Bottom photomultiplier tube array on the XENON 100 detector. Credit: the XENON collaboration

No Joy for Dark Matter Detector’s First 100 Days

15 Apr , 2011 by

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We’re still mostly in the dark about Dark Matter, and the highly anticipated results from the XENON100 detector has perhaps shed a tad more light on the subject – by not making a detection in the first 100 days of the experiment. Researchers from the project say they have now been able to place the most stringent limits yet on the properties of dark matter.

To look for any possible hints of Dark Matter interacting with ordinary matter, the project has been looking for WIMPS — or weakly interacting massive particles – but for now, there is no new evidence for the existence of WIMPS, or Dark Matter either.

The extremely sensitive XENON100 detector is buried beneath the Gran Sasso mountain in central Italy, shielding it from cosmic radiation so it hopefully can detect WIMPS, hypothetical particles that might be heavier than atomic nuclei, and the most popular candidate for what Dark Matter might be made of. The detector consists of 62 kg of liquid xenon contained within a heavily shielded tank. If a WIMP would enter the detector, it should interact with the xenon nuclei to generate light and electric signals – which would be a kind of “You Have Won!” indicator.

Dark Matter is thought to make up more than 80% of all mass in the universe, but the nature of it is still unknown. Scientists believe that it is made up of exotic particles unlike the normal (baryonic) matter, which we, the Earth, Sun and stars are made of, and it is invisible so it has only been inferred from its gravitational effects.

The XENON detector ran from January to June 2010 for its first run, and in their paper on arxiv, the team revealed they found three candidate events that might be due to Dark Matter. But two of these were expected to appear anyway because of background noise, the team said, so their results are effectively negative.

Does this rule out the existence of WIMPS? Not necessarily – the team will keep working on their search. Plus, results from a preliminary analysis from11.2 days worth of data, taken during the experiment’s commissioning phase in October and November 2009, already set new upper limits on the interaction rate of WIMPs – the world’s best for WIMP masses below about 80 times the mass of a proton.

And the XENON100 team was optimistic. “These new results reveal the highest sensitivity reported as yet by any dark matter experiment, while placing the strongest constraints on new physics models for particles of dark matter,” the team said in a statement.

Read the team’s paper.

More info on XENON100

Sources: EurekAlert, physicsworld

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Torbjorn Larsson OM
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Torbjorn Larsson OM
April 15, 2011 2:54 PM
Oh, joy. – Direct search for gravitons (gravity waves) in LIGO: no joy. Direct search for Higgs in LHC: no joy. Direct search for DM in XENON100: no joy. – Constraining inflation in Planck et al: simplest eternal inflation model (square potential) starts to be ruled out. Constraining symmetries in XENON100: simplest symmetry model (supersymmetry) starts to be ruled out. Constraining DE in Planck et al: simplest dark energy model (cosmological constant) can’t be ruled out, repeatedly. (What do you know, finally some joy.) Well, sucks to be supersymmetric today. At least the funny stuff in DAMA/CoGeNT (earlier experiments) are shown to be likely artifacts. Btw, it can bear to read Jester’s article @ RésonAAnces. The 3 filtrated… Read more »
Torbjorn Larsson OM
Member
Torbjorn Larsson OM
April 16, 2011 11:14 AM
Speaking of some joy, Jennifer Ouellette has an update clarification from Robin Stebbins, NASA’s Project Scientist for LISA dated 13/11: “LISA has not been cancelled. No money or other resources has been reprogrammed. The two agencies have ended their work on a joint project. ESA has ended the partnership with NASA, because NASA is financially unable to participate when ESA’s funding is available (2015). To preserve their program, ESA’s must solicit a downscaled mission concept that does not rely on the availability of NASA funding, which they are doing. With ESA out of the partnership, NASA has, of course, ended its participation in the partnership, and will proceed in other ways. That could be a minority role in… Read more »
Lawrence B. Crowell
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Lawrence B. Crowell
April 16, 2011 11:53 AM

This does put the program at risk. The prospects for successful detect of gravity waves are reduced. I do not know what is meant here by a downscaled mission, but this might imply a reduction in the signal to noise ratio.

