A constant speed of light in all reference frames? Surely you can't be serious. [Physics]

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From: Ste on 27 Feb 2010 21:59

On 27 Feb, 12:53, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au>
wrote:
> "Ste" <ste_ro...(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.

How on Earth have you drawn that conclusion? On the contrary, I hold
that it *is* a problem that there is no apparent physical explanation
for gravity (in terms of what it is, how it is mediated, how it
relates to other forces, etc).

From: mpc755 on 27 Feb 2010 22:01

On Feb 27, 9:59 pm, Ste <ste_ro...(a)hotmail.com> wrote:
> On 27 Feb, 12:53, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au>
> wrote:
>
>
>
> > "Ste" <ste_ro...(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.
>
> How on Earth have you drawn that conclusion? On the contrary, I hold
> that it *is* a problem that there is no apparent physical explanation
> for gravity (in terms of what it is, how it is mediated, how it
> relates to other forces, etc).

Aether is displaced by matter. The aether is not at rest when
displaced and applies pressure towards the matter. The pressure
associated with the aether displaced by massive objects is gravity.

From: Paul Stowe on 27 Feb 2010 22:06

On Feb 27, 6:59 pm, Ste <ste_ro...(a)hotmail.com> wrote:
> On 27 Feb, 12:53, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au>
> wrote:
>
>
>
>
>
> > "Ste" <ste_ro...(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.
>
> How on Earth have you drawn that conclusion? On the contrary, I hold
> that it *is* a problem that there is no apparent physical explanation
> for gravity (in terms of what it is, how it is mediated, how it
> relates to other forces, etc).

Sorry but this isn't true. Before I continue however tell me what
theories of gravity you're aware of?

Paul Stowe

From: Ste on 27 Feb 2010 22:20

On 27 Feb, 13:00, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au>
wrote:
> "Ste" <ste_ro...(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.

Then can we revise, what is your argument? As I understood your
argument, it was that the mathematical descriptions which account for
what is observed is to paraphrase the "full extent of physics", and
that anything else to do with the conceptual basis is "just
philosophy".

> 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?

Because you still don't seem to fully comprehend my plain words, that
a mathematical model of SR is quite different from a physical model.
You repeat over that "Minkowski is a physical model", but it isn't
according to the requirements of what I (and of course, many others in
society) hold to be "physical". Minkowski doesn't rest on physical
concepts. It doesn't lay any claim as to what "time" is, for example,
in a qualitative sense. Nor does SR explain qualitatively what
electromagnetic radiation is, or what its effects are. It necessarily
doesn't, as a purely mathematical theory, detail whether what you are
seeing is "reality", or whether it is merely an optical illusion, or
whether SR is a combination of "real" effects and optical illusions.

These are all significant questions to anyone with a sensible view of
"physics". After all, there are mathematical models that will describe
what you see in a curved mirror, and yet according to your argument
there is no need to go further in detailing whether you are seeing
"reality" or merely an illusion. Indeed it seems to me that, according
to your argument, the question of whether a curved mirror causes an
optical effect, or whether there is really another copy of my body
inside an alternate universe, is a question of "mere philosophy".

Of course, I await correction on my interpretation of your arguments,
but you can see just how spectacularly obtuse and narrow-minded it is
to say (if indeed you are saying) that the physical nature of various
observations are "a question of philosophy, not physics".

From: Ste on 28 Feb 2010 00:22

On 27 Feb, 15:44, PD <thedraperfam...(a)gmail.com> wrote:
> On Feb 26, 6:34 pm, Ste <ste_ro...(a)hotmail.com> wrote:
>
> > > > The fact that this conceptual model in a raw form
> > > > can permit predictions that are so permissive as to make almost no
> > > > prediction at all, does not mean they are not an essential component
> > > > to scientific enquiry and advance.
>
> > > No testable predictions = not science. Possibly philosophy, possibly
> > > fiction, possibly drug induced free association speech, possibly gibberish,
> > > possibly an incredibly profound insight into human emotions, possibly
> > > masturbation. But not science. Science makes testable predictions. (Note
> > > that this is a necessary but not sufficient condition. Astrology also makes
> > > predictions, just very poorly).
>
> > I think you're attributing an absurd definition to "science". Paul
> > Draper probably had a more tenable argument when he said that string
> > theorists are scientists doing science, but that they do not yet have
> > a "scientific theory". But I know from talking to him that he
> > attributes a very contorted meaning to the phrase "scientific theory",
> > that would condemn a lot of scientific knowledge, both historical and
> > current, as being "unscientific".
>
> Examples, please.

In physics I would raise the same old example: string theory . But
there are certainly more. We have things like "dark matter". Or even
Newton. Or Galileo. And more broadly, in biology we have evolution,
and in economics, rational choice theory.

All managed to fail your previously stated requirement of a
"scientific theory", which (amongst other things) is being falsifiable
(in a practical rather than just notional sense), not ad-hoc, and
predicting observations that are not already accounted for.