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Orac #51089 02/03/14 03:30 PM
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Originally Posted By: Orac
I mean Hawking is proposing QM and GR magically join inside each other no need to worry about the detail and that means the event horizon is all fuzzy just because he decided it must be even though he has no idea how the two theories merge.


You seem to be of the opinion that since we don't have a theory of quantum gravity then we should ignore all attempts to come up with one. I just want you to accept the fact that there will be a theory of quantum gravity. We don't know what it will really look like, but there will be one. So we can report on any research that we do in the search for it, hoping that what we find will help to reach the goal.

Bill Gill


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C is the universal speed limit.
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Bill #51091 02/03/14 04:30 PM
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Originally Posted By: Bill
You seem to be of the opinion that since we don't have a theory of quantum gravity then we should ignore all attempts to come up with one. I just want you to accept the fact that there will be a theory of quantum gravity. We don't know what it will really look like, but there will be one. So we can report on any research that we do in the search for it, hoping that what we find will help to reach the goal.

Bill Gill


You seem to keep ignoring the wording problem, I am somewhat of a QM zealot according to many and even for me you are going a step to far.

Yes GR and Quantum mechanics have to merge but there is no evidence it has to be in a quantum way it could be quantum mechanics gets slowly dissolved by GR or that there is another mechanism that encompasses both of them.

If you want a simple place holder for merging GR and QM it should not be called Quantum Gravity because that description is already in use and the meaning isn't general it is very specific indeed with QM effects being dominant. Use something like "total theory of gravity" or some more general phrase that isn't currently in use if you want a place holder.

My problem is not the testing of Quantum Gravity it is you have excluded other ways of merging by using that very specific phrase as the merge point language.

In the same way there is nothing wrong with testing pigs for an experiment but testing for "flying pigs" could never be a place holder for generic pig testing either because it already has meaning and form and just becomes totally misleading and/or just confusing.

I get what you mean now you have explained it but the confusion arises because of the attempt to use of an already defined expression as a generic place holder.

Last edited by Orac; 02/03/14 04:33 PM.

I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.
Orac #51093 02/03/14 10:24 PM
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Originally Posted By: Orac
If you want a simple place holder for merging GR and QM it should not be called Quantum Gravity because that description is already in use and the meaning isn't general it is very specific indeed with QM effects being dominant. Use something like "total theory of gravity" or some more general phrase that isn't currently in use if you want a place holder.

The way I see it is that we have a phrase which is widely understood. If you can come up with some new designation for that theory, whatever it may be, that will be widely accepted and understood then so be it. But I figure that what it has been called for many years now is what it will be called for many more years. Your campaign is somewhat like my campaign to replace the habit of defining C as the speed of light with a different definition. See my sig for my take on that. But I don't really expect to change how it is defined. I don't see any future in your insisting that we not call Quantum Gravity what it is almost universally called.

As I have said, the final theory may be something completely different, but it will have elements of both GR and QM in it. So there isn't any good reason not to use the phrase Quantum Gravity as a placeholder.

Originally Posted By: Orac
I am somewhat of a QM zealot according to many and even for me you are going a step to far.

I noticed that before, which is what brought on my earlier comment about your not liking GR. You seem to think that GR is not quite as good as QM, and I have been trying to point out that is just as valid as QM.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
Bill #51099 02/04/14 03:45 AM
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Originally Posted By: Bill
The way I see it is that we have a phrase which is widely understood. If you can come up with some new designation for that theory, whatever it may be, that will be widely accepted and understood then so be it.


No it is not widely understood as that Quantum Gravity has a precise meaning for how GR and QM join.

Please go and ask a scientist who is working on MOND if it is a quantum gravity theory and see what they say ... seriously go and do it because I doubt any will answer they are working on a Quantum Gravity theory.

My answer is Modified Newtonian Dynamics falls in the informal category of a "fringe theory" specifically, it falls in the category of an "alternative gravity theory" because it proposes fundamental changes to our understanding of the way gravity works. Hence it can't be described as a quantum gravity theory by any stretch of the definition. In MOND quantum mechanics basically stays as something that is crushed at large scales by macro effects so that is the join.

This is my issue I don't understand how you remotely call something like MOND a quantum gravity theory.

If you look at the definition of Quantum gravity the first sentence gives you the problem (http://en.wikipedia.org/wiki/Quantum_gravity)

=> Quantum gravity (QG) is a field of theoretical physics that seeks to describe the force of gravity according to the principles of quantum mechanics.

What does someone doing in science experiments in MOND give a rats about QM they don't view gravity has anything to do with QM so that is hardly according to the principles of QM????

If we go back to the flying pig if I called any experiment on pigs a "flying pig" test does that not make things more than a bit confusing to you. Just imagine how many "flying pig" tests a vet could do none of them remotely having anything to do with an actual flying pig.

