Who understands the matrix equation Ax=b?

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Offline jeffreyH

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Who understands the matrix equation Ax=b?
« on: 16/01/2016 16:58:48 »
To some this may sound like a trivial question. Others won't know what I am talking about. This is the crux of a problem with physics forums. If you don't know the answer and simply come to a forum such as this to have questions answered then I can see no problem with that. That is a learning exercise. If you don't know the answer and you are trying to postulate a new 'theory' to revolutionize physics then you have real problems with your understanding of the subject. You could always google it of course but you may miss the subtleties.

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Offline Bored chemist

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Re: Who understands the matrix equation Ax=b?
« Reply #1 on: 16/01/2016 17:32:21 »
It's not just a problem on science fora.
If you are not clear people don't understand you and it doesn't matter if it's science or flower arranging.
You have to put the effort into framing a sensible question.
Please disregard all previous signatures.

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #2 on: 16/01/2016 17:37:35 »
That's a very good point.

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #3 on: 17/01/2016 01:11:23 »
Just to add more to the mix we can rearrange the equation as x=A-1b. How does this relate to the reduced row echelon form and the identity matrix?

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Offline Colin2B

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Re: Who understands the matrix equation Ax=b?
« Reply #4 on: 17/01/2016 09:31:06 »
Just to add more to the mix we can rearrange the equation as x=A-1b. How does this relate to the reduced row echelon form and the identity matrix?
I assume you are not one of those seeking answers, but know the answer, but like me get irritated with certain people who think they know physics and maths and so make silly challenges to physics eg relativity without really understanding that theory.
I shall mention no names!

To be honest I'm no longer irritated as I realise they do not wish to learn, just to see their words.
and the misguided shall lead the gullible,
the feebleminded have inherited the earth.

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Offline evan_au

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Re: Who understands the matrix equation Ax=b?
« Reply #5 on: 17/01/2016 09:58:49 »
This could be read as a rhetorical question:
Quote from: jeffreyH
Who understands the matrix equation Ax=b?

But this addendum makes it sound like a request for a simple explanation of matrix arithmetic:
Quote
Just to add more to the mix we can rearrange the equation as x=A-1b. How does this relate to the reduced row echelon form and the identity matrix?

So if you are looking for a simple explanation of solving matrix equations, this site explains most things quite well:
https://www.khanacademy.org/math/precalculus/precalc-matrices/solving-equations-with-inverse-matrices/v/matrix-equations-systems

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #6 on: 17/01/2016 13:37:13 »
Thanks Evan that is very likely a good place to start. Since I don't need to read it I take it on trust.

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Offline dhjdhj

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Re: Who understands the matrix equation Ax=b?
« Reply #7 on: 17/01/2016 15:10:44 »
I am trying to fathom why you asked a question to which you obviously know the answer. The manipulation of matrix equations is obviously critical to the understanding of the mathematics of advanced physics, but so is advanced calculus and three dimensional geometry. Now some of us non physicists in trying to understand the status quo get lost in the maths either through lack of knowledge or in my case lack of practise. Its many years since I was required to do it. Some of us have ideas that seem to us OK, but we need you to tell us why they are not. Some of us have tried to study the basics as much as possible (in my case even buying expensive text books), but much of it is statement of fact, rather than how that fact was established. So theories ( or more correctly hunches) inevitably follow.
They are of course wrong, but why? It really comes down to what you see is the purpose of the forum. If it for professionals to exchange ideas. Then so be it, there is no point in me or other 'crackpots' contributing. If it is to promote alternatives, there is no point in professionals contributing. I believe it is neither of the above and that it should be an opportunity for interchange between both groups. It is easier to get a date with David Cameron than find a physicist to discuss any ideas you may have. I find the concept of needing to pass the matrix exam before you can discuss physics in a meaningful way a little bit upsetting and may actually prevent future questions through fear of embarrassment. Do you think we should only ask questions of a controversial nature to which we know the answer?

