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PF moderation policy and mainstream sources (was Einstein on v>c)

  1. May 30, 2007 #1
    I saw a website(?) that discussed Einstein's SR indicating that it could be possible for "objects"/particles to travel faster than speed of light "c"--relating this to "frames of references". How is this possible?:yuck:
     
  2. jcsd
  3. May 30, 2007 #2
  4. May 30, 2007 #3

    pervect

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    First off, I should point out that the reference quoted is not a mainstream website - many of the opinions expressed on this website are extremely odd, such as the proposal of a Newtonian background for space-time for example.

    Usually we try to limit discussion of physics to mainstream science, however we try and allow a little lattitude as long as this lattitude is not abused to promote or discuss crank theories.

    There is a valid point behind some of what the quoted website says which has however apparently been misinterpreted by the original poster, which merits discussion even though the original website quoted doesn't really meet PF standards.

    This is the fact that it may be possible in GR to take "shortcuts" through, for example, wormholes, and arrive at a destination faster than light does, without however ever exceeding the speed of light. The existence of this sort of shortcut has by no means been proven, but it has not been ruled out, either.

    The original poster has apparently mistaken the possible existence of these sorts of "shortcuts" for the actual ability to move at a velocity greater than 'c'.

    While the speed of light is never exceeded in taking such "shortcuts", there are some possible issues with causality - in popular language, wormholes can become time machines.

    The resolution to this issue is not currently known, though Hawking, for instance, has proposed a chronology protection conjecture. It turns out that a wormhole on the verge of becoming a time machine will have a very large flux of virtual particles passing through it. Detailed modelling of what happens is not possible at the current state of knowledge, but it has been suggested that this flux of virtual particles will destroy the wormhole.

    For some popular level references on this topic, I'll suggest:

    http://www.npl.washington.edu/AV/altvw33.html

    at longer length (but not available on the web) there is Kip Thorne's excellent [correction] Black Holes and Time Warps: Einstein's Outrageous Legacy
    So if wormholes exist, they may cause problems with causality, even though they would not allow objects to have a velocity larger than that of light.

    Wormholes may or may not exist, and if they do exist, mechanisms such as Hawking's chronology protection conjecture may or may not prevent them from becoming time machines.

    While serious papers have been written about this issue, see for instance the "Billiard ball paper" http://prola.aps.org/abstract/PRD/v44/i4/p1077_1, the resolution is still very much up in the air.
     
    Last edited: May 30, 2007
  5. Jun 1, 2007 #4
    Your comment about a..."mainstream website" could be very important for members posting from research websites. Just what would be considered "mainstream"?
     
  6. Jun 1, 2007 #5

    Chris Hillman

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    Take it to another forum please!

    In many cases, it will be self-evident to almost any adult of normal ability that some website is not mainstream. In some cases, only those who benefit from sound judgement plus considerable knowledge of and experience in physics (or whatever technical field we are talking about) will be able to quickly spot and debunk fringe assertions. IIRC, there is a tutorial somewhere around PF offering advice (not a magic bullet) on spotting crankery. IMO discussion of the question of where the boundaries lie between mainstream and fringe science websites should move to the Scepticism and Debunking forum. You can also ask questions at places like http://forums.randi.org/ TIA!
     
    Last edited: Jun 1, 2007
  7. Jun 1, 2007 #6

    pervect

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    Articles that have been published in respected peer review journals (Physical review, American Journal of Physics, etc.) are considered mainstream. This doesn't guarantee that they are free of all errors, but it's usually a good first start.

    Standard textbooks are also good sources for information.

    Self-published web sites are generally iffy, though there are a few self-published web sites that some of us like because they present useful information at a basic level. Unfortunately, there are a LOT of crank web sites on relativity, including a few by people with credentials in the field that are at least "on the fringe".

    Arxiv preprints are also very iffy unless they have been published in a journal as well as on arxiv.

    I'm not sure offhand how a layperson could find out that "The Journal Of Galielan Electrodynamics" (for example) is not very respected, even though it claims to be peer-reviewed.

