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dapifo
2012-Jul-29, 12:40 PM
Stephen Hawking says that quantum mechanics itself is deterministic, and it is possible that the apparent indeterminacy really is because there are no particle positions and velocities, but only waves.

So for Stephen Hawking, the uncertainty principle is only aparent, but not real (?)... is another way of seeing the Universe...in other scale ...were beings and laws are different!!!

ShinAce
2012-Jul-29, 03:50 PM
Stephen Hawking says that quantum mechanics itself is deterministic, and it is possible that the apparent indeterminacy really is because there are no particle positions and velocities, but only waves.

So for Stephen Hawking, the uncertainty principle is only aparent, but not real (?)... is another way of seeing the Universe...in other scale ...were beings and laws are different!!!

If you keep pushing your idea, you will get into trouble. I've seen it happen before.

Also, you and I don't have the same understanding of deterministic. If every part of the universe has but one fate, that simply means that quantum mechanics is incomplete. It does not imply new laws to compliment the existing ones.

Strange
2012-Jul-29, 04:13 PM
I think you might be confusing two different things.

Quantum mechanics describes things in terms of wave functions which define the probability of, say, the location of a particle. However, when you measure the position, you can measure it as accurately as you wish; there is no probability at that point. There are, perhaps, interpretations where this is deterministic. However, this probabilistic nature is "real"; it seems to be a fundamental part of the way the universe works.

The uncertainty principle, on the other hand, says that if you measure the location precisely then you cannot know the momentum precisely (and vice versa). This is "real" in the sense it is a fundamental limit, not just a problem with our measuring instruments, for example.

Neither of these are related to scale (except that quantum effects become increasingly more significant at small sizes).

dapifo
2012-Jul-29, 05:19 PM
If you keep pushing your idea, you will get into trouble. I've seen it happen before.

Also, you and I don't have the same understanding of deterministic. If every part of the universe has but one fate, that simply means that quantum mechanics is incomplete. It does not imply new laws to compliment the existing ones.

I am not pushing any idea...Iīam just trying to clarify some dubts and lacks I have with state of the art concepts... and trying to see if them fits better having a look from other point of view.

Uncertainty Principle has been always for me an strange and unintelligible concept... and always I though that was only a problem of measuring instruments...because we try to mesure them (location and momentum) precisely with inappropriate instruments larger than required).

dapifo
2012-Jul-29, 05:30 PM
I think you might be confusing two different things.

Quantum mechanics describes things in terms of wave functions which define the probability of, say, the location of a particle. However, when you measure the position, you can measure it as accurately as you wish; there is no probability at that point. There are, perhaps, interpretations where this is deterministic. However, this probabilistic nature is "real"; it seems to be a fundamental part of the way the universe works.

The uncertainty principle, on the other hand, says that if you measure the location precisely then you cannot know the momentum precisely (and vice versa). This is "real" in the sense it is a fundamental limit, not just a problem with our measuring instruments, for example.

Neither of these are related to scale (except that quantum effects become increasingly more significant at small sizes).

Just for it ....If Quantum mechanics describes things in terms of wave functions which define the probability ... there are not any position and momentum to determining !!!.... That is the point !!!... there are not any precisely location...only the waves and the probability to be in one point...!!!

Concerning that quantum effects become increasingly more significant at small sizes is what I understand by "different laws could govern (due to harder effect) at different scales".

Also Gravity effect becomes decresing less significant at small scales (due to coupling with the quantum effects )

korjik
2012-Jul-29, 06:07 PM
Just for it ....If Quantum mechanics describes things in terms of wave functions which define the probability ... there are not any position and momentum to determining !!!.... That is the point !!!... there are not any precisely location...only the waves and the probability to be in one point...!!!

Concerning that quantum effects become increasingly more significant at small sizes is what I understand by "different laws could govern (due to harder effect) at different scales".

Also Gravity effect becomes decresing less significant at small scales (due to coupling with the quantum effects )

You still dont understand. Once you measure the wavefunction, it takes on a specific value. If it is position you are measuring, then once you measure it, you know the postition precisely.

The uncertainty principle says that there is an inherent limit on knowing two things at once. The classic example is position/momentum, where if you know one, there is a limit to how well you know the other. This does not limit how well you can determine one, just that there is a limit on how well you can determine both at once.

John Jaksich
2012-Jul-29, 06:25 PM
Dear dapifo,

I was of (somewhat) the similar opinion---until it was pointed out (over and over and over)---given the position or velocity--let's say for sake of argument---no one can determine both---one will collapse (as a measurement) is made of the other.

You might try reading Feynman's take on it.----IMHO---> he explains it best----> and even admits that "no one truly understands QM"

ShinAce
2012-Jul-29, 06:33 PM
Quantum mechanics does not care about the size of things(or the distances involved). A photon is just as weird over the length of an atom as it is across the length of a galaxy. If you have a box with a single electron in it, you will never find the electron touching the wall, no matter how big the box is. Energy is conserved on all scales, the uncertainty part of it is that the conservation holds for long periods of time.

See? The uncertainty principle also applies to energy/time, instead of just position/momentum. It's not a single thing that only works on the quantum level. It's universal. The same laws apply on all scales. Thinking different causes an immediate problem. Where is the boundary between scales? Is it at 10 feet, 100 feet, 856.4 feet? Does the visible spectrum literally end at an exact wavelength, even when there are people that can still see beyond it? Electromagnetism is divided into scales for ease of recognition, but it's all the same photons.

I have to admit, you do have a certain 'style' in your posting. It's quite unique.

tusenfem
2012-Jul-29, 06:38 PM
Stephen Hawking says

Maybe you should stay off the Hawking for a while and read some other (popular) physics book.
I think Hawking is a great scientist, but I also think that a lot of his popular work is creating more confusion under the laymen than that it actually explains.
As said above, maybe you should take up Feynmann.

Strange
2012-Jul-29, 06:41 PM
Uncertainty Principle has been always for me an strange and unintelligible concept... and always I though that was only a problem of measuring instruments...because we try to mesure them (location and momentum) precisely with inappropriate instruments larger than required).

It is nothing to do with measuring instruments (and certainly nothing to do with their size). It is because the two parameters (position/momentum, or time/energy, for example) are related by a Fourier transform.

Fourier transforms are also used in signal processing. So, for example, the shorter a signal is, the greater the range of frequencies it contains. On the other hand, if you want to have a single frequency then the signal must be infinitely long. As you pin one of frequency or time down, the wider the other gets. The same applies to pairs of values in quantum mechanics.

Strange
2012-Jul-29, 06:42 PM
there are not any position and momentum to determining !!!


I don't know why you say that. Clearly, all particles have momentum and position. Even photons.

dapifo
2012-Jul-29, 07:14 PM
Dear dapifo,

I was of (somewhat) the similar opinion---until it was pointed out (over and over and over)---given the position or velocity--let's say for sake of argument---no one can determine both---one will collapse (as a measurement) is made of the other.

You might try reading Feynman's take on it.----IMHO---> he explains it best----> and even admits that "no one truly understands QM"

Which book of Feynman do you recomend?....What mean IMHO?

dapifo
2012-Jul-29, 07:29 PM
Quantum mechanics does not care about the size of things(or the distances involved). A photon is just as weird over the length of an atom as it is across the length of a galaxy. If you have a box with a single electron in it, you will never find the electron touching the wall, no matter how big the box is.

I donīt understand what do you mean here....


Energy is conserved on all scales, the uncertainty part of it is that the conservation holds for long periods of time.

What do you mean by...the conservation holds for long periods of time


See? The uncertainty principle also applies to energy/time, instead of just position/momentum. It's not a single thing that only works on the quantum level. It's universal.

Please, give me an example for larger scales (> 10^0)


The same laws apply on all scales. Thinking different causes an immediate problem. Where is the boundary between scales? Is it at 10 feet, 100 feet, 856.4 feet? Does the visible spectrum literally end at an exact wavelength, even when there are people that can still see beyond it? Electromagnetism is divided into scales for ease of recognition, but it's all the same photons.

I never said that there are boundaries between scales (???)....but yes that to different scales the phisics laws works some different (because different fields have more or less effort / power / relevance...but they are all consistents in all scales and dependent between them...although we still cannot link/involve / cover Gravity with the other (EM, S and W).


I have to admit, you do have a certain 'style' in your posting. It's quite unique.

I donīt know what do you mean with"style"... but I hope that you like it !!!

dapifo
2012-Jul-29, 07:34 PM
I don't know why you say that. Clearly, all particles have momentum and position. Even photons.

Just, because yiu said it "Quantum mechanics describes things in terms of wave functions which define the probability of, say, the location of a particle".

Really, it is true that in QM describes things in terms of probability....I agree on it

Strange
2012-Jul-29, 07:40 PM
Just, because yiu said it "Quantum mechanics describes things in terms of wave functions which define the probability of, say, the location of a particle".

And that wave function defines the probability of the particle having a particular location or momentum; so I don't understand why you say these things do not exist.

Noclevername
2012-Jul-29, 07:44 PM
What mean IMHO?

In My Humble Opinion

John Jaksich
2012-Jul-29, 07:44 PM
Which book of Feynman do you recomend?....What mean IMHO?

IMHO stands for: in my humble opinion.

You can try Six Easy Pieces---it is derived from lectures--->his lectures are difficult, also---> but "Six Easy Pieces" currently stands out in my memory

Take comfort in the fact that most Entry-level graduate students in chemistry or physics (on rare occasion) perform around the 60- 70 th percentile (at best) for their entrance level exams in QM.

I took mine more than once and only did well after studying Feynman (third volume of his lecture series) over a lengthy Summer study session.

John Jaksich
2012-Jul-29, 07:48 PM
You could also try The Character of Physical Law---a very well written book.

You will know that you may have some grasp of QM if you can complete problem sets out of a P. Chem text or Physics text without memorizing the answers before hand on an exam.

As many have noted ---> this subject is not for the faint of heart.

dapifo
2012-Jul-29, 08:10 PM
I have read

Dreams of a Final Theory: The Search for the Fundamental Laws of Nature (Steven Weinberg 1993),
Parallel Worlds (Michio Kaku 2004)

In addition to the physical I studied at the University----

John Jaksich
2012-Jul-29, 08:34 PM
One thing which I remember from my Undergraduate days in the States is that---> one must start with the Fundamentals and work up from there and I don't mean to imply anything---> but some popular accounts tend to water down fundamental and some important aspects of a theory.

If one needs an understanding of QM from a popularization ---> I would start with someone who is known for his/her understanding of QM---> Feynman is one

Another is Werner Heisenberg's: The Physical Principles of Quantum Theory---although the level is aimed at a practicing physicists of the early 20th century. I read it 2002 and remember having some comprehension of it.

I look at it now and it may take me a few moments (at least???) to get up to speed.

If you truly wish to have a deep appreciation of the subject--it must be read and practiced---that is why I mentioned performing problems. It forces you to think about the subject on a deeper level.

