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Dark matter (was: Re: Arp, haltoN)

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Michael J.  Strickland wrote:

> […] Thomas 'PointedEars' Lahn […] wrote:
>> Michael J.  Strickland wrote:
>>> […] noTthaTguY <abu.kuanysh05@gmail.com> wrote:
>>>>> > Radiation pressure is stronger than gravity for all
>>>>> > matter below a certain size (radius).
>>> […]
>>> Like I said we are not even 1 light year out yet.
>>And we have already found the point, through Voyager, where there is no
>>more solar wind.
> 
> I'm not referring to the solar wind. I'm referring to the dust pushed
> out by the radiation pressure component of it.

You are contradicting yourself.  If you think that radiation pressure is a 
“component” of the solar wind, then you *are* referring to the solar wind 
when you say “radiation pressure”.

JFYI: Radiation pressure is _not_ a component of the solar wind, and 
radiation pressure decreases as the distance from the source increases.

> Solar wind consists of particles and radiation currently emitted from
> the sun.

  [You are contradicting yourself again here.]

No, it does not.

  [You might have gotten that misconception from superficial reading.  For 
   example, the Encyclopaedia Britannica (see below) says: “The orbits of 
   interplanetary dust particles are easily altered by interaction with the 
   light and charged particles (solar wind) that emanate from the Sun.”]

See also:

<https://en.wikipedia.org/wiki/Solar_wind>
<https://en.wikipedia.org/wiki/Radiation_pressure#Comets>

  [Please stop bullshitting about Wikipedia.  By contrast to your 
   statements so far, all statements there must be sourced or they can be 
   removed by anyone, and the statements that I referred to *were* sourced.]
 
>>If you considered that and did the math incorporating the
>>distance to the nearest star, you would see that “squeezing between stars”
>>is not the appropriate expression to use for the effect on any "dust" that
>>might exist between stars, and that it certainly could not account for the
>>dark matter needed to explain rotation curves and gravitational lensing,
>>the fact aside that it exhibits different physical properties than dark
>>matter.
> 
> Gravity already explains gravitational lensing. Dark matter is not
> needed.

Incorrect.

  [Which you would have known had you followed the references I gave you, in 
   the posting that you did not reply to and apparently did not even read.]
 
> The dust should accumulate at the low radiation pressure regions
> (volumes) determined by the net radiation pressure from all sources in
> space between stars.

Your dust accumulation is pure fantasy.  Have you done the math yet?  How 
far is it from the heliopause of Sol to that of Proxima Centauri (or any 
other star you consider to be "in our vicinity"), where your dark-matter 
alternative dust is fabled to exist and be "squeezed between the stars"?
 
> Was it you that implied solar systems (mass concentrated at the
> center)

A star system does not have a center; it has a *barycenter*.  (For the Sol 
System, the barycenter lies approximately 705'820 km *above* the surface of 
Sol.)

> can be treated the same as galaxies (more even distribution of
> mass).

So you are unaware of the black hole at/near the center of the Milky Way 
galaxy (and other galaxies) whose mass must be at least 4 million times the 
mass of Sol, too.

<https://en.wikipedia.org/wiki/Sagittarius_A*>

> One look at them tells you they cannot be. You give me the
> light curve and I will give you the density distribution. For
> galaxies, the light curves should plateau at greater distances (which
> they do) as the density drops.

Not even wrong.  There are *light* curves of *stars*, which can tell you if 
an exoplanet orbits a distant star in the line of sight.  And then there are 
*rotation* curves of *galaxies*, which tell you how fast material is 
orbiting a galaxy’s nucleus, relative to the distance to the nucleus.

Dark matter is a good, and the current scientific, explanation for the 
observed *rotation* curves of *galaxies* (among other things).

<https://en.wikipedia.org/wiki/Light_curve>
<https://en.wikipedia.org/wiki/Galaxy_rotation_curve>
 
>> Furthermore, you are also ignorant of the actual particle density in
>> interplanetary and interstellar space – which we now know, thanks to the
>> Voyager probes.
> 
> Wrong again. We do not know the particle density we can only infer it.
> These probes you mention (Voyager & Pioneer) are out only a tiny
> fraction of a light year

I have only mentioned the two Voyager probes; they have already crossed 
interplanetary space, and are now in interstellar space.

<http://voyager.jpl.nasa.gov/where/>

Pioneer 10 and 11 are supposed to be in interstellar space now, too, but by 
contrast to the Voyagers, contact with the former two was lost in 2003 and 
1995, respectively.

<https://en.wikipedia.org/wiki/Pioneer_program#Outer_solar_system_missions> 
pp.

> and are no where near true "interstellar space" (~2.3 ly).

Your “true "interstellar space"” is another fantasy.  Interstellar space is 
defined to begin where interplanetary space ends: outside the heliopause of 
the star, which (AISB) for Sol, Voyager 1 has reached in 2012.  For crying 
out loud, NASA officially announced it back then, based on the measured 
conditions where the probe was:

<https://en.wikipedia.org/wiki/Interstellar_medium>

> Sorry I used "about 5 ly" for the distance to the Centauri system but I
> believe that was because I've actually calculated the average star
> distance in our vicinity and it came out to about that.