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #8 on: 17/01/2016 15:28:07 »
To some this may sound like a trivial question. Others won't know what I am talking about. This is the crux of a problem with physics forums. If you don't know the answer and simply come to a forum such as this to have questions answered then I can see no problem with that. That is a learning exercise. If you don't know the answer and you are trying to postulate a new 'theory' to revolutionize physics then you have real problems with your understanding of the subject. You could always google it of course but you may miss the subtleties.

I searched for this, I have no idea of what it means or what it is trying to explain, I have never learnt this so can not make any sort of assumptions,

it says that A = 3*3 xyz. I have no idea what that suppose to mean to start with, to me it means nothing, you cant have 3*3 xyz


p.s and not knowing this is not relative to any idea.


science keeps doing this , and never listens, that is the problem. Science is not the ''gods'' of thought, ''we'' can think just as well .




« Last Edit: 17/01/2016 15:31:35 by Thebox »

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #9 on: 17/01/2016 15:40:31 »
I am trying to fathom why you asked a question to which you obviously know the answer. The manipulation of matrix equations is obviously critical to the understanding of the mathematics of advanced physics, but so is advanced calculus and three dimensional geometry. Now some of us non physicists in trying to understand the status quo get lost in the maths either through lack of knowledge or in my case lack of practise. Its many years since I was required to do it. Some of us have ideas that seem to us OK, but we need you to tell us why they are not. Some of us have tried to study the basics as much as possible (in my case even buying expensive text books), but much of it is statement of fact, rather than how that fact was established. So theories ( or more correctly hunches) inevitably follow.
They are of course wrong, but why? It really comes down to what you see is the purpose of the forum. If it for professionals to exchange ideas. Then so be it, there is no point in me or other 'crackpots' contributing. If it is to promote alternatives, there is no point in professionals contributing. I believe it is neither of the above and that it should be an opportunity for interchange between both groups. It is easier to get a date with David Cameron than find a physicist to discuss any ideas you may have. I find the concept of needing to pass the matrix exam before you can discuss physics in a meaningful way a little bit upsetting and may actually prevent future questions through fear of embarrassment. Do you think we should only ask questions of a controversial nature to which we know the answer?

You have 1. Formulated some ideas. 2. Investigated the mathematical tools. 3. Looked at how those ideas may fit with established observations or theories. 4. Come to a physics forum to have your ideas scrutinized and criticized by your peers. 5. Appear willing to accept criticism in order to help improve your ideas.

Why do you think that my comments are in any way aimed at you?

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #10 on: 17/01/2016 15:45:46 »
To some this may sound like a trivial question. Others won't know what I am talking about. This is the crux of a problem with physics forums. If you don't know the answer and simply come to a forum such as this to have questions answered then I can see no problem with that. That is a learning exercise. If you don't know the answer and you are trying to postulate a new 'theory' to revolutionize physics then you have real problems with your understanding of the subject. You could always google it of course but you may miss the subtleties.

I searched for this, I have no idea of what it means or what it is trying to explain, I have never learnt this so can not make any sort of assumptions,

it says that A = 3*3 xyz. I have no idea what that suppose to mean to start with, to me it means nothing, you cant have 3*3 xyz


p.s and not knowing this is not relative to any idea.


science keeps doing this , and never listens, that is the problem. Science is not the ''gods'' of thought, ''we'' can think just as well .

Physics is a fascinating subject. As things become clearer it also becomes apparent just how little we actually know. Does that give us a licence to indulge in wild and uninformed speculation? You may say yes. Well if that had always been the case then we would still be living in a fifteenth century society.

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #11 on: 17/01/2016 16:04:26 »


Physics is a fascinating subject. As things become clearer it also becomes apparent just how little we actually know. Does that give us a licence to indulge in wild and uninformed speculation? You may say yes. Well if that had always been the case then we would still be living in a fifteenth century society.


It depends how you define wild and uninformed, science presumes some ideas are wild,but the opp knows very well what they are on about.

In this thread , I have read from looking 3*3 xyz , this sounds multi-dimensional , when n-dimensional explains .

added - what Matrix are you referring to?