I am truly unsure of how you envision QM---it should not be taken for granted....maybe I sound over-enthused on the subject.

My main background is synthetic organic chemistry---not physics nor astronomy--and I am late to the subjects. Depending on one's age and experience---educating one's mind should not be approached lightly in this day and age with the speed of scientific advancements.

I hope this makes some sense?

John Jaksich
2012-Jul-29, 08:43 PM
Does a Classic Popularization belong in standard curriculum or standard understanding of physics or physical science?

Feynman's three volumes?

(aforementioned) Heisenberg?

If anyone can think of any other---please chime in?----and if not ---why not?

dapifo
2012-Jul-29, 09:19 PM
OK...thanks..I have a lot of things to read....

But I donīt agree with "Experimental results always precede theory . . ."... aloso could be the other way

Noclevername
2012-Jul-29, 10:02 PM
But I donīt agree with "Experimental results always precede theory . . ."... aloso could be the other way

No, that's the scientific definition of theory. If it's not backed up by experimental evidence, it's a hypothesis, not a theory.

dapifo
2012-Jul-29, 10:24 PM
No, that's the scientific definition of theory. If it's not backed up by experimental evidence, it's a hypothesis, not a theory.

OK...theory yes...but hypotesis no...black holes, higgs boson,....

korjik
2012-Jul-29, 11:46 PM
OK...theory yes...but hypotesis no...black holes, higgs boson,....

Both have experimental evidence, so what is the problem?

Jens
2012-Jul-30, 01:37 AM
Uncertainty Principle has been always for me an strange and unintelligible concept... and always I though that was only a problem of measuring instruments...

No, it is a strange concept, period. It is a strange concept for physicists as much as anyone else. It's just something you have to accept.

dapifo
2012-Jul-30, 03:27 AM
Both have experimental evidence, so what is the problem?

That the Theory forsee them existence !!!

dapifo
2012-Jul-30, 03:29 AM
No, it is a strange concept, period. It is a strange concept for physicists as much as anyone else. It's just something you have to accept.

AMEN

korjik
2012-Jul-30, 08:30 AM
That the Theory forsee them existence !!!

And the theories that forsaw them had ample experimental evidence also. Still not seeing a problem.

To a large degree, the procedure hypothesis, experiment, then theory is a loop, not a line. Most theories have things to say about hypothesis that havent been experimented on yet. As many hypothesis probably come from 'what does this theory say about this situation' as come from 'Huh, that's funny' ('http://www.schlockmercenary.com/2002-05-28')

HenrikOlsen
2012-Jul-30, 10:16 AM
No, it is a strange concept, period. It is a strange concept for physicists as much as anyone else. It's just something you have to accept.
The difference is that physicists have developed a language for concisely and unambiguously discussing what's going on so they can communicate with each other without getting confused by the strangeness.
It's called mathematics, and if one doesn't know how to describe quantum phenomena mathematically, it's impossible to make predictions about how things behave because the strangeness is too much to understand in other terms.

dapifo
2012-Jul-30, 10:11 PM
The only thing that I have very clear is that for this small scales (10^ī35 to 10^-10 meters) the things and effects (and dominant laws) are very different that those we can see at Ours scale (10^-10 to 10^20 meters).

And that only maths theories and fuctions can give us an theoretical idea of this world !!!!

Shaula
2012-Jul-31, 05:57 AM
The only thing that I have very clear is that for this small scales (10^ī35 to 10^-10 meters) the things and effects (and dominant laws) are very different that those we can see at Ours scale (10^-10 to 10^20 meters).
Well, not really. The macroscopic laws emerge from the underlying smaller laws. They are not different, just ensemble averages or low energy residual effects. Rather like gas acts as a collection of particles at small enough scales but averaging the particle behaviour gives a set of behaviours that can be modelled using a fluid approximation at larger scales. The particle laws are still valid, still more fundamental, but are more effort to calculate so we tend to use the simpler model. The laws don't change, but the ways we solve problems using them may.

korjik
2012-Jul-31, 07:05 AM
The only thing that I have very clear is that for this small scales (10^ī35 to 10^-10 meters) the things and effects (and dominant laws) are very different that those we can see at Ours scale (10^-10 to 10^20 meters).

And that only maths theories and fuctions can give us an theoretical idea of this world !!!!

Incorrect. The same laws apply at all scales. The effects that you call very different at meter scale are only the large number statistical approximations of the laws that apply at the nanometer scale. That is alot of 'only' but it is well proven that the same rules apply.

Also, 'only maths theories and fuctions can give us an theoretical idea of this world' applies just as well to the 'ours scale' as it does to the quantum scale. It isnt 'You have a PhD so POOF! what you say must be true!' All theory has an experiment done to show that it works. Sometimes it is a pretty complex chain of experiment-theory-experiment to go from what you see to what the experiment is, but sometimes it is just a couple guys with a ruby that ends up making a massive industry.

korjik
2012-Jul-31, 07:09 AM
OK...thanks..I have a lot of things to read....

But I donīt agree with "Experimental results always precede theory . . ."... aloso could be the other way

It works both ways wether you like it or not. Photoelectric effect is a good example of experiment leading to theory, and lasers are a good example of theory leading to an experiment.

dapifo
2012-Aug-01, 01:43 PM
Donīt you have the feeling that the Universe around us is easily understood for those scales closest to us (10 ^-10 to 10^+10 meters)?: Classical Mechanics, Euclidean Geometry, Determinism, ...

But that it becomes more complicated as we move away from these scales?. And in a different way as we move towards negative or positive scales?:

-Negatives scales: Quantum Mechanics, Dirac-Newmann Geometry, Uncertainty Principle, ...
-Positive scales: General Relativity, Riemann Geometry, Space-Time Curvature, ...

It seams like we are in an virtual Universe and its limits are broadcast or difused !!!... Like if they were the limits of a software program ("The Thirteenth Floor" film, 1999).

Please, have a look to the following slide, and give to me your opinion:

17344

Shaula
2012-Aug-01, 02:23 PM
My opinion: same idea you keep presenting and having refuted redone as a slide

The laws are not different, you just don't really understand them and seem to be unwilling to listen to people's explanations.

Strange
2012-Aug-01, 03:12 PM
Your initial assumption that these different theories only apply at vastly different scales is wrong.

Relativity has to be taken into account when describing the universe or making measurements on Earth.

Quantum theory is required to fully describe everything from transistors to supermassive black holes.

QED (our most accurately tested theory. ever.) combines relativity and quantum mechanics.

So, once again, this idea just doesn't make any sense. It appears to be based on some fundamental misunderstandings of the relevant science. Maybe you need to spend a bit more time asking questions in the Q&A section of the forum.

DrChinese
2012-Aug-01, 05:10 PM
Uncertainty Principle has been always for me an strange and unintelligible concept... and always I though that was only a problem of measuring instruments...because we try to mesure them (location and momentum) precisely with inappropriate instruments larger than required).

This is incorrect, as has been pointed out by others. Here's why:

1. If it were correct, then it should not be possible to know the values of commuting observables precisely (position and spin, for example) either. But there is no limit there! The Heisenberg Uncertainty Principle (HUP) applies only to *non-commuting* observables.

2. The EPR argument hypothesized that you could "beat" the HUP using entangled particle pairs - measure the position precisely on one, measure the momentum precisely on the other. But experiments do not bear that hypothesis out. See Bell's Theorem. Basically, measuring momentum on one throws the other into an symmetric momentum eigenstate immediately. However, subsequent measurements of position will NOT yield symmetric values. So you didn't beat the HUP after all.

dapifo
2012-Aug-01, 06:44 PM
My opinion: same idea you keep presenting and having refuted redone as a slide

The laws are not different, you just don't really understand them and seem to be unwilling to listen to people's explanations.


Your initial assumption that these different theories only apply at vastly different scales is wrong.

Relativity has to be taken into account when describing the universe or making measurements on Earth.

Quantum theory is required to fully describe everything from transistors to supermassive black holes.

QED (our most accurately tested theory. ever.) combines relativity and quantum mechanics.

So, once again, this idea just doesn't make any sense. It appears to be based on some fundamental misunderstandings of the relevant science. Maybe you need to spend a bit more time asking questions in the Q&A section of the forum.

I donīt say that laws are different...I mean that the general models (laws, math, basic physics, concepts, ...) are differnt in a general way....but it is clear that they have some relationship and links between them....

And I think that it is very clear !!!!!... You cannot deny it....

Also is very strange and confusing that at the scales limits....the models need very complex math to try to make consistents the models...

Strange
2012-Aug-01, 07:40 PM
Also is very strange and confusing that at the scales limits....the models need very complex math to try to make consistents the models...

That has nothing to do with the scales. The universe is complex; it requires complex math to describe it (at any scale). Get over it.

dapifo
2012-Aug-01, 08:39 PM
That has nothing to do with the scales. The universe is complex; it requires complex math to describe it (at any scale). Get over it.

Yes...at any scales... except Ours Scale that it is very easy of understand !!!!,, Newton, Euclides,....

Shaula
2012-Aug-01, 09:29 PM
Yes...at any scales... except Ours Scale that it is very easy of understand !!!!,, Newton, Euclides,....
Show, using only Euclidean and Newtonian techniques, that the precession of Mercury's perihelion is consistent with your 'simple' physics.

The point I am trying to make is that at ALL scales there are simplifications you can make, easier to calculate theories. You seem to be taking this fact and reading too much into it.

tusenfem
2012-Aug-02, 01:14 PM
dapifo that is more than enough showing off your lack of understanding of physics.
People are giving you very good answers to what you asked, however as they do not seem to fit in your preconceptions about how (in this case) the uncertainty principle should work, you just reject any reply that is given to you.
One more time and you will be infracted and thrown into ATM where you can prove "except Ours Scale that is easy to understand !!!!"

HenrikOlsen
2012-Aug-02, 08:44 PM
Donīt you have the feeling that the Universe around us is easily understood for those scales closest to us (10 ^-10 to 10^+10 meters)?: Classical Mechanics, Euclidean Geometry, Determinism, ...

But that it becomes more complicated as we move away from these scales?. And in a different way as we move towards negative or positive scales?:
We evolved brains to survive at the 10-3-103 meter scale, it shouldn't really be a surprise that's the bit that's easiest to understand.

dapifo
2012-Aug-03, 11:33 AM
Why we need different math and geometry models (Neumann, Dirac,...) to understand QM?

HenrikOlsen
2012-Aug-03, 01:41 PM
We don't really need them, but they're a way to present the problems simpler by mapping them over into a space that fit them better.

It's a common technique in physics of all kinds, not just QM.

dapifo
2012-Aug-03, 01:46 PM
We don't really need them, but they're a way to present the problems simpler by mapping them over into a space that fit them better.

It's a common technique in physics of all kinds, not just QM.

If Riemannian geometry is just a generalization of Euclidean geometry ...and Hilbert space is a generalization ofe Euclidian sapace concept...Then, there must be an General Maths model / Geometric Model for Euclid, Riemann and Hilbert together... (??)

