Modified Newtonian Dynamics - a.k.a. "No Dark Matter"

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Modified Newtonian Dynamics - a.k.a. "No Dark Matter"
Posted by Iggle on Wednesday, November 06, 2013 12:21 PM

There was an article in the December issue of Astronomy (p.19), which for some reason I can't find on this site, about a new paper being published in the Astrophysical Journal.  Here is a summary from another site.

It seems that using MoND, scientists were able to correctly predict the movement of dwarf galaxies around Andromeda without reference to dark matter.  Many theorists have posited that dwarf galaxies must have a higher dark matter to normal matter ratio than other stellar groupings because of their behavior.  However, this team was able to correctly predict, before observations were taken, the motion of ten of these galaxies around Andromeda using this alternative model of gravity (thereby throwing out the "plug" figure that dark matter normally provides (OK, that last bit was my own editorializing)).

It seems like MoND has been around for awhile, but this may be its first big success.  As a confirmed hater of the concept of Dark Matter (for no good reason, I might add), this gives me great joy.  Ahhh....Confirmation Bias - it's like a drug.

Tags: dark matter , MoND
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Posted by Poppa Chris on Wednesday, November 06, 2013 3:11 PM

I've been a tad skeptical of Dark Matter / Dark Energy myself.  While I still maintain an open mind concerning DM/DE,  something about using a somewhat arbitrary factor just to make the math work when you can't get it to do so otherwise just doesn't ring true in my mind.  I have a similar skepticism about String Theory.  It's almost as though we dream up some sort of possibilty, however whimsical, then work up a theory to attempt to explain that unobserved possibility without any empirical evidence to back it up at all.  Then of course it becomes the latest in fashionable "boutique" theories, with everyone jumping aboard in the insane fear that if it turns out to be true they will somehow be left behind or denigrated by thier peers.  Where is the scientific method in that?

Once again, I will keep an open mind concerning these subjects.  But I will stand firm on the KISS principle (Keep It Simple - Stupid) since that principle has withstood nearly every thoughtful attack throughout the hisotry of scientific investigation. 

---Poppa Chris---

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Posted by Primordial on Thursday, November 07, 2013 12:36 PM

Iggle : I understand the need for a more suitable spproach to defining the physics at work. I have this gut feeling the answer lies in the presence of black holes.

Consider this, supermassive black holes appear to reject some visible matter as it approaches the Hill influence of the black hole however if dark matter exists, I would think it ( dark matter ) should accrete near the black hole and enter more readily into the black hole than visible matter, which can be pushed back through electromagnetic pressure generated by frictional sources, and what about the two jets which accompany this feeding cycle how much energy do they contain (?), and how much does the black hole retain as mass (?) should the dark matter be less in older galaxies (?) how all this works is a real puzzle. Just think about it.

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Posted by Poppa Chris on Thursday, November 07, 2013 4:19 PM

Agreed, Primordial.  I'm more inclined to jump on the wormhole bandwagon because of the physically observed presence of quasars and thier close relationship with black holes with thier spouting streams of X-ray radiation, which thereby give us indirect physical proof of black holes existence.  Since it is so closely related I also accept the theory of super-massive black holes at the center of galaxies.  With star formation being so much more prevelant near the galaxy centers, one could almost equate a galaxy as a "super-massive" quasar of sorts.  The same physics seems to apply to both.

To stretch the thinking a little further, (and thereby violate my own rules stated earlier) if a black hole has a corresponding quasar linked to it by a wormhole where matter consumed by the black hole is spouted out as energy at the quasar end, then why couldn't the super-massive black hole have a super wormhole with a corresponding galaxy in another location.  This would link galaxies together into thier known clusters. (the new string theory?)

None of the preceding paragraph has any supporting evidence.  But it sounds cool, so why not let it grow into the next boutique theory?  That is the question theoretical physicists and cosmologists must answer, how to channel the thought and conjecture back into the discipline of the scientific method.

---Poppa Chris---

Denham Springs, Louisiana USA

"Second star to the right - Then straight on until morning!" - Peter Pan

Celestron CPC1100GPS (XLT) - 279mm aperature, 2800mm Focal length. (f10) Celestron Ultima LX (70deg AFOV) Eyepieces 32mm thru 5mm, Canon EOS Rebel T2i DSLR, Backyard EOS imaging software, Orion Star Shoot Planetary Imager IV, Celestron Skymaster 15x70 binoculars

 

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Posted by Primordial on Thursday, November 07, 2013 5:51 PM

Poppa Chris : I'm sure some resovle will come of these mysteries, but only further technology and observations will solve these mysteries. Just an opinion.

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Posted by Tony383 on Thursday, November 07, 2013 7:04 PM

PoppaChris, I am with you on the KISS principle.  Check out this recent discussion:

http://news.vanderbilt.edu/2013/06/dark-matter/

I would lean toward a mechanism which we already know exists (electromagnetism) albeit in a slightly different form.  

