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Only two fundamental constants? (Matsas in Nature News)

  1. Dec 20, 2007 #1

    marcus

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    http://www.nature.com/news/2007/071220/full/news.2007.389.html

    this just came out in Nature News, comment?

    To be sure, they are talking about how many DIMENSIONAL fundamental constants you need. The main bunch of constants that people always want to measure and to explain are the dimensionless ones---pure numbers like 1/137, with no units attached.

    The idea that you just need two sounds wacky at first, but Nature News is a lot different from the New Scientist. If the Nature group of media publish it maybe there is something to it. George Matsas is at Sao Paolo, Brazil. Probably a colleague of Aldrovandi and Pereira who came out with a weird new version of General Relativity recently. Fits of innovation south of the equator.

    http://arxiv.org/abs/0711.4276
    The number of dimensional fundamental constants
    George E. A. Matsas, Vicente Pleitez, Alberto Saa, Daniel A. T. Vanzella
    7 pages, 2 figures
    (Submitted on 27 Nov 2007 (v1), last revised 4 Dec 2007 (this version, v2))

    "We revisit, qualify, and objectively resolve the seemingly controversial question about what is the number of dimensional fundamental constants in Nature. For this purpose, we only assume that all we can directly measure are space and time intervals, and that this is enough to evaluate any physical observable. We conclude that the number of dimensional fundamental constants is two. We emphasize that this is an objective result rather than a "philosophical opinion", and we let it clear how it could be refuted in order to prove us wrong. Our conclusion coincides with Veneziano's string-theoretical one but our arguments are not based on any particular theory. As a result, this implies that one of the three usually considered fundamental constants "G", "c" or "h" can be eliminated and we show explicitly how this can be accomplished."
     
    Last edited: Dec 20, 2007
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  3. Dec 20, 2007 #2

    cristo

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    It sounds interesting. I'll print off the paper and have a read on the train tomorrow.
     
  4. Dec 20, 2007 #3

    marcus

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    If there is some sense in which Matsas et al are getting away with something not quite legal, or "pulling a fast one", I have a guess about what it is.

    They may be ASSUMING a widely accepted equivalence between inertia and gravitational attractiveness. As if to say that Newtons G does not run but is universally and exactly correct at all scales. Which may be true. And if it is true then I guess you do not need a unit of inertia.

    you take the kilogram (unit of inertia) and multiply it by G and you get a quantity measured in m3/s2
    (cubic meters/square seconds)
    this tells things like escape velocity from a given distance, orbital speeds at a given semiaxis, in short it describes a certain quantity of gravitational attractiveness.

    So if one is willing to measure mass in terms of m3/s2
    then obviously one only needs to use meters and seconds to describe everything---one does not need the kilogram.

    I may be missing something, but it's possible that this is what is going on here.
     
  5. Dec 21, 2007 #4

    CarlB

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    Primitive man thought that space and time are two very different things so they invented units for them (fortnights and furlongs) as if they were distinct. In a theory where they're combined, c is just a conversion between units and might as well be set to be 1. That will get you down to 1 dimensional constant.

    I think that both my argument above, and the author's paper are more or less equally content free.
     
  6. Dec 21, 2007 #5

    J77

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    I like the title, but worth as a Nature article (even if News...)...?
     
  7. Dec 21, 2007 #6

    marcus

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    I hear what you are saying, Carl and J77, but I'm still undecided.

    I see they cite the trialog of Okun, Duff, and Veneziano---this was also about how many fundamental constants, and came up in a thread here recently, from Arivero I think.

    They also say how their thesis can be falsified in the laboratory. Perhaps it has already been disproven experimentally?

    They distinguish between active gravitational mass, and passive gravitational mass. What they call the active gravitational mass is what I was calling "gravitational attractiveness" and is quantified in terms of L3/T2 as they point out.

