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From: Peter Webb on 27 Feb 2010 07:53

"Ste" <ste_rose0(a)hotmail.com> wrote in message
news:f47fb4af-7f73-420b-b61b-73a4ce42b1e5(a)q15g2000yqj.googlegroups.com...
> On 27 Feb, 06:55, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au>
> wrote:
>> "Ste" <ste_ro...(a)hotmail.com> wrote in message
>>
>> news:2268f44a-518e-43b4-a3f8-a610f4e89e89(a)o30g2000yqb.googlegroups.com...
>>
>>
>>
>>
>>
>> > On 26 Feb, 12:31, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au>
>> > wrote:
>> >> "Ste" <ste_ro...(a)hotmail.com> wrote in message
>>
>> >> About this gravity thing. I am having a great deal of difficulty
>> >> forming
>> >> a
>> >> mental picture of how it is supposed to work.
>>
>> > At a fundamental level, I do too.
>>
>> >> If the planets are separated
>> >> by vacuum, how could one object possibly pull on another object when
>> >> there
>> >> is nothing between them? For that matter, how does one particle manage
>> >> to
>> >> pull on every other particle in the Universe at the same time? Are you
>> >> positing some array of invisible springs, 10^160 of them, connecting
>> >> the
>> >> 10^80 particles in the Universe?
>>
>> > I think a more credible argument is that there *is* in fact something
>> > in between the objects.
>>
>> >> Frankly, I find the suggestion that each time I move my finger to type
>> >> these
>> >> invisible gravity springs cause every other particle in the Universe
>> >> to
>> >> move
>> >> ludicrous. Apart from anything else, how is this spooky action at a
>> >> distance
>> >> supposed to work, physically? Springs and levers? What is gravity
>> >> supposed
>> >> to be, physically?
>>
>> > I don't find it hard to believe that every movement of the finger
>> > could have an effect on every other particle of the universe. In terms
>> > of what gravity is and how it works, that remains to be explained.
>>
>> Ohhh, so your mental model of the solar system contains "gravity", yet
>> your
>> mental model of the solar system provides no physical explanation of what
>> it
>> "really" is.
>>
>> Funny, you complained about SR and Minkowski for having components for
>> which
>> you have no physical model. Yet your own theory of the solar system
>> contains
>> concepts such as gravity which have no physical explanation at all within
>> the model.
>
> Yes, but I readily concede this, and accept that there needs to be
> work done to find out what gravity actually is. For the time being, I
> have a model that operates at a macro level, where gravity is assumed
> to be a fundamental manifestation of reality. Yet you speak as though
> I've let the cat out of the bag or something.
>

So you have no *physical* idea of what gravity really is, but that doesn't
stop you using it in a model.

Funny, the fact that SR contains things which you have no *physical*
explanation of was a huge problem for SR, but the same problem doesn't worry
you for your own model.


>
>
>> Newton's theory of gravitation and SR are not at all different in that
>> respect. Newton's theory of gravity says nothing at all about what
>> gravity
>> "really" is. SR says nothing about what length contraction "really" is.
>> The
>> theories don't need to. The equations all work; the rest is philosophy.
>> In
>> your case, bad philosophy.
>
> And you're an idiot if you think anything other than equations is
> "philosophy, not physics", and you typify the explanation for why
> theoretical physics won't move an inch until your kind are steadily
> retired out of the dominant positions in academia.

Theoretical physics is doing quite well without your advice, thanks all the
same.