LC

Bryan
Member
Bryan
April 15, 2011 3:03 PM

This may be because of my lack of understanding or knowledge, but couldn’t neutrinos interact with the liquid xenon? Why would WIMPS enter the detector but other particles would not? Or is that part of the noise that was mentioned?

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
April 16, 2011 8:34 AM

I assume they could. The link in my comment takes you to a graph & discussion of how they filter out events:

“Most of the events in the plot are due to photons scattering on electrons from the xenon atoms. The way to distinguish those from the more interesting nuclear recoils (expected when a dark matter particle scatters) is by simultaneously measuring the number of ionization electrons, […].”

[I haven’t hunted up if and how they handle neutrino events, though.]

pbfred
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pbfred
April 15, 2011 4:39 PM

{Violation of comment policy: text deleted.}

Astrofiend
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Astrofiend
April 15, 2011 11:43 PM

Let me get this straight. You have placed ‘test masses’ in between a ‘1000W hot source and a cold source’, and then measured a change in their weight of up to 16%?

Jesus mate – get some perspective. An effect of that magnitude would be blindingly and obviously noticeable in everyday life. Do you honestly think that by tinkering in your garage you have found a new effect unknown to physicists of the sort of magnitude you’re indicating? Do you honestly think that the great experimentalists of the past would have missed something like this? I mean, just think about it for two seconds.

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 16, 2011 10:22 AM

Is that why I weigh so differently before and after I have a cup of coffee or tea or have a hot shower? All this time, and I thought it was the bathroom scales!

Has this pbfred ever heard of the Kirchhoff’s law of thermal radiation? If it were true it would break the basis of thermal equilibrium, and destroy the equivalence of emissivity and absorptivity; let alone matter’s absorptivity and power.

…But go a ahead and ignore them, too.

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 16, 2011 10:45 AM

As George Orwell said, “To see what is in front of one’s nose needs a constant struggle.”

Isn’t this one of the exact reason why one should never consume illicit drugs!

I’m also interested that this theory is already two or more years old. Is there some reason why the scientific world has already rejected it as nonsense?

Also, why hasn’t your paper been published in a Physics Journal.?
viXra and arXiv are both pre-publication sites for comment and scrutiny prior to papers being publishing. So have all the good physics journals you have approach simply rejected the information contained in your somewhat alleged ‘paper’?

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 16, 2011 11:42 AM
This text from vixra (ArXiv backwards.) http://vixra.org/why explains it all. “A few of the cases where people have been blocked from submitting to the arXiv have been detailed on the Archive Freedom website, but as time has gone by it has become clear that Cornell have no plans to bow to pressure and change their policies. Some of us now feel that the time has come to start an alternative archive which will be open to the whole scientific community. That is why viXra has been created. viXra will be open to anybody for both reading and submitting articles. We will not prevent anybody from submitting and will only reject articles in extreme cases of abuse, e.g. where… Read more »
solarx2
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solarx2
April 16, 2011 12:36 PM

wow! bro, you really get choked up by the EM loonies huh!? lol! I wouldn’t worry about it too much, not many people are dumb enough to be fooled by this sort of nonsense… It seems obvious that in the face of the deep dark unexplainable mysteries of the universe, science will always use the best available description. I may not understand the math of it, but if science hasn’t suddenly converted to plasma cosmology then there’s probably a good reason why. This all seems totally obvious and I don’t feel the general public is at any real danger of being woefully mislead or deceived by this stuff.

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 16, 2011 12:56 PM

You may be right.
However, plasma cosmology is after recruits, and they seem to be getting a few of them. They are clearly more dangerous when they organised, but why should anyone be lead astray when they exploit others by using half-truths?
Frankly it still disgust me when people lets them get away with it.
(UT here doesn’t seemed to bothered by pseudoscience as long as your “nice”. They need to be more proactive in this regard, and just delete the garbage.)

Cheers. I’ll serious take your sensible point into consideration. Thankx!

