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

Prev: Quantum Gravity 357.91: Croatia Shows That Probability of Vacuum Energy Density is More Important than its Vacuum Expectation Value (VEV) of the Hamiltonian Density, in line with Probable Causation/Influence (PI)
Next: Hubble Views Saturn's Northern/Southern Lights

From: Ste on 26 Feb 2010 19:46

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.

From: Ste on 26 Feb 2010 19:54

On 26 Feb, 17:34, PD <thedraperfam...(a)gmail.com> wrote:
> On Feb 25, 9:05 pm, Ste <ste_ro...(a)hotmail.com> wrote:
>
> > I also doubt one exists at the moment, but I see that as a problem.
> > It's utterly irreconcilable, within any conceptual framework that I
> > know of, to have situations where, for example, a large ladder can end
> > up in a smaller barn according to an observer stationary in the barn,
> > but not according to an observer riding the ladder.
>
> Why? And here we can systematically trace back to the assumptions you
> are making and then question them. In this case, you have a firm
> belief that length is definable in such a way that it is intrinsic to
> the object and frame-independent, and that physical "fitting" is a
> function of the *intrinsic* lengths of two objects (or an object and a
> container).

My only contention is that it is *not realistic* to say that from the
barn frame frame the ladder contracts and fits inside, while saying
that from the ladder frame it is the barn that contracts and the doors
actually never shut simultaneously. It is simply not realistic. If
such a thing appears to happen, then it is obviously an artefact of
subjective observation.

> > > Your disbelief of SR stems from the fact that you don't understand it.
>
> > My disbelief, really, stems from the blatant lack of conceptual
> > understanding of the theory. I mean, as I repeatedly point out, I
> > don't know a single equation of relativity, and yet I can root out the
> > conceptual contradictions immediately when people here have a crack at
> > making meaningful qualitative statements in SR. The classic example,
> > of course, was Paul's contention that "what is simultaneous in one
> > frame can never be simultaneous in another", which of course isn't
> > true according to SR.
>
> I'm sorry? It is very much true in SR that two spatially separated
> events that are simultaneous in one frame are not simultaneous in
> another frame moving relative to the first.

But I contradicted that when I pointed out that two observers can be
moving relative to each other, and yet undoubtedly events can be
simultaneous for both. I seem to remember you conceded that point when
I gave you a situation where it was true.

From: Ste on 26 Feb 2010 19:59

On 26 Feb, 17:46, PD <thedraperfam...(a)gmail.com> wrote:
> On Feb 25, 9:42 pm, Ste <ste_ro...(a)hotmail.com> wrote:
>
>
>
>
>
> > On 25 Feb, 17:15, mpalenik <markpale...(a)gmail.com> wrote:
>
> > > On Feb 24, 10:22 pm, Ste <ste_ro...(a)hotmail.com> wrote:
>
> > > > I'm afraid I don't accept that this captures the certainty that many
> > > > people have in various scientific theories. I've just responded to
> > > > Mark who said that a theory with a 95% confidence should be accepted
> > > > universally by all
>
> > > I said I'm done with this conversation, but I'm not going to let you
> > > misquote me, you pathetic idiot.
>
> > > I said "it should be accepted by all as HAVING A 95% CHANCE OF BEING
> > > TRUE". I did not say it should be accepted as being true. I said it
> > > should be accepted that THERE IS A 95% CHANCE THAT IT IS TRUE BY
> > > EVERYONE. THERE IS A DIFFERENCE. I REPEAT, I DID NOT SAY IT SHOULD
> > > BE ACCEPTED AS TRUE--IT SHOULD ONLY BE ACCEPTED THAT THERE IS A 95%
> > > CHANCE THAT IT IS TRUE.
>
> > > If you are so mentally degenerate that you can't understand the
> > > difference, then it makes me wonder how you can make it through your
> > > every day life, you moronic imbicile.
>
> > > Once again, I will not discuss anything with you, but I sure as hell
> > > am going to call you on it if you make retarded inferences about
> > > things that I've said and then try to pass that off as my viewpoint.
>
> > Calm down. I see that perhaps I did explicitly misquote you, although
> > I'm not sure the inferences were so wrong.
>
> > If people accept that a particular theory has a 95% confidence, then
> > what are you saying they should do as a result? Do you think they
> > should devote just 95% of their time to that theory? 100% of their
> > time? Some other percentage?
>
> > And aside from what you think they should do, what do you think they
> > *actually* do?
>
> There's a variety of things one can do (and are done).
> 1) Explore other candidates, though at a level that is commensurate
> with risk-benefit analysis of the effort involved.
> 2) Continue to do other tests of this model vs other models to see
> where the 5% might lead (to either opening it up to 40% or closing it
> to 98%, say)
> 3) Let the community by itself determine organically which volunteers
> from the community will plumb the 5% doubt.
> 4) Design a bunch of devices that are based on a 95% assurance that
> the principles of that model are correct, again weighing risk vs
> benefit on the chance this is a mistake.

That's fair enough in abstract. But the question is still who pursues
which avenue, and what subjective perception they have of the
likelihood of a particular theory being correct.

After all, it's alight for scientists to pay lip service to doubt when
questioned strenuously. But what of their day-to-day conduct? And what
are their views of scientists who explore other avenues than
themselves?

From: Ste on 26 Feb 2010 20:00

On 26 Feb, 18:20, PD <thedraperfam...(a)gmail.com> wrote:
> On Feb 26, 1:31 am, Ste <ste_ro...(a)hotmail.com> wrote:
>
> > > In what sense can it be said to work if it doesn't predict what is observed.
>
> > It does predict what is observed, but only in a very loose way,
>
> No. It *accommodates*, it does not *predict*. And this is where there
> is a difference.
> It is one thing to say that a certain behavior is *conceivable* within
> a mental picture, it is another thing entirely to say that it is
> *demanded* from a model. A prediction is usually precise enough where
> it will be able to say, "you will see behavior X in quantity Qx,
> behavior Y in quantity Qy, and behavior Z in quantity Qz, but you will
> NEVER see behavior W and you will not see behavior Z in any other
> quantity." This your mental picture does not do.

But it does for example. My mental picture says that gravity will
never become stronger with increasing distance. That is a firm
prediction.

From: Paul Stowe on 26 Feb 2010 20:06

On Feb 26, 5:00 pm, Ste <ste_ro...(a)hotmail.com> wrote:
> On 26 Feb, 18:20, PD <thedraperfam...(a)gmail.com> wrote:
>
> > On Feb 26, 1:31 am, Ste <ste_ro...(a)hotmail.com> wrote:
>
> > > > In what sense can it be said to work if it doesn't predict what is observed.
>
> > > It does predict what is observed, but only in a very loose way,
>
> > No. It *accommodates*, it does not *predict*. And this is where there
> > is a difference.
> > It is one thing to say that a certain behavior is *conceivable* within
> > a mental picture, it is another thing entirely to say that it is
> > *demanded* from a model. A prediction is usually precise enough where
> > it will be able to say, "you will see behavior X in quantity Qx,
> > behavior Y in quantity Qy, and behavior Z in quantity Qz, but you will
> > NEVER see behavior W and you will not see behavior Z in any other
> > quantity." This your mental picture does not do.
>
> But it does for example. My mental picture says that gravity will
> never become stronger with increasing distance. That is a firm
> prediction.

But, in both the center of a spiral galaxy and the center of mass the
gravitational potential is zero, increasing in strength until one
reaches either the surface of a solid planet or, in the case of a
galaxy the rotation speed verses area density starts to drop off. So,
while I understand where you are coming from, technically, you're
wrong.

Paul Stowe