    Here is their note [14] on page 5:

    [14] The equality of inertial and passive gravitational mass
    finds an elegant explanation in the context of (and actually
    led to) metric theories of gravity. The relation between
    inertial and active gravitational mass, however, is
    more subtle and, to some extent, still unaddressed. In
    modern terms, why is the energy content of a system so
    intimately tied to its potential to curve the background
    spacetime?
    Answering this question is equivalent to explaining
    Einstein equations, which possibly requires (or
    would lead to) a “quantum gravity” theory.

    In their system the potential to curve background spacetime is measured in units of L3/T2
    and this is also their unit of mass. maybe it is the same thing, for them.
    =======================

    The guy Richard Davis that is quoted in that Nature News article "Two Constants to Rule Us All"
    from 1972-1990 he was with the mass group of NIST and became its group leader
    and then from 1990-2007 he is at BIPM Sevres which is the international version of NIST
    and starting 1993 he was the head of the mass section at BIPM.
    You know they are trying various ways to redefine the kilogram without using a metal prototype (essentially basing it on the atomic clock frequency standard like everything else). Well presumably Richard Davis is a world expert on mass units, definitions, and mass standards.

    the four Brazilians have no international standing, that I know of. but Davis does and he says their idea is interesting.
    I think I'll wait a day or two before i decide it's trivial.

    Two months ago I didn't know that Sao Paolo State University existed, or that it had an ITP (institute for theoretical physics) then I ran into Aldrovandi Pereira's paper, from there, and now this paper from the same ITP. In neither case can I confidently say if the work is good or bad, but it is beginning to put the Sao Paolo ITP on the map for me. The authors have a kind of modest optimism and originality. They don't seem especially nervous. Maybe life is good in some subtle way. I could imagine going there.
     
    Last edited: Dec 21, 2007
  8. Dec 21, 2007 #7
    the four Brazilians have no international standing

    Eh eh. Here we go again...

    Marcus, in Brazil you will find brilliant people as well as idiot people as anywhere else in the world.

    Who would you say is a Brazilian physicist of international status? I know only a very few of them, most already deceased:

    http://en.wikipedia.org/wiki/César_Lattes (deceased, deserved a nobel prize)

    "Although he was the main researcher and the first author of the historical Nature article describing the meson pi, Cecil Powell alone was awarded the Nobel Prize for Physics in 1950 for "his development of the photographic method of studying nuclear processes and his discoveries regarding mesons made with this method". The reason for this apparent neglect is that the Nobel Committee policy until 1960 was to give the award to the research group head, only." -- have seen this episode again in the Nobel 2007.

    http://en.wikipedia.org/wiki/José_Leite_Lopes (deceased)

    http://en.wikipedia.org/wiki/Jayme_Tiomno

    etc.

    What makes a scientist of "international standing" is a complicated issue when it comes to the fact that Brazil is seen as a country where you can only find poverty, violence, samba and forests, right? What is Brazil anyway???

    The problem I see here is: when someone is evaluating some other's work, one generally does not make the reference "he/she is Italian" or "he/she is American" or "he/she is French", etc, but if he/she is from countries like Brazil, the caveat always comes "he/she is Brazilian" -- so let us see whether he/she has internatinal standing to be sure it is a really good/professional work...

    Now, concerning Matsas (I've been at some of his talks; he's a clever and creative guy), it is not the first time that he is at Nature's news. A few years ago, he clarified a paradox in relativity:

    http://www.nature.com/news/2003/030728/full/news030728-3.html

    I saw his new paper, but have not read it carefully yet, so I have nothing to add at this time. If I do, I'll came back later.

    Best,
    Christine
     
  9. Dec 21, 2007 #8
    Maybe life is good in some subtle way. I could imagine going there.

    In Brazil, life is very good for a few and bad for most.

    Overall, it's a good country. I like where I live. A semi-rural city with little violence. São Paulo city is a difficult city to live. It's a megalopolis. But very cultural. I did a postdoc at São Paulo University (at the Institute of Astronomy, Geophysics and Atmosferic Science).

    Best,
    Christine
     
    Last edited: Dec 21, 2007
  10. Dec 21, 2007 #9

    Demystifier

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    I loved this paper. For me, the Duff's argument for the zero number of fundamental dimensional constants was the only convincing one.
     
