1 JanPB  SRT critique  Wednesday 25 March 2020 
2 JanPB  Re :SRT critique  Wednesday 25 March 2020 
3 JanPB  Re :SRT critique  Wednesday 25 March 2020 
4 JanPB  Re :SRT critique  Thursday 26 March 2020 
5 tjrob137  Re :SRT critique  Friday 27 March 2020 
6 tjrob137  Re :SRT critique  Friday 27 March 2020 
7 JanPB  Re :SRT critique  Friday 27 March 2020 
8 Ned Latham  Re :SRT critique  Friday 27 March 2020 
9 V�n� Biganska  Re :SRT critique  Friday 27 March 2020 
10 V�n� Biganska  Re :SRT critique  Friday 27 March 2020 
11 beda pietanza  Re :SRT critique  Friday 27 March 2020 
12 JanPB  Re :SRT critique  Saturday 28 March 2020 
13 Thomas Heger  Re :SRT critique  Saturday 28 March 2020 
14 tjrob137  Re :SRT critique  Sunday 29 March 2020 
15 RichD  Re :SRT critique  Monday 30 March 2020 
16 Dr. Wheat Faartz  Re :SRT critique  Monday 30 March 2020 
17 Nicolaas Vroom  Re :SRT critique  Monday 30 March 2020 
18 Thomas Heger  Re :SRT critique  Monday 30 March 2020 
19 JanPB  Re :SRT critique  Monday 30 March 2020 
20 maluw...@gmail.com  Re :SRT critique  Tuesday 31 March 2020 
21 Nicolaas Vroom  Re :SRT critique  Tuesday 31 March 2020 
22 Nicolaas Vroom  Re :SRT critique  Tuesday 31 March 2020 
23 maluw...@gmail.com  Re :SRT critique  Tuesday 31 March 2020 
24 maluw...@gmail.com  Re :SRT critique  Tuesday 31 March 2020 
25 Nicolaas Vroom  Re :SRT critique  Tuesday 31 March 2020 
26 Engr. Ravi  Re :SRT critique  Tuesday 31 March 2020 
27 JanPB  Re :SRT critique  Tuesday 31 March 2020 
28 JanPB  Re :SRT critique  Tuesday 31 March 2020 
29 JanPB  Re :SRT critique  Tuesday 31 March 2020 
30 maluw...@gmail.com  Re :SRT critique  Wednesday 1 April 2020 
31 Ned Latham  Re :SRT critique  Wednesday 1 April 2020 
32 maluw...@gmail.com  Re :SRT critique  Wednesday 1 April 2020 
33 Nicolaas Vroom  Re :SRT critique  Wednesday 1 April 2020 
34 Nicolaas Vroom  Re :SRT critique  Tuesday 5 May 2020 
35 Nicolaas Vroom  Re :SRT critique  Tuesday 5 May 2020 
SRT critique
66 posts by 17 authors
https://groups.google.com/forum/?fromgroups#!topic/sci.physics.relativity/jMht0Qxed6c
keywords = SR
> 
Hi Ng
this is a reply to Tom Roberts on the subject of my critique of SRT. The discussion started in thread about LIGO, but I wanted my text (which I have written last night and which follows now) to be found more easily than in the 'backyard' of an old thread about LIGO. This text is actually the rewritten version from what I have written earlier in German and covers now only a certain part (first part of �3) of 'On the Electrodynamics of Moving Bodies' by A. Einstein from 1905, translated into English in this version in 1923: https://www.fourmilab.ch/etexts/einstein/specrel/specrel.pdf  � 3. Theory of the Transformation of Coordinates and Times from a Stationary System to another System in Uniform Motion of Translation Relatively to the Former Thomas Heger 
You should learn physics first. Right now you are wasting your time.
 Jan
>  JanPB wrote: 
> >> 
The equation �[t(0, 0, 0, t) + t(0, 0, 0, t +x�/(c � v)+x�/(c + v)]=t(x�, 0, 0, t
+x�/(c � v)) is in my opinion wrong, since tau is a
linear function, that has four vectors as arguments.
�Linear function� allows to multiply the argument with a constant
factor. So we could multiply the factor � inside the function. Then we
could multiply � to all of the components of the vector.
This would make all of the first three components zero. Another rule
for linear functions is f(a) + f(b) = f(a+b).
So the right side of the equation could not have any nonzero value in
the first position of the vector. 
> > 
You should learn physics first. Right now you are wasting your time. 
> 
seemingly you just wasted yours. Quote less if have nothing to add or subtract. 
My point was basically that one cannot reasonably add anything to a discussion with someone whose entire argument consists of nonsequiturs (FAPP).
 Jan
>  Am 25.03.2020 um 15:43 schrieb Paparios: .. 
> >  Not a single one of the hundreds of thousands physicists that have read and studied SR and GR, have had any problem in reading and understanding Einstein's papers. Thousands published scientific books are being used to learn and teach relativity and all of them just reprint most of the equations Einstein introduced in his 1905 paper. 
> 
Wrong.
For instance there are several regulars in this forum, who have criticized SRT for several reasons. There were also others, like  for instance Herbert Dingle, who wrote a massive book, which criticized SRT ('Science at the crossroads'). So, there is and was critique. I personally didn't like SRT and simply ignored it. But from time to time people (like you for instance or several others) annoyed me and so I made the decision to actually read it. 
The intellectual trap you've fallen into has been discussed here many times over the, literally, decades (this forum exists since ca. 1995).
