On May 5, 2007, at 7:04 PM, Jones Beene wrote:
Once upon a time ... it was believed that our sun was paired with a
hypothetical companion star, 'Nemesis' which might orbit at a
distance of a light year or so. Nemesis was introduced to explain
an apparent periodicity in the occurrence of mass extinctions of
around 65 million years. In the past 26 years of intense searching,
Nemesis was never found - and it should be relatively easy to find
if it were there. In the mean time, we have discovered dozens of
planets orbiting stars at similar distances, for instance. This
companion star, if it existed, would need to be much larger than
any planet. ERGO, it is most likely that no such companion star
exists.
Reference was recently made on Vo to the 'ecliptic,' which is the
apparent path that the Sun traces out along the sky, and the
imaginary disk of the ecliptic which is enclosed within the larger
Milky Way disk. As it turns out the ecliptic may be the 'real
nemesis,' responsible for past mass extinctions on earth.
The ecliptic plane is canted wrt the galactic plane, and the result
is that the sun traces what is in effect a circumferential sine
wave, such that it swings sequentially closer, and then furhter
away from the the MW plane and the protection (from extremely
strong comic rays) which is afforded within the galactic plane, but
not when we swing outside pf it.
It appears you are confusing the ecliptic, which is the plane that
includes the earth's orbit around the sun (and thus the apparent
annual path of the sun against the stars), and the solar system's
glactic orbit, i.e. the path of the sun about the galactic center.
The cycle of this swing is around 63 million years, which is a
close fit with the cycle of mass extinctions.
The "fit" is not all that close, except statistically. See the data
I present at:
http://mtaonline.net/~hheffner/Nemesis.pdf
It seems to me the evidence is more for gravitation entanglement with
a nemesis cloud.
There is an short article in 'Science News' two weeks ago:
http://www.sciencenews.org/articles/20070421/fob3ref.asp
"Northern Exposure: The inhospitable side of the galaxy?" by Davide
Castelvecchi
Executive Summary: Our solar system's periodic motion from one side
of the galaxy to the other could expose life on Earth to massive
amounts of cosmic rays and cause recurring, catastrophic mass
extinctions.
References:
Medvedev, M.V., and A.L. Melott. In press. Do extragalactic cosmic
rays induce cycles in fossil diversity? Astrophysical Journal
Abstract and preprint available at http://arxiv.org/abs/astro-ph/
0602092.
This article gives no quantitative analysis of the effect of cosmic
rays on albedo - a very long stretch of the imagination. I think it
is more likely the effect is the other way around, a large solar
anomaly plus meteor hits strip the earth of cosmic ray and UV
protection. Further, the hypothesis doesn't give a reason the major
extinctions start about 600 My ago. Again, a gravitational
entanglement event 600 MY ago, to me, provides a better explanation.
In addition, there have been correlations of some of the extinctions
with meteor hits, which are sufficient to explain the extinctions.
This is coincidence? I think not. There are extinctions for which
no meteor craters of sufficient size have been found. What is not
commonly realized, and what my 2004 Nemesis article brings to the
table, is the notion that it may not be the earth hits that are most
important, but rather solar meteor hits, which are much more likely,
and vastly more energetic events. Sun spots affect the upper
atmosphere. The effects on the atmosphere and earth environment of
huge sun spots resulting from solar meteor hits, and the huge
increase of solar output resulting from large volumes of solar meteor
hits, to me, provide a much more plausible explanation for all the
data, especially the *lack* of extinctions prior to 600 My ago.
Regards,
Horace Heffner