 I don't know if this helps you Jeffrey but I have done you a diagram.

[attachment=20793]

[attachment=20795]








« Last Edit: 17/01/2016 16:22:11 by Thebox »

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #12 on: 17/01/2016 16:20:03 »
The A in the equation is an m by n matrix with m rows and n columns. The x is a vector with n rows and 1 column.The resulting b is also a vector with m rows and 1 column. This means that the two vectors x and b may not be of the same dimension. They will be if matrix A is a square matrix so that m = n but not if this matrix is rectangular so that m <> n. Nowhere does it state that the matrix A has to be 3 rows by 3 columns.

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #13 on: 17/01/2016 16:27:11 »
The A in the equation is an m by n matrix with m rows and n columns. The x is a vector with n rows and 1 column.The resulting b is also a vector with m rows and 1 column. This means that the two vectors x and b may not be of the same dimension. They will be if matrix A is a square matrix so that m = n but not if this matrix is rectangular so that m <> n. Nowhere does it state that the matrix A has to be 3 rows by 3 columns.


arrr, ok, I now understand, yes I now understand it is easy, similar to my poker idea. You have a 3 dimension cube matrix, XYZ, at each point in the matrix there is a variable, does this sound about right for the Matrix you are talking about?


So A is area and X is a piece of paper stacked on a piece of paper and so on?
« Last Edit: 17/01/2016 16:37:04 by Thebox »

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Offline dhjdhj

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Re: Who understands the matrix equation Ax=b?
« Reply #14 on: 17/01/2016 16:36:51 »
Thank you Jeffrey. I didn't actually think it was directed at me specifically but I was trying to explain how difficult it is to find any other means to bounce ideas other than these fora. So if I ask more dumb questions that's OK then? However like you I do get irritated when perfectly Ok answers are ignored for some ones own ill thought out dogma.

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #15 on: 17/01/2016 16:38:43 »
Thank you Jeffrey. I didn't actually think it was directed at me specifically but I was trying to explain how difficult it is to find any other means to bounce ideas other than these fora. So if I ask more dumb questions that's OK then? However like you I do get irritated when perfectly Ok answers are ignored for some ones own ill thought out dogma.

I have tried your approach, trying to stand out doe's not work.   Just keep plugging at the ideas and hope someone who has influence takes a shine for your ideas. Thatis all you could hope for, perhaps a co-write.

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #16 on: 17/01/2016 16:40:43 »
Thank you Jeffrey. I didn't actually think it was directed at me specifically but I was trying to explain how difficult it is to find any other means to bounce ideas other than these fora. So if I ask more dumb questions that's OK then? However like you I do get irritated when perfectly Ok answers are ignored for some ones own ill thought out dogma.

I'm glad we sorted that out then.

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #17 on: 17/01/2016 16:42:20 »
Thank you Jeffrey. I didn't actually think it was directed at me specifically but I was trying to explain how difficult it is to find any other means to bounce ideas other than these fora. So if I ask more dumb questions that's OK then? However like you I do get irritated when perfectly Ok answers are ignored for some ones own ill thought out dogma.

I'm glad we sorted that out then.

No comment, I know what science thinks of me, that is why I put in little effort, nobody ever really listens, so why should I care , I know deep down I am wasting my time.

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Offline timey

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Re: Who understands the matrix equation Ax=b?
« Reply #18 on: 17/01/2016 16:44:05 »
Is advanced physics based on observation, or is it based on mathematics?

What if there is another, better means to equating the matrix equation, or the concepts a matrix equation describes?

Why would one need to understand the matrix equation to understand relativity?  There are umpteen books that make full description without reference to maths.  Combining the facts with observation and employing ones imagination, a visual representation is apparent.  Some people are better at this than others... some may need the mathematical representation because they are not good at visual representation.

What would have happened if the person who started looking at round things with a different perspective had not done so?  Would we still be a society without the wheel?
I'm pretty damn certain that the wheel was not mathematically derived!