"The problem with quotes on the internet is that it is hard to determine whether they are genuine"  Abraham Lincoln

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Posted by Primordial on Friday, November 08, 2013 8:04 AM

Tony383 : Deja vu, thanks for the link. I have learned someone else had the same idea, and used an inertially referenced system ( the molecule ) to establish the required inertial reference. My problem was in the establishment of an inertial reference so I assigned it the function of a seed within degenerate matter which forms the black hole, it just happens the photon and it is a photon, must have an inertial reference;  ( a mass ) a complex of a mechanism similar to the HIGGS boson and the photon, which at the time and is still one of my stumbling blocks. The amount of relativistic mass which composes this guy is enormous approximately equal to 2.72956495649X10^- 8 kg. or 1.39097135X10^22 Mev/c^2.  It has only one resonant frequency, which provides it with and isolation from electromagnetic interaction but allows it through its relativistic mass interaction with an intertial system to interact with space-time as mass.  This guy and all his derivaties take advantage of energy density within an inertial system. Just my opinion.

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Posted by Poppa Chris on Friday, November 08, 2013 10:40 AM

Great article, Tony!  Sounds like this theory will fit a lot of parameters we've discussed. 1) Simple 2) Builds upon known facts 3) Should be verifiable through experimental observation.  Simple form of electromagnetism... Excellent!  I must read more on this...

 

---Poppa Chris---

Denham Springs, Louisiana USA

"Second star to the right - Then straight on until morning!" - Peter Pan

Celestron CPC1100GPS (XLT) - 279mm aperature, 2800mm Focal length. (f10) Celestron Ultima LX (70deg AFOV) Eyepieces 32mm thru 5mm, Canon EOS Rebel T2i DSLR, Backyard EOS imaging software, Orion Star Shoot Planetary Imager IV, Celestron Skymaster 15x70 binoculars

 

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Posted by DaveMitsky on Friday, November 08, 2013 2:16 PM

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

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Posted by Bullfox on Friday, November 08, 2013 5:55 PM

I wonder to what extent dark matter and dark energy are like cold fusion and polywater.  The latter two being disproved scientific ideas based on the results of experiments at the limit of detectability and yielding very small samples for further testing.  

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Posted by Primordial on Saturday, November 09, 2013 8:33 AM

Bullfox : You are correct, something must exists long enough to establish a repeatable observation. This is one of those things, which has a great resemblance to an assumed attribute of space-time ( the medium ) , as in, eta, and mu ( permittivity and permeability )in intermediate states of induction during propagation of the quanta of an electromagnetic moment ( the photon ), which may also be compared to a magnetic quality, that being paramagnitism. Another way of looking at it is as a virtual particle, without entropy or inertial moment. Just my opinion.

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Posted by Bullfox on Saturday, November 09, 2013 10:05 AM

Promordial,

Dark matter and dark energy are incomplete ideas invoked to explain observations which have been reproduced by multiple observers.  However, it seems to me that some modification of gravity might do away with the need for both.

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Posted by Primordial on Saturday, November 09, 2013 12:23 PM

Bullfox : Yes, a good many facts about what mechanisms occupy our universe is unexplored. I do think math helps to point out possibilities, but observation helps to correct in maths choices (e.g. the magnetic nonopole, the sparticle ect. ) . I'm sure there is some underlying aspect of space-time and quantum uncertainty, which will give us a better explanation as to the properties of overall gravitational interaction.

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Posted by DaveMitsky on Saturday, November 09, 2013 5:29 PM

General relatively has been experimentally confirmed many times, as has quantum theory.  However, GR gravity does not work in the quantum realm or when singularities are involved (i.e., black holes and the Big Bang) and has resulted in concepts like supergravity and loop quantum gravity.

http://abyss.uoregon.edu/~js/glossary/supergravity.html

http://phys.org/news/2013-05-theorists-loop-quantum-gravity-theory.html

The sub-atomic particle zoo that resulted from the construction of ever-more-energetic particle accelerators led to concepts like supersymmetry (SUSY) and eventually to (super)string theory and M-theory.  String theory at least offers the possibility of uniting gravity with the other three fundamental forces to produce a Theory of Everything (TOE).

http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/particle_zoo.html

http://hitoshi.berkeley.edu/public_html/susy/susy.html

http://superstringtheory.com/blackh/blackh4.html

http://searchcio-midmarket.techtarget.com/definition/superstring-theory

http://searchcio-midmarket.techtarget.com/definition/unified-field-theory

Unfortunately, experimentally "proving" string theory, which operates at the Planck scale, is an extremely daunting task and has led to justifiably referring to it as philosophy rather than scientific theory.