    Note that PF is not "on the cutting edge", at least not in the general forums. The rules are relaxed a bit in the "Independent research" forum, see the PF guidelines at https://www.physicsforums.com/showthread.php?t=5374.

    People doing advanced research generally don't need any advice on what is mainstream or not mainstream - they have enough education to tell, and if a few of them go off in strange directions anyway, they will in the end either be successful or unsuccessful at convincing other people in the field as to the merits of their ideas.

    However, students and laypersons can use a little more guidance on what is considered mainstream and what is not. That is one of the functions of moderators and mentors - to try and provide some guidance to laypeople and students as to what is mainstream and what is not.

    One of the problems we face at PF is the issue of people who can't get their ideas published in mainstream journals who try to use PF as an outlet to promote their ideas. That's not what we are here for, that's why we need and have a moderation process.
     
    Last edited: Jun 1, 2007
  8. Jun 1, 2007 #7

    Chris Hillman

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    Ditto pervect. (Moderator comments being exempt from my injunction to take general discussion to another subforum. Maybe we need a sticky in the Feedback subforum explaining some of the problems at PF which can lead to polite requests and other events which some might otherwise find puzzling...)

    BTW, pervect mispelled the name of the crank journal described in http://en.wikipedia.org/w/index.php?title=Galilean_Electrodynamics&oldid=107206306
    Note that this WP article has been the subject of edit wars between those pushing the POV that this journal is respectable and members of WikiProject Physics, who disagree. The version I linked to above is at least mercifully brief and makes clear that this point is controversial. Most such issues have in fact been controversial at WP, if only because all points of view are treated with equal weight there. See for example the Salon article http://archive.salon.com/people/feature/2000/07/06/einstein/index.html or google for posts by John Baez and others in sci.physics.research to find quotations from numerous leading physicists which support my assertion that physicists generally agree that Galilean Electrodynamics is not and has never been a respectable scientific journal.
     
    Last edited: Jun 1, 2007
  9. Jun 1, 2007 #8

    pervect

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    I think the original question has been answered, and the thread has taken off in the direction of disucssing PF policy, so I'm going to move it to the PF feedback forum with an expiring redirect.
     
    Last edited: Jun 1, 2007
  10. Jun 2, 2007 #9
    These postings are very helpful. I have emailed Prof-Dr. Laro Schatzer (the author of this article) to get his comments, too.
     
  11. Jun 6, 2007 #10

    jtbell

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    Two other journals that I would be suspicious of are "Physics Essays" and "Annals of the Louis de Broglie Foundation."
     
  12. Jun 6, 2007 #11

    robphy

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    One might be able to take an extra step
    to google names from the "Editorial Board" and see their webpages or where [else] they publish.
     
  13. Jun 7, 2007 #12
    Foundations of Physics is a crank journal, right?

    From this thread and from answers to some posts I figure that the definition of mainstream in PF does likely not include Absolute Euclidean Spacetime (AEST), as put forward by one Montanus, right?

    The Foundations of Physics publishes his work, see http://www.springerlink.com/content/f7k660327682v275/ for example.

    Consquently I reckon that I have to be careful to discuss here any ideas of the editors of Foundations of Physics, because they endorse such non-mainstream stuff. The physicists to be careful with then include at least: Jeffrey Bub, Arthur Fine, Bas van Fraassen, Robert Geroch, GianCarlo Ghirardi, Sheldon Goldstein, Tim Maudlin, D. Carlo Rovelli, Abner Shimony, Lee Smolin, C. Anton Zeilinger and Wojciech H. Zurek.

    Is that true or are there other rules that I should know of that somehow remove them from the blacklist again?

    Harald.
     
  14. Jun 7, 2007 #13
    Gerard 't Hooft is the editor in chief of this publication. A person who does not seem so narrow minded to exclude ontologies different from curved spacetimes in understanding gravitation, as if some religious dictum is violated.

