Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site newton.ARPA
Path: utzoo!watmath!clyde!cbosgd!ihnp4!inuxc!pur-ee!pucc-j!pucc-h!pur-phy!newton!clt
From: clt@newton.ARPA (Carrick Talmadge)
Newsgroups: net.physics
Subject: Re: "Fifth" force.
Message-ID: <416@newton.ARPA>
Date: Mon, 3-Feb-86 16:39:06 EST
Article-I.D.: newton.416
Posted: Mon Feb  3 16:39:06 1986
Date-Received: Wed, 5-Feb-86 02:02:11 EST
References: <621@harvard.UUCP>
Reply-To: clt@newton.UUCP (Talmadge)
Organization: Physics Dept., Purdue Univ., W. Lafayette, IN
Lines: 106
Summary: Response to Kosower

David Kosower has raised a number of objections to the the paper involving
the reanalysis of the Eotvos experiment, which I feel compelled to respond
to.  I am going to apologize ahead of time for not going into too much
technical detail, mainly due to time constraints on my part (I simply don't
have the time to "work up" a longer reponse).

I should comment that I was one of the coauthors of the article, so that 
my remarks may be biased.

His substantial criticisms were:

(1) Geophysical data is only a 2 sigma effect.

In the original article we quoted a value for the coupling strength (relative
to gravity) due to the geophysical data of alpha = -0.0076 +- 0.36.  Kosower
is correct if the errors were really symmetric.  In reality, experimental
errors are rarely symmetric, and here we have no exception.  The bounds
on the coupling strength at the 3 sigma levels are -0.0071 <= alpha <= -0.0128.
The tolerance level for alpha = 0 is approximately at the 100 sigma level
(that is, the geo results are consistent with alpha=0 only at the 100 sigma
level).

(2) Magnitudes inconsistent (factor of 20 between Eotvos and geo results),
    and  sign of interaction is wrong.

If you examine our paper, you'll notice that we assumed a uniform spherical
Earth to model the size of the effect in the Eotvos experiment.  This, as
it turns out, is a highly dubious model in light of the short range (200 meters)
nature of the proposed interaction.  The results of a more detailed analysis
indicates that it probably isn't possible to extract either the
magnitude or the sign of the effect, without detailed knowledge of the
local mass distributions where Eotvos performed his experiment (this may have
unfortunately been lost to history).  What we do know about the local
mass distributions, however, gives the proper sign and magnitude (to within
a factor of 2).

Secondly, we quoted in the paper a limit on the range of the interaction
to be lambda = 200 +- 50 meters.  It turns out that the quoted error was
seriously underestimated (Stacey admitted this to us latter), but we
had no choice but to quote that number he wanted us to quote.  In reality,
the 3 sigma limit on the range is 50 meters <= lambda <= 6000 meters.
Since the Eotvos result can only measure the quantity alpha*lambda,
you can see that even a factor of 20 can be accommodated by the geophysical
results.

Actually there is a profound consequence of the relative insensitivity
of Stacey's experiment to the range -- there is no direct evidence that
the interaction must really be a Yukawa-type coupling...

(3) Renner's work was disregarded

As Kosower mentioned, Dicke showed in 1964 that Renner's experiment
contained an internal conflict -- that is his quoted errors were
1/3 the theoretical error due to the diffraction limit of his telescope.
If one were to inflate Renner's error by this factor of 3, then the
probability of Renner having correctly performed the experiment and
achieved his quoted outcome was less than 1 chance in 10 million.
As Dicke stated in this same article, he was unable to find any similar
problem with Eotvos' work.

The real question here is why would one be more inclined to believe
Eotvos than Renner.  It turns out that Eotvos was doing this sort
of thing for a living for almost 20 years before actually performing the
Eotvos experiment.  The apparatus he used was actually a device designed
to measure local gravity anomalies, from which one could deduce the
presense of heavy mineral concentrations.  In 1935, Renner actually
used Eotvos' original apparatus (which had been sitting on the shelf
for 20 years) and claimed to achieve sensitivities with the same apparatus
4 times better than Eotvos.  This is just a bit hard to swallow, as are
Renner's results -- even before inflating his error bars ala Dicke,
his seven quoted results were all less than 1 standard deviation from zero,
again an improbable outcome.

Dicke also examined Eotvos' work in 1964 and was unable to find
any problem whatsoever with this work (he also was one of the referee's
of our work, by the way, so that if he were aware of such criticisms
of the Eotvos experiment, he would almost certainly have pointed it out
to us!).

(4) Weinberg "showed" that a hypercharge interaction leads to contradictions.

In Weinberg's famous paper on a possible hypercharge interaction, it was
demonstrated that, if a hypercharge interaction were of sufficiently
long range, it would lead to catastrophic decay rates in certain
types of elementary particles, such as the K-meson (hence this is
called "Weinberg's catastrophe").

In the same article, Weinberg also noted that, if the range of the interaction
were less than 10**6 meters or so, that this catastrophe would be avoided.
Since the proposed range of the interaction is on the order of 200 meters,
there is no such difficulty for this theory.

*****

In summary, as far as I am aware, no substantial criticisms of this
paper have yet been forthcoming.  The good thing about this work is
that it is easily testable -- we expect that the first result will
be announced within six months.

For people interested in looking into this question on their own,
the reference to our paper is Physical Review Letters, Vol. 56, 1986, page 3.
This paper references most of the other works I've talked about here.

Regards,

Carrick Talmadge