Here is what makes this trap so characteristic and insidious: SR happens to be the only theory in physics which is BOTH fundamental AND requiring an extremely small set of mathematical prerequisites. This lures many hobbyists into a "serious" investigation of it since the very easy mathematics can easily fool one into thinking one "understands it".
Obviously, anyone with some knack for easy mathematics and a logical cast of mind will _immediately_ be able to poke seeming "holes" through the theory. The problem is that it's _everything else_ that makes SR go, and that _everything else_ is completely unknown to the naive hobbyist.
That's why I said that what you need to do first (assuming you are being honest with yourself about your desire to understand relativity) is to learn all that _everything else_: meaning, simply, physics.
SR is _impossible_ to _really_ understand and appreciate its true ramifications without getting both Newtonian mechanics and  especially  Maxwell's electrodynamics under your belt. So Maxwell's equations in full detail, the potential formulation, radiation, all that stuff.
Only _then_ you can begin to understand the depth of the problem the physics was facing in the late 19th century and why SR was accepted so quickly by everyone. Consider:
1. Einstein was a FAPP complete unknown at the time, 2. Einstein did not own an oil well in Texas to pay his way to fame, 3. Einstein was Jewish which was a strike against at the time, 4. There already WAS a resident saint of physics and mathematics, a Christian one and very well liked and respected: Henri Poincare: it would be extremely easy to assign the credit to him instead of some unknown patent clerk, 5. Many, MANY, famous names have been trying to solve the "aether problem".
You cannot sensibly critique SR without understanding what it's based on IN FACT. Your understanding of its mere mathematical layer is what's deluding you.
No other major theory in physics has such an amazingly lowmathematical barrier to entry, that's why SR is so singularly susceptible to this sort of amateur mucking around and shouting "Eureka!" on Internet forums (this is not the only one devoted to the topic). You've certainly noticed that there are no hobbyists dissecting the fine points of Feynman diagrams? Same thing happens on sci.math: the unending 100%nonsensical discussions about (at best) elementary calculus, it's never about characteristic classes of vector bundles, say.
Don't waste your time trying to play Chopin's Revolutionary Etude when you cannot even play a G major scale without confusion. Start your honest "piano lessons" now, come back to the SR problem in +/10 years.
For now, lay off it, it will only now lead you to an everexpanding maze of seeming nonsense and phantoms.
 Jan
>  Am 25.03.2020 um 21:50 schrieb JanPB: 
> >> 
> >>>> 
The equation �[t(0, 0, 0, t) + t(0, 0, 0, t +x�/(c � v)+x�/(c + v)]=t(x�, 0, 0, t +x�/(c � v)) is in my opinion wrong, since tau is a linear function, that has four vectors as arguments. �Linear function� allows to multiply the argument with a constant factor. So we could multiply the factor � inside the function. Then we could multiply � to all of the components of the vector. This would make all of the first three components zero. Another rule for linear functions is f(a) + f(b) = f(a+b). So the right side of the equation could not have any nonzero value in the first position of the vector. Thomas Heger 
> >>> 
You should learn physics first. Right now you are wasting your time. 
> >> 
seemingly you just wasted yours. Quote less if have nothing to add or subtract. 
> > 
My point was basically that one cannot reasonably add anything to a discussion with someone whose entire argument consists of nonsequiturs 
> 
A paper in theoretical physics should not contain any algebraic errors. 
It doesn't. The English _Dover_ translation does have a few typos. One algebraic one is in the second ("Electrodynamical") part. Use the new, correct, English translation here: https://einsteinpapers.press.princeton.edu/vol2trans/154
>  This is so because in this realm everything depends on consistent logic. So at least there should be zero mathematical errors. 
There are zero mathematical errors. As I mentioned in another posting on this thread (I recommend you read it), the level of mathematics in the _first part_ of the paper ("Kinematical") is very basic, FAPP highschool, so no error at this level would even survive the Annalen der Physik peer review, let alone the 115 years of scrutiny worldwide.
Just stop daydreaming, it's a waste of your time.
>  If there are such errors, the paper could be thrown into the bin, without further considerations. 
There are no errors in the paper.
>  Of course it should be possible to correct the errors and create a new paper, which is better, at least mathematically. 
Sure in general but N/A in this case.
>  The idea could be still wrong. But any mathematical error would derail the paper immediately. 
Sure but it doesn't in this case.
>  Here I tried to show, that a certain important equation of SRT is wrong. 
Stop wasting your time. Read the corrections to your posts and try to understand them. This may be difficult without the necessary background that you lack at this moment.
>  In a better world, the theory would be done, if the error would be regarded as error. 
This is how it is in this world, actually. The world is not perfect, there do happen abuses now and then but in this case what you are trying to suggest is simply ludicrous.
>  But seemingly we have here believes and opposing such quasireligious statements 
All right all right, just stop it. It's all nonsense. Just learn physics if that's what you want. Fantasising won't get you anywhere.
 Jan
>  To really understand STR, you have to understand ELECTRODYNAMICS. 
That is just plain not true. To understand SR you need to understand GEOMETRY.
It is merely an historical accident that Einstein discovered SR via electrodynamics. The actual underlying basis of SR is GEOMETRY. Today we can easily derive all the equations of SR without any mention of light or electrodynamics  what is needed is SYMMETRY (i.e. group theory).
>  STR is also physically absurd, 
Only to fools who attempt to write about it without understanding it.