HenrikOlsen
2012-Aug-03, 01:58 PM
If Riemannian geometry is just a generalization of Euclidean geometry ...and Hilbert space is a generalization ofe Euclidian sapace concept...Then, there must be an General Maths model / Geometric Model for Euclid, Riemann and Hilbert together... (??)
Not necessarily, Riemann and Hilbert geometries are defined by different sets of properties which must be true. Both sets or properties happen to hold for Euclidean geometry but there are no reason to expect a general Riemann space to also have the necessary properties to be a Hilbert space and vice versa..
This is why they can both be seen as generalizations, but they're generalized in different directions and expecting the existence of a unified model may not make sense.

Strange
2012-Aug-03, 02:49 PM
Different tools for different jobs.

dapifo
2012-Aug-03, 10:18 PM
Different tools for different jobs.

...And different scales?....

dapifo
2012-Aug-03, 10:24 PM
We evolved brains to survive at the 10-3-103 meter scale, it shouldn't really be a surprise that's the bit that's easiest to understand.

I agree wiyh you...our brain envolced to understand Our Scale (10^-6 to 10^+6 meters)... as much we move away of them...more dificult we have to understand everything....if we only consider the parameters that our brain understand !!!!.... we have to change our way of seeing and understanding the things...we have to think in another way....if not, we will not be able to underatand All The Universe !!!

korjik
2012-Aug-04, 03:11 AM
I agree wiyh you...our brain envolced to understand Our Scale (10^-6 to 10^+6 meters)... as much we move away of them...more dificult we have to understand everything....if we only consider the parameters that our brain understand !!!!.... we have to change our way of seeing and understanding the things...we have to think in another way....if not, we will not be able to underatand All The Universe !!!

so?

You dont seem to understand that the same theories apply at all scales. The fact that we are set up to see a small range of the possible scales dosent change that.

Also, it may be that you do not understand it, but that does not mean that others do not understand.

Shaula
2012-Aug-04, 08:44 AM
we have to change our way of seeing and understanding the things
Not really. We have the tools and the methodology to ask questions outside the scales our brains are most familiar with. We do this regularly.

Do you consider your question answered? We seem to have moved to to another round of unsupported assertions based on a lack of knowledge of physics. If you have any more questions ask away, I am happy to take part in useful discussions. If you just want to keep saying that everything changes at different scales then I am out.

Strange
2012-Aug-04, 09:32 AM
we have to think in another way....if not, we will not be able to underatand All The Universe !!!

We have developed another way, its called mathematics. This allows us to understand things that happen at scales beyond our understanding and that require more then 3 dimensions to describe.

The trouble is, all the things you say we should be doing are being done. You just don't understand them.

dapifo
2012-Aug-04, 02:14 PM
Ok...thank...Iīve learn a lot with your explanations.

I hope that my questions have give you also some idea or reflexion about.

Just last cosideration: Some times it seam like if you confuse scales with a far away position: It is not the same a scale of 10^+20 meters than a location of 10^+20 meters far away of us...

primummobile
2012-Aug-04, 07:56 PM
Ok...thank...Iīve learn a lot with your explanations.

I hope that my questions have give you also some idea or reflexion about.

Just last cosideration: Some times it seam like if you confuse scales with a far away position: It is not the same a scale of 10^+20 meters than a location of 10^+20 meters far away of us...

Are you saying we don't understand the difference between something with a diameter of 10^20 m and something that is 10^20 m away from us? That doesn't make a lot of sense.

dapifo
2012-Aug-04, 08:08 PM
Some times... some of your answer or comments seem to confunde them...

For example....that weak or strong field iare governig also in the scales of 10^+20 meters... because they are important for black holes (???)... or in the Big-Bang !!!

OK...black holes are very far away (or not so much).....but they donīt have a diameter of 10^+20 meters !!!!

The influence of weak or strong fields for scales of 10^+20 meters is very few and almost nule ....isnīt it?

Some times is confusing...and is easy to do this mistake of confunde a diameter of 10^20 m and something that is 10^20 m away from us

primummobile
2012-Aug-04, 10:20 PM
I really don't think anyone confuses the two.

tusenfem
2012-Aug-05, 07:01 AM
Nobody is making that confusion, except for you dapifo, which is probably caused by your lack of knowledge of physics and english not being your mother tongue.

dapifo
2012-Aug-05, 07:54 AM
I really don't think anyone confuses the two.


Nobody is making that confusion, except for you dapifo, which is probably caused by your lack of knowledge of physics and english not being your mother tongue.

OK...just an example...http://cosmoquest.org/forum/showthread.php/137012-Is-the-Uncertainty-Principle-only-an-scale-problem?p=2049840#post2049840

But do you agree with me that?:

- The influence of weak or strong fields for scales of 10^+20 meters is very few and almost nule ....isnīt it?
- And that the influence of Gravity field for scales of 10^-20 meters is also very few and almost nule ....isnīt it?

It seems that you donīt want to accept what is an evidence !!!

Shaula
2012-Aug-05, 09:08 AM
We accept that forces behave differently over different distances. No one is arguing that. What we are pointing out that this is in no way evidence for anything other than the force being associated with a potential. You seem to be trying to spin this into some incredibly significant aspect of the way the universe works.

Plus at tiny scales gravity can become important. It depends on the mass in that tiny area. That is the whole problem we hit trying to push the big bang cosmology backwards in time - at some point gravity has to be taken into account at the smallest scales. And we don't know how to do that. So your second point about gravity is patently false if you consider the history of the cosmos and not just what you can look at now.

dapifo
2012-Aug-05, 10:12 AM
We accept that forces behave differently over different distances. No one is arguing that. What we are pointing out that this is in no way evidence for anything other than the force being associated with a potential. You seem to be trying to spin this into some incredibly significant aspect of the way the universe works.

Here you have another example were there are an confusing between distance and scale:

http://cosmoquest.org/forum/showthread.php/136537-have-different-force-fields-different-scales-of-influence?p=2043416#post2043416

And your first explanation is a clear confusing in the same way: "We accept that forces behave differently over different distances. No one is arguing that. What we are pointing out that this is in no way evidence for anything other than the force being associated with a potential"...Here you make the same mistake.


Plus at tiny scales gravity can become important. It depends on the mass in that tiny area. That is the whole problem we hit trying to push the big bang cosmology backwards in time - at some point gravity has to be taken into account at the smallest scales. And we don't know how to do that. So your second point about gravity is patently false if you consider the history of the cosmos and not just what you can look at now.

But if we see the cosmos just what you can look at now...Which influence has the gravity within a molecule or an atom? (SCALE 10^ī10)....And Which influence has the weak and strong between two stars? (ESCALE 10^+10).

I understand that is difficult to become accustomed to think in this way...it needs just a change of mind.

Please, if you have any graph soft tool...make the following graph over a 2D coordinate axis:

X = coodinate: UNIVERSE SCALES in a logarithmic scale (10^EXP)....Were in the origin is the 10^0 and EXP negatives goes to left and EXP positives to right.

Y = FIELS (Gravity, weak, strong and EM) INFLUENCE: I donīt have clear how to represent it???... What magnitude? ...Will be somethig like Force between bodies and distances of different magnitudes (??).

I see something like:

EM is a horizontal line (constant)
Weak and Strong will be something like an non symetric gaussian law with the middle on the aprox. 10^-14 meters.
Gravity like and exponential line Y= K (10 ^ EXP) ^ 2

Hornblower
2012-Aug-05, 12:09 PM
OK...just an example...http://cosmoquest.org/forum/showthread.php/137012-Is-the-Uncertainty-Principle-only-an-scale-problem?p=2049840#post2049840

But do you agree with me that?:

- The influence of weak or strong fields for scales of 10^+20 meters is very few and almost nule ....isnīt it?
- And that the influence of Gravity field for scales of 10^-20 meters is also very few and almost nule ....isnīt it?

It seems that you donīt want to accept what is an evidence !!!

Can you tell us, in appropriate technical detail, what sort of evidence you think we are rejecting? I don't think anyone denies that gravity is vanishingly weak compared with nuclear forces at extremely short distances, or that the nuclear forces are vanishingly weak compared to gravity at large distances.

Shaula
2012-Aug-05, 12:50 PM
I am perfectly aware of the difference between distance and scale and am not mixing the two up. You are pointedly ignoring the problems with positing change in rules over different scales as has been pointed out over and over again to you. You also seem to be mixing up the ideas of coupling constants and the strength of a force. And ignoring unification theories. EM and weak forces are the same force, for example. Which rather damages your ideas about them being examples of scale dependent forces.

You are also ignoring evidence yourself. We have plenty of evidence for the big bang cosmology and plenty of evidence from it that over small scales gravity can be important. But you dismiss this. Why? Because it doesn't fit into your ideas?

You tell me to plot a graph and then cannot even tell me what to plot? Really? Suggest you go firm up your ideas before suggesting nugatory work.


I understand that is difficult to become accustomed to think in this way...it needs just a change of mind.
Yes, it would require me to ignore and forget what I know about physics, adopt a handwaving approach to physical modelling and ignore about fifteen years of experience. Not sure I want to do that just to see the universe as a rainbow, thanks.

dapifo
2012-Aug-05, 11:43 PM
Can you tell us, in appropriate technical detail, what sort of evidence you think we are rejecting?

Just the following sentence you say latter:


I don't think anyone denies that gravity is vanishingly weak compared with nuclear forces at extremely short distances, or that the nuclear forces are vanishingly weak compared to gravity at large distances.

It is the first time that I read this from somebody in this forum.....till now no body accepted this !!!

With the only difference that when you say distances...I say scales...that is very different !!!...you agree with this change?


I am perfectly aware of the difference between distance and scale and am not mixing the two up.

Then...do you agree with the above sentence?: "gravity is vanishingly weak compared with nuclear forces at extremely short scales, or that the nuclear forces are vanishingly weak compared to gravity at large scales."


You are pointedly ignoring the problems with positing change in rules over different scales as has been pointed out over and over again to you.

I donīt understand what do you mean....


You also seem to be mixing up the ideas of coupling constants and the strength of a force.

No...I donīt


And ignoring unification theories. EM and weak forces are the same force, for example.

Yes...that is new for me!!!....Is it true that EM farce (field) is the same than weak force (field)???... or unification theories only define a unifyed model to join both forces (fields)???


Which rather damages your ideas about them being examples of scale dependent forces.

I donīt understand what do you mean....


You are also ignoring evidence yourself. We have plenty of evidence for the big bang cosmology and plenty of evidence from it that over small scales gravity can be important. But you dismiss this. Why? Because it doesn't fit into your ideas?

I never said this!!!...I only said: "gravity is vanishingly weak compared with nuclear forces at extremely short scales[/B], or that the [B]nuclear forces are vanishingly weak compared to gravity at large scales."


