From: Robert J. Bradbury (bradbury@ilr.genebee.msu.su)
Date: Sat Nov 20 1999 - 04:11:00 MST
Mitch Porter wrote re:
> http://xxx.lanl.gov/abs/hep-ph/9911386
> 1) There are extra dimensions whose radius is only a bit less
> than a millimeter.
> 2) The reason we don't observe atoms leaking out into the
> extra space is because ... [snip of things not worth repeating...]
I believe, I'm paraphrasing Eliezer on another topic, when I say
BLECH! PHOOEY!! GROAN!! KASHMAR!!
I've got a theory on how gravitational effects on DNA at the time
of chromosomal segregation explains astrological observations
but I'm not going to waste good paper by writing it down. The
problem here is that data storage bits have gotten too damn cheap...
Please bear in mind a comment offered by a participant at one
of the SETI conferences -- if you give the theoretical
physicists long enough they can explain *anything*!
Hal offered some comments on dark matter abundances that
need clarification.
I believe he expressed the opinion that dark matter abundances
are the same in all galaxies. I don't believe this statement
may be made with any degree of universality.
Dark matter abundances are "derived" from the rotational rates
of the galaxies. Galaxies that show relatively rapid orbital
velocities of the outer stars (a failure to decrease in expected
orbital velocity with distance from the center of the galaxy, as is
the case with the planets relative to the sun) are assumed to have
dark matter.
These velocities are determined by the doppler shifts of the stars
(or star "aggregates") from the outer to the inner to the outer
edge of the galaxy to determine the velocity towards or away from us.
Doing this type of experiment requires a fairly accurate spectroscopic
equipment and a fair amount of telescope time. The only galaxies this
type of measurement can be done accurately for are those that are viewed
relatively "edge-on" to us. Due to the equipment and sight restrictions
I suspect that quantitative dark matter estimates are available for
only a few dozen galaxies. I do not believe there are any estimates
on whether the amount of dark matter is increasing or decreasing with
the age of the universe (because to accurately determine this we would
need the rotational curves of very distant galaxies).
There is also the problem that there is more dark matter in galactic
clusters (derived from galactic velocities) than in the galaxies
themselves (including the galactic dark matter). There is some
recent evidence that some of the dark matter may be neutral hydrogen,
but I haven't seen anyone suggest that this explains away the entire problem.
Amara, if I've gotten any of this wrong, please correct it.
Robert
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