>  I intuitively feel that STR, like Ptolemy's model, is an absurd approximation to a simpler, physically sensible reality. 
Only because you do not understand the elegant simplicity of SR.
>  Some people might ask what is the point of trying to find a 'better' model when STR matches all known data,[...] 
No PHYSICIST would ask that  seeking better models is what physics is all about. It's just that YOU do not understand physics, or physicists, or our motivations.
And, of course, alternatives to SR are VERY difficult to imagine. Look up "Doubly Special Relativity" or "String theory". It appears that at the fundamental level, relativity and quantum mechanics may well be inextricably intertwined. The incompatibility between QM and GR seems to be indicative that somewhere we have gotten something wrong....
Tom Roberts
>  this is a reply to Tom Roberts [...] 
Such nonsense you write! You merely show that you did not understand my points at all.
Tom Roberts
>  On 3/26/20 1:13 PM, Engr. Ravi wrote: 
> >  To really understand STR, you have to understand ELECTRODYNAMICS. 
> 
That is just plain not true. To understand SR you need to understand GEOMETRY. 
I strongly disagree. Geometry is just mathematics, it doesn't say anything about the context and why geometry ended up relevant in the first place. And why it was accepted so easily.
>  It is merely an historical accident that Einstein discovered SR via electrodynamics. 
That may be but the justification for it remains electrodynamics. Theories that followed (QED, etc) are consistent with this, of course, but nobody can study QED without studying SR first and SR cannot be understood without the theories that have led to it.
 Jan
>  The incompatibility between QM and GR seems to be indicative that somewhere we have gotten something wrong.... 
Ya think?
>  On 3/26/20 1:13 PM, Engr. Ravi wrote: 
>>  To really understand STR, you have to understand ELECTRODYNAMICS. 
> 
That is just plain not true. To understand SR you need to understand GEOMETRY. It is merely an historical accident that Einstein discovered SR via electrodynamics. The actual underlying basis of SR is GEOMETRY. Today we can easily derive all the equations of SR without any mention of light or electrodynamics  what is needed is SYMMETRY (i.e. group theory). 
not at all, it's a logical step to take, for instance, suspecting EM travelling same speed as light. I believe at that time it wasn't overall established that light is EM. The young Einstein was not extremely clever, but clever enough. Which makes all the difference.
Then it has nothing to do with _geometry_, I'm tired of this nonsense. Nowhere in his papers are references to geometry. No sin, no cos etc. Mostly you can say is projection on some given coordinates/references, of course you get some axis and unit vectors, but that's not to say _geometry_. The young Einstein is my hero.
>  On Thursday, March 26, 2020 at 7:07:46 PM UTC7, tjrob137 wrote: 
>>  On 3/26/20 1:13 PM, Engr. Ravi wrote: 
>> >  To really understand STR, you have to understand ELECTRODYNAMICS. 
>> 
That is just plain not true. To understand SR you need to understand GEOMETRY. 
> 
I strongly disagree. Geometry is just mathematics, it doesn't say anything about the context and why geometry ended up relevant in the first place. And why it was accepted so easily. 
>> 
It is merely an historical accident that Einstein discovered SR via electrodynamics. 
> 
That may be but the justification for it remains electrodynamics. 
Yes, sure, the young Einstein dared taking the next logical step, implying indirectly, that the light was EM. (not particle yet). A derivation based on mistake, leading to something shown to be correct. I guess he gotten a lot of enemies those days.
>  On Thursday, March 26, 2020 at 7:07:46 PM UTC7, tjrob137 wrote: 
> >  On 3/26/20 1:13 PM, Engr. Ravi wrote: 
> > >  To really understand STR, you have to understand ELECTRODYNAMICS. 
> > 
That is just plain not true. To understand SR you need to understand GEOMETRY. 
> 
I strongly disagree. Geometry is just mathematics, it doesn't say anything about the context and why geometry ended up relevant in the first place. And why it was accepted so easily. 
> > 
It is merely an historical accident that Einstein discovered SR via electrodynamics. 
> 
That may be but the justification for it remains electrodynamics. Theories that followed (QED, etc) are consistent with this, of course, but nobody can study QED without studying SR first and SR cannot be understood without the theories that have led to it. 
It is very instructive to follow you and Tom Roberts, your disagreement here is close to the core of the total disagreement of many vs the SR theory. It is a very understandable accident that SR geometrical structure based on the magic of the SR gamma factor gives the very approximate experimental results, notwithstanding its absurdity. Your suggestion to study before criticize is correct, but war cannot be handled only by army generals since the dying are the na�ve soldiers.
Regards Beda pietanza
>  Il giorno venerd� 27 marzo 2020 10:05:37 UTC+7, JanPB ha scritto: 
> >  On Thursday, March 26, 2020 at 7:07:46 PM UTC7, tjrob137 wrote: 
> > >  On 3/26/20 1:13 PM, Engr. Ravi wrote: 
> > > >  To really understand STR, you have to understand ELECTRODYNAMICS. 
> > > 
That is just plain not true. To understand SR you need to understand GEOMETRY. 
> > 
I strongly disagree. Geometry is just mathematics, it doesn't say anything about the context and why geometry ended up relevant in the first place. And why it was accepted so easily. 
> > > 
It is merely an historical accident that Einstein discovered SR via electrodynamics. 
> > 
That may be but the justification for it remains electrodynamics. Theories that followed (QED, etc) are consistent with this, of course, but nobody can study QED without studying SR first and SR cannot be understood without the theories that have led to it. 