From: Peter Webb on 27 Feb 2010 08:00

"Ste" <ste_rose0(a)hotmail.com> wrote in message
news:2726fc2b-b860-4c84-96a9-3776df684de4(a)e7g2000yqf.googlegroups.com...
> On 27 Feb, 07:02, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au>
> wrote:
>> "Ste" <ste_ro...(a)hotmail.com> wrote in message
>>
>> news:f1c82fe9-c833-4262-9bca-d62d9181c8b0(a)i39g2000yqm.googlegroups.com...
>> On 26 Feb, 12:52, "Inertial" <relativ...(a)rest.com> wrote:
>>
>> > "Ste" <ste_ro...(a)hotmail.com> wrote in message
>>
>> > > Of course I'm not claiming to know anything profound about the solar
>> > > system. The conceptual model has been accepted for centuries, and I'm
>> > > not pretending to add anything new to it. The point I was making
>> > > about
>> > > it is that the conceptual model is required to give any real meaning
>> > > to the equations.
>>
>> > We already have such model .. that's the whole POINT of physics .. it
>> > is
>> > modeling reality. How reality behaves is the meaning to the equations
>> > ..
>> > they describe what is going on.
>>
>> Then show the equations to a child. Ask him if he understands what is
>> going on. And remember, you're not allowed to mention the conceptual
>> aspect, or appeal to sensory perception. You must only use the
>> equations. If these equations alone describe what is going on
>> meaningfully, then the child ought to understand immediately.
>>
>> ___________________________________
>> Why a child?
>>
>> Why not try and explain the equations of SR to a nematode worm? If they
>> really do encompass SR, then the nematode worm should understand SR
>> immediately. Or so your logic would suggest.
>
> No, my logic wouldn't suggest that. My logic says that these equations
> are meaningless without a conceptual model that gives them meaning.
>

What's wrong with Minkowski space-time? It gives me and lots of other people
a very clear conceptual model of SR.



>
>
>> Here are the facts. To fully understand SR, you need to be reasonably
>> intelligent, have a basic maths ability, and have some knowledge of
>> physics.
>>
>> A child, a nematode worm, and yourself all miss out on some or all of
>> these.
>>
>> If you want to understand SR, you are going to need to learn some maths
>> and
>> physics. Some things actually require work. Sorry.
>
> You can teach the child maths. But you can't tell him anything about
> the nature of the universe (because otherwise you're providing the
> conceptual model by the back door, when it is your argument that this
> is not necessary to understand physics, only the maths is required).


That was not my argument.

But I still don't get what your problem is with the conceptual model of SR
provided by Minkowski space-time? It is isomorphic to SR, uses only simple
geometry, and all the key equations of SR become simple geometric
constructs. Minkowski contributed nothing to SR except a superb conceptual
model, apparently exactly the thing you want.

So why not learn it?


From: Jerry on 27 Feb 2010 08:42
On Feb 27, 7:00 am, "Peter Webb"
<webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote:
> "Ste" <ste_ro...(a)hotmail.com> wrote in message

> > You can teach the child maths. But you can't tell him anything about
> > the nature of the universe (because otherwise you're providing the
> > conceptual model by the back door, when it is your argument that this
> > is not necessary to understand physics, only the maths is required).
>
> That was not my argument.
>
> But I still don't get what your problem is with the conceptual model of SR
> provided by Minkowski space-time? It is isomorphic to SR, uses only simple
> geometry, and all the key equations of SR become simple geometric
> constructs. Minkowski contributed nothing to SR except a superb conceptual
> model, apparently exactly the thing you want.
>
> So why not learn it?

You should give Ste a specific book recommendation:

Spacetime Physics, by Taylor and Wheeler

The second edition can generally be picked up used for about $25.
The first edition is frequently found on eBay with a "Buy it now"
price of $5 to $10.

To Ste:
I actually prefer the first edition. It is a relatively thin,
large format paperback that is deceptively easy to skim through
without understanding. It is not a book for skimming. It has lots
of problems with solutions, and the only way to truly learn the
subject is to WORK THE PROBLEMS!!! None of the problems uses
advanced math. If you can work the problems and get the correct
answers, only then will you really understand what relativity is
all about.

As Peter pointed out, Minkowski spacetime is a superb conceptual
model, and not at all difficult to understand provided that you
take the time to learn it properly.