Olaf
Member
Olaf
April 16, 2011 4:48 PM

My studies show a 1.9%, 8.9%, 9.6% and a 16% increase in the weight of the test mass when these test masses were placed between a 1000 W hot source and a cold source.

So you claim that the meat I put in my barbecue gains 3×16% mass?
My Barbecue is 3000 W!

I tell you one thing, you never did these tests.

And E=mc^2 will indeed increase the mass of my meat, but C^2 is an awful big number and I tell you that even not a hydrogen fusion bomb of energy would add one nano-gram to my meat.

Olaf
Member
Olaf
April 16, 2011 5:27 PM

Ok correction, a theoretical 100 Megaton Tsar bomb with 4.2e17 Joule would add 4.67 kg to my meat on my Barbecue.

Shikyo
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Shikyo
April 15, 2011 4:44 PM

What if there is no dark matter? what if gravity doesn’t work the way it is currently theorized?

Olaf
Member
Olaf
April 15, 2011 6:28 PM

You mean that all our satellites and space ships we launched into orbits of other planets are impossible to be there?

Gravity actually works great.

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
April 16, 2011 8:40 AM

That is the MOND idea, among others.

First, it won’t work to predict DM observations such as clusters, since you can’t fit one such theory to all individual observations.

[You can turn that around, and say that DM doesn’t predict galaxies as good as MOND, say. But then MOND will be small (as in few good predictions) and an isolated ad hoc hypothesis.]

Second, IIRC there are independent GR tests out to many z (huge redshift, ie long distances) to rather good precision.

lotusface
Member
lotusface
April 15, 2011 5:42 PM

I have a feeling that the unknowns from all of the separate branches and fields of science will have similarities, or roots which are shared through their interactions which are observed by some or all of the many fields of scientific study.
I.e. unexplainable phenomena should be put in the center of a table with representative from all fields and factions thereof there to do a skunkworks type brainstorm session. I feel that the unification of all scientific effort will be the unlocking of the greatest secrets of the universe.

Olaf
Member
Olaf
April 15, 2011 9:54 PM

This is what is already happening, as peer review and scientific publications.

Mr Mike
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Mr Mike
April 16, 2011 2:43 PM
@ Olaf I agree, however, the real reason there is not more progress toward a general solution for these events and conundrums we see and their causes is the lack of comradely feeling induced by significant quantities of humor, wit, beer for some, mirth for others. Get the folks into a room and toss the data in the air, some will grab a bit of fluff to be sure but that is the way of a brain-storming session. The rapid interactions work to an advantage in the search for a reason, a cause, rather than a more considered and staid approach to the matters as is common in both publications and peer review. Those are the things we… Read more »
Peter
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Peter
April 15, 2011 11:16 PM
Larsson, I can’t make sense of your fourth paragraph. Does it need a “Is it” in front of the second sentence? pbfred, the object with the MOST gravitation is a black hole. NOT very luminous. Also, Earth hardly has any intrinsic luminosity, lightning here, forest fire there, and it weighs every bit as much as we think it should. Methinks your theory is silly at best. I think much of this will be explained through some wildly divergent theory like other dimensional influence. The dark stuff is there but undetectable? Surely, it’s just an effect from real matter in another universe. Gravitons/gravity waves is another matter altogether tho, and for Einstein’s sake, I think we ought to come… Read more »
Torbjorn Larsson OM
Member
Torbjorn Larsson OM
April 16, 2011 8:48 AM

Huh. I though that Q&A was a common english construction; the 4th and 5th paragraph goes together, separated for effect only:

“The 3 filtrated events after the unblinding of data “that passed the S1 coincidence requirement only because of correlated electronic noise that is picked up from an external 100 kHz source” that the paper speaks of?

They “were static from the electric can opener wink ”.”

English isn’t my primary language, so it will lack nuance that should be there and try to insert nuance that shouldn’t be there. I’m sorry for the confusion, and glad for any and all help!

