in a nutshell why classic physics is incompatable with QM there it is.
Bill G doesn't like it but classic physics can lead to really wrong answers ... like above
You see classic physics isn't approximately giving the right answer or understanding, and we are going to need to rethink teaching this stuff.

The take home memo is we are never going back to classic physics and QM is never going to disappear, the higgs told you

Here is your classic physics

On cue for you today the announcement of the discovery of the Weyl fermion by two different groups

http://phys.org/news/2015-07-year-massless-particle-next-generation-electronics.html
http://phys.org/news/2015-07-weyl-years.html
http://spectrum.ieee.org/tech-talk/semic...ter-electronics

Background how the Weyl fermion fits into QFT.

http://www.quora.com/Quantum-Field-Theory/What-is-a-Weyl-fermion

They have long been sought after because they give you the equivalent to superconductivity at room temperature.

There is no indication of whether these things are likely to show up in the wider universe.
Everyone is hassling the experts in the "standard model and beyond" for that answer as it is outside the realm of QFT/QCD

Lubos Motl covered it superficially back in an article in 2010
http://motls.blogspot.com.au/2010/12/beauty-of-dirac-equation-and-its.html


Watch what insights the theorists can give but in general massless particles must be massless for a reason and of coarse there are versions of string theory that predict it, which will get a lot of interest now.

Using the tools of QFT it was always known you could not show that massless charged fermions did not exist and hence the search so a hint of physics beyond the standard model.

Given you know the basics as a layman now, I would be interested in your evaluation of the different science media articles on it.

Interesting looking links, all I need now is time to read them.

In the meantime, I assume you know about the pentaquark.

http://www.nature.com/news/forsaken-pent...=NzIxOTI5MjIzS0

My apologies, AR11, I,ve just realised you beat me to the pentaquark.

So a small challenge Bill S. Using your new understanding describe the good and bad in this article

https://medium.com/starts-with-a-bang/embracing-your-fifth-dimension-2e02d9a0572c

Do you think it successfully portraits an accurate representation of science?

My personal view is it basically comes across as an anti-string rant, which isn't really even relevant to many holographic theories. It then tries to put together a mumbo jumbo argument around what it refers to as a bulk spacetime which actually it doesn't ever define. I know what a spacetime bulk is in string theory but it doesn't make sense in this article which basically tries to avoid the stringy stuff.

The key point is it completely misses the fact in physics we are now forced to treat particles as excited states of an underlying physical field that is always already there. That is what makes it look holographic and is at complete odds to the classic physics where the field arise and expand out into space. Many people who don't believe in string theory accept and believe in a holographic scheme.

You said it yourself under QFT you are forced to see an electron or any "real" particle in classic physics as a sort of hologram of the field (Matrix like) ... it's not complicated and nothing to do with string theory or space bulk or the rest of the trash in the article.

Again it looks like another one of those situations that is an article by someone completely out of there depth. If I was being honest it looks like a case of google "holographic principle" and try and write an article using lots of catch phrases and google only picks up the story when the idea is formalized into string theory.

The article as written should have been called AdS/CFT correspondence and basically follows this story
https://en.wikipedia.org/wiki/AdS/CFT_correspondence

Perhaps had they googled a little better they would have found
http://www.thedailybeast.com/articles/2014/08/31/is-the-cosmos-just-a-big-hologram.html


You will also find conflicting claims of who created the concept of holographic principle. The earliest reading I know of the claim is 1947 by Denis Gabor who actually invented Holography and want a guess what made him think of the idea
https://en.wikipedia.org/wiki/Dennis_Gabor

Perhaps I could suggest a reasonable read
https://books.google.com.au/books/about/...amp;redir_esc=y

I graded the article D- as misdirected or misunderstanding.

BTW Bill S if you want a funny read on holographic principle without string theory

http://arxiv.org/abs/1004.1285

Solves the whole thing in only 9 pages and 7 formulas

I love this bit