You tell me to plot a graph and then cannot even tell me what to plot? Really? Suggest you go firm up your ideas before suggesting nugatory work.

I will try to do by my self....I was just was trying that you think about this... and that you understand what I tryed to say to you.


Yes, it would require me to ignore and forget what I know about physics, adopt a handwaving approach to physical modelling and ignore about fifteen years of experience. Not sure I want to do that just to see the universe as a rainbow, thanks.

Shaula...I thanks to you very much for your very good explanations...I said to you several times that I learned a lot with them...But only there are some misunderstandings with you, possible due to my poor English and my low level of of academic physics....and its state of the art....but what I am saying is not anything strange...possible we donīt understand one to the other !!!

Shaula
2012-Aug-06, 12:02 AM
.Is it true that EM farce (field) is the same than weak force (field)???
Yes. They are both part of an underlying electroweak force. This is very important to modern physics because the Higgs mechanism was first proposed to explain why the vector bosons of the weak field are massive while the photon is massless. So when you say "weak forces are small scale forces and "gravity is a large scale force" you are hitting issues in that above certain energy scales they are the same force with the same coupling constants.


gravity is vanishingly weak compared with nuclear forces at extremely short scales
And I am saying to you that the scale is irrelevant. If I jam a few solar masses of material into something the size of an atom then gravity is important. As I said, there is a potential which defines an effective range for a force and associated charges. The interplay between the two defines the effective strength/range of a force.

And as was pointed out elsewhere the concept of symmetry and gauge invariance are very important to modern field theories. With appropriate transformations forces have to be scale independent in order to satisfy the conditions for some of their conservation laws. Changing the rules at different scales makes these symmetries approximate and would have observable effects on things like energy conservation.

dapifo
2012-Aug-06, 12:20 AM
OK...So now we can say that there are tree fields; Gravity, Strong ans...electroweak !!!

For me weak was the field who mantain the electrons arround the nucleus... and EM the magnetic field and EM waves and photons.....then weak field (force) is an EM field ?!!!

OK I agree that if you jam a few solar masses of material into something the size of an atom then gravity is important..at nuclear size...BUT... IS IT POSSIBLE?

And OK, I Know that the concept of symmetry and gauge invariance are very important to be space (location) independent... but I didnīt that also to be scale independet !!!... You told me it somewere...but I thought you confunde scale and space.... But are you sure that reffers to scale???

Nereid
2012-Aug-06, 12:51 AM
Shaula...I thanks to you very much for your very good explanations...I said to you several times that I learned a lot with them...But only there are some misunderstandings with you, possible due to my poor English and my low level of of academic physics....and its state of the art....but what I am saying is not anything strange...possible we donīt understand one to the other !!!(bold added)

This is an interesting thread. I applaud the CQuestians who have tried so hard to explain various aspects of modern physics with just words and no reference to underlying mathematics.

I have a question for you, dapifo, if I may: given that you yourself acknowledge a (very?) limited understanding of modern physics, why is it that you think* you can grasp the key concepts folk such as Shaula refer to?

To use my own experience as an example: after I grasped (albeit only vaguely) the intimate relationship between conservation laws (in physics) and symmetries, I gained an appreciation of just how wide and deep the concepts of 'force laws' is, at least as applied to the electro-weak and strong forces. For gravity, my 'aha moment' came when I realised just how radically different General Relativity is, as a description of gravity, from the other forces (or, more accurately, the theories of those forces); just five words can capture such profound insights: 'background dependent vs background independent'. I would say, based on my own experience, that when you can grasp what those five words mean (in this context), you will be able to answer nearly all the questions you have asked in this thread, for yourself.

On the other hand, I feel that as long as you continue to struggle with these deep concepts, without the benefit of a decent physics education, you will continue to fail to grasp the core essentials.

* I should add "apparently", as in apparently think

Nereid
2012-Aug-06, 12:57 AM
OK...So now we can say that there are tree fields; Gravity, Strong ans...electroweak !!!

For me weak was the field who mantain the electrons arround the nucleus... and EM the magnetic field and EM waves and photons.....then weak field (force) is an EM field ?!!!

I think this post of yours, dapifo, neatly illustrates what I mentioned in my last post.

The electroweak force is one force ... but at the low energies we encounter, here and now, it manifests itself as two difference forces (i.e. the weak, and electromagnetism). But how is that possible?!? Cue 'symmetry breaking' ...


OK I agree that if you jam a few solar masses of material into something the size of an atom then gravity is important..at nuclear size...BUT... IS IT POSSIBLE?

As a Gedankenexperiment, yes, of course it's possible.

Does the universe seem to do something like this? Yes, frequently (cue a discussion of 'black holes').


And OK, I Know that the concept of symmetry and gauge invariance are very important to be space (location) independent... but I didnīt that also to be scale independet !!!... You told me it somewere...but I thought you confunde scale and space.... But are you sure that reffers to scale???

Other CQuestians may have a different opinion, but I think you have no hope of being able to understand - really understand - the distinction here (as it applies to the force laws of modern physics) unless and until you have a certain minimal facility in certain areas of mathematics. And that leads me to this question: are you prepared to put the time and effort in to acquire that minimal capability?

Xelebes
2012-Aug-06, 01:12 AM
Parallel Worlds (Michio Kaku 2004)

Is there anyone else out there bothered by Michio Kaku? I see him everywhere but I have yet to hear anything from him that is anything more than tortured metaphor and poppycock.

Anywhich way, as a layman reading through various papers on QM research and theory, the less I'm convinced that there at the quantum level that there are particles and more that the particles we ascribe to our observations is more quanta of energy being absorbed and exciting atoms. The more you try to say that what we are observing are particles, the more I think it is poppycock.

But then again, I'm only a layman.

I won't enter the whole determinism debate or any of the philosophical woo.

Shaula
2012-Aug-06, 07:18 AM
For me weak was the field who mantain the electrons arround the nucleus... and EM the magnetic field and EM waves and photons.....then weak field (force) is an EM field ?!!!
No no no no no. The weak field is the one responsible for stuff like beta decay. The EM force is responsible for the attraction between the nucleus and electronics. The weak field is NOT an EM field. This is really critical. The weak field and the EM field are both low energy manifestations of a fundamental underlying force, the electroweak force. The weak and EM field are equal in the relationship, the weak field is not an EM field, the EM field is not a weak field.


OK I agree that if you jam a few solar masses of material into something the size of an atom then gravity is important..at nuclear size...BUT... IS IT POSSIBLE?
Yes. As I have said before, look at the big bang cosmology. To the best of our knowledge it happened. And our inability to unify gravity with the other forces is intimiately linked to why we don't have a model that goes back further than our current ones do.


And OK, I Know that the concept of symmetry and gauge invariance are very important to be space (location) independent... but I didnīt that also to be scale independet !!!... You told me it somewere...but I thought you confunde scale and space.... But are you sure that reffers to scale???
In String theory the scale factor is critically important. One of the core dualities is related to the scale transforms of one theory being analogous to coupling constant transforms of another.


OK...So now we can say that there are tree fields; Gravity, Strong ans...electroweak !!!
Go back further and it is pretty well established that there are probably only 2. Further back it is thought that there is only 1.

Strange
2012-Aug-06, 08:22 AM
With the only difference that when you say distances...I say scales...that is very different !!!...you agree with this change?

No. As already stated above, scale and distance are not the same thing. You also need to define what you mean by "scale" because it isn't entirely clear.


Then...do you agree with the above sentence?: "gravity is vanishingly weak compared with nuclear forces at extremely short scales, or that the nuclear forces are vanishingly weak compared to gravity at large scales."

Only if you define "scale" to mean "distance".

dapifo
2012-Aug-06, 03:19 PM
What do you mean with 'background dependent vs background independent'....

Wel...Iīll try to introduce you my self...I am Industrial Engineer with a large experience in management of multidisciplinary technological and industrial projects.

My background is not the more basic and academic physics...and also the last state of the art of it.

My knowledge and xperience is more focussed to "practical" physics and technology (within Euclid Space andNewton and Maxwell Physics)...but also I know roughly about more complex physics from my University years and reading about it.

But never I had the possibility of eschanging opinions and ideas with Academic and Experts Physics with a deeper knowledge of these concepts.

So...it is not true that I donīt have the enough background and education to understand high maths and physics concepts...I just only need to refresh and update myself about them.

It is possible that the way to do it has been fortuitous ...just trying to contrast with experts an old idea that was in my head...Idea, that I think, it is not so crasy and fetched as you say...but possible it needs some academic physics and maths contents...

dapifo
2012-Aug-06, 03:23 PM
Other CQuestians may have a different opinion, but I think you have no hope of being able to understand - really understand - the distinction here (as it applies to the force laws of modern physics) unless and until you have a certain minimal facility in certain areas of mathematics. And that leads me to this question: are you prepared to put the time and effort in to acquire that minimal capability?

Yes..sure I do !!!...but only in a general way...Main ideas...I am not able now to go deeper in very complex maths and physics details !!!

Shaula
2012-Aug-06, 03:47 PM
Then I would suggest you start with quantum mechanics. Go from there to quantum field theory. Then you can delve into the symmetry groups that are key to a lot of these arguments. You have an idea but to be honest you are simply not able to make statements like:

Idea, that I think, it is not so crasy and fetched as you say...but possible it needs some academic physics and maths contents...
Until you understand the arguments being put to you.

I am a physicist, although my theoretical stuff is rusty. I would not say to you "I have an idea for a way to better run your production lines and design teams. Never really done it before, don't have any evidence, but I don't think your arguments are good enough to dismiss my idea".

dapifo
2012-Aug-06, 03:55 PM
No no no no no. The weak field is the one responsible for stuff like beta decay. The EM force is responsible for the attraction between the nucleus and electronics. The weak field is NOT an EM field. This is really critical. The weak field and the EM field are both low energy manifestations of a fundamental underlying force, the electroweak force. The weak and EM field are equal in the relationship, the weak field is not an EM field, the EM field is not a weak field.

OK..I see...I was wrong...

What do you mean with : the weak field is not an EM field, the EM field is not a weak field...That there are only an electroweak field?


Yes. As I have said before, look at the big bang cosmology. To the best of our knowledge it happened. And our inability to unify gravity with the other forces is intimiately linked to why we don't have a model that goes back further than our current ones do.

I donīt understand what means with: "why we don't have a model that goes back further than our current ones do"


In String theory the scale factor is critically important. One of the core dualities is related to the scale transforms of one theory being analogous to coupling constant transforms of another.

These concepts are out of my knowledge....


Go back further and it is pretty well established that there are probably only 2. Further back it is thought that there is only 1.

Do you mean that if we are able to unify forces theories... then we are also unifying the fields?

Nereid
2012-Aug-06, 04:00 PM
OK, thanks for the responses, dapifo. Though I must say I'm rather puzzled; with your background (per your post), I can't see why you have - apparently - so badly confused 'scale' and 'distance'.

