XENON100 and Dark Matter: The Real Story IV
There are a gazillion and one "dark matter" searches going on, some of which went up in flames in the xenon100 "test" that you simply don't want to accept.
You know, Mozina has been called a liar so many times, by so many people, it hardly seems worth repeating. Liar, idiot, what's the difference, really? In any case, this statement has no shred of truth in it at all. Pure garbage. Of course, the XENON100 test was not a failure, and nothing went up in flames except Mozina's wishful thinking. I have made this clear in my earlier posts
XENON100 and Dark Matter: The Real Story &
XENON100 and Dark Matter: The Real Story III. The attentive reader will note that Mozina was unable to make any substantial response, limiting himself to a few no-content one liners, and ignoring most of the posts altogether.
To begin with, Mozina rather dishonestly treats his version of the XENON100 results as if they are a definitive proof, ignoring the fact that the claims made on behalf of the XENON100 experimental results are seriously questioned by other scientists working in the field (already
twice documented by me and ignored by Mozina in this thread; see the linked posts above).
Remember that Mozina always prefers to deal with news reports and press releases, avoiding any contact with real science, or any necessity to engage in genuine intellectual exercises, whenever possible. This is a case in point, where Mozina relies on a press release, combined with its claims, and his more grandiose claims, while ignoring the scientific description of the experiment. In fact, he ignores all of the scientific descriptions of all dark matter laboratory experiments, and this makes his radical claims all the more untrustworthy. Consider, for instance,
First Dark Matter Results from the XENON100 Experiment (Aprile,
et al., 11 May 2010). One need only read the abstract to see this: "
... we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross sections above 3.4 x 10-44 cm2 for 55 GeV/c2 WIMPS at 90% confidence level. Below 20 GeV/c2, this result challenges the interpretation CoGeNT and DAMA signals as being due to spin-independent, elastic light mass WIMP interactions." Now, if we set aside the fact that the claims of the 2nd sentence are being actively challenged in the literature, and simply assume that it is true as stated, in what way does this "blow away" or "send up in flames", as Mozina likes to say, the idea of non-baryonic, non-standard dark matter? We see here, for instance, a restriction on WIMPS with a mass of 55 GeV/c
2, but the WIMP mass range is likely to be roughly 10 - 1000 GeV/c
2. Furthermore, WIMP interactions can be either spin-dependent or spin-independent, but XENON100 is directly sensitive only to spin-independent interactions. And finally, WIMP scattering cross sections are not well constrained, and might be anywhere from 10
-42 to 10
-48 cm
2, but the XENON100 experiment has restricted its claims only to cross-sections greater than 10
-44, leaving a few orders of magnitude of cross-section search space left untouched. One need only remember the caveat that these results are based on only 11.17 days of data, a very small amount for experiments of this nature. So as time goes by, and assuming the claims stand up to scrutiny, the XENON100 experiment will further restrict the parameter search space for low mass WIMP dark matter.
So if we restrict ourselves to only WIMP dark matter candidates, we can see that XENON100 has barely scratched the available search-space. Mozina seriously over-reacts to the lack of a direct detection in this experiment, ignoring both the technical scope of the experiment, as well as the very much disputed nature of the result. Mozina's posturing is exposed as pure propaganda, his usual offering in any case.
WIMP dark matter is most common in the literature because it is the easiest to look for, but do be aware that there is more to dark matter than simply WIMPS. See, for instance,
Dark Matter Candidates from Particle Physics and Methods of Detection by Jonathan Feng (9 Apr 2010);
Gif Lectures on Direct Detection of Dark Matter by Eric Armengaud (11 Mar 2010);
Direct Detection of WIMPS by David Cerdeno & Anne Green (9 Feb 2010);
Physics at underground laboratories: Direct detection of dark matter by Igor Irastorza (15 Nov 2009);
Deep Underground Science and Engineering Lab - Dark Matter Working Group 2007 White Paper by D.S. Akerib & R.J. Gaitskell (2 Feb 2009). And see the
October 2009 issue of the New Journal of Physics (an open-access online journal of physics) and scroll to the "focus on dark matter" section, for several papers on dark matter detection. These papers describe the physics of dark matter particles, and will give the reader an idea of the entire possible search space for non-baryonic, non-standard dark matter
You know this whole aversion to even "questioning" your "faith" really demonstrates the religious-like nature of what's going on. You have "faith" in some idea. You have no idea if it's really valid or not. You don't really care what the results might suggest to date, you simply "go on believing" without even a single shred of evidence to support any of the three of your made up entities.
Mozina paints a nice self portrait, describing his own completely religious, faith based position & activities quite well. There is of course a great deal of very substantial and completely empirical evidence in favor of both the dark matter & dark energy hypotheses, and this is well documented in many of my own posts on this and other threads (e.g.,
Dark Energy and Empirical Science,
Dark Matter, Dark Energy, Inflation and Real Science (copy 2) and posts cited within these). As we already know, Mozina's refuge from the truth is to invent his own personal version of "empirical" to hide behind, for fear that he might someday be forced to deal with real but unpleasant (to him) facts.
It's all really very simple when you just bother to think about it. Mass results in gravity. We look at the universe and see more gravity than the visible mass can account for. So we assume there is extra mass that we can't see (yet). Does not sound like a radical assumption to me, though Mozina will tell you it is. This observation of extra gravity (it was called "missing mass" at the time, for hopefully obvious reasons) has been the case since the early 1930's. At first it was simply assumed that the "missing mass" was just ordinary stuff (dim stars, planets, dust clouds, & etc.) that astronomers just could not see. But since then we have opened up whole new vistas of multi-wavelength astronomy; infrared & radio on the long wavelength end, and ultraviolet & X-ray on the short wavelength end. We can now see all that stuff, even over intergalactic distances, and we can see it well enough now to assert with confidence that we don't see it because it is not there, and not because we just can't look deep enough. That was the case before, but is no longer the case today. So where is the "missing mass"? If it's not ordinary baryonic matter, that only leaves unordinary, non-baryonic dark matter. A perfectly reasonable assumption, though Mozina will tell you it is not.
So can we confirm by laboratory experiment that non-baryonic dark matter exits? Been there, done that. We all know that neutrinos exist and neutrinos are, whether we like it or not,
non-baryonic dark matter. But there are not enough neutrinos to account for the astronomical observations that imply extra mass. So we have to extend the search to more massive particles. But once again, the idea is no more exotic than the simple hunch that there is more stuff laying around the universe, just like all the stuff we already know about, just more of it, and in some slightly different form, like maybe a neutrino with more mass (sometimes called a sneutrino, the supersymmetric partner for a neutrino; e.g.,
Demir, et al., 2010). Hopefully the reader will realize that none of this is really terribly exotic thinking, and the assumptions all along the way are reasonable and actually fairly ordinary. But Mozina will tell you it is all woo. Mind, he will never be able to give you a reason way, he will just say it and expect you to take his claims on faith, just as he himself takes a purely faith-based position.
Dark matter is entirely empirical and entirely scientific despite Mozina's wimpy claims to the contrary.