> 
It is very instructive to follow you and Tom Roberts, your disagreement here is close to the core of the total disagreement of many vs the SR theory. 
Our disagreement is only in the pedagogy. I agree with Tom that the current understanding of SR (as a geometry) is correct. Problem with it that to an newbie or a hobbyist without experience of the relevant physics such understanding will frequently appear whimsical and/or without foundation and/or devoid of common sense and/or stupid and/or absurd and/or etc. etc.
Explaining SR to a newbie by using geometry is a bit like explaining Newtonian mechanics by starting with the HamiltonJacobi theory. It's correct and powerful and supremely elegant and also quite incomprehensible.
>  It is a very understandable accident that SR geometrical structure based on the magic of the SR gamma factor gives the very approximate experimental results, notwithstanding its absurdity. 
There is no absurdity. Certainly Hamiltonian mechanics let alone QED is much more "absurd".
 Jan
Progress is most of the time made in this manner: two steps ahead and one step back.
But that is not bad at all. You check things out and if there seems to be a promising path, you try to progress. But from time to time you end up in a dead alley and must go back.
Then you can check the next possibility and so forth.
But if you insist on an error, you will remain in that dead end.
Therefor it is very important to identify things, that are not good as possible and try better solutions.
>  In science we aim to find truth. 
That is completely WRONG. This misunderstanding is a major part of your confusion.
We have learned that "truth" is inapplicable to science in general, and physics in particular, because we can never really know what nature is actually doing. The best we can do is MODEL what nature does, and then refine and improve the model via experiments and observations.
This is called "science". You should learn about it.
After all, models are how humans survive in the world. You cannot find your bed at night without a model of your domicile  you mentally traverse that model to your bed, and manipulate your body correspondingly.
Tom Roberts
>>>  To really understand STR, you have to understand ELECTRODYNAMICS. 
> 
>> 
That is just plain not true. To understand SR you need to understand GEOMETRY. It is merely an historical accident that Einstein discovered SR via electrodynamics. 
> 
That may be but the justification for it remains electrodynamics. ... SR cannot be understood without the theories that have led to it. 
Is it conceivable that someone might have developed relativity at that time, strictly from geometric and symmetry considerations, without reference to electrodynamics?
 Rich
>  On March 26, JanPB wrote: 
>>>>  To really understand STR, you have to understand ELECTRODYNAMICS. 
>> 
>>> 
That is just plain not true. To understand SR you need to understand GEOMETRY. It is merely an historical accident that Einstein discovered SR via electrodynamics. 
>> 
That may be but the justification for it remains electrodynamics. ... SR cannot be understood without the theories that have led to it. 
> 
Is it conceivable that someone might have developed relativity at that time, strictly from geometric and symmetry considerations, without reference to electrodynamics? 
infact there is no reference to electrodynamics in his 1905 paper. If any, that's nut much, but only explanatory.
>  On 3/28/20 2:00 PM, Thomas Heger wrote: 
> >  In science we aim to find truth. 
> 
That is completely WRONG. This misunderstanding is a major part of your confusion. We have learned that "truth" is inapplicable to science in general, and physics in particular, because we can never really know what nature is actually doing. 
IMO the purpose of science is to try to predict the future as accurately as possible. With future I mean the evolution of any (physical) process you want (to study)
>  The best we can do is MODEL what nature does, and then refine and improve the model via experiments and observations. 
You can not define a model, starting from nothing. The first step is to do observations. The second step is to do experiments. The third step is to define a model. A model means to subdivide a physical process into different parts and to see how they influence each other. With a model in a more general context I have in mind: a theory, a law or some mathematical equations (or the periodic table)
I advise for further reading this document: https://www.nicvroom.be/The_purpose_of_Science.htm
> 
This is called "science". You should learn about it.
After all, models are how humans survive in the world. You cannot find your bed at night without a model of your domicile  you mentally traverse that model to your bed, and manipulate your body correspondingly. 
To discuss models as part of human behaviour is not what I have in mind, but this is also in medicine and economics.
Nicolaas Vroom.
>  On Sunday, 29 March 2020 07:19:11 UTC+2, tjrob137 wrote: 
>>  On 3/28/20 2:00 PM, Thomas Heger wrote: 
>>>  In science we aim to find truth. 
>> 
That is completely WRONG. This misunderstanding is a major part of your confusion. We have learned that "truth" is inapplicable to science in general, and physics in particular, because we can never really know what nature is actually doing. 
> 
IMO the purpose of science is to try to predict the future as accurately as possible. With future I mean the evolution of any (physical) process you want (to study) 
Well, actually not.
There are many things in science, which are not oriented into the future. History, for instance, is also a science, but about the past.
E.g. if you dig out Dinosaur remains, you don't think about making them alive.
Other scientific endeavors are related to subjects so chaotic, remote, small or otherwise inaccessible, that science is happy with less then predictions.
>>  The best we can do is MODEL what nature does, and then refine and improve the model via experiments and observations. 
> 
You can not define a model, starting from nothing. The first step is to do observations. The second step is to do experiments. The third step is to define a model. A model means to subdivide a physical process into different parts and to see how they influence each other. With a model in a more general context I have in mind: a theory, a law or some mathematical equations (or the periodic table) I advise for further reading this document: https://www.nicvroom.be/The_purpose_of_Science.htm 
I generally like the site, but think this is wrong:
"Experiment 1
In a dark corner of the universe it is not possible to define a point by other means than a material object.