Lawrence B. Crowell
Member
Lawrence B. Crowell
April 15, 2011 11:33 PM
Dark matter exists. Based on the Einstein lensing of distant objects by nearer galaxies it is very clear there is an excess amount of mass in these galaxies than what can be accounted for as ordinary matter. The collision between two galaxies in the Bullet cluster also illustrates how this dark matter passed through the collision, leaving the “sticky” luminous matter to clump together. The spacetime curvature associated with DM exists outside of the luminous stuff. I am not going to go through those arguments in detail, but it is very clear there exists by a ratio of 5:1 nonluminous matter or dark matter in the universe. This is not to be confused with dark energy, which is… Read more »
Torbjorn Larsson OM
Member
Torbjorn Larsson OM
April 16, 2011 9:06 AM

I had to take a crash course on that.

PAMELA detects excess positrons from the direction of the galactic centre. I also found that pulsars, such as the Geminga and others in that very direction, are believed to be mundane sources of excess positrons.

So while positron excess is good indirect data for weakly interacting DM, it is also, presumably, good indirect data for pulsars which we already know exist.

Is there any data to distinguish between those two predictions?

Question
Member
Question
April 16, 2011 11:24 PM

my unhappiness with your definitive “Dark matter exists” statement is cancelled out by my happiness for your suggestion that ” the assumption DM is made of particles [might be] wrong”.

so i guess that leaves me feeling… neutral. it’s obvious that some explanation is needed to explain the observations: perhaps a form of true mass, an unknown extension of a known force (or combination of forces), a currently unknown “new” force, or simply an error in observation / interpretation of data.

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 17, 2011 6:37 AM
I do get your point, but I basically disagree in what you say here. “Dark matter exists”, because we observationally see its gravitational signature. The actual problem is we are still uncertain what the composition of that dark matter is. This is made worst by the possibility of the existence of dark energy (as a force.) [It is like Darth Vadar using “the force.” You see it in action, but explaining how it is manifested in the physical world is the real fundamental problem!] In the nittty-gritty of it all, Lawrence here has not contradicted himself. The other point is that in physics all matter and energy are interchangeable (equivalence). We assume that dark matter and dark energy… Read more »
wjwbudro
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wjwbudro
April 17, 2011 6:13 PM

If indeed “equivalent” then how can we reconcile the proposed density ratios? Not a challenge, just a question.

HOLOGRAMUNIVERSE@wordpress.com
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The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 16, 2011 3:11 AM

” Good bye Universe Today…”

Good bye Mr. Hologram. You should have moved on after your first post. You will not be missed!

Please. Get some help for your unsubstantiated delusions.

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 16, 2011 6:41 AM
“Newtonian Gravity is not plasma…” This guy is a freaking genius!!! Who among us didn’t know this basic fact. We all must be dumber than dumb. Oh dear. …as for the rest of the diatribe, I have never read so many very simple mistakes, completely wrong theory, and combinations of totally unrelated parts of science. Even creationists do not make such wild claims! Worst all these alternative claims have absolutely no observational basis. ANY scientific theory must be able to explain the phenomena and provide observational tests or avenues to investigate to support the framework. The foolishness here is this individual is dismissing the science even before the experiment is complete. It takes not just 100 days, but… Read more »
Greg
Member
Greg
April 16, 2011 7:31 AM
If you want me to even consider any of these wild claims then at least do me the favor of providing references that validate them. The more exceptional the theory, the more exceptional the evidence must be. These would provide a much needed break from a post that is otherwise painful to read. The lack of a dark matter detection is not surprising at this stage. There is a wide consensus that dark matter exists, but there is still much speculation about what it is composed of. As more evidence piles up the case has become more convincing for dark matter and less convincing than MOND or other competing theories. I am one to bet that the size… Read more »
The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 16, 2011 10:01 AM
I do often either discredit individuals like this one and take a chance of UT moderator would not (again) silence me. Most I know question why even I do not just ignore such people, but now and again I am so dumbstruck I am lost for words. However in this case, I think it is very worthwhile to actually rationally point out the many, many wrong things of this illogical post. “Light speed slows down ~5,000 miles per sec passing through water, and no perfect vacuum exists for a constant c and relativity to be real.” Plainly you deny relativity, which is probably the most proven and test theory in science. The density of water is so much… Read more »
tripleclean
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tripleclean
April 16, 2011 12:51 PM

HSBC keep it up!