There are many ways to skin a cat... the best mathematical procedure for doing so is arbitrary.  Mathematics are not concepts and are only as good as the concepts they are attached to.  It is visionary people who come up with concepts, and mathematics is purely the tool with which one concept can be checked against another.

Do you think there is a mathematical formula for the physical act of looking so far down ones own nose that one can't see beyond one's own face?  I'm quite sure there must be a 'constant' in there somewhere!

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #19 on: 17/01/2016 16:52:47 »
The A in the equation is an m by n matrix with m rows and n columns. The x is a vector with n rows and 1 column.The resulting b is also a vector with m rows and 1 column. This means that the two vectors x and b may not be of the same dimension. They will be if matrix A is a square matrix so that m = n but not if this matrix is rectangular so that m <> n. Nowhere does it state that the matrix A has to be 3 rows by 3 columns.


arrr, ok, I now understand, yes I now understand it is easy, similar to my poker idea. You have a 3 dimension cube matrix, XYZ, at each point in the matrix there is a variable, does this sound about right for the Matrix you are talking about?


So A is area and X is a piece of paper stacked on a piece of paper and so on?

OK. Say we have 3 equations

2x + y - 4z = 3
4x + 5y - z = -6
       3y - 3z = 50

What values for x, y and z solve these equations?

Matrix A hold the coefficients (the multipliers of x, y and z)

2    1   -4
4    5   -1
0    3    3

b is the column vector containing the results.

3
-6
50+

the vector x is then
x
y
z

I leave it to the reader to pursue the operations necessary for a solution. (There may of course be no solution).

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #20 on: 17/01/2016 17:01:11 »
If all you have is a hammer everything looks like a nail. If all you have is the description of a hammer how do you even know what a nail is?

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #21 on: 17/01/2016 17:03:56 »




OK. Say we have 3 equations

2x + y - 4z = 3
4x + 5y - z = -6
       3y - 3z = 50


Hmm,


you are saying 2 * vector(x) +y-(4*z)=3?

what happened to A?

Sorry you threw me off track, I am not even sure I am picturing the matrix correctly you did not answer.

A is area X is a vector? 

2*X = 2?

is Y 5?








« Last Edit: 17/01/2016 17:08:59 by Thebox »

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Offline dhjdhj

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Re: Who understands the matrix equation Ax=b?
« Reply #22 on: 17/01/2016 17:12:59 »
I think there may more of a grain of truth in Timey's post . Mathematics may have become the primary partner in the marriage with concept. Dirac took the view that structure didn't matter as long as the maths was correct. I can't reconcile myself to that view. Even the fact that Heisenberg and Schrodinger ended up with compatible maths from different concepts gives me pause for thought. From what I have read there have been notable physicists who were not good at maths. Faraday for a start. Of course if the maths is wrong, the idea cant be right ,but if the maths is right it does not necessarily mean the idea is right. I take it Jeffrey you want some one specific to solve your problem.

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Offline timey

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Re: Who understands the matrix equation Ax=b?
« Reply #23 on: 17/01/2016 17:16:43 »
If all you have is a hammer everything looks like a nail. If all you have is the description of a hammer how do you even know what a nail is?

A hammer is a tool, and so is a nail.  Play with your tools all you like, they are fun I must admit, but if you are to use your tools to build a representation of the universe, it is necessary to refer back to reality.

The reality is that the tools haven't quite been able to fully represent the reality, so why are you blowing a trumpet over the tools?

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #24 on: 17/01/2016 17:17:32 »
I think there may more of a grain of truth in Timey's post . Mathematics may have become the primary partner in the marriage with concept. Dirac took the view that structure didn't matter as long as the maths was correct. I can't reconcile myself to that view. Even the fact that Heisenberg and Schrodinger ended up with compatible maths from different concepts gives me pause for thought. From what I have read there have been notable physicists who were not good at maths. Faraday for a start. Of course if the maths is wrong, the idea cant be right ,but if the maths is right it does not necessarily mean the idea is right. I take it Jeffrey you want some one specific to solve your problem.