  11. Dec 21, 2007 #10
    Oops! Marcus, I thought that you were talking about this *November* Nature news article about Matsas's paper on naked singularity (which I was aware):

    http://www.nature.com/news/2007/071107/full/450147a.html

    Now I see what you mention is an even more recent one! (which I was not aware!)

    So Matsas was at least in 3 Nature news.
     
    Last edited: Dec 21, 2007
  12. Dec 21, 2007 #11

    Fra

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    I think this shows the social and political dimension of science, and how the collective opinion influences our expectations.

    It's like when companies are rated. In the business world, just analyzing the actual company, is insufficient because in the "big game" the environments expectations is a major factor since it affects it's actual value, and the concept of value is inherently relative. And the one and same company could be rated differently depending on the environments expectations. If your entire environment have and confident and contradictory opinion, then the collective dynamics may suffocate ideas that could in principle take off if it only had higher relative impact.

    I guess in as much as this may make it more difficult for unexpected ideas to propagate, it could also lead to the opposite where ideas that perhaps are not so terribly good are given inappropriate thrust from the collectives expectations. Because anyone objecting to the collective will not be favoured, this is elementary and unfortunately no way around it as I see it. The small guy must be way smarter than the big guy to get around bully tactics.

    The business field got the international standing dot.com bubble, and I think got the feeling we got the international standing super.string bubble, except this one hasn't bursted quite yet :cry:

    However I am not sure if there is a way around this. I think the only correction one could make is to make sure everybody tries to make their evaluations beeing aware of these mechanisms and use our information on these mechanisms to our advantage.

    /Fredrik
     
  13. Dec 21, 2007 #12

    marcus

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    Well I would probably say Matsas has international standing by my standards, simply because of what you told me. That he has published several times recently in highly visible international media.

    I am not thinking just of Nobel laureates, but of any scientist with considerable name-recognition in his field, especially if he gets invited to give plenary talks at some major international conferences.

    I would LIKE to think that Jose Geraldo Pereira is an internationally known and respected relativist, but so far when I mention him and his work I am not hearing any echos. I must say it is reassuring to get an echo when I say Matsas :smile:
    =================

    I will tell you what is on my mind----and it doesn't have to do only with Brazil but also with South Africa, Australia, New Zealand, Chile, Argentina. I am looking for, and seeing some uncertain signs of, what might be a southern hemisphere science trend.

    I referred to this humorously in the first post as "fits of inventiveness below the equator" but what i see happening is a shift of creativity and significant research activity.

    Notice that in astronomy there is ESO in Chile and Auger in Argentina. The cosmologist I have learned most from is an Australian. I am constantly seeing interesting work from South Africa that impresses me as unusually original. Bilson-Thompson's preon model is extremely original (to the point that one admires his nerve). Pereira's new version of General Relativity is also original, in my view, almost to the point of recklessness.

    What I like about some of these people is that, while they are not crackpots, they act like they are not overly restricted by carreer worries. They gamble.

    Now you can say that I have a distorted vision and that there is just as much of that going on in the more crowded nervous institutions north of the equator. You can say that there is no trend or shift occurring, and that my impression is just an OPTICAL ILLUSION resulting from my only recently discovering how much was going on in science in the S. hemisphere.

    that is probably right to some extent. But I intend to keep alert to the possibility. Just to be clear, I am not talking about conditions in society at large which vary from place to place, but about scientific activity and style (if one can separate that out.)
     
