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The Pioneer Anomaly & Other Breaking Physics News

Posted by kdawson on Sun Apr 13, 2008 01:30 PM
from the explaining-the-unseen dept.
Science
David Harris, editor-in-chief at Symmetrymagazine.org (a joint publication of Fermilab and SLAC), sends us to his blog covering the American Physical Society meeting now going on in St. Louis. Among the breaking physics news relating to topics we have discussed in the past: results that explain about 1/3 of the Pioneer anomaly by differential heat flow in the spacecraft; an analysis of the Fermilab Tevatron's chances of spotting the Higgs "God particle"; and a hint that an Italian team has replicated their results from the year 2000 pointing to a detection of dark matter.
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Related Stories

[+] Missing Matter... Still Missing 370 comments
squidfrog writes "Nature.com, PhysicsWeb, and the BBC all report on the latest results from the Cryogenic Dark Matter Search. 'The most powerful search yet for the Universe's missing matter has come up empty handed, contradicting an earlier study that claimed to have seen new particles.' 'A favoured theory is that the dark matter consists of Wimps (weakly interacting massive particles) about a thousand times more massive than a proton, one of the particles found in an atom's nucleus... on the rare occasions a Wimp strikes an ordinary atom, the effect should be noticeable.' 'Writing in the Physical Review Letters, the team says that while a detection has yet to occur, there is now a better idea of how much dark matter must exist.' They 'hope to improve the sensitivity of the experiment by another factor of 20 over the next few years.' What's 20 times 0? And don't tell me zero!"
[+] Mysterious Force Affects Pioneer 10 & 11 Probes 829 comments
JabbaTheFart writes "The Guardian is writing that something strange is tugging at America's oldest spacecraft. As the Pioneer 10 and 11 probes head towards distant stars, scientists have discovered that the craft - launched more than 30 years ago - appear to be in the grip of a mysterious force that is holding them back as they sweep out of the solar system. Some researchers say unseen 'dark matter' may permeate the universe and that this is affecting the Pioneers' passage. Others say flaws in our understanding of the laws of gravity best explain the crafts' wayward behaviour."
[+] Search for Higgs "God Particle" Gets Interesing 392 comments
holy_calamity writes "The Large Hadron Collider is in trouble again. It will start work sometime in spring 2008, not November this year as planned. The delay has been blamed on an 'accumulation of minor setbacks,' and comes on top of a 'design fault' that saw breakdown of magnets supplied by the competing Fermilab. Yesterday Slate nicely rounded up increasingly loud rumors among physicists that Fermilab may already have seen the Higgs particle, the 'holy grail of particle physics' the LHC was build to find."
Submission: Pioneer anomaly a step closer to resolution by PhysicsDavid (561995)
[+] Rosetta Fly-By To Probe "Pioneer Anomaly" 89 comments
DynaSoar writes "On Friday November 13th, ESA'a Rosetta probe will get its third and final gravity assist slingshot from Earth on its way to its primary targets, the asteroid Lutetia and Comet 67P/Churyumov-Gerasimenko. But the slingshot itself will allow ESA scientists to examine the trajectory for unusual changes seen in several other probes' velocities. An unaccountable variation was first noticed as excess speed in Pioneers 11 and 12, and has since been called the Pioneer Anomaly. More troubling than mere speed increase is the inconsistency of the effect. While Galileo and NEAR had appreciable speed increases, Cassini and Messenger did not. Rosetta itself gained more speed than expected from its 2005 fly-by, but only the expected amount from its 2007 fly-by. Several theories have been advanced, from mundane atmospheric drag to exotic variations on special relativity, but none are so far adequate to explain both the unexpected velocity increases and the lack of them in different instances. Armed with tracking hardware and software capable of measuring Rosetta's velocity within a few millimeters per second while it flies past at 45,000 km/hr, ESA will be gathering data which it hopes will help unravel the mystery."
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  • Sloppy editing (Score:5, Insightful)

    by Harmonious Botch (921977) * on Sunday April 13 2008, @01:33PM (#23055422) Homepage Journal
    We have three separate subjects crammed together in one article. So some of the briliant, insightful comments by my fellow shashdotters may get buried. How about three separate articles?
    Or is this a new trend? Are we going to see twenty subjects crammed into the one daily article tommorow?

    • Re:Sloppy editing (Score:4, Funny)

      by Anonymous Coward on Sunday April 13 2008, @01:41PM (#23055462)

      So some of the briliant, insightful comments by my fellow shashdotters may get buried.