In the example there are only spaceships present and one of these ships is therefore the only choice for the definition of a coordinate system and its center.
Also directions are hard to define, if there is nothing stable.
TH
>  RichD wrote: 
> > 
On March 26, JanPB wrote: 
> >>>>  To really understand STR, you have to understand ELECTRODYNAMICS. 
> >> 
> >>> 
That is just plain not true. To understand SR you need to understand GEOMETRY. It is merely an historical accident that Einstein discovered SR via electrodynamics. 
> >> 
That may be but the justification for it remains electrodynamics. ... SR cannot be understood without the theories that have led to it. 
> > 
Is it conceivable that someone might have developed relativity at that time, strictly from geometric and symmetry considerations, without reference to electrodynamics? 
> 
infact there is no reference to electrodynamics in his 1905 paper. If any, that's nut much, but only explanatory. 
His 1905 paper is about electrodynamics, its second part ("Electrodynamical part") is what the paper is REALLY about. The first part ("Kinematical part") was intended only to provide a modified kinematics for its use in the second part AND the first part also showed that it was strong enough to derive the known (by then) Lorentz transformation as well as provide a better justification for it than just saying "Maxwell's equations are invariant under it".
Of course what happened very soon after the publication was that everyone realised the paper's first part was in fact the more fundamental part: it affected the whole of physics. So today hardly anyone even READS the second part (it requires more mathematical sophistication to understand it anyway) and esp. amateurs get from it the idea that the first part is all there was to SR originally, with the usual result: the false conclusion that the theory is somehow "wrong" or "stupid", etc.
 Jan
>  On Sunday, 29 March 2020 07:19:11 UTC+2, tjrob137 wrote: 
> >  On 3/28/20 2:00 PM, Thomas Heger wrote: 
> > >  In science we aim to find truth. 
> > 
That is completely WRONG. This misunderstanding is a major part of your confusion. We have learned that "truth" is inapplicable to science in general, and physics in particular, because we can never really know what nature is actually doing. 
> 
IMO the purpose of science is to try to predict the future as accurately as possible. With future I mean the evolution of any (physical) process you want (to study) 
> > 
The best we can do is MODEL what nature does, and then refine and improve the model via experiments and observations. 
> 
You can not define a model, starting from nothing. 
Of course you can. Face it: a model is not a physical being, you're simply incompetent on the subject.
>  On Friday, 27 March 2020 at 11:00:53 AM UTC7, beda pietanza wrote: 
> >  It is very instructive to follow you and Tom Roberts, your disagreement here is close to the core of the total disagreement of many vs the SR theory. 
> 
Our disagreement is only in the pedagogy. I agree with Tom that the current understanding of SR (as a geometry) is correct. 
I'm not arguing if the current explanation of SR is correct.
My question is if the current explanation using spacetime is required.
IMO you can do it simpler.
But before you can answer the question you must first answer the question:
What is SR? What type of physical issue do we want to solve using SR?
It's like you wrote before:
>  Problem with it that to a newbie or a hobbyist without experience of the relevant physics such understanding will frequently appear whimsical and/or without foundation and/or devoid of common sense and/or stupid and/or absurd and/or etc. etc. 
We should not blame the students of science.
Part of the problem is that both concepts SR and GR are not clearly defined.
SR looks like an amalgamation of certain concepts like time dilation,
length contraction, Lorentz transformation, the relativity of simultaneity
and the speed of light, which are each difficult to demonstrate and to
understand.
For GR the picture is more or less the same. GR is more than the Einstein
field equations, the cosmological constant, gravity waves, invariance
and Black holes, which are each difficult to demonstrate and understand.
In that sense, Newton's Law is much simpler because its main purpose is
to describe the movement of the planets around the Sun.
Maybe that's also true for GR, but my impression is that its purpose
is much broader.
Nicolaas Vroom
>  Of course, you can. Face it: a model is not a physical being, 
When I was a small boy I made a 3D drawing of a castle.
I also made a 3D model of a house.
You can only do these things if you have either seen a castle or a house
in real, from a painting or from another drawing.
That means an effort first requires certain observations.
>  you're simply incompetent on the subject. 
Nicolaas Vroom
>  On Saturday, 28 March 2020 04:25:31 UTC+1, JanPB wrote: 
> >  On Friday, 27 March 2020 at 11:00:53 AM UTC7, beda pietanza wrote: 
> > > 
It is very instructive to follow you and Tom Roberts, your disagreement here is close to the core of the total disagreement of many vs the SR theory. 
> > 
Our disagreement is only in the pedagogy. I agree with Tom that the current understanding of SR (as a geometry) is correct. 
> 
I'm not arguing if the current explanation of SR is correct.
My question is if the current explanation using spacetime is required.
IMO you can do it simpler. 
Your assumption that you want SR to solve any physical issue is totally wrong. You want it to feel gurulike, high above mortal worms. And if not you, Jan and Tom for sure.
>  On Tuesday, 31 March 2020 07:56:11 UTC+2, maluw...@gmail.com wrote: 
> >  On Monday, 30 March 2020 18:40:49 UTC+2, Nicolaas Vroom wrote: 
> > >  On Sunday, 29 March 2020 07:19:11 UTC+2, tjrob137 wrote: 
> > > > 
The best we can do is MODEL what nature does, and then refine and improve the model via experiments and observations. 
> > > 
You can not define a model, starting from nothing. 
> > 
Of course, you can. Face it: a model is not a physical being, 
> 
When I was a small boy I made a 3D drawing of a castle.