Take this part of your post, for example: "Then...do you agree with the above sentence?: "gravity is vanishingly weak compared with nuclear forces at extremely short scales, or that the nuclear forces are vanishingly weak compared to gravity at large scales."" As Strange already pointed out, it seems that you are using 'scale' as a synonym for 'distance' here; are you?

Here's one take on what you seem to be interested in: the three 'force laws' of modern physics - electroweak, strong, and gravity - seem to be able to describe (or account for, or explain) every reliable, relevant experimental result and every astronomical observation so far. So, we can say that he universe seems to behave exactly as these three force laws describe, to the limits of our powers of experiment and observation.

If you accept that, then answer to your original question - "Is the Uncertainty Principle only an scale problem?" - is no. As has been pointed out, by many others, earlier in this thread.

If you do not accept that, well, a new thread in the ATM section beckons ...

But, and this is a very big "but", the very foundations of the "gravity force law" and of the "electroweak and strong force laws" are mutually inconsistent, or incompatible! Which is an astonishing and wonderful thing. And a powerful motivation to physicists to develop better theories, ones which 'reduce to' the three force laws of modern physics, 'in the appropriate limit', and which do not contain fundamental inconsistencies.

Sadly, there seems no way to be able to reliably test any such better theories, if only because the physical regimes in which the mutual incompatibility of the two types of force laws become manifest are far, far, far, far, far beyond anything we can hope to create in any lab, and likely far, far beyond any astronomical observations we can hope to make (at least in the lifetime of anyone reading this post in 2012).

dapifo
2012-Aug-06, 04:01 PM
No. As already stated above, scale and distance are not the same thing. You also need to define what you mean by "scale" because it isn't entirely clear.

It is clear...SCALE of dimension...size....


Only if you define "scale" to mean "distance".

No..that is different !!!

One atom has an scale (dimension, size) of aprox 10^-13 meters...The Earth ..10^+7 meters...and galaxy 10^+20 meters

But the distance between them could be very different....it depends on X1-Y1-Z1 vs X2-Y2-Z2 positions

dapifo
2012-Aug-06, 04:14 PM
Then I would suggest you start with quantum mechanics. Go from there to quantum field theory. Then you can delve into the symmetry groups that are key to a lot of these arguments.

OK...Iīll try...but only in a general way...

I will try to know more about "symetry groups"....



You have an idea but to be honest you are simply not able to make statements like:

Until you understand the arguments being put to you.

I agree with you...but what I donīt see so strange...(??)

What I donīt like to believe is that the Universe (physics laws,...) we know are all that exist....I am sure that it only is a very small part of it...and that if we see it in this way...then we could understand it better.

Strange
2012-Aug-06, 04:18 PM
One atom has an scale (dimension, size) of aprox 10^-13 meters...The Earth ..10^+7 meters...and galaxy 10^+20 meters

But the distance between them could be very different....it depends on X1-Y1-Z1 vs X2-Y2-Z2 positions

Which is why the important factor is distance not size (scale).

Two protons in the nucleus are bound by the strong nuclear force because they are close together. There is also a gravitational force between them but it is much, much smaller and can be ignored.

Two protons on opposite sides of the galaxy are "bound" by gravity (of each other and all the other mass in the galaxy). The strong force between them is non-existent.

See, distance not scale.

Strange
2012-Aug-06, 04:22 PM
What do you mean with : the weak field is not an EM field, the EM field is not a weak field...That there are only an electroweak field?

The electromagnetic force (field/interaction) is different from the weak force (field/interaction). But they can be unified at sufficiently high energy to a single electroweak force (field/interaction).


I donīt understand what means with: "why we don't have a model that goes back further than our current ones do"

Back in time, earlier in the history of the universe.


Do you mean that if we are able to unify forces theories... then we are also unifying the fields?

Forces/fields - different aspects of the same thing.

Strange
2012-Aug-06, 04:28 PM
OK...Iīll try...but only in a general way...

I don't think it is possible to understand symmetry groups in a "general way"; it certainly isn't useful.


What I donīt like to believe is that the Universe (physics laws,...) we know are all that exist

All scientists are quite certain the the physics we currently know is all that exists. There are all sorts of areas of research going on the extend the boundaries of what we know.


if we see it in this way...then we could understand it better

What you are doing is equivalent to someone coming to your production line and say, "you could improve that by using a frobulator." You say, "what's a frobulator?" and he says, "I don't know, I'm not the expert - you work it out."

[As English is not your native language I should, perhaps, point out that frobulator is a meaningless word I made up for this example]

dapifo
2012-Aug-06, 04:28 PM
OK, thanks for the responses, dapifo. Though I must say I'm rather puzzled; with your background (per your post), I can't see why you have - apparently - so badly confused 'scale' and 'distance'.

No...I think is the contrary...see the previous thread:

One atom has an scale (dimension, size) of aprox 10^-13 meters...The Earth ..10^+7 meters...and galaxy 10^+20 meters

But the distance between them could be very different....it depends on X1-Y1-Z1 vs X2-Y2-Z2 positions


Take this part of your post, for example: "Then...do you agree with the above sentence?: "gravity is vanishingly weak compared with nuclear forces at extremely short scales, or that the nuclear forces are vanishingly weak compared to gravity at large scales."" As Strange already pointed out, it seems that you are using 'scale' as a synonym for 'distance' here; are you?

No...here I mean scale..and this sentence is not mine...is from Hornblower, just changin distance by scale !!!

http://cosmoquest.org/forum/showthread.php/137012-Is-the-Uncertainty-Principle-only-an-scale-problem?p=2051076#post2051076


If you accept that, then answer to your original question - "Is the Uncertainty Principle only an scale problem?" - is no. As has been pointed out, by many others, earlier in this thread.

No....I agree...It seems to be an basic principle...but I donīt like that "God plays dice"....

Strange
2012-Aug-06, 04:49 PM
No...here I mean scale..and this sentence is not mine...is from Hornblower, just changin distance by scale !!!

But you have just been arguing that they are different, so why are you arbitrarily changing one to the other?


No....I agree...It seems to be an basic principle...but I donīt like that "God plays dice"....

Well, it seems that not only does the universe play dice but it doesn't care what you think about it :)

dapifo
2012-Aug-06, 07:08 PM
But you have just been arguing that they are different, so why are you arbitrarily changing one to the other?

If you read this post...you will understand:

http://cosmoquest.org/forum/showthread.php/137012-Is-the-Uncertainty-Principle-only-an-scale-problem?p=2051230#post2051230


Well, it seems that not only does the universe play dice but it doesn't care what you think about it :)

Still I have to speak seriously with him !!!!:)

dapifo
2012-Aug-06, 07:23 PM
Then I would suggest you start with quantum mechanics. Go from there to quantum field theory. Then you can delve into the symmetry groups that are key to a lot of these arguments.

Well...I can try to understand routhly the QM: forces, particles,...

But I have to admit that will be impossible to understand "symmetry groups": Lagrangian mechanics, Gauge theory,...

If it is necessary to know them to understand roughly physics....then I have to to resign !!!!:(

Paul Wally
2012-Aug-06, 07:34 PM
I think the term "uncertainty" is a bit misleading, because it implies that there is something that is the case but that we just can't be certain exactly what it is. For example if we say that if we know the position of a particle then we can't know the momentum with certainty; but this is the misleading part: If we can't know the momentum with certainty this means there exists in reality a momentum that we are uncertain of. My understanding is that if we measure the position exactly it makes no sense to make a simultaneous exact measurement of momentum. This is because the experimental setups for measuring these variables are fundamentally mutually exclusive (complimentary).

Strange
2012-Aug-06, 07:51 PM
If you read this post...you will understand:

http://cosmoquest.org/forum/showthread.php/137012-Is-the-Uncertainty-Principle-only-an-scale-problem?p=2051230#post2051230

That is the post where you decided to replace "distance" with "scale".

On the one hand you say they are different and shouldn't be confused, but then you decide to switch them about. Why is that?

Shaula
2012-Aug-06, 08:31 PM
If it is necessary to know them to understand roughly physics....then I have to to resign !!!!
Then you will have to resign. To do what you are trying to do requires more than just rough physics. It requires some quite indepth study. If you are not going to do that then you will always be relying on someone else to do that hard work for you. And since people are generally not willing to spend all their time working out the details of someone else's vague ideas you are not going to get very far.


What do you mean with : the weak field is not an EM field, the EM field is not a weak field...That there are only an electroweak field?
Strange covered this pretty well. There is only one underlying field but at low energies it manifests as two forces due to an underlying symmetry breaking (which coincidentally gives mass to the vector bosons and gives us some very important insights into the universe)


I donīt understand what means with: "why we don't have a model that goes back further than our current ones do"
As Strange said, our models break down in the very early universe at the point when gravity becomes equal in strength (roughly) to the other forces due to the extreme conditions. Since QM And GR are so far highly resistant to unification we cannot model what is happening at this point in time or any moments in time preceding this point.


These concepts are out of my knowledge....
They are highly relevant to what you are talking about. Suggest you read someone like Brian Greene who has written some very accessible String Theory books. While it may not be the theory we are looking for the underlying maths and concepts are valuable things to study.


Do you mean that if we are able to unify forces theories... then we are also unifying the fields?
This is highly related to symmetry groups. This page (http://en.wikipedia.org/wiki/Grand_Unified_Theory) gives you some idea what you need to study to understand unification of forces more completely. I am rusty on the underlying theory, but the essence is that each of the force is associated with a symmetry group (a set of transformations under which it is invariant). These symmetry groups are in turn part of larger groups and by finding groups that contain all the observed symmetries we can unify the forces into one description. It is easier to do this at higher energy scales because the coupling constants for all the forces are affected by energy scale. At higher energy scales the forces behave more like each other and can be described as one force when their coupling constants run together. The structure of the symmetry groups are critical to understanding how this happens. This page (http://en.wikipedia.org/wiki/Electroweak_interaction) gives a description of how the groups SU(2) and U(1) are unified as electroweak force. The U(1) part eventually relates (in a non-trivial way) to the EM part of the theory while the SU(2) and a component of the U(1) field (strictly this is only true thanks to the Higgs mechanism, the basic weak field is described by SU(2) but the Z boson has a relationship to the U(1) group thanks to it being a mixed state of the W and B bosons) show up in the weak force.

I hope I have not made any glaring errors in this. Physics is not easy when you are getting into this level of detail and I am trying to remember stuff I studied fifteen years ago and have only read stuff on since. If you want to develop a TOE then you need to understand this far better than I do.

dapifo
2012-Aug-06, 09:39 PM
That is the post where you decided to replace "distance" with "scale".

On the one hand you say they are different and shouldn't be confused, but then you decide to switch them about. Why is that?

If you see ,,,in the thread Iīm asking if the change is accepted.

From my poin of view the sentence of Hornblower is incorrect....but if we change distance by scale...for me is correct !!!

Hornblower
2012-Aug-06, 09:58 PM
If you see ,,,in the thread Iīm asking if the change is accepted.

