Re: Science Disproves Evolution

Another distortion of truth and spreading of misinformation! Where is
your integrity? You tarnish it to spread your beliefs while preaching
a religion of truth and honesty!!

In his debate with Dr. Hilpman, Dr. Hovind stated that comets lasted
10,000-15,000 years before being blown apart by the solar wind!
Really! Any high school kid with a keen interest in astronomy will
tell you that it is the heat of the sun which is a comet's undoing.
Each time a comet, which is akin to a dirty snowball, passes near the
sun it loses tons of material to vaporization. Thus, the number of
orbits such a comet can make before being reduced to a swarm of gravel
is limited. The solar wind along with the heat and light of the inner
solar system are responsible for a comet's magnificent tail. Thus,
comets brighten up as they near the sun, their tails pointing away
from the sun. A few comets occasionally crash into one of the planets,
especially Jupiter, or into the sun itself. Others are thrown out of
the solar system forever.

In passing, let me point out that the projected life span of one
short-
period comet, that of Halley's comet, is 40,000 years (Chaisson and
McMillan, 1993, p.339). Thus, we can forget about Dr. Hovind's 10,000-
year figure! A comet's actual life span depends on its size.

Short-period comets can be used to support a young solar system, hence
a young earth, only if they have no reasonable source of
replenishment. By definition, they orbit the sun at least once every
200 years. Since they lose material each time they pass near the sun,
they soon burn out and must constantly be replaced over billions of
years. To destroy the creationist argument, we need only throw
reasonable doubt on their claim that short-period comets are not
replaced. If that point is in doubt, then the whole argument crumbles
away.

Creationism's main argument seems to be that we don't have close-up
photos of the Oort Cloud and, therefore, cannot be 100% certain that
it really exists! Sorry fellas, but if you want to use this comet
argument it is up to you to prove, beyond a reasonable doubt, that the
Oort Cloud and other sources don't exist! (The Oort Cloud, named after
Jan Hendrik Oort, is a calculated accumulation of comets and cometary
material occupying the fringes of the solar system at a distance of
roughly 50,000 to 100,000 AU. One AU is the average distance of the
earth from the sun, i.e., 93 million miles. Various computer studies
of cometary orbital data in conjunction with other evidence strongly
supports the existence of the Oort Cloud.)

Let's briefly summarize what science knows about comets. In 1950,
based on a study of the orbits of several long-period comets, the
Dutch astronomer Jan Oort proposed that a great spherical shell of
them existed at the remote frontiers of our solar system. Better
statistics in more recent years have supported the existence of the
Oort Cloud and put it at a distance of 50,000 AU (1.3 light-years).

During the 1980s, astronomers realized that Oort Cloud comets may be
outnumbered by an inner cloud that begins about 3,000 AU from the Sun
and continues to the edge of the classical Oort Cloud at 20,000 AU.
Most estimates place the population of the inner Oort Cloud at about
five to ten times that of the outer cloud -- say, 20 trillion or so --
although the number could be ten times greater than that. The
innermost portion of the inner Oort Cloud is relatively flattened,
with comets extending a few degrees above and below the ecliptic. But
the cloud rapidly expands, forming a complete sphere by the time it
reaches several thousand AU. (Benningfield, 1990, p.33)

This inner cloud of comets is called the Hills Cloud. Originally, it
was thought that short-period comets were merely long-period comets
from the Oort Cloud which had been converted by close encounters with
Jupiter or the other large outer planets. That may well be true for
some of them, but modern studies of short-period comets have
identified their probable origin in a region of space now named the
Kuiper Belt, which resembles a flattened ring just beyond the orbit of
Neptune. Computer simulations show that such a source would account
beautifully for the low-inclination, short-period, prograde orbits,
and other features associated with short-period comets. The Kuiper
Belt probably has anywhere from 100 million to several billion comets,
which probably formed there when the planets formed. The gradual pull
of the giant gas planets over time continually send a few of those
comets towards the sun. Thus, the short-period comets are replenished
from the Kuiper Belt. The Kuiper Belt is no longer "just" a
theoretical construct. As of 1998, more than 60 of the larger objects
in the Kuiper Belt have been directly observed! That translates to
some 70,000 objects out there whose diameter exceeds a whopping 100
kilometers--not to mention countless numbers of normal-sized comets.
Jim Foley was kind enough to pass along an Internet site for those of
you who may be interested in these new discoveries. The Kuiper Belt
web page (http://www.ifa.hawaii.edu/~jewitt/kb.html) is maintained by
David Jewitt, who personally discovered many of these objects.