Dav_Daddy
Member
April 18, 2011 10:29 AM

Vorticle Heliospheres? That sounds really cool! But what does it mean. HSBC wait a minute I’m not sure about where your from but in my neck of the woods when a man invents a new word he also gets to make up the definition. Lol you know like pertnerts, or tig bitties. Rofl!

Button Pusher
Member
Button Pusher
April 18, 2011 1:19 PM

HSBC, ever heard of the concept “Don´t feed the Trolls” smile love your comments but feeding them will just make them grow you know, even if you feed them the truth smile

Anyways interesting article and i always love the mini dramas in the comments.

Aqua4U
Member
April 16, 2011 12:17 AM

Short story subject: Dark matter… another distraction? Sometimes it seems that there are nefarious forces at work whose intentions are meant to slow scientific progress? The injection of qualified distractions might work… So who might have gone down that lane before? or seen the results of a chase after dark matter elsewhere and decided to use that here… to slow things up.

Aqua4U
Member
April 16, 2011 12:25 AM

Been reading too much Sci Fi….

Aqua4U
Member
April 17, 2011 3:42 PM

I missed completely ‘Holographicgalaxy’s statements… probably a good thing? It was not my intention to set off another firestorm – all too easily done within this forum – rather, I wanted to point out the possibility, however remote, that mankind’s progress toward the stars sometimes appears intentionally slowed by elements whose goals are counter to our evolutionary expansion into space.

Continuing along this line of thought. WHY would an outside element determine to slow our reach for the stars? We’re a peaceful, organized society here on earth. All beings are treated equally, even the fish in the sea are given their lead…

sol88
Member
sol88
April 16, 2011 5:08 AM

@holograph

Way to go bud! How many days are we going to give in the hunt fo DM?

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 16, 2011 6:43 AM

According to this guy… less than a nanosecond!
That is also equal to the time it takes to know everything being said is so wrong.

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
April 16, 2011 9:18 AM
I note that it is only 99.99 % plasma now. An order of magnitude step in the right direction, perhaps. How many days are we going to give Fair question. It is only the area itself (with some input from money “investors”) that can answer that. Generally the question ties into the general ideas of the field, how useful the research is if still not complete, how easy it is to test. As an example, string theory has been on the table long. It is difficult to test, but has: – given vital results as shoring up old results (black hole entropy, say) – supported new ideas (holography, supersymmetry, multiverses) – given new calculation tools (models of quark… Read more »
Torbjorn Larsson OM
Member
Torbjorn Larsson OM
April 16, 2011 9:27 AM

Oops, I forgot: ~ 96 % of the universe content (besides spacetime itself, natch) is _not_ plasma.

Which is why the “99.99 %” figure is so funny. I believe it derives from applying the figure for our solar system, 0.1 % of mass non-plasma (Jupiter vs Sun), without considering the standard cosmology. It is “a heliocentric” cosmology, if you will.

Oh well, at least it isn’t “flat Earth” or geocentric cosmology, it is just pre-relativity. That is pathological science progress, I guess.

Lawrence B. Crowell
Member
Lawrence B. Crowell
April 16, 2011 12:25 PM
The argument that gravitational lensing is an optical effect due to a changing index of refraction is one way of modeling weak gravity. One thing which occurs is that the index of refraction is dependent on the radial distance to the gravity source n = n(r) , which pretty much corresponds to the Schwarzschild g_{tt} metric term n(r)^2 = g_{tt} = 1 – 2GM/rc^2 This means the index of refraction in a weak gravity case (2GM/rc^2 << 1) has the functional appearance of a gravity field. As the saying goes, if it looks like duck, … well this is due to gravitation and the curvature of spacetime. The claim negative pressure is not gravity is interesting. Of course… Read more »
The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 16, 2011 12:33 PM

It is a deliberate fraud. (See my last response.)