I also made a 3D model of a house. 
How about modelling alien civilizations, Millenium Falcon or  being more TG  event horizons?
>  in real, from a painting or from another drawing. That means an effort first requires certain observations. 
> > 
you're simply incompetent on the subject. 
>  Maybe. But who is competent? 
About modelling  informaticians. We're doing it every day and have written many, many books about it. About truth  Tarski has done a piece of good work.
>  On Saturday, 28 March 2020 04:25:31 UTC+1, JanPB wrote: 
> > 
Problem with it that to a newbie or a hobbyist without experience of the relevant physics such understanding will frequently appear whimsical and/or without foundation and/or devoid of common sense and/or stupid and/or absurd and/or etc. etc. 
> 
We should not blame the students of science. 
To get a better understanding about the subject please read this document: "Student_understanding of time in SR" by Rachel E. Scherr e.a. http://cds.cern.ch/record/573634/files/0207109.pdf
I have also written a review of this article. Please read:
https://www.nicvroom.be/Article_Review_Student_understanding_of_time_in_SR.htm
Nicolaas Vroom
>  Am 31.03.2020 um 12:26 schrieb Engr. Ravi: 
> >  On Tuesday, March 31, 2020 at 12:42:17 PM UTC+5:30, Thomas Heger wrote: 
> >>  The paper starts with a serious error about induction and how magnets induce currents into wires. 
> > 
What error? 
>  A magnet does not produce an electric field around it when moving 
That is precisely the puzzle that Einstein is addressing in the paper:
A moving magnet DOES NOT produce an electric field around it WHEN VIEWED FROM A COMOVING FRAME in which the magnet is at rest, while the same moving magnet produces an electric field around it as per the MaxwellFaraday Law: gradXE = ?B/?t, when viewed from a 'rest' frame in which the magnet is moving.
This observed fact requires two entirely different explanations in Maxwell's model, depending on which frame of reference is used, the one in which the magnet is at rest or the one in which the conducting ring is at rest. If viewed from the frame in which the conducting ring is stationary and the magnet is moving, the MaxwellFaraday Law: gradXE = ?B/?t is used. But if viewed from the magnet's frame in which the magnet is stationary and the conducting ring is in motion, gradXE = ?B/?t = 0, i.e., no electric field arises in the neighborhood of the magnet, and the Lorentz' force law must be used: F = q(vXB) which results in the same EMF as in the earlier case.
As Einstein notes, "The observable phenomenon here depends only on the relative motion of the conductingring and the magnet, whereas the customary view draws a sharp distinction between the two cases in which either the one or the other of these bodies is in motion."
It is this and similar "asymmetries which do not appear to be inherent in the phenomena" that Einstein is trying to explain. It is a totally different issue that his "explanation" is COMPLETELY PHYSICALLY ABSURD, but completely mathematically consistent.
>  and an electric field outside of a wire does not generate currents inside a wire. 
The electric field is both outside as well as inside the wire, as the MaxwellFaraday Law states.
> >> 
I also disagree with Einstein's quotes of Maxwell.
In fact there are no quotes at all, but the name Maxwell is mentioned. But If I look at the original book of Maxwell, I cannot find the equations that Einstein 'quoted'. So: where do they come from? 
> > 
The equations in the 1905 paper are the MaxwellHertz equations. 
> 
Where could I find them??? 
Except for the use of the del or grad operator and maybe some constants, the MaxwellHertz equations are the same as Heaviside's equations, and these you will find in any text book on classical electrodynamics.
https://www.feynmanlectures.caltech.edu/II_18.html#Ch18S1
>  The 'Hertz Ansatz' is not know that well, so I have not found it yet. 
> > 
Maxwell's original set of 20 equations published in the 1879 Treatise contained both the E, B fields as well as the scalar potential (phi) and vector potential (A). Both Heaviside and Hertz "didn't like" the potentials and eliminated them to get equivalent equations. The modern form using the grad operator are due to Heaviside, and the ones in Einstein's paper are due to Hertz. 
> 
I don't like Heaviside, because I like quaternions and it was actually him, who 'eliminated' things, which are worth to rediscover. So I stick with Maxwell's 'treatise' (possibly Tait's book). 
How about using the right mathematical tool for the job? Classical electrodynamics is best expressed using vectors and Heaviside's ? notation. Relativistic electrodynamics with 4vectors and Quantum electrodynamics with the PauliDirac quaternion equivalents and of course Feynman's diagrams.
>  On Saturday, 28 March 2020 04:25:31 UTC+1, JanPB wrote: 
> >  On Friday, 27 March 2020 at 11:00:53 AM UTC7, beda pietanza wrote: 
> > > 
It is very instructive to follow you and Tom Roberts, your disagreement here is close to the core of the total disagreement of many vs the SR theory. 
> > 
Our disagreement is only in the pedagogy. I agree with Tom that the current understanding of SR (as a geometry) is correct. 
> 
I'm not arguing if the current explanation of SR is correct. My question is if the current explanation using spacetime is required. 
This is a model which is both the simplest and consistent with the theory (as set up in 1905) AND directly amenable to the GR enhancement.
>  IMO you can do it simpler. But before you can answer the question you must first answer the question: What is SR? What type of physical issue do we want to solve using SR? 
It started with the discrepancy between Newtonian mechanics and classical
electrodynamics.