Jeffrey already knows the answer, I think he is trying to educate us a bit, why not try to solve the answer, I could do it in ''time'' by simply trial and error, going through all the numbers until I find the value of z and x that fits the answer.

Quite easy but time consuming, I don't know the answer but I could work it out with ''time'' .



2x + y - 4z = 3
4x + 5y - z = -6
       3y - 3z = 50


first answer 3, so we can try 2*x+Y-(4*z)=3        we can try x at 1, and we can try z at 1 and Y at 5 to give 3 as the answer

4x + 5y - z = -6  we can try the values, we conclude they dont fit, so we know our answer to the first one is wrong,


and so until we get the answer





« Last Edit: 17/01/2016 17:23:30 by Thebox »

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #25 on: 17/01/2016 17:19:14 »


A hammer is a tool, and so is a nail.  Play with your tools all you like, they are fun I must admit, but if you are to use your tools to build a representation of the universe, it is necessary to refer back to reality.

The reality is that the tools haven't quite been able to fully represent the reality, so why are you blowing a trumpet over the tools?

Some tools work very well, yet some nails have no hammers. The tools are only as good as the user.

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Offline dhjdhj

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Re: Who understands the matrix equation Ax=b?
« Reply #26 on: 17/01/2016 17:22:03 »
I think you have made your point Jeffrey

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #27 on: 17/01/2016 17:30:31 »
I think there may more of a grain of truth in Timey's post . Mathematics may have become the primary partner in the marriage with concept. Dirac took the view that structure didn't matter as long as the maths was correct. I can't reconcile myself to that view. Even the fact that Heisenberg and Schrodinger ended up with compatible maths from different concepts gives me pause for thought. From what I have read there have been notable physicists who were not good at maths. Faraday for a start. Of course if the maths is wrong, the idea cant be right ,but if the maths is right it does not necessarily mean the idea is right. I take it Jeffrey you want some one specific to solve your problem.

You are missing the point entirely. If you are fixing trucks you need particular tools. You could try just using any old thing. You could try a chainsaw to get the wheels off, or the exhaust etc etc. However it is required to use the tools of the trade. The problem with the mathematics of physics is not that it is fuzzy and bodged together but that the language used and the terms involved are understood by an exclusive set of individuals. However the same is true of the parts on a vehicle. Unusual names should not be a reason to rubbish the tools of the trade. It just means a shallow learning curve. (yes that does mean difficult unlike the misused steep learning curve.) That is no reason to avoid the learning process altogether.

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #28 on: 17/01/2016 17:30:41 »
I think you have made your point Jeffrey

Understanding the equation is relative to what you learnt, understanding any sort of matrix is a matter of thought, I don't think there is a point .


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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #29 on: 17/01/2016 17:32:56 »


You are missing the point entirely. If you are fixing trucks you need particular tools. You could try just using any old thing. You could try a chainsaw to get the wheels off, or the exhaust etc etc. However it is required to use the tools of the trade. The problem with the mathematics of physics is not that it is fuzzy and bodged together but that the language used and the terms involved are understood by an exclusive set of individuals. However the same is true of the parts on a vehicle. Unusual names should not be a reason to rubbish the tools of the trade. It just means a shallow learning curve. (yes that does mean difficult unlike the misused steep learning curve.) That is no reason to avoid the learning process altogether.

It is also not wise to ignore possible new tools. Maybe your tools are old and rusty and some new tools are just better ?


An object on Earth in a inertial reference frame the Fn=0


this tool is rusty, the Fn= a  where (a) is the force of acceleration.

proof your tools can be broke.
« Last Edit: 17/01/2016 17:35:26 by Thebox »

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Offline timey

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Re: Who understands the matrix equation Ax=b?
« Reply #30 on: 17/01/2016 18:25:23 »
Yes, mathematics 'is' a vital tool in physics, and in the understanding of physics.  But, it is not by any means the only route to understanding physics, or making a contribution to physics...  I believe it was evan-au who recently stated to me that Einstein himself had to rely on colleagues with greater mathematical skills than he to describe the concepts he'd come up with.