Black holes were first proposed by John Mitchell in 1783 but weren't confirmed until the HST was launched and M87's supermassive black hole was able to be studied.*  Alfred Wegener hypothesized what was to become plate tectonics in 1912 but conclusive proof was not found until the 1960s.  The neutrino was proposed by Wolfgang Pauli in 1930 but wasn't detected until 1956.  The Cosmic Microwave Background Radiation (CMBR) was predicted in 1948 by Ralph Alpher and Robert Herman but wasn't discovered until 1964.

So, IMO, it's still far too early in the game to rule out dark matter and energy or to call string theory a whimsical, boutique theory

Dave Mitsky

* Convincing evidence for stellar mass black holes such as Cygnus X-1 wasn't available until the past decade and mid-sized black holes were discovered only recently. 

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

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Posted by Primordial on Sunday, November 10, 2013 4:17 PM

DaveMitsky : Thanks for the links. I agree , Mr. Einstein most likely in the formulation of the General theory of Relativity would have used the function of acceleration as the primary purpose of gravity and not the possibility the fabric of space-time at the quantum level, ( other than the relationship of permaebility and permittivity which were at that time the understanding of why the velocity of light possed the value of C) could have something to add to his formulation, be it dark matter, or the need for a variable which could change the application, dependent on the relative magnitude of its application ( as in mond ). If you look closely, the magnitude of the application relative to the Planck space-time where quantum uncertainty is most prevalent, exists a markable difference. I think the possibility of occurrances within this difference might enter into the equation. In addition, I also think the possibility of dark matter may actually occupy the Planck volume, so I do not rule out dark matter nor do I rule out mond.  Just my opinion.

Consider this bit of information possibly linking dark matter and the higgs.

http://www.astronomy.com/magazine/2012/10/why-you-should-care-about-the-higgs-boson?page=1

 

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Posted by Glitch on Thursday, March 13, 2014 11:59 AM

I think it is fairly common knowledge that Newton's Law of Universal Gravitation only applies to weak gravitational fields.  Einstein's Theory of General Relativity corrects this deficiency.

It is rather difficult to refute the existence of Dark Matter when we have maps of its distribution as a result of gravitational lensing.  Something, that does not interact with the electromagnetic spectrum, is exerting a tremendous amount of gravity.  We know Dark Matter exists because it has observable gravity, we just do not know what it is.

 

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Posted by Iggle on Thursday, March 13, 2014 1:01 PM

Glitch,

I thought this was a great short video talking about Dark Matter (Neil D Tyson).  The point is that we know something is going on, but we aren't sure if it is caused by some form of matter.  NDT actually thinks Dark Matter is a bad name for it because it implies that it is matter.

Also, Bob Berman had an article about MOND in the latest issue of astronomy.  It was the cover story.

 

Edit: well, it seems I failed in the embedding of the video.  Here's a link.

)

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Posted by Primordial on Thursday, March 13, 2014 6:44 PM

Iggle : Thanks for the link.

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Posted by Glitch on Thursday, March 13, 2014 7:43 PM

Iggle:  I think we all understand that Dark Matter is merely a label for something that we do not know what it is.  There are only two things we can say with any assurity concerning Dark Matter:

1)  It does not interact with electromagnetic radiation; and

2)  It exerts a lot of gravity.

We do not know if it is baryonic matter, although we have never found anything that exerts gravity that also did not have mass.  Dark Matter could be the hypothetical elementary WIMP particle, that no one has been able to find ... yet.  Or perhaps Dark Matter could be another hypothetical elementary particle, gravitons, bleeding over from different branes (as in M-theory), so that we witness the effects of gravity in our universe with no mass.  This is entirely speculation, of course.

In either case we know Dark Matter exists (that much is not speculation), we just do not know what it is.

 

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Posted by Primordial on Friday, March 14, 2014 9:58 AM

Iggle & Glitch: I am at the same position as Bob Berman in his article.

If I understand Mr. Einstein, he considered spacetime as a fabric, elastic dependent on mass density. I also understand he was introduced to the concept of " nothing " by a fellow physicist.

Now my question is, does space-time expand or does the nothing separate the space-time, diffusing relativistic space-time at the micro-scale dependent on the reference system of the observer(?). Does space-time curve or does the nothing as a result of this space-time diffusion result in the curving(?) Does mass influence the curvature of the nothing or of the relativistic space-time relative to an observer(?) Does space-time as a relativistic fabric increase in its substance or is it simply diffused by the nothing relative to an observer(?) Is it possible for nothing to difuse the dark matter(?). Is it possible the dark matter is simply a more pure form of space-time relative to an observer(?) Just think about it.

Something else to consider, When we were first presented with the concept of black holes, we were given the idea of the mass which initiated the black hole had left our universe and left only the space-time contraction which represented this mass. Does this separate mass from the potential energy of space-time ( gravity )(?). Just think about it.

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