Slashdot Mirror
Space Observatory May Have Found Dark Matter
KentuckyFC writes to mention that new data from the orbiting observatory PAMELA may shed some additional light on the question of dark matter. Still only a preliminary announcement, the new findings apparently support the "Minimal Dark Matter" model, in which a particle called a "Wino" is responsible.
I very often see articles saying the Dark Matter is found. This has been going on for years already. Articles titled "Dark Matter Found". But later another article pops up again saying "Dark Matter Found" and it'll have a totally different explanation, be it some new particle type, some mathematical construct, something that says that in fact it doesn't exist and it's another effect, or again another particle type. So basically, they just don't know?
lol pmg Mitch Hedberg
I've always heard the opposite... That dark matter isnt any different at all from normal matter, it's just that we don't know where it is. We know it's out there someplace because the mathmatical models rely on there being "extra" mass out there still work when compared to reality.
The linked article is a summary of a paper that has an analysis of data not written by the original PAMELA team who collected the data. The PAMELA team have not yet published their data or findings, although apparently have presented them at a conference in Stockholm.
The summary quotes the paper thusly: "The preliminary data points for positron and antiproton fluxes plotted in our figures have been extracted from a photo of the slides taken during the talk, and can thereby slightly differ from the data that the PAMELA collaboration will officially publish."
I am not familiar with the conference in Stockholm that the PAMELA data were originally presented at, but at every large conference I have attended, it is official policy that no photographs are allowed. Taking unpublished data without permission of the authors is theft, pure and simple. Submitting a paper on that data before the original authors do is unethical.
Certainly, such proclamations are made with scant and incomplete information (it could be that Cirelli and Strumia, the non-PAMELA authors, did indeed get permission from the PAMELA team, and everything is kosher), and I hope that either members of the PAMELA team or authors of the new paper might read Slashdot to explain what's going on.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
The very first thing that astronomers reached for to explain these phenomena was as yet unseen, or "dark" matter. Personally... I think Dark Matter raises more questions than it answers.
The reason they reached for Dark Matter is that it is the simplest explanation. It is very easy to imagine that there is more mass there than you can see. It is a lot harder to start adding new forces or modifying existing ones. It certainly raises new questions but that does not exclude it from being the simplest solution.
dark matter, a substance which is invisible, intangible, and undetectable expect through its gravitational effects is too far of a step for physics to take without more evidence.
Er...what do you think we are doing? We are looking for that evidence. You are contradicting yourself here: we think DM is the best explanation to date so we are now looking for evidence to confirm it. If we had "taken the step" and truly accepted Dark Matter as the truth why would we bother searching for evidence of it? Also there are very good reasons to think that it interacts through the weak force as well as gravity - although it is not a requirement.
The particle physics community has had a history of success using assumptions and models that are counterintuitive and often bizarre.
We have? What part of particle physics is counter-intuitive? I think you are getting confused between Quantum Mechanics (which is very counter-intuitive) and particle physics. The Standard Model of particle physics is generally very simple, straight forward and easy to understand at a basic conceptual level - it is even sometimes taught at secondary school level.
When a theory like MOND fails in a particular case, this has the effect of strengthening confidence in the Dark Matter model, even though it should do nothing of the sort.
Why is this wrong? If, as is the current case, all alternative theories to DM have series flaws, then you end up with only one candidate theory to test so naturally there will be more work being done on it. I think you are confusing belief with knowledge. A lot of us believe that DM is likely to be correct but none of us know it to be correct. As the best theory to date there is a lot of interest in proving it correct so we look for data to do that.
we have no way of measuring dark matter, even indirectly.
Wrong - there are ways to measure it directly but they depend on the type of dark matter. We can produce it directly in the LHC, we can search for its interactions with nuclei in low background locations deep underground like SNOlab. These experiments have already put limits on what the Dark Matter could be. So far they have not seen anything but that does not preclude them from seeing it.
Exotic matter, while it may work in subatomic circles, will not I think stand up to scrutiny in the macroscopic domain.