It sounds as if you are saying that if you do not understand the maths for general relativity then you cannot understand physics...  I've been speaking to physicists of considerable note for quite some amount of time now, and not one has been able to give me a blow by blow account of how the GR field equations are put together, usually completely ignoring me subsequently.  The most honest account of abilities I've come across is "I'm a bit rusty"... and little wonder when Leonard Susskind himself states in his GR lecture, concerning the field equations, that he's not going to give an example of the equations in use, and anyone wishing to use them should refer to a computer program!

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #31 on: 17/01/2016 19:05:50 »
The solution to the problem is

x = -13.145
y =  7.495
z = -9.205

Go here http://www.bluebit.gr/matrix-calculator/

Type the following with spaces into the matrix text area and click matrix inverse and then calculate

2    1   -4
4    5   -1
0    3    3

You should then get a new matrix with the values:

-0.750  0.625 -0.792
 0.500 -0.250  0.583
-0.500  0.250 -0.250

Copy this then click on back to online matrix calculator and then click the link matrix multiplication.

Copy the results matrix into the matrix a box then type the following into the matrix b box

3
-6
50

Then click multiply A*B. You will then get the solution for x, y and z.

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Offline dhjdhj

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Re: Who understands the matrix equation Ax=b?
« Reply #32 on: 17/01/2016 19:13:58 »
You are missing the point entirely. If you are fixing trucks you need particular tools. You could try just using any old thing. 

I don't think I am. I absolutely agree that you need the tools and the skills to use them and maths is a tool to help understand physics, but to use your analogy if you fixing trucks the tools are determined by the job, you don't change the job to suit the tools. In my own experience as a young engineer I was required to plan the design and construction of complex projects with multiple resources and numerous uncertainties. We used many of the same mathematical tools that Physicists use, as well as creating some of our own, but the whole purpose was to get the job done our only output was progress. I don't people find the maths is so much of a barrier as the language of physics. You may have noticed I deliberately avoid this language where ever possible because it has to so precise and even physicists writing popular science books can get it wrong. My point is that maths is vital to understanding existing theories and vital to confirming new ones but surely it can not be a substitute for thought as to what is actually happening. 

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #33 on: 17/01/2016 19:21:08 »
Physics is a creative process. But you have to be able to take the idea that has been created and test it rigorously. I have nothing against creativity in physics but please don't expect others to finish off the job. If you can't take your own idea further then that is your problem. Why should anyone give up their time and take it away from time with family or friends on a whim? Criticism is one thing but investment of time is another.

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #34 on: 17/01/2016 19:39:59 »
Physics is a creative process. But you have to be able to take the idea that has been created and test it rigorously. I have nothing against creativity in physics but please don't expect others to finish off the job. If you can't take your own idea further then that is your problem. Why should anyone give up their time and take it away from time with family or friends on a whim? Criticism is one thing but investment of time is another.

The problem I see is that science thinks every idea needs maths and that every idea can be explained in extent. You say why should anyone give their time to help an idea which the goal  is to get it publicised and recognised .  I ask why should we give our time and even contribute to a science forum if the only aim of science is to snub us and not help us?
It saves time if we work together with ideas.   Maxwell helped Faraday yet modern day is selfish, the sort of question you ask is a selfish question, why should you give the time really means , what is in it for us.

We clearly can see that some ideas are just plain stupid, but we can also see the ideas that do have premise for argument.  These ideas with the help of a science type and the crackpot could develop into something that little bit special.




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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #35 on: 17/01/2016 19:49:56 »
The solution to the problem is

x = -13.145
y =  7.495
z = -9.205

Go here http://www.bluebit.gr/matrix-calculator/

Type the following with spaces into the matrix text area and click matrix inverse and then calculate

2    1   -4
4    5   -1
0    3    3

You should then get a new matrix with the values:

-0.750  0.625 -0.792
 0.500 -0.250  0.583
-0.500  0.250 -0.250

Copy this then click on back to online matrix calculator and then click the link matrix multiplication.