Lawrence B. Crowell
Member
Lawrence B. Crowell
April 16, 2011 5:08 PM
All of this EU stuff is wrong, and in a sense a fraud. I am not sure what the motivation is for the fraud. It might be that these people have an idea of how they would like the universe to be, which is contrary to how we have come to understand it. This is similar to religion, where the denial of evolution and other aspects of science are ultimately due to the fact these contradict the hopes believers have surrounding their origins, the nature of sin and their eternal salvation from it. By steadfastly promoting EU on these means they are promoting a sort of delusion amongst themselves and trying to project it onto the rest of… Read more »
Richard Kirk
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Richard Kirk
April 16, 2011 2:21 PM
I worry that someone who visits UT but does not understand much science (nothing wrong in that in itself – very few of us understand all of it, and I am certainly not one of them) might mistake the strong sentiments expressed herein for some disagreement between scientific cliques. It is not completely unknown for astronomers to disagree. Look up the story of Fred Hoyle: he was a fine scientist, but his arguments may look similar in tone to the ones we see here. For years, he fought against the idea of the Big Bang, and would readily accuse his detractors of fraud and censorship, and used the media freely. Here is a comment of his after he… Read more »
alcyone
Member
alcyone
April 16, 2011 9:38 PM
EU = D (D is disinformation). Anti-intellectual, anti-science, religious and political ideas co-mingle on the web and vector in this case to the comments section on UT. This movement, if I can call it that, sees an opening where it takes advantage of the current situation in astronomy and cosmology where things like dark matter and dark energy cannot be fully explained because the tools of science have not yet been developed to observe and explain what they are. In addition, they know cosmological concepts, theories about time and space, relativity are difficult to understand: for a segment of the population, instead of belief, there is a void. That is the target of disinformation. The way the disinformation… Read more »
Olaf
Member
Olaf
April 16, 2011 10:50 PM
I agree, EU is the equivalent of the creationists trying to undermine evolution. The exact same quote mining, the exact same trying to sneak in doubt, the exact same technique to pretend to be interested with the intention to guide the conversation to the EU outcome, the exact same none-scientific claims… The exact same stupidity to keep on coming back even when they are shot down a 100 times. And the EU proponents have become so predictable like clockwork. When they are shot down they stay low and then 2-3 articles later they come back with the exact same message format contianing a question and then a link to some obscure astronomical paper that somehow contain that one… Read more »
Aqua4U
Member
April 17, 2011 10:32 PM

Tra la! Watts that you say? That is, if I apply my voltage squared over your resistance!

Aqua4U
Member
April 17, 2011 10:34 PM

Shocking….

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
April 20, 2011 11:24 AM

That would have been funny if it had any relevance. As it is, there is no potential here, so no energy in the argument.

Dav_Daddy
Member
April 18, 2011 11:14 AM
Personally I give Creationists far more credibility than this PC/EU crap. Creationists often make some interesting observations. You mentioned evolution, assuming we evolved from lower primates that would mean at some point in the past we could survive with neither clothing nor shelter. What possible advantage could come from our species being less hearty? Actually I read a paper not long ago that laid out very convincing evidence that the process of evolution is more survival of the luckiest than of the fittest. But back to my point creationists at least put forth a comprehensible argument. Vorticle Heliospheres, galactic magnetic fields, along with just about everything else that I have heard is from them is incomprehensible jibberish. P.S.… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
April 18, 2011 12:37 PM

There are large scale magnetic fields with galaxies. They have very small field strengths, around 10^{-6} Gauss, but they extend over vast distances. However, galactic magnetic fields do not play quite the dramatic role EU types think they do.

LC

Aqua4U
Member
April 18, 2011 7:04 PM

Since we cannot detect intergalactic magnetic fields very well, except by measuring gamma ray deflection, or at least detect them well enough to know their entire 3D structures or strengths, then who is to say exactly how predominant their effects upon our universe is… due to scale?

