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Saturday, December 12, 2009

Sounding Off on the Dark Matter Issue

Fermilab

If dark matter can pull gravitationally, it has mass

So here is an article of 2006 with some interesting information. Now these experimental procedures are always interesting to me because of the type of detectors that were dreamt up in which to measure some aspect of the reality supposed, and realized, by noise in the background.


For scientists to "hear" a dark matter particle, it must hit an atom in one of the crystals at the heart of the CDMS detectors. The crystals are kept cold—close to absolute zero—to reduce atomic movement, keeping the crystals quiet. The detectors "listen" for vibrations inside the crystal, like ears listening for vibrations in the air.

The detectors contain two kinds of crystals, germanium and silicon. A germanium atom is larger than a silicon one: Its nucleus has 73 protons and neutrons compared to silicon's 28. This size difference helps CDMS sort out yet another source of background—neutrons. High-energy cosmic rays and radioactive decays in the matter surrounding the detectors can produce neutrons. Hitting atoms in the crystals, these neutrons cause a "sound" in the detectors similar to the one made by the predicted dark matter particles.
See: Listening for whispers of dark matter




Model of the Cryogenic Dark Matter Search which translates actual data into sound and light. We have not yet had a dark matter interaction, but we have lots of particles hitting the detectors and that is what you are watching. A downloadable version is at my webpage http://www.hep.umn.edu/~prisca More info on our experiment can be found at http://cdms.berkeley.edu and http://www.soudan.umn.edu

So lets mover forward here to Dec 10, while waiting to hear on Dec 17 for more news.

The CDMS collaboration has completed the analysis of the final CDMS-II runs, which more than doubled the total data from all previous runs combined. The collaboration is working hard to complete the first scientific publication about these new results and plans to submit the manuscript to arXiv.org before the two primary CDMS talks scheduled for Thursday, Dec. 17, at Fermilab and at SLAC. See:The search for dark matter:has CDMS found something?

Update:
Latest Results in the Search for Dark Matter
Thursday, December 17, 2009

Dark Matter Detected, or Not? Live Blogging the Seminar

by JoAnne

8 comments:

Steven Colyer said...

I have a question. Will the results on Dec. 17 out of Minnesota claim to prove Dark Matter, or disprove (falsify) it?

Well, I guess we'll have to wait until Dec. 17th won't we? Unless somebody on the inside leaks before then, of course.

In any event, how will this affect John Moffat's MOG i.e., Scalar-Tensor-Vector Theory that is MOdified Gravity Theory?

Plato said...

Steven:In any event, how will this affect John Moffat's MOG i.e., Scalar-Tensor-Vector Theory that is MOdified Gravity Theory?

Honestly Steven I did not know very much until I started reading and realized Variable Speed of Light was something I had come across as I was doing my own research on João Magueijo's VSL an area John Moffat was working on. I had recognize Lee Smolin's help in this area of quantum gravity search.

Glast/Fermi was much on my mind then as well calorimetric measures.


Modified Gravity Theory:The resulting theory describes well, without invoking dark matter, the rotation curves of galaxies and the mass profiles of X-ray galaxy clusters.

This also revive some interest in Sean Carroll's work. Here as well.

I am not sure if this is conclusive evidence, but part of my "recursive thinking" is that something has to be a contributor to the state of the universe? A arrow of time perspective and time that flows one way(?), how can such a feature exist?

Local regions in space had to somehow contribute and in seeing the jets in production I thought this relevant. Relevant to the state of the universe at any given time. What are then the contributing factors to dark matter? How can gravity not be associated without this factor inclusive in the arrow of time scenario as the universe?

Best,

Plato said...

Scalar-Tensor-Vector Gravity Theory

The equations of motion for a test particle lead to a modified gravitational acceleration law that can fit galaxy rotation curves and cluster data without non-baryonic dark matter. The theory is consistent with solar system observational tests.

I'll certainly have to do some more reading.

Steven Colyer said...