    Last edited: Dec 21, 2007
  14. Dec 21, 2007 #13

    marcus

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    Oh, I see what i did. Here is George Matsas 37 papers on Arxiv
    http://arxiv.org/find/grp_physics/1/au:+Matsas/0/1/0/all/0/1
    with a good publication record----places like Physical Review Letters

    Yesterday, when I checked, I accidentally used a restricted search and got only TWO papers
    http://arxiv.org/find/physics/1/au:+Matsas_G/0/1/0/all/0/1

    37 papers puts things in a different light.

    this is even better. with Spires I get 65 papers and I would estimate 100-200 citations
    http://www.slac.stanford.edu/spires...IND+A+MATSAS&FORMAT=www&SEQUENCE=citecount(d)
     
    Last edited: Dec 21, 2007
  15. Dec 21, 2007 #14

    Hans de Vries

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    Well, I'm happy to spend a while in Brasil going next week to our home there. Having lived 10 years in the center of San Francisco gave me a somewhat different opinion about bad and good.... I have lots of Brazilian friends in the SF bay area. I took samba lessons :smile: from two Brazilian "SF summer carnival queens" As far as I know they still give lessons once a week on the campus of the UC of Berkeley. They're very professional.


    Regards, Hans
     
    Last edited: Dec 21, 2007
  16. Dec 21, 2007 #15

    marcus

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    WOW!

    Just to re-stabilize after that heady thought, Matsas appears to be saying that you can determine any physical quantity with two observations.

    In particular you should be able to determine the mass of an object by measuring a distance and a time. To get down to basics with a crude example suppose someone gives you a solid ball of platinum-iridium alloy and says that its mass is a million kilograms, how could you check to see?

    Well assuming your laboratory is in space you could place a small object in circular orbit around the ball at a given orbit radius and time how long it takes to go around.

    That would establish the mass of the object. It seems to me that Matsas is prepared to define the kilogram in terms of what he calls active gravitational mass. It seems not to be very practical because the value of G is not known very precisely. It seems like he wants to declare an exact value for it and define the kilogram as a derived unit based on some amount of meter3/second2.

    Now that we have established (with Christine's help) that this is a reputable internationally known scientist who publishes a lot in places like Physical Review Letters (PRL) does anybody want to comment. Is this trivial, or boring, or fantastic. Or just funny? Or could it actually be interesting (as I still think possible.)
     
    Last edited: Dec 21, 2007
  17. Dec 21, 2007 #16
    Hi Marcus,

    Well, now that I know your criteria :wink: I can say there is a very good number of Brazilian physicists that meet them.

    Best,
    Christine
     
  18. Dec 21, 2007 #17
    Eh eh, my sister used to give lessons of samba and many other styles, like tango, etc. Nice to know you're coming to Bras(z)il. There are places here that I wouldn't change for any other place in the world.

    Best,
    Christine

    PS - Sorry for diverting from the main topic; please continue.
     
    Last edited: Dec 21, 2007
  19. Dec 21, 2007 #18
  20. Dec 21, 2007 #19

    rbj

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    to me, Duff's position is still the only one that makes sense. how does one measure dimensionful constants or parameters other than against another like-dimensioned quantity? and if one does that, they are still, in the final run, measuring a dimensionless quantity.

    i would agree that Planck Units are fundamental in the sense that they define the scale of measurement from the POV of Nature, but it seems odd to define those as fundamental constants of nature since, if any of them changed while no dimensionless parameters changed (no ratio of any like-dimensioned quantities has changed), then there is simply no way we mortals would know the difference. if [itex]l_P[/itex] doubled in quantity (i dunno from the perspective of who, other than the supernatural) our meter sticks, atoms, and everything else would also be twice as long (so that the ratios stay the same) and there would be no operational difference.

    only the dimensionless constants from nature (most notably the fine-structure constant) are truly fundamental.
     
  21. May 14, 2010 #20
    So, I just ran into the Matsas article and simply ignore his background as below the Equator and try to apply his concept to my background. So if I understand correctly, meters and seconds can define energy such that Kg-m^2/(sec^2 , with mass as m^3/sec^2 , becomes (m^5)/sec^4 , or simply (c^4)(distance). Thermodynamically then energy, as E, = (c^4)(X) , where "X" is a distance. Differentiating, one gets the 1st law (Q-W) as E(2) - E(1) = 4( c^3) X dc - c^4 dX which implies for delta E = 0 that dc/dX = - c^4/(4c^3 X) = c/4X, Hmmmm, an "inverse time"? I'll be back with more if no one destroys this approach.
     
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