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
April 20, 2011 11:36 AM
Not “who” but “what”, and that would be the weak field. As opposed to weakness of dark energy, say, the long range force of EM is not pervasive – it is a vector force, not a scalar potential. [And the dinky B field goes as r^(-3) anyway. Who would put “-dominant … effects” and “magnetic fields” in the same sentence anyway? Like gravity, _local_ effects can be awesome in special cases, say jets. Unlike gravity, _global_ effects are nuttin’, because the universe is uncharged on the whole so magnetic fields are, as matter, mere garnish on the universe. And ‘we’ know these fundamental properties and their difference, and get to know this in early studies, it is pointed… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
April 20, 2011 12:26 PM
Somebody more acquainted with this research might want to comment in greater depth to complete what I say. There are a number of ways this field is measured indirectly and estimated. It is my understanding that one method galactic magnetic fields are estimated by measuring the energy of cosmic rays associated with some source and the incident angle of deviation of these particles from the source. The force on a charged particle is F = q(vxB) q = charge, v velocity and B = magnetic field intensity. The charged particle travels on a long arc from the source (the x above is a cross product) and this is used to back out the field. Other methods involve measurements… Read more »
HOLOGRAMUNIVERSE@wordpress.com
Member

{Most of this comment was deleted, in violation of Universe Today’s Comment Policy. }

…. Crumb always says that galaxies do not even have a magnetic field, though it seems weak, the strength is enormous when compared to the sizes of galaxies, and their relative distances apart. I am very nice about him for Nancy…. (for reference to comment below)

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 19, 2011 6:30 AM
No. Most of what you write here is plainly wrong. On first read I found twenty-seven factual errors. Most of this falls into “personally theory”, and nearly of this is both unrelated to the story. Also you says; “Crumb always says that galaxies do not even have a magnetic field,” I never said that. Most galaxies are LIKELY to have weak magnetic fields. What I said was that they HAVE NO BEEN OBSERVED to any great extent. That is a big difference. You said ““Galaxies are surrounded by huge magnetic fields…” That is simply not true. it is no OK at all to bumble on about literally in dark when comes to theory on any level, however it… Read more »
The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 19, 2011 6:32 AM

Correction : HAVE NOT BEEN OBSERVED except in a few galaxies.

HOLOGRAMUNIVERSE@wordpress.com
Member
The facts and observations are blatantly obvious, that the cosmic web of dark matter is not missing any gravity, Everybody can see photos of actual real million degree cosmic filaments where galaxies form great walls, and where galaxy clusters collide. We know these are plasma forces at work in zero gravity outer space. If Crumb was to float into outer space, he would expand and blow apart, just like galaxies are doing ! The cosmic web is labeled as dark matter, just to support the big-bang model, with the intent of searching for missing gravity dark matter particles. Scientists should exclusively try to detect gravity on earth, by analyzing the changing ocean tides from the moon’s pull, instead… Read more »
The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
April 20, 2011 3:55 PM

Sorry, but, err, generally no.
(If you buy me a Virgin Galactic ticket, I could float in space, though. Ta muchly!)

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 20, 2011 4:36 AM
I have been reading up on my dark matter knowledge and the problems faced in detecting it. There is a lot of disinformation and confusion about the experimentation to find it, and most novices kind of think that there is nothing tangible to latch on to the idea. Clearly the idea has not been plucked out of the air nor has it been dreamt up for funding. So instead of attacking the naysayers, I went look for an independent article that was both balanced and informative; and importantly gives an historical background. I came across and online article that might help others get a better grasp on the topic, that is; “Nature of Dark Matter” – by Ricky… Read more »
The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 20, 2011 10:51 AM

….or at least yet another 100 days.

Torbjorn Larsson OM
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Torbjorn Larsson OM
April 20, 2011 11:49 AM

Thanks, that was a useful link, duly bookmarked! I can’t remember seeing such a DM collection before, and I learned more detail and certainly history.

Here is a good place to point out that the DAMA part is (likely) obviated by the more sensitive XENON100 negative result.