More reading ?! LOL, who doesn't have to do that? :-) Aye yai yai, that's the thing about Knowledge. The more you read, the more ignorant you feel, because you realize how much more there IS to know! And you don't know it! :-)

Yes, well thanks for those links. I already read the Wiki ones. The Sean Carroll ones were interesting, thanks. In the first link I see SciFi author Greg Egan of Perth, Australia weighs in (post #23). Egan is a friend of former loop quantum gravitationist John Baez and one of the best informed Sci-Fi authors on the planet. I recommend Schild's Ladder by him for the uninitiated.

In any event, remember that MOG requires a fifth force to work (as does Technicolor, extended Technicolor, and walking Technicolor), just as Kaluza-Klein theories (String theory) require a 5th dimension, or more.

And we have proof of none of them. Not yet, and not ever if they don't exist.

Plato said...

Steven:In the first link I see SciFi author Greg Egan of Perth, Australia weighs in (post #23). Egan is a friend of former loop quantum gravitationist John Baez and one of the best informed Sci-Fi authors on the planet. I recommend Schild's Ladder by him for the uninitiated.

Yes, I found Greg Egan's work quite early as well, as leading perspective under "methods of measure." It was about the same time Robert's orbitals(self-similarity) made their appearance.


Periodic Impingement Orbits:Interference Patterns?I was looking for the right image to show this rotation and quickly I find Greg Egan's for consideration here, but I had another one as well. When I find it will bring it back for consideration

It was in Egan's work that a certain visualization in my mind makes it's way toward identification of how one may interpret quantum chlorophyll as a photosynthesis process toward finalization of the energy "from any direction."

This is important, not just a holographic understanding of photocells.

Of course who hasn't heard of John Baez.

In my perspective electromagnetism needed to be joined to gravity, and thus initiates the basis of my color of gravity. What did the photon come to mean then as it represented itself in a artistic sense for me as it represented then environ through which it passed?

Computerization work then becomes significant in terms of the geometries of expression and how we see in a 5d. Banchoff's work is leading here. A 2d version of our computer screen representing a 5d expression.

There is some confusion as you say for me that when I read more, the links between the neurons greatly expand them self, while rogue images formulate while the information is not all totally connected.

Gravity Wave Spectrum You'll never look at the universe the same again?:) Let's see how color in painting changes as one garners these principles in science?

Best,

Steven Colyer said...

Ha HA! Whoo hoo! Dark Matter has NOT been detected, or it "may have been" in Minnesota, but only within 1.5 Sigma, which is the same as background noise!

What an inCREDible disappointment!

Looks like we'll have to take a closer look at John Moffat and his MOdified Gravity Theory.

Wow.

Thanks for your links, Plato.

Plato said...

Hi Steven,

I guess they might as well stop the next phase since the results were conclusive?:)

As to John Moffat, should continued experimentation stop a theoretical approach?

The inductive/deductive process I mention to Phil is a foundational one here in Dialogos of Eide as demonstrate in Raphael's painting that highlight the baner of this blog.

Perfecting the way in which deductions takes place can be correlated to the way in which experimentation has to take place.

Nothing is conclusive until it has become "self evident." This is Phil's mistake.

Understanding the truth of it while the verdict is still out?

Best,

Steven Colyer said...

Oh no Plato, I'm all in favor of further Experimentation and look forward to the results.

I should point out that I am heavily skeptical of SUSY to begin with, but am open-minded enough to change my mind if further experiments prove supersymmetic particles exist.

I highly doubt it, though. It seems far too neat, too ad hoc IMO. String Theory collapses without it and it's back to the drawing board on The Hierarchy Problem if or when SUSY particles are NOT detected when they should be, either at Minnesota, Tevatron, or the LHC.

As far as Dark Energy and Dark Matter are concerned, I very much suspect a Geometrical explanation will suffice rather than a Particle one but shrug, who knows?

The experiments are up and running, the satellites are collecting their data, and hopefully very soon we can move out of this very unsatisfying "Age of Speculation" we have been in for the better part of a generation, and actually LEARN stuff.

Very exciting.