      On the other hand, we may get somebody posting a fantastic Theory of Everything that shows that the other two-thirds of the reason why Pioneer is off-course is because it is being bombarded with Higgs particles while bumping into dark matter.

      But yes, I suppose that your prediction of stupid comments is also possible. It's 50/50 really.

    • You must be new here. (Score:5, Insightful)

      by Valdrax (32670) on Sunday April 13 2008, @01:44PM (#23055466)

      So some of the briliant, insightful comments by my fellow shashdotters may get buried.
      When's the last time you've read the comments section on any science article on Slashdot, particularly over discoveries in physics?

      Insightful comments are *always* buried under senseless meme-tossing and political (or other off-topic) ranting.

      • Re: (Score:2, Insightful)

        by McGiraf (196030)
        self fulfilling prophecy

      • On the Pioneer anomaly (Score:5, Informative)

        by Anonymous Coward on Sunday April 13 2008, @02:20PM (#23055624)
        I read a discussion somewhere that many spacecraft pick up a sizable electric charge and keep it (they are after all in a vacuum), and that electrostatic forces from the Sun and the solar wind are enough to account for course deviations. It's certainly true that gravity is not the only force operating out there.

      • Re: (Score:2, Funny)

        by Anonymous Coward
        buried under senseless meme-tossing

        In soviet russia, memes toss you!

      • Re: (Score:3, Insightful)

        by PopeRatzo (965947) *

        When's the last time you've read the comments section on any science article on Slashdot, particularly over discoveries in physics?
        Quite regularly thank you.

        I happen to believe Slashdot, even with minuscule expense of a subscription, is an excellent bargain.

        Except for the time I waste on whiners like you, Valdrax. As pointed out by McGiraf, do you really think you're going to improve the senseless meme-tossing by doing your own senseless meme-tossing?

  • Before LHC though? (Score:4, Interesting)

    by stevedcc (1000313) * on Sunday April 13 2008, @01:52PM (#23055504)
    The article states that Fermilab can begin exploring to 160GeV in the summer. LHC is due to be switched on before that. From all I've read, LHC has a MUCH better chance of being sure of what it finds at around those energies. I think any article on this subject can't even pretend to be balanced without discussing LHC.

    • Re:Before LHC though? (Score:5, Informative)

      by yomegaman (516565) on Sunday April 13 2008, @02:00PM (#23055540)
      The LHC will probably switch on this year, but it won't generate very much luminosity at first. Perhaps by the end of 2009 it will have made a couple of inverse femtobarns which would be enough, but it will be another year or so after that before the data are processed and analyzed. It takes quite a bit of time to understand and interpret the detector readout. The Tevatron does have a chance if the Higgs is around 160 GeV, but only with about one-in-a-thousand level statistical significance, and so far we are not seeing any excess of events there, but in fact somewhat fewer events than expected.

      • and so far we are not seeing any excess of events there, but in fact somewhat fewer events than expected.

        So you are seeing Anti-Higgs? :-)

      • Re:Before LHC though? (Score:5, Informative)

        by bockelboy (824282) on Sunday April 13 2008, @03:19PM (#23055930)
        It's going to be a race, really, to see what happens first - the Tevatron squeaking out enough events to confirm detection, or the LHC operating smoothly enough to get all the calibration and background processes established, then finding the Higgs.

        It's going to be a close race. On one hand, the LHC will ramp up to have a huge advantage over the Tevatron. On the other hand, the Tevatron folks are at the top of their game.

  • Enough of the "God Particle" please (Score:4, Insightful)

    by smolloy (1250188) on Sunday April 13 2008, @02:21PM (#23055626)
    Who first used the name "The God Particle" for the Higgs? It certainly wasn't a high energy physicist!

    The Higgs field is supposedly responsible for mass generation -- and that's it. Nothing else. Maybe something about "spontaneous symmetry breaking...mumble... big bang.. mumble... inflationary expansion... mumble", but hardly anything "God-like".

    This nickname comes across as something dumb invented by the popular press in a half-assed attempt to communicate to regular folk how exciting the LHC is to us physicists.

    Maybe /. could lead the charge to kill this nickname?

    • Re:Enough of the "God Particle" please (Score:5, Interesting)

      by yomegaman (516565) on Sunday April 13 2008, @02:28PM (#23055652)
      I think it was Leon Lederman who coined it in his book. He is definitely a high-energy physicist, he was director of Fermilab for years and won a Nobel Prize for discovering the bottom quark. I agree with the sentiment, though, if I never heard it again it would be fine with me. I read the book some years ago but can't remember why he called it that.
        • But hey - charm quark. What the heck a name is that?
          (Especially for a German like me... where quark means white cheese.)