Whether that is not a bold lie depends on which stars you consider to be “in 
our vicinity”.  I find it more likely that you are starting to weasel around 
your statements, to bend the facts in order to be somehow right on some of 
your points, as crackpots usually do.
 
>> Put simply, there is insufficient "dust" that could be
>>"blown away" from stars to be "squeezed between stars" even if the
>>heliospheres would be much larger than they actually are and the distances
>>between neighboring stars would be much shorter than they actually are.
> 
> Maybe there is insufficient dust now, but this dust was pushed out
> billions of years ago

No, it was not.  *This* dust *accumulation* *outside* star systems is your 
fantasy, so that you do not have to accept the scientific, confirmed *fact* 
that there is dark matter.  You are living in a fantasy world.

>>There is an interplanetary dust cloud in the Sol System (from comet trails
>>etc.), but 1) most of the dust in a star system goes into or forms into
>>stars, its planets, asteroids, and occasionally comets and 2) its mass is
>>too small to account for dark matter.
> 
> Again, we know the density of interplanetary dust in our solar system
> now, but that has nothing to do with the amount of dust that was
> pushed out early in our solar system's history.

Assuming there was such dust, how is it relevant for (a) dark matter 
(alternative) what was back then?  Dark matter does not even figure in the 
equation for star systems, it figures at the scale of *galaxies* instead, 
*now*.  AISB, no interplanetary dust pushed out heliospheres could *ever* 
account for the dark matter needed to explain the rotation curves and the 
additional gravitational lensing in distant (5 × 10⁹ light years) galaxy 
clusters.

To give you a quantitative idea of how wrong your idea is: The particles of 
interplanetary dust that can be blown out of the Sol System by the solar 
wind – instead of spiraling towards Sol – have to have a diameter of less 
than 0.5 µm.

<https://www.britannica.com/topic/interplanetary-dust-particle>

The particle density in interstellar space is 10⁶ molecules per cm³ *at 
maximum*:

<https://en.wikipedia.org/wiki/Interstellar_medium>

>>There are dust clouds where there are *no* stars in the vicinity (because
>>their solar wind *does* push the dust away within their heliosphere (but
>>different to your misconception, not it is originating from the star, but
>>the solar wind is), and they do not consist of dark matter either.
> 
> Could you please rewrite the above paragraph in coherent English?

It *is* coherent English.  You have a reading problem instead.
Further evidence of that:

> ...
> ---------------------------------------------------
> Michael J. Strickland                   Reston, VA
> ---------------------------------------------------

Which part of “That is _not_ a properly separated Usenet signature” did you 
not understand?

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

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Thread

Galactic Interface Dark Surface Alan Folmsbee <omnilobe@gmail.com> - 2016-08-09 14:12 -0700
  Re: Galactic Interface Dark Surface Michael J. Strickland <michael06582@comcast.net> - 2016-08-09 19:45 -0400
    Re: Galactic Interface Dark Surface benj <benj@nobody.net> - 2016-08-09 20:23 -0400
    Re: Galactic Interface Dark Surface Alan Folmsbee <omnilobe@gmail.com> - 2016-08-09 17:39 -0700
    Re: Galactic Interface Dark Surface Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-10 18:54 +0200
      Arp, haltoN noTthaTguY <abu.kuanysh05@gmail.com> - 2016-08-10 11:10 -0700
        Re: Arp, haltoN Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-10 20:19 +0200
        Re: Arp, haltoN Michael J. Strickland <michael06582@comcast.net> - 2016-08-10 23:27 -0400
          Re: Arp, haltoN Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-11 06:27 +0200
            Re: Re: Arp, haltoN Michael J. Strickland <michael06582@comcast.net> - 2016-08-11 06:10 -0400
              Dark matter (was: Re: Arp, haltoN) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-11 18:52 +0200
                Dark matter (was: Re: Arp, haltoN) john <johnsefton288@gmail.com> - 2016-08-11 11:59 -0700
                Re: Dark matter (was: Re: Arp, haltoN) Michael J. Strickland <michael06582@comcast.net> - 2016-08-12 06:09 -0400
                Re: Dark matter Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-13 17:27 +0200
      Re: Galactic Interface Dark Surface Mike Duffy <mqduffy001@bell.net> - 2016-08-10 21:35 -0400
        Re: Galactic Interface Dark Surface Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-11 05:48 +0200
          Re: Galactic Interface Dark Surface noTthaTguY <abu.kuanysh05@gmail.com> - 2016-08-11 13:59 -0700
            Re: Galactic Interface Dark Surface Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-08-12 06:46 +0200
              a.s.c.i.i noTthaTguY <abu.kuanysh05@gmail.com> - 2016-08-12 12:35 -0700

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