HOLOGRAMUNIVERSE@wordpress.com
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Murphy’s Dark Matter Website is factual, but they just can’t find the invisible gravity particles. Figure 9 shows the N-Body model, which is the same filamentary structure found in the SDSS 6dFGS view. The Center for Cosmological Physics at the University of Chicago, states that the greatest challenge is to understand these “dark matter” filaments within the framework of the accepted big-bang cosmology. There is actually no need to call it “dark matter”, because the filamentary structure is real and actually exists. They show galaxies and galaxy clusters forming in their simulation along these cosmic filaments. Big-bangers believe the cosmic filaments formed shortly after the big-bang, which lead to galaxies forming before galaxy clusters, and later superclusters (no… Read more »
The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 4:43 AM

zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz……

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 4:44 AM

No. Little of this is at all relevant.

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 4:46 AM

“…and am not at all alone in the scientific community of professional astrophysicists,…”

Oh dear. You’re no astrophysicist.

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 4:52 AM

Nancy, feel quite free to remove Mr. Hologram and my responses.
Really. Intelligence is one this. Being intelligible is quite another.
Clearly this latest response here is quite ridiculous and nonsensical.

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 5:03 AM

“Murphy’s Dark Matter Website is factual….”

That’s why I posted it, you digbat!

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 5:18 AM

“Newton’s gravitational constant becomes a mere approximation,”

Wow. Is an 6.67259(85) × 10?11 an approximation?

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 5:19 AM

6.67259(85) × 10-11

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 5:24 AM

“…charged relativistic moving ions in zero gravity outer space plasma.”

Hang on. Before you were saying relativity was wrong and unproven.

Eh? Ions in plasma. I though plasma was ions, that are highly ionised?

So which is it?

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 5:28 AM

Ooopsy daisy!
“I thought”

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 5:27 AM

“…holding such sound reasoning,…”

You’re kidding are you not?

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 5:49 AM

“Hooke’s Law helps explain how stars orbit a galaxy,…”
You humour is so drool, isn’t!
“Hope springs eternal”, as they say.

Holy cow!! I’d have thought the ol’ lissajous pattern or some spiral animation would be far more useful. Are you trying to hypnotise us into believing Hooke’s law us even relevant? Very strange indeed!

(Hook here, could be a sly spin on Peter Pan and Tinkerbell… “I do believe in fairies, I do I do”; but I don’t thing your that clever!)

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 6:46 AM

Actually defining spirals is mostly by the constant angular and (&betawink radial velocities (vr). Motion in polar coordinates is best described as (r, &phiwink where r(t) = r0 + vr t, and φ(t) = φ0 + βt. The spiral radius maximum (rmax) spans a finite time, where the slower radial motion relative to the faster angular motion. Effective velocity of the spiral is approximately given by the time-variable v(t) = βr(t).

This has absolutely nothing to do with Hooke’s law, or the funny caveated adoption of bouncy springs!

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 6:50 AM

Oops! “Actually defining spirals is mostly by the constant angular velocity (&betawink and radial velocities (vr).”
(Sorry. I’m more error prone today for some reason!)

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 5:53 AM

“Since galaxies are not really rounded,…”
Some are spirals. Some are even almost perfectly spherical.
Sorry. ‘Rounded’ is in two dimensional, not three dimensions.

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 5:58 AM

Oops! Wrong place.
“…flat spiral vortex nebulaes”
Please, give us at least one or two examples.

Also the word is nebula, whose plural is nebulae.
‘nebulaes’ is just needless tautology.

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 24, 2011 1:47 AM

“I hold steadfast to my rejection of the big-bang theory, and am not at all alone in the scientific community of professional astrophysicists, holding such sound reasoning, which far surpasses the intelligence and understanding capable of Crumb.”

Psst… Wanna know a real secret? The rejection is not because the Big Bang or not. Its just the utter craziness of what your mixed up and incessant mad ravings. No real prove, no real evidence, just some airy-fairy notions without a semblance of good ol’ common sense.
The Big Bang is mostly accepted because it best explains the observations and the evidence. Simple. Gosh! That took a lot of intelligence, didn’t it?

The Eclectic Exterminator of Stupid Electricians
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The Eclectic Exterminator of Stupid Electricians
April 21, 2011 5:57 AM

“…flat spiral vortex nebulaes”
Please, give us at least one or two examples.

Also the word is nebula, whose plural is nebulae.
‘nebulaes’ is just needless tautology.

wpDiscuz