          God particle is not much worse.

          • Re: (Score:3, Interesting)

            by SteelAngel (139767)
            The quarks are supposed to be named in pairs thusly:

            Up down

            Strange Charm

            Truth Beauty

            But somewhere in the 70's some particle group with little sense of wonder renamed Truth and Beauty to Top and Bottom, thus leaving Strange and Charm as sounding anachronistic.
        • It actually isn't such a bad name, except for the unfortunate resonance with some silly people. At the time it was coined those people weren't as high profile, so it was more like "God doesn't play dice."

          The Higgs field is supposed to suffuse everything. We're constantly immersed in it, and it is responsible for both some of the fundamental properties of the basic constituents of the universe and its largest features. That is, it sticks its fingers in pretty much everything.
            • The Higgs field is supposed to be the same everywhere. Unvarying, and an intrinsic part of space itself. Gravity is associated with a very obvious and material cause.
    • Its from the book The God Particle: If the Universe Is the Answer, What Is the Question? [wikipedia.org]. It's a joke, son, laugh.

    • Re: (Score:2, Insightful)

      by kfort (1132)
      Mass generation is as God-like as it gets.

    • Re: (Score:3, Insightful)

      by turgid (580780)

      Unfortunately, "regular folk" who are interested in celebrity affairs, plasitc surgery and drug abuse ,pay for physics experiments.

      It's impossible to convince them how important such experiments are, so we need to patronise them.

    • Re: (Score:3, Informative)

      by emm-tee (23371)

      Maybe /. could lead the charge to kill this nickname
      That would be nice. It's correct name is the Higgs boson. http://en.wikipedia.org/wiki/Higgs_boson [wikipedia.org]

      I'm amazed that currently no comment on this article contains the word "boson". I've heard it called the Higgs boson more times than I have the "god particle". Maybe it's just the media I choose to read/watch.

  • Breaking Physics News (Score:2, Funny)

    by Anonymous Coward
    hey baby, wanna see my large hardon collider? I'll make you see the God particle.

  • Fermi and the Higgs (Score:4, Interesting)

    by stox (131684) on Sunday April 13 2008, @03:15PM (#23055898) Homepage
    Sadly, 10% of Fermi's staff is being laid off, and the rest must take a mandatory week off of unpaid leave every two months due to the funding SNAFU at the DOE.

  • Pioneer Anomaly (Score:3, Insightful)

    by calidoscope (312571) on Sunday April 13 2008, @04:12PM (#23056320)
    I was a bit put off by the tone of TFA with respect to the Pioneer anomaly. While it is unlikely that the anomaly will disprove our models of gravity, it is an excellent example of a gap in our understanding of physics.

    • Re: (Score:3, Interesting)

      by Protonk (599901)
      Well, let's be fair. the Pioneer anomoly is just that, anomalous. We don't see the impact in other situations, we don't have a good explanation for it and it isn't very large. It is entirely possible that this could be the same sort of anomaly as the orbit of Mercury or the Michelsonâ"Morley experiment. It's possible, but it is also possible that it falls into the category of experimental error.

      Please understand that the pioneer anomaly isn't treated in the same way as we remember (historically) an
      • My Newtonian physics is a little weak - does the effect of gravity within a sphere change as you travel from the center to the surface?

        I'm wondering whether the Pioneer Anomaly can be explained by the Oort cloud. /Hey, I may be ignorant, but I'm ASKING, right?
        • kind of. Imagine gravity as a vector field pointing toward the center of the celestial body (assuming here that the body is a point mass). So as you move from the center to the surface, the vector field appears to be less and less curved--you go from seeing things flow like they would into a funnel (where you are close to the source) to seeing a field that effectively looks like it is perpendicular to the surface. Again, this assumes that you have a point mass. but this is basically why you can do those
          • I was thinking of the Oort cloud as the surface of a sphere - would there be a lessening of gravitational effect while inside the sphere (because some of the mass is still ahead of you) followed by an increase once you passed it?

            Or, does it all effectively balance out at the center of the sun as far as the math is concerned...