Let me throw a specific case at you, so you are happy to call Newton's Mach inspired rubbish a Quantum Gravity theory?

I just find using Quantum Gravity in the way you are as confusing as a vet using "flying pig" tests as a place holder, you can do it if you like but it's weird and confusing to me. I think I have said all I need to so if you still feel Quantum Gravity works as a general place holder I guess I will just have to work my way through any confusion when you use the term there is no point me going on and arguing about it because I doubt I can change your mind.

For my part I will never accept Newtons stuff or MOND as a Quantum gravity theory because they put the cause of gravity coming from something other than a quantum field of gravity as a fundamental force.

Anyhow argument closed lets just agree to disagree because it's not really a science issue.

Last edited by Orac; 02/04/14 08:43 AM.

I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.
Orac #51104 02/04/14 04:24 PM
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Originally Posted By: Orac

This is my issue I don't understand how you remotely call something like MOND a quantum gravity theory.

I don't think of MOND as a quantum gravity theory. As far as I know it is an attempt to explain away the need for dark matter. And it isn't being very successful. Notice that the N in MOND stands for Newtonian. Newtonian dynamics are not GR.

Can you think of a theory of everything, or whatever you want to call it, which replaces either GR or QM with something totally different? The huge successes of both of them tell us that while they may need to be modified the chance of either of them being totally replaced is extremely remote.

Whatever final theory we get when we resolve the conflicts between GR and QM, it WILL include both GR and QM, because they are both extremely successful. Therefore Quantum Gravity is a very useful term, because it encapsulates the idea in just 2 words.

And of course Newton's rantings have nothing to do with science, so we don't even need to consider them.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
Bill #51105 02/04/14 06:30 PM
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Originally Posted By: Bill
Can you think of a theory of everything, or whatever you want to call it, which replaces either GR or QM with something totally different?


There are many which work through a theoretical fifth force. If you have a fifth force and it isn't a quantum field then there really isn't anything to merge between QM and GR beyond what already has, Ideas I can think of off the top of my head

MOND
Quintessence
Graviphoton


The key point about all of the above is they remove the force of gravity as being a Quantum field which to most scientists and me is the essence of Quantum gravity.

Originally Posted By: Bill
I don't think of MOND as a quantum gravity theory.


You agree Mond isn't a quantum gravity theory now so I am really confused because aren't these theories a merge between GR and QM and that is what you wanted your place holder to be?

You actually seem to be now agreeing with me so I am totally lost because this is the essence of my complaint.


Originally Posted By: Bill
Whatever final theory we get when we resolve the conflicts between GR and QM, it WILL include both GR and QM, because they are both extremely successful. Therefore Quantum Gravity is a very useful term, because it encapsulates the idea in just 2 words.


Now you have flipped back to the former, the problem I have is you assume that GR and QM have conflicts and have to merge, neither of which is proved to be true.

As discussed above a simple way out of the problem would be to have a fifth force and hence gravity and QM never meet directly.

That is what I find weird I would love quantum gravity to be the answer (because it means gravity is a quantum field) and here I am having to complain about you using the term as a place holder because it sort of implies that it is the only answer.

This is the same problem I had with Hawkings paper it assumes quantum gravity (that is gravity is a quantum field) and if any of the above ideas are correct gravity isn't so the paper is complete garbage. So it's a flying pig argument show me a flying pig (AKA gravity is a quantum field) before you start arguing what the flying pig eats (AKA what the event horizon looks like).

I should be happy that Hawking and you both think what I think but I am also a janitor and if something has no real solid validity I issue warnings, even if I believe in it.

Last edited by Orac; 02/04/14 06:38 PM.

I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.
Orac #51107 02/04/14 08:48 PM
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Well, let's look at MOND. Wikipedia says "In physics, Modified Newtonian Dynamics (MoND) is a theory that proposes a modification of Newton's law of gravity to explain the galaxy rotation problem."

I don't see anything there about a universal law, such as we need to fix the disconnect between GR and QM. It is simply a different approach to Newton's law of gravity. It certainly doesn't seem to be trying to replace GR.

Once again there is no theory out there, real or proposed, that can possibly work if it doesn't include both GR and QM. After all, both GR and QM fix problems with Newtonian Dynamics (ND). Neither of them completely replaced ND in areas where ND was good enough. For example classical thermodynamics is quite adequate for a large percentage of engineering needs. QM probably could give better results, but not enough better that engineers are ready to give up the relative simplicity of classical thermodynamics. So whatever theory we wind up with it won't throw GR and QM in the trash heap. They will both wind up being subsets of the theory, which can, at least for the time being, be called Quantum Gravity.

Here we go again. The final theory WILL include both GR and QM in its final form. This is necessary because they have both been tested in great detail. There is NO tenable theory out there which will completely displace one or both of them

So a question. Do you feel that there is a chance that whatever the final theory is it will completely displace GR or QM, or both of them?

