Article 1632 of sci.skeptic:
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From: jwm@APLSTAR.JHUAPL.EDU (James W. Meritt)
Newsgroups: sci.skeptic
Subject: Astronomy and Origins
Message-ID: <8911011849.AA05397@aplstar.jhuapl.edu>
Date: 1 Nov 89 18:49:51 GMT
Article-I.D.: aplstar.8911011849.AA05397
Posted: Wed Nov 1 13:49:51 1989
Sender: daemon@ucbvax.BERKELEY.EDU
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Topics:
} - Helmholtz's contraction theory says the sun is < 20,000,000 years.
} - Sun is shrinking by ~5 feet per hour.
} - Lunar dust--only 1 to 3 inches, not 54 feet.
} - Deterioration of earth's magnetic field
} - Atmospheric helium should have built up
} - Receding moon would have been touching earth
} - All comets would have disintegrated after 10,000 years.
} - galaxy formation.
) - biblical cosmology
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} - Helmholtz's contraction theory says the sun is < 20,000,000 years.
This (suns energy comes from contraction) is decades old and discarded soon
after the discovery of radioactivity. See the Scientific American article
from August 1989. The German physicst Hermann von Helmholtz formulated
this concept around 1869. It has been soundly rebuffed in the last
100 years.
- The guy who thought that we were detecting 0 (zero) solar neutrinos,
thus proving his theory that the sun was shining due to the
gravitational energy released as it shrank.
(they are there, and have been detected)
} - Sun is shrinking by ~5 feet per hour.
}i.e losing 0.01% per year. 6,000 creation = ~6% shrinkage, but 20,000,000
}years ago the sun touched the earth and 100,000 years ago the sun was twice
}as large (making life impossible).
I am interested in how you decide that this is a steady-state system?
A "Sun" that large could not possibly have this solar system.
A brief discussion of this is found in "Looking Inside the Sun", ASTRONOMY,
March 1989.
Analysis of historical records of eclipses and transits give varying
numbers. One result gives 2.25 arcseconds per century, similar to the
above figure. Another result gives an upper limit of 0.3 arcsecond per
century, but is also consistent with no shrinkage. Two more historical
analyses indicate that the sun was a bit larger a century ago than
today. Current measurements indicate that the sun is not now shrinking.
The long term stability of the size of the sun remains unknown.
} - Lunar dust--only 1 to 3 inches, not 54 feet.
The calculation you refer to is given by Henry Morris on pp.
151-153 of _Scientific Creationism_. It is based on a grossly erroneous
figure of 14 million tons of meteoritic dust per year, quoted by Petterson
in 1960. Morris misinterpreted Petterson's article. Petterson published a
figure of 15 (not 14) million tons per year as an _upper limit_. In
other words, Petterson said that the value is _not more than_ 15 million
tons per year. He was not able to measure an actual value. Morris
erroneously chose to interpret it to mean it was _equal_ to 14
million tons per year. Accurate values were measured in the late
1960's. The actual value is much lower than 15 million tons per year.
Dalrymple gives the value of 22,000 tons per year, nearly 700 times
smaller than your figure. That changes your 54 foot figure into about
2 cm, which is quite consistent with the amount of surface soil the
astronauts found on the Moon (it was considerably more than 1-2 mm).
My copy of "Everyman's Astronomy" indicates that the earth collects
about 9000 kg per day from meteors of visual magnitude 5.0 or brighter.
Assuming a typical rock density of 3 g/cc, this corresponds to an
accumulation rate of one inch per 10 billion years. Unfortunately no
data is presented for fainter meteors. I wouldn't be surprised to find
that the actual rate is one or two orders of magnitude higher, but "1
inch in 8000 years" is off by six orders of magnitude.
A dust accumulation rate of "one inch per 8000 years" should should
create a spectacular yearround meteor shower, and cause severe pitting
of the space shuttle windshields in just a single orbit. My quick estimates
give values far higher than have been actually observed.
} - Deterioration of earth's magnetic field, at present rates, implies an
} excessive field 10,000 years ago.
> Decay of Earth's Magnetic Field - Result of research by Thomas Barnes
> during his tenure as Physics Professor at UTEP. Published in _Origin and
> Destiny of Earth's Magnetic Field_, 1973. Barnes notes the measured
> values over the last 150 years and models according to uniformitarian
> principles.
The decay is not a steady state. In fact, there is considerable evidence
for reversals. The atlantic ocean floor as it spreads shown the weakening
- reversing - strengthening recorded in its stone as the contenents
spread from the mid-atlantic ridge.
The field is expected to reverse sometime in the next few thousand
years. A time scale on page 78 shows the reversals over the past 170
million years, as deduced from the magnetic patterns in oceanic crust.
I counted about 200 reversals on the chart.
Briefly, Barnes took approximately 150 years of data on the Earth's
dipole magnetic field and extrapolated it backwards to about 10000
years Before Present (B.P.). He stated that the field 10,000 years ago
would, on this calculation, have been as strong as that of a magnetic
star, and stated (correctly) that this was absurd. However, there
are four fatal flaws in his analysis.
In the first place, Barnes studied only the *dipole* component of the
Earth's magnetic field, In fact, the very same data that Barnes used
show that the *nondipole* component of the field *increased* during
the same period of time, almost exactly cancelling the decrease in
the dipole field that Barnes calculated (D. Brent Dalrymple, U. S.
Geological Survey, Menlo Park CA, in *Reviews of 31 Creationist Books*).
This alone is sufficient to destroy the basis of his work.
The second failure of Barnes' study was the idea that one can take data
from a short period of time and simply extrapolate it backwards to obtain
a reliable estimate at a time remotely removed from the data. Anyone
competent in analyzing scientific data knows that extrapolations are good
only for a relatively short period of time, if at all, and that the further
away from the actual data one goes, the less reliable it becomes. Barnes
extrapolated 150 years' worth of data back 10,000 years! In real life,
one would be surprised if extrapolation of these data more than a few
hundred years back were accurate.
The third failure of Barnes' study was the mathematical model he
chose. He decided to fit the data to an exponential. The data fit
a straight line just as well (see Figure 1 of Stephen G. Brush's
article in *Scientists Confront Creationism*), but a straight line
would have given a much older age for the Earth than the 10,000 years
that Barnes, because of his Biblical literalism, wishes to promote.
The fourth failure of Barnes' study was his failure to consider any other
evidence than the 150 years worth of data from geomagnetic observatories
that he used. There exists, in paleomagnetic data, a long record of
the Earth's magnetic dipole strength (extending backwards for millions
of years). The data are in agreement with the observatory data Barnes
used over their common intersection, but they differ drastically from
Barnes' extrapolation when one goes further back in time.
} - Atmospheric helium should have built up more from U decay.
This statement is false. It falls precisely within predicted limits.
Please read:
Calculations on the Composition of the terrestrial Planets
Reynolds & Summers, Journal of Geophysical Research vol 74, no 10
May 15, 1969 p 2494
The formation of the Earth from Planetesimals
Wetherill, Scientific American June 1981
Cloud, Preston E., Jr., "Atmospheric and Hydrospheric Evolution on
the Primitive Earth", Science 160, (17 May 1968), pp 729 - 736
Mart, Michael H, "The Effect of a Planet's Size on the Evolution of
its Atmosphere", published in some conference or another; I
got a copy from the author. (ave Allen
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