            • Re: (Score:3, Interesting)

              by Protonk (599901)
              Oh. Well that is an interesting problem. Keep in mind that the oort cloud isn't really as dense as we might think it would be. If we assume only regular matter (no dark matter), then the density of the oort cloud is fantastically low. It is higher than the density of space between the earth and Mars only because there isn't the tidal and graviational forces of a Jupiter like body to pull stuff out of it.

              Then, from a gravitational standpoint, we are looking at VERY small curvature imposed by the comets a
        • The Oort cloud would have to have a lot of mass in it to have much effect, and you wouldn't see much effect until a good part of that mass was between you and the sun.
    • It's kind of like the Schwarzchild radius. Instead of slowing down and being forever entrapped by the immense gravitational point source of the black hole, it's like being entrapped in the immense graviational field of a sun.

      No, wait....

      • It's kind of like the Schwarzchild radius. Instead of slowing down and being forever entrapped by the immense gravitational point source of the black hole, it's like being entrapped in the immense graviational field of a sun.

        No, wait....
        Or it's like the doppler effect, except it is really small and happens only over long distances but we don't see it too far away because.....

        no, wait.... :)

  • Something doesn't fit...like.... (Score:3, Funny)

    by 3seas (184403) on Sunday April 13 2008, @04:54PM (#23056676) Homepage Journal
    ....the god particle????

    Is god that small?

    • Re:Rumor/conjector (Score:4, Informative)

      by FooAtWFU (699187) on Sunday April 13 2008, @01:52PM (#23055506) Homepage

      I read the article on Higgs, and it is entirely conjecture based on specified rumor after rumor. Is this TMZ.com?
      It's a summary of a physics conference. This is news of physicists describing to each other the state of the art and what they're busy conjecturing, considering, and hoping to prove. Perhaps you were looking for Nature?

    • Re:Rumor/conjector (Score:5, Informative)

      by yomegaman (516565) on Sunday April 13 2008, @02:07PM (#23055572)
      The bump in the CDF two-tau decay channel went away with more data, which wasn't too surprising. I'm not sure how all that got so blown up in the science press, the original blog post that started it at Cosmic Variance surely didn't make any discovery claim. Having said that, the other half of the story, the rumored huge excess in the D0 three-b-quark channel, is still unresolved as they have not released any results for over a year. We'll probably see something within a few weeks I guess, I have heard that it is close to ready.

    • Re:Rumor/conjector (Score:5, Funny)

      by evil agent (918566) on Sunday April 13 2008, @02:12PM (#23055602)
      I know right? And what about that sensationalist headline: "Breaking Physics News"??? If they had actually broken physics, I probably would have heard it on the news...

    • Re:Rumor/conjector (Score:5, Funny)

      by HiggsBison (678319) on Sunday April 13 2008, @02:51PM (#23055778)

      I read the article on Higgs, and it is entirely conjecture based on specified rumor after rumor. Is this TMZ.com?

      Rumors? About me? *sigh* I'm always the last to hear of them.

    • Re: (Score:3, Insightful)

      by jmorris42 (1458) *
      > Is it so hard to see that they're just dealing with the (luminiferous) (a)ether?!?

      Oh course. History doesn't repeat exactly but it does tend to rhyme. Is it any wonder that science falls prey to the same human failings since it IS just another human activity?
    • It is hard to see that because they AREN'T just dealing with the aether. This isn't some substrate at rest upon which the motions of the galaxy play out. I know it is comforting to take refuge in crackpot science, but there really isn't a zero speed reference frame. It doesn't exist. I'm sorry.
    • I would post that sort of nonsense as an AC, too. For those that are unaware, the theory of a luminiferous aether posits that there exists some sort of medium in interstellar space which conducts light. It was completely superseded around the beginning of the last century, mostly by the theories of a man named Einstein. Which explain quite well our observations of the universe on a large scale. Dark matter is an entirely unrelated question related to the amount of matter in the universe. Dark energy, zero-point field...you're just throwing around terms. What we know about the forces in the universe is not exhaustive, but to invent a completely new one just to account for a minor anomaly is not good science. What you are doing here is the equivalent of fighting for the Flat Earth theory, and it disturbs me to see that modded informative here...

    • Re: (Score:3, Interesting)

      by ceoyoyo (59147)
      The Higgs field and dark energy are about the closest things directly comparable to the aether in modern physics. Dark matter is very different: it clumps, so it isn't everywhere.
      • Er, no, not really. Falling forever does not violate conservation of energy in the slightest. Actually, every single piece of matter in the universe is in a constant state of falling, it's just a matter of whether or not it's falling into something else.

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