Copy the results matrix into the matrix a box then type the following into the matrix b box

3
-6
50

Then click multiply A*B. You will then get the solution for x, y and z.

Using a calculator is cheating and I still have no idea of what it is trying to show or represent?

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Offline timey

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Re: Who understands the matrix equation Ax=b?
« Reply #36 on: 17/01/2016 19:59:29 »
Physics is a creative process. But you have to be able to take the idea that has been created and test it rigorously. I have nothing against creativity in physics but please don't expect others to finish off the job. If you can't take your own idea further then that is your problem. Why should anyone give up their time and take it away from time with family or friends on a whim? Criticism is one thing but investment of time is another.

You are aware that there are massive prizes for break through's in all areas of science and mathematics?  The break through prize alone is 3 mill, this being each for physics, maths and other areas in science.  Depends how interesting you think another's ideas are I'd expect...

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #37 on: 17/01/2016 20:01:22 »
I could go through it step by step but I won't. Google row echelon form and do a bit of reading. You might actually learn something.

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Offline timey

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Re: Who understands the matrix equation Ax=b?
« Reply #38 on: 17/01/2016 20:16:46 »
Why would I look up and learn how to manipulate a series of mathematics that I have had explained to me by Leonard Suskind via his lectures, that I recall reading that you have watched, or are watching yourself, and that I have come to the conclusion are faulty, as did their creator Einstien.

Defies logic really.

Furthermore, I'll bet that you cannot in fact give me an example of the GR field equations in use without recourse to a maths program, or another persons work.

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #39 on: 17/01/2016 20:24:24 »
I could go through it step by step but I won't. Google row echelon form and do a bit of reading. You might actually learn something.

I looked it up and I am still no wiser to what it suppose to represent apart from grid reference frames.


000
000
000

we could cube that giving a cube of zero value, i.e ''empty space''


Is what you are on about something to do with computer programming?  otherwise I am at a loss to the relevance of this.


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Offline dhjdhj

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Re: Who understands the matrix equation Ax=b?
« Reply #40 on: 17/01/2016 20:28:26 »
Jeffrey I think you are referring to my idea/hypothesis/hunch and you are right I am a bit stuck, and I would like some help, but only IF the idea is worth pursuing. Now unlike timey I have no paranoia, I am a retiree with a good life style. I don't need any fame or fortune. What I do need is someone to tell me what's wrong so I can either work round it or move on. Now if you are saying that what I have proposed contains no obvious violations of basic physics, but needs mathematical validation either positive or negative then that's a whole new ball game. Mathematicians I can find. Physicists are like hen's teeth, good ones even rarer.

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #41 on: 17/01/2016 20:39:24 »
Jeffrey I think you are referring to my idea/hypothesis/hunch and you are right I am a bit stuck, and I would like some help, but only IF the idea is worth pursuing. Now unlike timey I have no paranoia, I am a retiree with a good life style. I don't need any fame or fortune. What I do need is someone to tell me what's wrong so I can either work round it or move on. Now if you are saying that what I have proposed contains no obvious violations of basic physics, but needs mathematical validation either positive or negative then that's a whole new ball game. Mathematicians I can find. Physicists are like hen's teeth, good ones even rarer.

which idea dh? 

this one

''concept of time is that time makes things exist.''


time does not exist,

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Offline dhjdhj

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Re: Who understands the matrix equation Ax=b?
« Reply #42 on: 17/01/2016 20:45:11 »
Well then there you go. Julian Barbour agrees with you, but not many others

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Offline Thebox

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Re: Who understands the matrix equation Ax=b?
« Reply #43 on: 17/01/2016 20:48:03 »
Well then there you go. Julian Barbour agrees with you, but not many others

I do not care about Julian Barbour , I do not care about prizes, I care that science gets it right, I  have proved time does not exist , do you not read other threads?