From my poin of view the sentence of Hornblower is incorrect....but if we change distance by scale...for me is correct !!!

Please show me, in appropriate mathematical detail, what you think is wrong with what I previously posted.

Strange
2012-Aug-06, 10:04 PM
From my poin of view the sentence of Hornblower is incorrect....but if we change distance by scale...for me is correct !!!

And it isn't. His statement is correct. Your is, at best, wrong. But possibly just meaningless.

dapifo
2012-Aug-06, 10:17 PM
I hope I have not made any glaring errors in this. Physics is not easy when you are getting into this level of detail and I am trying to remember stuff I studied fifteen years ago and have only read stuff on since. If you want to develop a TOE then you need to understand this far better than I do.

Thanks Saula...this idea is so good for me....I cannot go in more detail... I would like but I see it so complex...I donīt want to develope TOE...I just want to have a better idea about State of the Art in MQ and GR....to understand better Our Universe.

You say: "by finding groups that contain all the observed symmetries we can unify the forces into one description"...thatīs good...but there we are developing an unifyed model that explain all the forces....but the different forces they exist independent (!!)...or they are only manifestations of a fundamental underlying Global Force?

I mean: We can unifying the model because there are only One Unic Basic and Global Force with different manifestations....or we are jast puting together in the same math model the 4 forces that are independent between them?....or some of them are dependent like weak and EM?

caveman1917
2012-Aug-06, 11:33 PM
I don't think it is possible to understand symmetry groups in a "general way"; it certainly isn't useful.

That's why it's called abstract nonsense :)

Seriously, the general framework in which to understand symmetry groups is category theory, specifically the study of morphisms (symmetry groups are intimately related to automorphisms of structures), which (ie category theory) is at times called "abstract nonsense" (in a fun, non-derogatory way).

dapifo
2012-Aug-07, 12:51 AM
I think the term "uncertainty" is a bit misleading, because it implies that there is something that is the case but that we just can't be certain exactly what it is. For example if we say that if we know the position of a particle then we can't know the momentum with certainty; but this is the misleading part: If we can't know the momentum with certainty this means there exists in reality a momentum that we are uncertain of. My understanding is that if we measure the position exactly it makes no sense to make a simultaneous exact measurement of momentum. This is because the experimental setups for measuring these variables are fundamentally mutually exclusive (complimentary).

For me it is a good point !!!...I donīt know what will say the experts (??)

dapifo
2012-Aug-07, 01:03 AM
Please show me, in appropriate mathematical detail, what you think is wrong with what I previously posted.


And it isn't. His statement is correct. Your is, at best, wrong. But possibly just meaningless.

Hornblower said: "I don't think anyone denies that gravity is vanishingly weak compared with nuclear forces at extremely short distances, or that the nuclear forces are vanishingly weak compared to gravity at large distances."

Distance of what ?...that is the question....distance is relative to two points...and scale (size) is absolute in one point.

But for me distance is different than scale (size):

One atom has an scale (dimension, size) of aprox 10^-13 meters...The Earth ..10^+7 meters...and galaxy 10^+20 meters

But the distance between them could be very different....it depends on X1-Y1-Z1 vs X2-Y2-Z2 positions

And my opinion is that the correct sentence would say:

"gravity is vanishingly weak compared with nuclear forces at extremely small scales (sizes), or that the nuclear forces are vanishingly weak compared to gravity at large scales (sizes)"."

dapifo
2012-Aug-07, 01:08 AM
Nereid....What do you mean with 'background dependent vs background independent' ?....

Noclevername
2012-Aug-07, 01:11 AM
"gravity is vanishingly weak compared with nuclear forces at extremely small scales (sizes), or that the nuclear forces are vanishingly weak compared to gravity at large scales (sizes)"."

Even I know that's wrong! Hornblower said distance because he meant distance. Specifically, in this case, the distance between the objects being attracted together by those forces-- whether those objects are protons or galaxies.

Shaula
2012-Aug-07, 06:20 AM
I mean: We can unifying the model because there are only One Unic Basic and Global Force with different manifestations....or we are jast puting together in the same math model the 4 forces that are independent between them?....or some of them are dependent like weak and EM?
At high enough energies the four forces are thought to be indistinguishable. They will act like one more complex force. Whether that means that they are all low energy manifestations of one force or just that they become impossible to untangle from each other is an open question as I understand it. The motivation of unification theories is basically linked to the first idea, that they are all aspects of one underlying force. But this is the sort of semantic or philosophical distinction I try to avoid. It is believed that one model will describe them all, that is all I am saying. All that means to me is that one model describes them all. I try not to get too caught up in what the maths 'really truly means'.

Shaula
2012-Aug-07, 06:25 AM
My understanding is that if we measure the position exactly it makes no sense to make a simultaneous exact measurement of momentum. This is because the experimental setups for measuring these variables are fundamentally mutually exclusive (complimentary).
It is not just experimental set ups it is because the two properties are genuinely non-commutative. In fact you can measure the two properties for one system fairly precisely using a system of weak measurements, you just cannot do it at once and you need to be very careful to avoid causing the system to decohere.

Strange
2012-Aug-07, 07:41 AM
And my opinion is that the correct sentence would say...

And you are still wrong. As Noclevername says, it is the distance between the points. Look at Newton's law for gravitation as a simple example.
F = G \frac{m_1 m_2}{r^2}

The distance, r, appears in this equation. Size doesn't.

dapifo
2012-Aug-07, 09:38 AM
Even I know that's wrong! Hornblower said distance because he meant distance. Specifically, in this case, the distance between the objects being attracted together by those forces-- whether those objects are protons or galaxies.


And you are still wrong. As Noclevername says, it is the distance between the points. Look at Newton's law for gravitation as a simple example.
F = G \frac{m_1 m_2}{r^2}

The distance, r, appears in this equation. Size doesn't.

I have very clear the Newton formula....and I know it depends on the mass and distance between objects....

But I am talking about an more abstract concept...that, possibe, it is difficult to understand !!!..

I know that gravity field is different in every space point depending on the distance to nearest mass....and it will be a (vectoriall) sume of them...

But this field will be different at different scales:

- Between galaxies (10^+20 meters)
- Between stars (10^+15 meters), inside a galaxy
- Between planets (10^+10 meters), inside n star
- Between atoms (10^-14 meters), inside a body

Strange
2012-Aug-07, 09:57 AM
But I am talking about an more abstract concept...that, possibe, it is difficult to understand

Because it is nonsense.



But this field will be different at different scales:
- Between galaxies (10^+20 meters)
- Between stars (10^+15 meters), inside a galaxy
- Between planets (10^+10 meters), inside n star
- Between atoms (10^-14 meters), inside a body

Because the distance is different.

dapifo
2012-Aug-07, 11:13 AM
Because it is nonsense.
Because the distance is different.

Well ...lets go to try to analyse these two sentences:

Hornblower: "anyone denies that gravity is vanishingly weak compared with nuclear forces at extremely short distances, or that the nuclear forces are vanishingly weak compared to gravity at large distances."


Dapifo: "anyone denies that gravity is vanishingly weak compared with nuclear forces at extremely small scales (sizes or dimension), or that the nuclear forces are vanishingly weak compared to gravity at large scales (sizes or dimension)"."

Please, anybody could explain the differences between both, and if both, no one or one of them is the correct????

Perikles
2012-Aug-07, 11:30 AM
Please, anybody could explain the differences between both, and if both, no one or one of them is the correct????To me, Hornblowers makes total sense, because distance makes sense. I don't know what yours means: "at extremely small scales" doesn't sound like English to me.

Strange
2012-Aug-07, 11:40 AM
Please, anybody could explain the differences between both, and if both, no one or one of them is the correct????

See post 101.

pzkpfw
2012-Aug-07, 11:43 AM
...
Hornblower: "anyone denies that gravity is vanishingly weak compared with nuclear forces at extremely short distances, or that the nuclear forces are vanishingly weak compared to gravity at large distances."
...

You mangled this into a misquote. You'd be better off just using the normal quote function.


... I don't think anyone denies that gravity is vanishingly weak compared with nuclear forces at extremely short distances, or that the nuclear forces are vanishingly weak compared to gravity at large distances.

tusenfem
2012-Aug-07, 11:45 AM
To use the word "scale" in a scientific context it only makes sense when it is compared to something. Interestingly, the word "scale" does not have an entry in my Oxford concise science dictionary.
The word "size" that you use as in "(sizes or distances)" is completely wrong.

dapifo
2012-Aug-07, 06:47 PM
To use the word "scale" in a scientific context it only makes sense when it is compared to something. Interestingly, the word "scale" does not have an entry in my Oxford concise science dictionary....The word "size" that you use as in "(sizes or distances)" is completely wrong.

It is possible that I make an error of language (???)....possibly, for this reason you may not understand it....

By scale I mean a magnitude scale....of size or dimension of space....

Earth is within the scale of 10^+7 meters
Galaxies are within the scale of 10^+20 meters
Atoms are within the scale of 10^-14 meters
Neutrinos are within the scale of 10^-24 meters


If we use the formula 17383 and we put the distance, as much large is the distance then weaker is the Force.

The sentence of Hornblower donīt reffer to this formula !!!...he is comparing nuclear and gravity forces at different SCALES !!!! (no distances !!!)

"anyone denies that gravity is vanishingly weak (compared with nuclear forces) at extremely short distances, or that the nuclear forces are vanishingly weak (compared to gravity) at large distances."


I am talking about the gravity field to different scales (dimensions or sizes).

ShinAce
2012-Aug-07, 07:03 PM
I don't follow you. The nuclear force is strong compared to gravity when looking at a single atom, but gravity is strong compared to the nuclear force for an entire galaxy. There, I said the same thing as Hornblower but worded it with strong instead of weak.

However, this has nothing to do with size. It simply means that gravity is a bit different than the other forces in the sense that it never gets cancelled. It just adds up when you consider more mass/energy. The electric force for earth cancels out. There are the same number of negative charges as positive charges.

Now, is the electromagnetic force weak because I can't measure a net charge for earth? If yes, then why is lightning so strong? Why is the electric force basically zero overall yet we have a magnetic field protecting us. Your concept of weak vs strong will mislead you in trying to answer these questions. The electromagnetic force is considered strong because it has the same formulation as gravity but the constant or 'coupling constant' is bigger than for gravity. That's it. The nuclear force being strong or weak has to do with the fact that it is inverse cube instead of inverse square.

Like everyone else, I wonder what you mean by: scale, strong, weak, and of course 'the state of the art in QM and GR'. Saying the same thing over and over again does not add any clarity to your point.

edit: make note there are plenty of cases where two forces balance each other. Look at the sun. The strong nuclear force makes it 'explode' at the same rate that gravity makes it 'implode'. I can say that they are equal in strength for the entire sun. At this scale, which force is stronger? You can't pin it on size, because stars of different sizes show the same balancing act.

