On Mon, 15 Jan 2001 09:21:47 -0500 "bivalve"
<bivalve@mail.davidson.alumlink.com> writes:
> Although a YEC could suggest that a comet was created in a long
> orbit, that would run into problems if there is evidence for its
> having been around before. For example, associated meteor showers
> show that the comet has been around several times already.
Meteor showers do occur somewhat regularly, and are probably the remains
of comets. However, if we have seen multiple meteor showers in
historical times from a single cloud of meteors, then that would likely
have been a short-period comet, and short-period comets don't last too
long. As I understand it, comets tend to disintegrate after about a
dozen trips past the sun. Van Flandern, in his book _Dark Matter,
Missing Planets & New Comets_, indicates that it can be determined from
the composition of a comet's tail whether the comet has been past the sun
before. The lighter elements tend to boil off during the first pass.
> With regard to the exploding planet hypothesis, how is a 3.2 million
> year period for comets expected?
You can find the answers at:
http://www.metaresearch.org/solar%20system/eph/eph2000.asp
Quoting from the site
"Comets are so strikingly similar to asteroids that no defining
characteristic to distinguish one from the other has yet been devised.
This is rather opposite to expectations of the solar nebula hypothesis,
because comets should have been formed in the outer solar system far from
the main asteroid belt. A traceback of orbits of “new” comets (that have
not mixed with the planets before) indicates statistically that these
probably originated at a common time and place, 3.2 Mya. [[i]] But it
should be noted that galactic tidal forces would eliminate comets from
any bodies that exploded prior to 10 Mya, so only very recent explosions
can produce comets that would remain visible today."
"The Opik test is cleanly passed by the exploded planet hypothesis, but
not by the Oort cloud model. Anyone working with the published new comet
data could arrive at the same conclusion. If skeptical readers suspect
that the author may have consciously or unconsciously selected the data
so as to give a favorable outcome, recall that Opik, who strongly doubted
the eph when he thought of this test, came to the same conclusion even
with the smaller amount of comet data available to him 20 years ago. In
essence, we have proved that Lagrange’s instinct 200 years ago was right
on target: Comets (at least most of them) acquired their extremely
elongated, planet-crossing orbits by ejection in an explosion that we can
now date at 3.2 million years ago. New comets are the continuing rainback
of debris from that explosion."
> I would think that an exploding
> icy planet would put comets into all sorts of orbits, in addition to
> the further disruption by gravitational encounters.
Astonishingly, a great many comets are discovered that have energy
parameter values close to zero, the threshold of gravitational escape, in
units where Earth’s energy parameter is –100,000. Before mixing with the
planets, a clustering of energy parameters near –5 exists, as shown in
the left half of Figure 3. However, as these same comets recede again far
from the planets, the clustering property is virtually destroyed, as
shown on the right side of Figure 3. The scattering is so great that no
clustering near –5 or any other value will exist the next time around. So
these comets must have been making their first visit to the planetary
part of the solar system. For that reason, they are called “new comets”.
"These new comets, first noted by Oort, were not the belt of comets
beyond Pluto expected by the primeval solar nebula hypothesis. They
arrive from all directions on the sky, with no tendency to be
concentrated toward the plane of the planets. Also, they move in
directions opposite to the planets as often as in directions consistent
with the planets. Because of these traits and a mean distance of 1000
times greater than that of Pluto from the Sun, the far-away source of
Oort’s new comets was designated the “Oort cloud”.
"The exploded planet hypothesis predicted something similar. The energy
parameter implies a particular period of revolution around the Sun. If a
planet exploded “x” years ago, then new comets returning for the first
time today would arrive on orbits with period “x”. Comets with shorter
periods would have returned in the past, mixing with the planets and
eventually being eliminated (or now in the process of being eliminated).
Comets with longer periods would not yet have returned for the first
time. So the eph predicts that all new comets should have the same period
“x”, and therefore the same energy parameter corresponding to a period of
“x”. The center of the spike on the left side of Figure 3 corresponds to
a period of 3.2 million years, which is therefore the time since the last
explosion event."
Bill
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