There is no shortcut to learning how to do the math.
But the math is simple!

Jerry
From: Androcles on 27 Feb 2010 09:17

"Jerry" <Cephalobus_alienus(a)comcast.net> wrote in message
news:ed4a3f66-304c-474b-88e7-5ac987bdbd3d(a)d2g2000yqa.googlegroups.com...
On Feb 27, 7:00 am, "Peter Webb"
<webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote:
> "Ste" <ste_ro...(a)hotmail.com> wrote in message

> > You can teach the child maths. But you can't tell him anything about
> > the nature of the universe (because otherwise you're providing the
> > conceptual model by the back door, when it is your argument that this
> > is not necessary to understand physics, only the maths is required).
>
> That was not my argument.
>
> But I still don't get what your problem is with the conceptual model of SR
> provided by Minkowski space-time? It is isomorphic to SR, uses only simple
> geometry, and all the key equations of SR become simple geometric
> constructs. Minkowski contributed nothing to SR except a superb conceptual
> model, apparently exactly the thing you want.
>
> So why not learn it?

You should give Ste a specific book recommendation:

Spacetime Physics, by Taylor and Wheeler

The second edition can generally be picked up used for about $25.
The first edition is frequently found on eBay with a "Buy it now"
price of $5 to $10.

To Ste:
I actually prefer the first edition. It is a relatively thin,
large format paperback that is deceptively easy to skim through
without understanding. It is not a book for skimming. It has lots
of problems with solutions, and the only way to truly learn the
subject is to WORK THE PROBLEMS!!! None of the problems uses
advanced math. If you can work the problems and get the correct
answers, only then will you really understand what relativity is
all about.

As Peter pointed out, Minkowski spacetime is a superb conceptual
model, and not at all difficult to understand provided that you
take the time to learn it properly.

There is no shortcut to learning how to do the math.
But the math is simple!

Jerry
=====================================================
So simple that it's pathetic enough to treat time as if it were a vector
as if it were magic.

You should give Ste a specific book recommendation:

Harry Potter and the Philosopher's Stone, by J. K. Rowling.

The second edition can generally be picked up used for about $2.50.
The first edition is frequently found on eBay with a "Buy it now"
price of $1 to $2.

To Ste:
I actually prefer the first edition. It is a relatively thin,
large format paperback that is deceptively easy to skim through
without understanding. It is not a book for skimming. It has lots
of problems with solutions, and the only way to truly learn the
subject is to WORK THE PROBLEMS!!! None of the problems uses
advanced math. If you can work the problems and get the correct
answers, only then will you really understand what magic is
all about.

As the fuckwit pointed out, magical physics is a superb conceptual
model, and not at all difficult to understand provided that you
take the time to believe in nonsense.

There is no shortcut to learning mathematics, take a course in vector
algebra.


From: PD on 27 Feb 2010 10:46
On Feb 26, 6:46 pm, Ste <ste_ro...(a)hotmail.com> wrote:
> On 26 Feb, 12:52, "Inertial" <relativ...(a)rest.com> wrote:
>
> > "Ste" <ste_ro...(a)hotmail.com> wrote in message
>
> > > Of course I'm not claiming to know anything profound about the solar
> > > system. The conceptual model has been accepted for centuries, and I'm
> > > not pretending to add anything new to it. The point I was making about
> > > it is that the conceptual model is required to give any real meaning
> > > to the equations.
>
> > We already have such model .. that's the whole POINT of physics .. it is
> > modeling reality.  How reality behaves is the meaning to the equations ..
> > they describe what is going on.
>
> Then show the equations to a child. Ask him if he understands what is
> going on. And remember, you're not allowed to mention the conceptual
> aspect, or appeal to sensory perception. You must only use the
> equations. If these equations alone describe what is going on
> meaningfully, then the child ought to understand immediately.

I'm not sure I buy the argument that anything should be fundamentally
understandable to a child.
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