To this day nobody has found a way to reasonably resolve
this problem other than the SRT. Later (after QM) it became clear more
discrepancies of similar nature persist that nobody has managed to
resolve in any other way than via SRT. This is simply how it is, I am
not asking anyone to like it.
> 
It's like you wrote before:

That's not a requirement for a physical theory. Problem is we don't necessarily know what the label "physical" should entail in all contexts.
>  If yes then first we should define the experiments on how to test the behaviour of a clock. Please read: https://www.nicvroom.be/The_purpose_of_Science.htm 
> > 
Problem with it that to a newbie or a hobbyist without experience of the relevant physics such understanding will frequently appear whimsical and/or without foundation and/or devoid of common sense and/or stupid and/or absurd and/or etc. etc. 
> 
We should not blame the students of science. 
I'm blaming the teachers.
I understand where this comes from, having spent
a bit of time in the academia: the permanent lack of time and the relative
rigidity of the curriculum (a problem that's particularly visible in
the US, this hurts undergraduates especially  but I digress).
So it's
very tempting for a professor to present a concise and supremely elegant
theory which can then easily end up looking completely off the wall.
>  Part of the problem is that both concepts SR and GR are not clearly defined. SR looks like an amalgamation of certain concepts like time dilation, length contraction, Lorentz transformation, the relativity of simultaneity and the speed of light, which are each difficult to demonstrate and to understand. 
Well, yes, if that's what this theory looks like to someone, then you're already out to lunch as far as any paedagogical effort goes :)
> 
For GR the picture is more or less the same. GR is more than the Einstein
field equations, the cosmological constant, gravity waves, invariance
and Black holes, which are each difficult to demonstrate and understand.
In that sense, Newton's Law is much simpler because its main purpose is to describe the movement of the planets around the Sun. Maybe that's also true for GR, but my impression is that its purpose is much broader. 
Plus it's a classical theory, that's another little problem.
 Jan
>  On Tuesday, 31 March 2020 14:42:55 UTC+2, Nicolaas Vroom wrote: 
> >  On Saturday, 28 March 2020 04:25:31 UTC+1, JanPB wrote: 
> 
> > > 
Problem with it that to a newbie or a hobbyist without experience of the relevant physics such understanding will frequently appear whimsical and/or without foundation and/or devoid of common sense and/or stupid and/or absurd and/or etc. etc. 
> > 
We should not blame the students of science. 
> 
To get a better understanding about the subject please read this document: "Student_understanding of time in SR" by Rachel E. Scherr e.a. http://cds.cern.ch/record/573634/files/0207109.pdf 
Very interesting, thanks! Do you know which year this paper is from?
 Jan
>  On Friday, March 27, 2020 at 7:37:46 AM UTC+5:30, tjrob137 wrote: 
> >  On 3/26/20 1:13 PM, Engr. Ravi wrote: 
> > >  To really understand STR, you have to understand ELECTRODYNAMICS. 
> > 
That is just plain not true. To understand SR you need to understand GEOMETRY. It is merely an historical accident that Einstein discovered SR via electrodynamics. The actual underlying basis of SR is GEOMETRY. Today we can easily derive all the equations of SR without any mention of light or electrodynamics  what is needed is SYMMETRY (i.e. group theory). 
> 
Trying to teach STR as KINEMATICS or worse ABSTRACT GEOMETRY has been a PEDAGOGICAL DISASTER. It is likely that 99% of the posts in this newsgroup would not have existed if the educational establishment had heeded V.I.Arnold's advice instead of the Bourbaki school. 
Thanks for the link. Very interesting! I disagree with him on a couple of specific points but the remaining 98% is on the nose.
 Jan
>  On Tuesday, March 31, 2020 at 5:42:55 AM UTC7, Nicolaas Vroom wrote: 
> >  On Saturday, 28 March 2020 04:25:31 UTC+1, JanPB wrote: 
> > >  On Friday, 27 March 2020 at 11:00:53 AM UTC7, beda pietanza wrote: 
> > 
> > > > 
It is very instructive to follow you and Tom Roberts, your disagreement here is close to the core of the total disagreement of many vs the SR theory. 
> > > 
Our disagreement is only in the pedagogy. I agree with Tom that the current understanding of SR (as a geometry) is correct. 
> > 
I'm not arguing if the current explanation of SR is correct. My question is if the current explanation using spacetime is required. 
> 
This is a model which is both the simplest and consistent with the theory (as set up in 1905) AND directly amenable to the GR enhancement. 
> > 
IMO you can do it simpler. But before you can answer the question you must first answer the question: What is SR? What type of physical issue do we want to solve using SR? 
> 
It started with the discrepancy between Newtonian mechanics and classical electrodynamics. 
Samely as commumism, The Shit is obvious historical necessity.
>  To this day nobody has found a way to reasonably resolve this problem other than the SRT. 
Samely as communism. The Shit is te only reasonable way.
>  Later (after QM) it became clear more discrepancies of similar nature persist that nobody has managed to resolve in any other way than via SRT. 
Samely as communism. The Shit is te only way.
>  This is simply how it is, I am not asking anyone to like it. 
In the case of communism it was also  simply how it is.
>  Engr. Ravi wrote: 
> >  tjrob137 wrote: 
> > >  Ravi wrote: 
> > > > 
To really understand STR, you have to understand ELECTRODYNAMICS. 
> > > 
That is just plain not true. To understand SR you need to understand GEOMETRY. It is merely an historical accident that Einstein discovered SR via electrodynamics. The actual underlying basis of SR is GEOMETRY. Today we can easily derive all the equations of SR without any mention of light or electrodynamics  what is needed is SYMMETRY (i.e. group theory). 