Strange
2012-Aug-07, 07:55 PM
The sentence of Hornblower donīt reffer to this formula !!!...he is comparing nuclear and gravity forces at different SCALES !!!! (no distances !!!)

He said distance and he meant distance. Please show, in appropriate mathematical detail, how "scale" is relevant to gravity or the strong nuclear force.

Once again, people are explaining how and why you are wrong. You ignore them and keep repeating that you are right with no basis for your claims.

dapifo
2012-Aug-07, 08:17 PM
I don't follow you. The nuclear force is strong compared to gravity when looking at a single atom, but gravity is strong compared to the nuclear force for an entire galaxy. There, I said the same thing as Hornblower but worded it with strong instead of weak..

What you are saying here is what I am trying to explain you all the time !!!...I agree with it!!!... http://cosmoquest.org/forum/showthread.php/137012-Is-the-Uncertainty-Principle-only-an-scale-problem?p=2051062#post2051062 ....but here you donīt talk about "distance, scale,..." Now you are using another terminology:

- when looking at a single atom,
- for an entire galaxy.

For me here you are talking about bodies, entities, spaces, volums, (sizes, dimensions, scales)....But not DISTANCES !!!

I think that all we are talking about the same...but with different terminology (???)

Only SHAULA understud what i mean!!!!

Shaula
2012-Aug-07, 09:54 PM
Essentially I think that what you proposing is that the gauge invariance of the different forces under a dilaton type scaling (one where you can vary the spatial scale factor and the coupling constant in such a way as to preserve the properties of the field) is not valid over all scales. However this introduces issues as the coupling constant relates to the vacuum expectation value of the dilating field's potential. Essentially you would be replacing one field with an infinite series of overlapping fields, a sum over all scales. I would imagine that renormalising this would be brutally hard.

dapifo
2012-Aug-07, 11:45 PM
Essentially I think that what you proposing is that the gauge invariance of the different forces under a dilaton type scaling (one where you can vary the spatial scale factor and the coupling constant in such a way as to preserve the properties of the field) is not valid over all scales. However this introduces issues as the coupling constant relates to the vacuum expectation value of the dilating field's potential. Essentially you would be replacing one field with an infinite series of overlapping fields, a sum over all scales. I would imagine that renormalising this would be brutally hard.

This is too complex for me...

I think that with the following phrases we want to give the same meaning (and I agree with it):

"The nuclear force is strong compared to gravity when looking at a single atom, but gravity is strong compared to the nuclear force for an entire galaxy. There, I said the same thing as Hornblower but worded it with strong instead of weak.."

"gravity is vanishingly weak (compared with nuclear forces) at extremely short distances, or that the nuclear forces are vanishingly weak (compared to gravity) at large distances."

"gravity is vanishingly weak compared with nuclear forces at extremely small scales (sizes or dimension), or that the nuclear forces are vanishingly weak compared to gravity at large scales (sizes or dimension)"."

Although...."distance" and "scale" is not the same concept:

One atom has an scale (dimension, size) of aprox 10^-13 meters...The Earth ..10^+7 meters...and galaxy 10^+20 meters

But the distance between them could be very different....it depends on X1-Y1-Z1 vs X2-Y2-Z2 positions

ShinAce
2012-Aug-08, 01:48 AM
If the scale isn't the distance the force has to travel, then what is the scale? Or better yet, what is the gauge?

Shaula
2012-Aug-08, 05:51 AM
I am guessing that the simplest way to incorporate a scale factor into the equations would be to make the coupling constants functions of distance. But that doesn't work. Just looking at the fine structure constant should make it pretty clear why. I guess you could argue that it is not a continuous function but then you hit the same issues the Standard model has when you try to reconcile it with GR.

In short: The idea doesn't work as far as I can tell and Dapifo, you need to get a far bit more maths and physics under your belt if you want to show me I am wrong. Good luck, but until you have a far more formalised idea I would be wary of trying to get people to agree with you about it. You have no justification or evidence, no reason for anyone to believe in the theory and at first glance it appears incompatible with observations.

ShinAce
2012-Aug-08, 02:48 PM
I think that with the following phrases we want to give the same meaning (and I agree with it):

"The nuclear force is strong compared to gravity when looking at a single atom, but gravity is strong compared to the nuclear force for an entire galaxy. There, I said the same thing as Hornblower but worded it with strong instead of weak.."

"gravity is vanishingly weak (compared with nuclear forces) at extremely short distances, or that the nuclear forces are vanishingly weak (compared to gravity) at large distances."

"gravity is vanishingly weak compared with nuclear forces at extremely small scales (sizes or dimension), or that the nuclear forces are vanishingly weak compared to gravity at large scales (sizes or dimension)"."

Those three sentences already have the same meaning.

What is the meaning of: "Now, is the electromagnetic force weak because I can't measure a net charge for earth? If yes, then why is lightning so strong? Why is the electric force basically zero overall yet we have a magnetic field protecting us. Your concept of weak vs strong will mislead you in trying to answer these questions. The electromagnetic force is considered strong because it has the same formulation as gravity but the constant or 'coupling constant' is bigger than for gravity. That's it. The nuclear force being strong or weak has to do with the fact that it is inverse cube instead of inverse square."

Or even the meaning of: "For a neutron star, which is stronger at any point on the surface: strong nuclear or gravity? What is the scale of the interplay between these forces? Is the strong force not acting as the result of nearby interactions and gravity the result of all that not so nearby mass?"

Feel free to ignore those questions since they would require you to define your ideas.

Hornblower
2012-Aug-08, 04:06 PM
Those three sentences already have the same meaning.

What is the meaning of: "Now, is the electromagnetic force weak because I can't measure a net charge for earth? If yes, then why is lightning so strong? Why is the electric force basically zero overall yet we have a magnetic field protecting us. Your concept of weak vs strong will mislead you in trying to answer these questions. The electromagnetic force is considered strong because it has the same formulation as gravity but the constant or 'coupling constant' is bigger than for gravity. That's it. The nuclear force being strong or weak has to do with the fact that it is inverse cube instead of inverse square."

Or even the meaning of: "For a neutron star, which is stronger at any point on the surface: strong nuclear or gravity? What is the scale of the interplay between these forces? Is the strong force not acting as the result of nearby interactions and gravity the result of all that not so nearby mass?"

Feel free to ignore those questions since they would require you to define your ideas.

My bold. The function for the strong nuclear force is vastly steeper than that. See this Wiki article:
http://en.wikipedia.org/wiki/Nuclear_force
According to the author, it is strongly attractive at a separation of about 1 femtometer, but drops to being insignificant beyone about 2.5fm. Inside about 0.7fm it becomes repulsive, setting the characteristic radius of a nucleus or a neutron star as the case may be.

As always, Wiki is not the last word, but my experience has been that they are pretty good on matters like this.

When I was in college, a source whose name I cannot remember roughly approximated that attractive zone as an inverse 9th power, meaning that the attractive force would drop by a about a factor of 1000 in going from 1 to 2fm.

Strange
2012-Aug-08, 09:46 PM
- when looking at a single atom,
- for an entire galaxy.

For me here you are talking about bodies, entities, spaces, volums, (sizes, dimensions, scales)....But not DISTANCES !!!

Well, obviously, the distances in an atom or a galaxy are very different. That may be where your confusion comes from. Unless you are able to show some quantitative (mathematical) relationship between force and "scale" (whatever that means).

Hornblower
2012-Aug-08, 10:32 PM
I am puzzled by the recurrence of remarks about "scale" being something distinct from distance. For the purpose of this discussion I think in terms of appropriate units of measurement which in turn are defined in terms of the distance between two suitable reference points. These points could be the centers of adjacent atoms in a crystal, the ends of a meter stick, the centers of the Earth and the Sun, or the centers of two galaxies a megaparsec apart, depending on whether we are analyzing a system on very large scales, very small, or somewhere inbetween. Dapifo keeps on insisting that the Earth, among others, has a "scale" of some number of meters, which appears to be nothing more than the distance between two reference points on opposite sides of it.

What different concept of "scale", if any, is pertinent here? Someone please clarify.

Shaula
2012-Aug-09, 06:26 AM
Well, as I said, the simplest way I could see to add scale to the force equations was to make the coupling constants a function of distance. Perhaps best shown by an example of a preserved symmetry. Take gravity. Assume 1Kg masses because I am lazy.

F = G / (r^2)

if we scale the distance by a factor of two and apply an appropriate geometric scaling to the coupling constant it should reduce back to the same relationship:

F = (G/4) / ((2r)^2)
F = G / (r^2)

In other words at all scales the relationship between Force and Distance is the same. In the simplest form of this idea G is a function of r. So we get:

F = G(r) / (r^2)
Scaling it
F = (G(2r)/4) / ((2r)^2)
F = G(2r) / (r^2)

Which is no longer the same. So now F is not a simple function of distance but has some awful 'scale' term creeping in. Mathematically this is horrible to deal with, it should also result in pseudo-Nambu-Goldstone bosons associated with this symmetry breaking and mean that conservation laws get shaky at different scales. I personally believe (although i would have to do more research than I am willing to do to prove it) that this is already ruled out or highly constrained by observation.

Scale to me is a transformation, a factor that can be applied to all the terms in the equation (given the right modifications) and then drop out to leave them the same (scale invariance).

dapifo
2012-Aug-16, 07:05 PM
If the scale isn't the distance the force has to travel, then what is the scale? Or better yet, what is the gauge?


Well, obviously, the distances in an atom or a galaxy are very different. That may be where your confusion comes from. Unless you are able to show some quantitative (mathematical) relationship between force and "scale" (whatever that means).


Scale to me is a transformation, a factor that can be applied to all the terms in the equation (given the right modifications) and then drop out to leave them the same (scale invariance).

I am going to try to explain again what I mean by the “scale factor”.

We (Humans) are living in a range of scale with middle 10^0 meters (since 10^-10 to 10^+10 meters).

Within this range of scale we develop (by evolution) a brain and senses appropriate for this range… and we understand every thing we see in this range.

But as we move away from this range of scale, things change and we become more strange and different from what we are accustomed.

If we move to a range of scale with middle 10^- 20 meters (since 10^ -30 to 10^ -10 meters), everything will be different…and although the force fields (gravity, EM, weak and strong) could be the same, their influence and importance will be different.

It is obvious that things will be different also if we move into a crystal structure or by contrast we move into a gas place or into vacuum space.

The same will happen if we move to a larger scale range with middle 10^+20 meters (since 10^ +10 to 10^ +30 meters). Things will be different that in the other range of scale.

I donīt know if now it is more clear the concept of the “scale factor”.

Shaula
2012-Aug-16, 07:27 PM
You have explained nothing, really. Your definition of scale remains nebulous.

All you seem to be saying is that forces have different potentials and therefore different strengths at different differences. We know that.

dapifo
2012-Aug-16, 08:22 PM
Well, as I said, the simplest way I could see to add scale to the force equations was to make the coupling constants a function of distance. Perhaps best shown by an example of a preserved symmetry. Take gravity. Assume 1Kg masses because I am lazy.