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
Bill #51108 02/05/14 01:01 AM
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Originally Posted By: Bill
Well, let's look at MOND. Wikipedia says "In physics, Modified Newtonian Dynamics (MoND) is a theory that proposes a modification of Newton's law of gravity to explain the galaxy rotation problem."


Perhaps keep reading smile

Originally Posted By: http://en.wikipedia.org/wiki/Modified_Newtonian_dynamics
The original purpose of MoND was to explain the galactic rotation curves for spiral galaxies.


It doesn't go into really enough detail but it does the 2011 tests of MOND versus GR

Originally Posted By: http://en.wikipedia.org/wiki/Modified_Newtonian_dynamics

On the other hand, another 2011 study observing the gravity-induced redshift of galactic clusters found results that strongly supported general relativity, but were inconsistent with MoND


Now we can actually get to the answer far faster by asking wikipedia for alternatives to general relativity.

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

Look down near the bottom under the section "Modern theories 1980s to present" and you find your friend MOND and it gives you the history of its adaption to become a fully fledged competitor to GR.

So make no mistake MOND if correct adjusts general relativity so in your words it replaces it.

Originally Posted By: Bill
I don't see anything there about a universal law, such as we need to fix the disconnect between GR and QM. It is simply a different approach to Newton's law of gravity. It certainly doesn't seem to be trying to replace GR.


Is it clear now that GR and MOND are on a collision coarse and it is because MOND alters what gravity is and is an "alternative gravity theory" meaning it is in direct competition to GR.

That MOND wikipedia article is terrible it has all the hallmarks of an article written by scientists who don't really like it smile

Originally Posted By: Bill
Here we go again. The final theory WILL include both GR and QM in its final form. This is necessary because they have both been tested in great detail. There is NO tenable theory out there which will completely displace one or both of them


MOND replaces GR as per above it is in a list of alternatives to general relativity so that statement isn't holding up. I worry about the QM side as well but pick that up in a bit.

Originally Posted By: Bill
So a question. Do you feel that there is a chance that whatever the final theory is it will completely displace GR or QM, or both of them?


In GR we haven't isolated what specifically gravity is caused by so there is always that option. You start adding in fifth forces and gravity is just a composite effect between two forces like the electroweak interaction and things get interesting but at this point in time we still view such things as unlikely. However the problem of Dark Matter weighs heavily and until that mystery is fixed I think things remain fragile and theories like MOND will get breathing space.

At the moment QM has no alternative theory you won't even find it as an entry in wikipedia but it has a big problem like gravity that no real identifiable cause has been found and as we freeze out string theory it becomes a real issue. As many in QM would say it is back to the drawing board for cause.

This leaves us in a strange position that we have two strong mathematical theories but no underlying causes and so there definitely is a chance both theories will not remain in there current form and be completely displaced.

I like most would prefer that our current theories stay as they are and we just fill in gaps but often nature doesn't play along with what we want so I am wary and vigilant and I don't dismiss the possibility both will end up like Newtons gravity laws are viewed these days.

Last edited by Orac; 02/05/14 01:25 AM.

I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.
Orac #51117 02/05/14 03:27 PM
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Ok Orac, I give up. Now we need to get the word out to the scientific community that they need to stop researching both GR and QM because they are deeply flawed and will have to be replaced from the ground up. Thank you for finally getting through to me.

Oh, and we also need to let the scientific community know that Orac has all the answers.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
Bill #51125 02/06/14 12:47 AM
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Originally Posted By: Bill
Ok Orac, I give up. Now we need to get the word out to the scientific community that they need to stop researching both GR and QM because they are deeply flawed and will have to be replaced from the ground up. Thank you for finally getting through to me.

Oh, and we also need to let the scientific community know that Orac has all the answers.

Bill Gill


Your comments are so stupid and ridiculous

You want to infer GR and QM are DEFINITELY going to be in some final theory of everything that is the point of why we keep testing because we aren't sure. Oh no scientists wouldn't have jobs if we did that so I guess we just keep doing it to stay employed according to you.

If you want to use words such as "likely to be in" I wouldn't have a n issue but use the word DEFINITELY hell lets stop testing GR and QM now they are "in" lets stop wasting money. Are there any other things that are "in" and we can stop testing and wasting money ... how about evolution theory?

Tell you what why don't you tell us the full list of "in" and we can adjust our science.

I tell you what you go and find me a scientist that agrees with statement and I will bother to answer this BS perhaps you need to go and look at the definition of science again.

This BS discussion is definitely terminated we have just gone into Bill Land which looks all the same as Newton land.

THE END ... DISCUSSION TERMINATED ITS GONE TO LALA LAND.

Last edited by Orac; 02/06/14 01:05 AM.

I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.
Orac #51133 02/06/14 05:20 AM
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Sorry Orac, I got in there first by giving up.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
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