Thanks to the Hubble Space Telescope, astronomers have finally proven
that short-period comets come from a vast region of space beyond
Neptune. This is the realm of the Kuiper disk -- an enormous
population
of shadowy mini-ice worlds that slowly orbit the Sun in near total
darkness. (Astronomy, October 1995, p.28)

Theoretical calculations indicate that the great bulk of comets were
originally formed in the region between Uranus and Neptune. They
represent planetesimals which escaped being gobbled up by the outer
planets. Gravitational interactions eventually tossed them into
elliptical orbits which took them thousands of astronomical units (AU)
away from the sun. This region, then, is the ultimate source of those
comets making up the Oort Cloud.

Oort determined that comets tossed into highly elliptical orbits by
Uranus and Neptune would be nudged into more nearly circular orbits by
encounters with passing stars. Stellar encounters also would scatter
comets above and below the ecliptic plane, creating a sphere of comets
instead of a flattened disk. After four decades of refinements to
Oort's original ideas, astronomers today believe the Oort Cloud
extends from about 20,000 to 100,000 AU (almost 2 light-years) from
the Sun and contains as many as two trillion comets with a total mass
several times Earth's. (Benningfield, 1990, p.31)

A star passing within a few light-years would likely perturb the
orbits of the comets in the Oort Cloud, sending some of them towards
the sun. Statistics indicate that about 5000 stars have passed that
closely during the earth's lifetime. An encounter with a giant
molecular cloud, which is likely to happen every few hundred million
years as our sun orbits our galaxy, would also perturb the Oort Cloud.

Another newly discovered agent for perturbing Oort Cloud comets is
gravitational tides. Created by the gravitational force of material in
the Galactic disk, these tides could alter the orbits of Oort Cloud
comets. In fact, some astronomers estimate that as many as 80 percent
of the long-period comets entering the inner solar system for the
first time were shoved from their previous orbits by the gentle tug of
Galactic tides. (Benningfield, 1990, pp.32-33)

Once in a great while, perhaps 9 times during the lifetime of our
Earth (Astronomy, February 1982, p.63), a star will pass so close as
to stir up even the Hills Cloud of comets (the innermost Oort Cloud
which is shaped mostly like a disk). A collision with a giant
molecular cloud would have a similar effect.

Occasionally, though, a star or giant molecular cloud passes directly
through both Oort Clouds, scattering comets like a cue ball striking
the neatly racked balls on a billiard table. Such an event kicks many
comets into the outer cloud, replenishing those lost to other
processes. (Benningfield, 1990, pp.33-34) Thus, we have adequate
sources for replenishing both our long-period comets and our short-
period comets over a period of several billion years. In the case of
the latter, we can actually see some of the larger ones lurking in the
Kuiper Belt!

Granted, we don't have photos of comets in the Oort Cloud or the Hills
Cloud. At those distances comets are too small to show up even in the
best telescopes. The fact that the Oort and Hills Clouds are still
"theoretical" does not mean that they are based on guesswork and rank
speculation. Computer simulation, as already mentioned, matched the
short-period comets to the Kuiper Belt. Now, we have visual
confirmation. Similar studies of long-period comets, even from the
1950s, points clearly to their origin in the Oort Cloud. All in all, a
great deal of computer work has been done that supports and refines
the above models. The astronomical community treats the Oort Cloud, at
the very least, as an excellent working hypotheses.