F = G / (r^2)

if we scale the distance by a factor of two and apply an appropriate geometric scaling to the coupling constant it should reduce back to the same relationship:

F = (G/4) / ((2r)^2)
F = G / (r^2)

In other words at all scales the relationship between Force and Distance is the same. In the simplest form of this idea G is a function of r. So we get:

F = G(r) / (r^2)
Scaling it
F = (G(2r)/4) / ((2r)^2)
F = G(2r) / (r^2)

Which is no longer the same. So now F is not a simple function of distance but has some awful 'scale' term creeping in. Mathematically this is horrible to deal with, it should also result in pseudo-Nambu-Goldstone bosons associated with this symmetry breaking and mean that conservation laws get shaky at different scales. I personally believe (although i would have to do more research than I am willing to do to prove it) that this is already ruled out or highly constrained by observation.

Scale to me is a transformation, a factor that can be applied to all the terms in the equation (given the right modifications) and then drop out to leave them the same (scale invariance).

You are talking about Model Scale Factor: Dimensional Analysis and the Great Principle of Similitude

http://en.wikipedia.org/wiki/Dimensional_analysis

Paul Wally
2012-Aug-16, 08:59 PM
I am going to try to explain again what I mean by the “scale factor”.

We (Humans) are living in a range of scale with middle 10^0 meters (since 10^-10 to 10^+10 meters).

Within this range of scale we develop (by evolution) a brain and senses appropriate for this range… and we understand every thing we see in this range.

But as we move away from this range of scale, things change and we become more strange and different from what we are accustomed.

If we move to a range of scale with middle 10^- 20 meters (since 10^ -30 to 10^ -10 meters), everything will be different…and although the force fields (gravity, EM, weak and strong) could be the same, their influence and importance will be different.

It is obvious that things will be different also if we move into a crystal structure or by contrast we move into a gas place or into vacuum space.

The same will happen if we move to a larger scale range with middle 10^+20 meters (since 10^ +10 to 10^ +30 meters). Things will be different that in the other range of scale.

I donīt know if now it is more clear the concept of the “scale factor”.

I think I understand intuitively what you mean by "scale". Essentially it's like zooming in/out on a picture. When we zoom in (e.g. with a microscope) we observe different phenomena e.g. micro-organisms and when we zoom in further we "see" atoms. We can also zoom out (e.g. with the Hubble telescope) then we can see the large scale phenomena like galaxies. As a result of this, when we study large scale phenomena like galaxy formation or the dynamic interactions between stars we consider gravity only and ignore the other forces and when we study the interaction between two electrons then we consider electromagnetic force and ignore gravity between the two electrons.

Shaula
2012-Aug-16, 09:11 PM
You are talking about Model Scale Factor: Dimensional Analysis and the Great Principle of Similitude
I am familiar with dimensional analysis, that is not what I am doing. Look more carefully - I am talking about something more complex than just changing the units.


I think I understand intuitively what you mean by "scale".
The argument the OP keeps on making is not that different models have to be use but that different laws actually apply. This is why pinning down his concept of scale is important, because essentially we are trying to show that it is at odds with several deep symmetries in physics and leads to conservation law problems.

dapifo
2012-Aug-16, 10:44 PM
You have explained nothing, really. Your definition of scale remains nebulous.

All you seem to be saying is that forces have different potentials and therefore different strengths at different differences. We know that.


I think I understand intuitively what you mean by "scale". Essentially it's like zooming in/out on a picture. When we zoom in (e.g. with a microscope) we observe different phenomena e.g. micro-organisms and when we zoom in further we "see" atoms. We can also zoom out (e.g. with the Hubble telescope) then we can see the large scale phenomena like galaxies. As a result of this, when we study large scale phenomena like galaxy formation or the dynamic interactions between stars we consider gravity only and ignore the other forces and when we study the interaction between two electrons then we consider electromagnetic force and ignore gravity between the two electrons.

Please, suppose we shrink in size to a range of scale ....with middle 10^- 20 meters (since 10^ -30 to 10^ -10 meters), inside a rock of the Earth....which will be our vision of the universe?...It is hardly clear that we were able to detect and visualize the sun, but surely we will not be able to distinguish other stars, galaxies, black holes ...Which laws we would develope?...Did we know the gravity and EM fields?

ShinAce
2012-Aug-16, 11:39 PM
Science isn't about what you eyes see. Sure, it helps to use examples that people can visualize, but it has nothing to do with what you see, or what an atom sees, or what a galaxy sees.

They can all be detected and modeled as forces.

Shaula
2012-Aug-17, 06:17 AM
Please, suppose we shrink in size to a range of scale ....with middle 10^- 20 meters (since 10^ -30 to 10^ -10 meters), inside a rock of the Earth....which will be our vision of the universe?...It is hardly clear that we were able to detect and visualize the sun, but surely we will not be able to distinguish other stars, galaxies, black holes ...Which laws we would develope?...Did we know the gravity and EM fields?
Given sensitive enough instruments we would come to exactly the same laws of physics as we would at any other scale. Your artificial "in a rock" might prevent us observing the larger universe but the laws that govern our scale would be just as applicable to it as they would to our scale. It may take longer for some aspects, less time for others, but the laws would be the same.

dapifo
2012-Aug-17, 09:57 AM
Given sensitive enough instruments we would come to exactly the same laws of physics as we would at any other scale. Your artificial "in a rock" might prevent us observing the larger universe but the laws that govern our scale would be just as applicable to it as they would to our scale. It may take longer for some aspects, less time for others, but the laws would be the same.

I agree with: "Given sensitive enough instruments we would come to exactly the same laws of physics as we would at any other scale"... or more !!!...because possibly we could observe also smaller things than now we do.

But given similar or equivalent sensitive instruments than we have now...we will be only able to observe till 10^+10 meters....till the Solar System !!!...but possible for smaller scales we will be able to observe smaller scales than now we do (10^-50 meters) !!!!!

There we will observe another range of the scale spectrum....and it is possible that we could develope a different universe model and laws....although the real fields and laws could be the same, there we can model them in another way...in the way is more familiar for us.... the point of view of an scale of 10^-20 meters....were QM is mainly governing....and we will have more info and understanding about smaller dimensions (till 10^-50 meters) that now we unknown !!!

That is what I mean by the "SCALE FACTOR"... We have make a universe model (to explain the real universe) that is good and valid from our point of view ....from our range of scale...since 10^-30 till 10^+30 meters.

And possibly, for the range of scale of 10^-20 meters (within 10^ -50 to 10^ +10 meters), ....the uncertainty principle can have no other meaning or explanation that we give now.(!!??)

Hornblower
2012-Aug-17, 12:52 PM
I agree with: "Given sensitive enough instruments we would come to exactly the same laws of physics as we would at any other scale"... or more !!!...because possibly we could observe also smaller things than now we do.

But given similar or equivalent sensitive instruments than we have now...we will be only able to observe till 10^+10 meters....till the Solar System !!!...but possible for smaller scales we will be able to observe smaller scales than now we do (10^-50 meters) !!!!!

There we will observe another range of the scale spectrum....and it is possible that we could develope a different universe model and laws....although the real fields and laws could be the same, there we can model them in another way...in the way is more familiar for us.... the point of view of an scale of 10^-20 meters....were QM is mainly governing....and we will have more info and understanding about smaller dimensions (till 10^-50 meters) that now we unknown !!!

That is what I mean by the "SCALE FACTOR"... We have make a universe model (to explain the real universe) that is good and valid from our point of view ....from our range of scale...since 10^-30 till 10^+30 meters.

And possibly, for the range of scale of 10^-20 meters (within 10^ -50 to 10^ +10 meters), ....the uncertainty principle can have no other meaning or explanation that we give now.(!!??)

You are acknowledging that the characteristics of the universe would be the same regardless of our observing capability, but that our ability to infer details that are not apparent at all scales would be diminished if we cannot observe at extremely large or small scales. I don't think anyone who knows how science works is denying that. Do you still have any questions that have not been answered to your satisfaction?

tusenfem
2012-Aug-17, 01:49 PM
And possibly, for the range of scale of 10^-20 meters (within 10^ -50 to 10^ +10 meters), ....the uncertainty principle can have no other meaning or explanation that we give now.(!!??)


As the uncertainty principle is inherent to QM and does not have anything to do with at which "scale" you are measuring at all, I think that it is time to move this discussion to ATM where you will have to prove that indeed the uncertainty principle is something made up as I think you still are claiming it to be. This has long passed the line between asking questions to arguing against the mainstream. So unless, as hornblower asked there are unanswered questions, the buck stops here.

dapifo
2012-Aug-17, 01:56 PM
You are acknowledging that the characteristics of the universe would be the same regardless of our observing capability, but that our ability to infer details that are not apparent at all scales would be diminished if we cannot observe at extremely large or small scales. I don't think anyone who knows how science works is denying that. Do you still have any questions that have not been answered to your satisfaction?

Just read my firm....do you understand now?

Shaula
2012-Aug-17, 02:06 PM
Am getting very, very tired of repeating this. So I will make this my last attempt to make the point to you that you have already acknowledged you need more background reading to validate yourself:

Our models have a series of symmetries in them that would be strongly violated by your scale idea. Therefore we can rule out some (note: not all, some) of the wilder changes you would see at different scales. That is the beauty of having physics models - we can use them to infer what is happening at larger and smaller scales.

If all you are saying is that observations at different scales can reveal new physics, not issues at all. But you seem to keep veering off into suggesting that the laws we observed locally are going to suddenly drastically change at larger scales.

ShinAce
2012-Aug-17, 02:41 PM
And here I thought this thread was about the uncertainty principle.

Just for fun, let's suppose that the universe is best understood in terms of scales. How many scales are there? The universal scale, the galactic scale, the planetary scale, the living being scale, the atomic scale? What stops there from being a scale more vast than the universal scale? Why can't there be sub planck scales?

Which is to say, even if could identify precise scales(which we cannot), who gets to decide how many there are? You alone? They're not detectable, right? If I say there are an infinite number of scales, can you prove me wrong?

dapifo
2012-Aug-17, 03:26 PM
If all you are saying is that observations at different scales can reveal new physics, not issues at all.

OK..that is whay I mean...but not "new physics"...only new points of view and new models of the physics....that will try to explain the same real physics.


But you seem to keep veering off into suggesting that the laws we observed locally are going to suddenly drastically change at larger scales.

I never said that "the laws we observed locally are going to suddenly drastically change at larger (or smaller) scales"...but yes that they change slowly and gradually---although they are based on dependent (note: not independent) laws that possibly in the future we can unify in a general model....M-Theory only unify our spectrum or range of scale... but possibly will be not enough for understanding and modeling a larger spectrum or range of scale.

Do you understand now?

tusenfem
2012-Aug-17, 03:32 PM
Okay enough about scales, uncertainty principle well answered and alive, something you cannot say of this thread because it is closed.