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Offline timey

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Re: Who understands the matrix equation Ax=b?
« Reply #44 on: 17/01/2016 20:51:26 »
Jeffrey I think you are referring to my idea/hypothesis/hunch and you are right I am a bit stuck, and I would like some help, but only IF the idea is worth pursuing. Now unlike timey I have no paranoia, I am a retiree with a good life style. I don't need any fame or fortune. What I do need is someone to tell me what's wrong so I can either work round it or move on. Now if you are saying that what I have proposed contains no obvious violations of basic physics, but needs mathematical validation either positive or negative then that's a whole new ball game. Mathematicians I can find. Physicists are like hen's teeth, good ones even rarer.

Why would you say I am paranoid?  Jeff and I have a history, I think you may be missing the subtleties.  Jeff btw is a self professed non physicist who 'is' pretty nifty with the maths, at least.

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Offline dhjdhj

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Re: Who understands the matrix equation Ax=b?
« Reply #45 on: 17/01/2016 21:12:23 »
It was your reference to money and people stealing ideas. If I got the wrong end of the stick I apologise.

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #46 on: 17/01/2016 21:42:57 »
Jeffrey I think you are referring to my idea/hypothesis/hunch and you are right I am a bit stuck, and I would like some help, but only IF the idea is worth pursuing. Now unlike timey I have no paranoia, I am a retiree with a good life style. I don't need any fame or fortune. What I do need is someone to tell me what's wrong so I can either work round it or move on. Now if you are saying that what I have proposed contains no obvious violations of basic physics, but needs mathematical validation either positive or negative then that's a whole new ball game. Mathematicians I can find. Physicists are like hen's teeth, good ones even rarer.

How much particle physics have you learned? Also do you know quantum mechanics?

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Offline jeffreyH

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Re: Who understands the matrix equation Ax=b?
« Reply #47 on: 17/01/2016 21:55:03 »
The solution to the problem is

x = -13.145
y =  7.495
z = -9.205

Go here http://www.bluebit.gr/matrix-calculator/

Type the following with spaces into the matrix text area and click matrix inverse and then calculate

2    1   -4
4    5   -1
0    3    3

You should then get a new matrix with the values:

-0.750  0.625 -0.792
 0.500 -0.250  0.583
-0.500  0.250 -0.250

Copy this then click on back to online matrix calculator and then click the link matrix multiplication.

Copy the results matrix into the matrix a box then type the following into the matrix b box

3
-6
50

Then click multiply A*B. You will then get the solution for x, y and z.

Using a calculator is cheating and I still have no idea of what it is trying to show or represent?

We started out with 3 equations

2x + y - 4z = 3
4x + 5y - z = -6
       3y - 3z = 50

The solution is the values for x, y and z that solved ALL 3 equations.

Using the calculator was a way to show, via an online tool, what the correct answer was.

The answer came out as:

x = -13.145
y =  7.495
z = -9.205

So the equations now become

2 * -13.145 + 7.495 - 4 * -9.205 = 3
4 * -13.145 + 5 * 7.495 - -9.205 = -6
       3 * 7.495 - 3 * -9.205 = 50

I don't know how much more straightforward I can make it.

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Offline dhjdhj

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Re: Who understands the matrix equation Ax=b?
« Reply #48 on: 17/01/2016 21:58:34 »
The answer to both questions is enough to get into trouble but not enough to get out. I certainly understand the basic posits and incidentally most of the disagreements. That's why I need a physicist.

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Offline timey

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Re: Who understands the matrix equation Ax=b?
« Reply #49 on: 17/01/2016 22:01:24 »
It was your reference to money and people stealing ideas. If I got the wrong end of the stick I apologise.

Ah, I see.  Yes, wrong end of stick.  Jeff was asking why a mathematician would bother to take time out from family and life to equate another's ideas.  I was saying because the prize money for both maths and physics is a worthy cause, and it would depend on how interesting the mathematician thought the other persons ideas are, as to wether doing so could be considered worthwhile.