    But you have to realize that this forum is not a forum about critical thinking on theories it is about helping people understand these theories. But unfortunately things are often presented here by giving the impression that there are no open issues or controversies in those theories, that everything is cut and dried, this is particular to the relativity and QM forum.
    While I personally think that that is not the best way for people to learn to understand, it seems to be the prevailing opinion here.

    Come to think of it, Gerard 't Hooft wrote some very nice lecture notes called Introduction to General Relativity using, at least in the beginning, imaginary time, which might be another item that is simply not acceptable to some on this forum.
     
    Last edited: Jun 7, 2007
  15. Jun 7, 2007 #14

    robphy

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    As a novice to the editorial process, I would say this.

    A paper should be reviewed for its content, not its author (or its author's other papers). So, if the paper under review meets the criteria of the particular journal and its editorial policies (e.g. http://www.springer.com/west/home/p...35680179-0&detailsPage=journal|aimsAndScopes ), it's probably okay to publish. (Of course, different journals will have different policies. [edit: In forming an opinion about a paper, a person reading it should be aware of where it is published [if at all] and be familiar with its editorial policies. In other words, try to know your sources.])

    I'm guessing that only a small number of the reviewers [chosen by an editor] will actually review the paper. (In addition, the list of editors and reviewers probably varies with time.)

    (I welcome any enlightenment from those more familiar with the editorial process.)

    [edit: I should add that online communities [such as PF] probably have their own policies of what is appropriate for discussion.]


    My $0.02.
     
    Last edited: Jun 7, 2007
  16. Jun 7, 2007 #15

    chroot

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    When we get into the territory of the "personal theories" of professional physicists, we have to be a little careful and take posts one at a time.

    The purpose of our guidelines is certainly not to stifle discussion of genuine questions in science. We're simply trying to stop the sort of people who think that they've invented ways to go faster than light by goofing up grade-school algebra.

    We welcome well-formed and plausible theories (worthy of professional discussion and experimentation) from any author of any credentials in our Independent Research forum. If a significant portion of scientific community takes an idea seriously (which does not imply that it is believed to be correct), then it's welcome anywhere on the site.

    - Warren
     
  17. Jun 12, 2007 #16
    If I have read about some non-standard theory and don't understand myself why it is wrong, how would I phrase questions here? Any question that contains a hint at comparison between an established theory and some other theory will likely be understood as supportive for the other theory.

    This happened already in the form of a lemmings argument (so many physicists come to these conclusions) and a suggestion not to think myself (why don't you believe what the textbooks say). To understand why one theory is preferred, it is certainly necessary to know the flaws of other theories. But if they cannot be discussed here, these forums are less helpful than they could be.

    I know that the danger is always high to drift into nonsensical discussions, so some guidance as to how to compare good theories against bad seems to be necessary.

    Harald.
     
  18. Jun 12, 2007 #17

    chroot

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    If you know it's non-standard, don't even post it here at all. We do have a skepticism and debunking forum, but it's not really intended for the debunking of crackpot theories.

    Our guidelines against personal theories do make the site less helpful in debunking personal theories. On the other hand, our guidelines make it vastly more helpful at everything else. Long ago, we collectively sided with everything else.

    If you can't find it in a textbook, peer-reviewed journal, reputable publication, conference, etc., then it doesn't belong here. If you aim to discuss some specific personal theory, and you know it's not mainstream, this is not the place. There are hundreds of other places on the web which welcome such discussions.

    - Warren
     
  19. Jun 12, 2007 #18
    Specific suggestions would be welcome.

    Thanks,
    Harald.
     
  20. Jun 12, 2007 #19

    chroot

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  21. Jun 16, 2007 #20
    Boaah, not sci.physics. There is no sensible way to discuss anything relativity or quantum related in the newsgroup. It tried this and any discussion immediately gets out of hand. This is what the rules in PF are for to prevent, of course. Only sometimes I feel they are just a bit to strict.

    I'll see what happens on sciforums.

    Thanks,
    Harald.
     
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