> > 
Trying to teach STR as KINEMATICS or worse ABSTRACT GEOMETRY has been a PEDAGOGICAL DISASTER. It is likely that 99% of the posts in this newsgroup would not have existed if the educational establishment had heeded V.I.Arnold's advice instead of the Bourbaki school. 
> 
Thanks for the link. Very interesting! I disagree with him on a couple of specific points but the remaining 98% is on the nose. 
Are you saying it stinks?
>  On Friday, March 27, 2020 at 7:37:46 AM UTC+5:30, tjrob137 wrote: 
> >  On 3/26/20 1:13 PM, Engr. Ravi wrote: 
> > >  To really understand STR, you have to understand ELECTRODYNAMICS. 
> > 
That is just plain not true. To understand SR you need to understand GEOMETRY. It is merely an historical accident that Einstein discovered SR via electrodynamics. The actual underlying basis of SR is GEOMETRY. Today we can easily derive all the equations of SR without any mention of light or electrodynamics  what is needed is SYMMETRY (i.e. group theory). 
> 
Trying to teach STR as KINEMATICS or worse ABSTRACT GEOMETRY has been a PEDAGOGICAL DISASTER. It is likely that 99% of the posts in this newsgroup would not have existed if the educational establishment had heeded V.I.Arnold's advice instead of the Bourbaki school. 
"Mathematics is a part of physics."
Whatever to pretend your moronic physics is incredibly
important and you are incredibly important.
>  On Tuesday, 31 March 2020 14:45:09 UTC+2, Nicolaas Vroom wrote: 
> > 
When I was a small boy I made a 3D drawing of a castle. I also made a 3D model of a house. You can only do these things if you have either seen a castle or a house 
> 
How about modelling alien civilizations, Millenium Falcon or  being more TG  event horizons? 
All these three subjects have to do with science. Millennium Falcon(Star wars). event horizons (1997 Horror movie) That is not part of my daily interest. I'm more a fan of Jules Verne
>  About modelling  informaticians. We're doing it every day and have written many, many books about it. About truth  Tarski has done a piece of good work. 
To understand Tarski the reader should read:
https://web.archive.org/web/20141229081319/http://people.scs.carleton.ca/~bertossi/logic/material/tarski.pdf
If that link does not work please select this link:
https://en.wikipedia.org/wiki/Alfred_Tarski#Works
and search for this line:
* 1969. "Truth and Proof", Scientific American 220: 6377.
The Article "Truth and Proof" is a brilliant article by Alfred Tarski. He mentions Aristotle's Metaphysics by this quote:
The word physics is only mentioned once in this article on page 7.
" It seems clear that under this program much of contemporary mathematics
would disappear, and theoretical parts of physics, chemistry, biology, and
other empirical sciences would be severely mutilated."
As said above this is not very helpful to study SRT.
However, almost all that Tarski writes on page 7 is interesting to read.
Nicolaas Vroom
>  Am 30.03.2020 um 18:40 schrieb Nicolaas Vroom: 
> > 
IMO the purpose of science is to try to predict the future as accurately as possible. With the future, I mean the evolution of any (physical) process you want (to study) 
> 
Well, actually not. There are many things in science, which are not oriented into the future. History, for instance, is also a science, but about the past. 
That is correct, but studying what happened in the past, can teach you what to do if a similar situation arises.
>  E.g. if you dig out Dinosaur remains, you don't think about making them alive. 
Digging out Dinosaur remains, observing these remains and comparing them with the animals surrounding us, is the first step to perform science.
> >>  The best we can do is MODEL what nature does, and then refine and improve the model via experiments and observations. 
> > 
You can not define a model, starting from nothing. The first step is to do observations. The second step is to do experiments. I advise for further reading this document: https://www.nicvroom.be/The_purpose_of_Science.htm 
> 
I generally like the site, but think this is wrong: "Experiment 1

>  In a dark corner of the universe it is not possible to define a point by other means than a material object. 
There is nothing wrong to consider the three points A, O and B as material objects. The most important thing is that they are 'in the same direction' along the xaxis.
Nicolaas Vroom
>  Am 30.03.2020 um 18:40 schrieb Nicolaas Vroom: 
> > 
IMO the purpose of science is to try to predict the future as accurately as possible. With the future, I mean the evolution of any (physical) process you want (to study) 
> 
Well, actually not. There are many things in science, which are not oriented into the future. History, for instance, is also a science, but about the past. 
That is correct, but studying what happened in the past, can teach you what to do if a similar situation arises.
>  E.g. if you dig out Dinosaur remains, you don't think about making them alive. 
Digging out Dinosaur remains, observing these remains and comparing them with the animals surrounding us, is the first step to perform science.
> >>  The best we can do is MODEL what nature does, and then refine and improve the model via experiments and observations. 
> > 
You can not define a model, starting from nothing. The first step is to do observations. The second step is to do experiments. I advise for further reading this document: https://www.nicvroom.be/The_purpose_of_Science.htm 
> 
I generally like the site, but think this is wrong: "Experiment 1

I have improved the Experiments 14 and make them clearer. Please study them again.
>  In a dark corner of the universe it is not possible to define a point by other means than a material object. 
There is nothing wrong to consider the three points A, O and B as material objects. The most important thing is that they are 'in the same direction' along the xaxis.
Nicolaas Vroom
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