That there is some kind of large comet reservoir beyond the range of
our telescopes follows directly from a simple observation. Astronomers
detect new long-period comets at the rate of about one per month. By
that rough estimate, 24,000 long-period comets have entered the inner
solar system since the time of Christ! Orbital analysis show that
these approaching comets generally take several million years to orbit
the sun, and, as they are more or less randomly distributed in their
orbits, we may deduce that the bulk of them are presently beyond the
range of our telescopes. Only the exceptional comet, at any given
moment, would be in that small portion of its orbit which crosses the
inner solar system.

For the sake of argument, suppose that it takes each of these comets
four million years to orbit the sun. In 2000 years we see only
2000/4,000,000 or 1/2000 of them. Thus, we would have about 48 million
comets altogether. However, even that figure is extremely low since
only the exceptional comet would have an elongated orbit which takes
it anywhere near the sun. Oort showed that most of them would happily
orbit the fringes of our solar system and never come near the inner
regions. Obviously, as you can see from this ballpark calculation,
there is an ample source of comets beyond the range of our telescopes.

This reservoir of cometary nuclei surrounding the Sun is called the
Oort Cloud . . . Estimates of the number of "dirty snowballs" in the
Oort Cloud range as high as 12 billion. Only such a large reservoir of
cometary nuclei would explain why we see so many long-period comets,
even though each one takes several million years to travel once around
its orbit. (Kaufmann, 1994, p.304)

Another simple observation applies to the short-period comets, which
means that we didn't even need the visual confirmation of the Kuiper
Belt to win the argument! If there were no means for replenishing
comets, then all of them would have the same age. In creationist eyes,
they would all be 6000 years old. Yet, observations show that short-
period comets with equivalent orbits and sizes have a variety of ages.
They range from gaseous "babies," which could hardly have gone around
the sun more than a few times, to burnt-out gravel heaps, which have
been around the sun once too often. This simple observation proves,
beyond a reasonable doubt, that the short-period comets are being
replaced.

Benningfield (1990, p.32) gives some interesting evidence indicating
that vast comet clouds exist around certain stars, but we shall not
pursue the matter further. The point has already been made. In order
to win this argument, the creationist must prove that there are no
reasonable sources for replenishing comets. Instead, we find
compelling evidence for cometary reservoirs!
.

Relevant Pages

  • Re: Science Disproves Evolution
    ... In his debate with Dr. Hilpman, Dr. Hovind stated that comets lasted ... tell you that it is the heat of the sun which is a comet's undoing. ... orbits such a comet can make before being reduced to a swarm of gravel ... Oort Cloud and other sources don't exist! ...
    (alt.religion.christian)
  • Re: Interstellar Propulsion idea using an Asteroid and a few comets!
    ... The Oort Cloud of comets go well beyond the ... to exist at some 30,000 to 50,000 AUs out from the Sun. ... limiting distance for *solar* illumination of objects. ... forward path and illuminate any oncoming target comets / ice balls. ...
    (sci.astro.amateur)
  • Re: Interstellar Propulsion idea using an Asteroid and a few comets!
    ... The Oort Cloud of comets go well beyond the ... to exist at some 30,000 to 50,000 AUs out from the Sun. ... limiting distance for *solar* illumination of objects. ... forward path and illuminate any oncoming target comets / ice balls. ...
    (sci.space.policy)
  • Re: Interstellar Propulsion idea using an Asteroid and a few comets!
    ... The Oort Cloud of comets go well beyond the ... to exist at some 30,000 to 50,000 AUs out from the Sun. ... limiting distance for *solar* illumination of objects. ... forward path and illuminate any oncoming target comets / ice balls. ...
    (sci.physics.relativity)
  • Re: Detecting the Oort cloud.
    ... could the planned 100 meter telescopes resolve them at the 1 light-year distance of the Oort cloud? ... Could a 100 meter telescope detect an Oort comet as a point light source? ... Since there is theorized to be a cloud of comets there could a 100 meter telescope detect them as a cloud of objects if not individually? ... Could we then detect Oort cloud comets at radio wavelengths? ...
    (sci.astro)