The Moon Dust Argument
The basic theory goes something like:
There is a constant influx of meteoric dust to the Moon. If the Moon is 4.6 billion years old, this constant influx should produce a layer of moon dust "X" feet thick. Since the actual Moon dust is only a few centimetres thick, the Moon cannot be billions of years old and thus the Earth and the Moon must be recent.
In order to calculate the X factor, young Earth creationist almost inevitably quote Patterson (1960) and use a figure of 14 million tons of meteoric dust per year (for example, Morris 1974, Morris & Parker 1982). The actual figures are (from Morris 1974):
- Influx: 14 million tons/yr
- Density: 140lb/ft^3
- Area of Earth: 5.5 x 10^15 ft^2
- Age of Earth: 5 billion years
- Layer: 182 ft (50.48 mtrs)
The figure for the layer is used as an approximate figure for the Moon.
Now whilst this may seem straightforward, as is usual with young Earth creationist claims, it isn't.
In his 1960 article in Scientific American, Patterson described how he collected dust from the top of Mauna Loa, on Hawaii, and from the top of Haleakala, on the island of Maui. He then goes on to say,
" It was nevertheless apparent that the dust collected in the filters would come from terrestrial sources. To distinguish the portion contributed from space, my scheme was to rely upon the high nickel-content of meteorites. Analysis of large meteorites had shown that the 'irons' characteristically contain 7.5% nickel and that even the 'stones' have 1%. According to Fletcher G. Watson of Harvard University, the average nickel-content of all kinds is 2.0 to 2.8%. Since nickel is a rare element in terrestrial dust, it was reasonable to assume that any nickel found in dust samples came from meteoric sources. Taking 2.5% as a fair average of Watson's estimates, I needed only to multiply the weight of the nickel by 40 to find the total weight of the dust from meteoric sources." (P. 132)
Patterson's implicit assumption here was that all the nickel measured came from meteoric dust. As will be shown, this was incorrect. He continues,
"Most of the samples contained small but measurable quantities of nickel along with a large amount of iron. The average for 30 filters was 14.3 micrograms of nickel from each 1,000 cubic metres of air. This would mean that each 1,000 cubic feet of air contains 0.6 milligrams of meteoric dust. If meteoric dust descends at the same rate as the dust created by the explosion of the Indonesian volcano Krakatoa in 1883, then my data indicate that the amount of meteoric dust landing on the earth every year is 14 million tons. From the observed frequency of meteors and from other data, Watson calculates the total weight of meteoric matter reaching the Earth to be between 0.365 and 3.65 million tons a year. His higher estimate is thus about a fourth of my estimate, based on the Hawaiian studies. to be on the safe side, especially in view of the uncertainty as to how long it takes meteoric dust to descend, I am inclined to find 5 million tons per year plausable." (p. 132).
Patterson was well aware that the nickel content in dust was not entirely of meteoric origin, for as early as 1951 he wrote, concerning the nickel content of central Pacific sediments,
"Assuming that the whole [original emphasis] of this nickel is of cosmic origin and that the distribution is uniform within the time-span involved, the total accumulation of the element to the whole of the surface of our planet becomes 40x10^12 g per 1000 years or 40,000 tons per annum. Ascribing an average nickel content of 2% to the cosmic dust, the latter figure has to be multiplied by 50 in order to reach the total contribution of extraterrestrial matter to the Earth in the course of one year which gives 2 million tons*". (Patterson & Rotschi 1951, p. 88-89)
The"*" refers to a footnote at the bottom of page 89 which says:
"*It has been assumed in these calculations the all [original emphasis] the nickel found is of cosmic origin in order to obtain a maximum value for the accumulation of the material required. Obviously this assumption cannot be correct for a considerable part of the nickel is probably of terrestrial origin. . . . This would reduce the total quantity of such material carried to the Earth from 2 million to 1.4 million tons annually."
Patterson's original assumption that all nickel was of extraterrestrial origin was incorrect, Patterson knew this. That is why in his paper he rounded down the calculated influx rate fron an original value of 14 million tones per year to 5 million tones per year, but he was still guessing. As early as 1955 the link between influx levels and nickel abundance had been challenged. Leavasta and Mellis (1955) has taken some deep sea core material from which Patterson had previously measured nickel abundance and counted magnetic spherule abundance. Since the magnetic spherules are of extraterrestrial origin, they gave a far more accurate measure of influx. If the nickel abundance was totally due to extraterrestrial influx as well, the amounts of both through the core should correlate. Leavasta and Mellis found no correlation between spherule abundance and nickel abundance. Thus the abundance of nickel was being augmented from terrestrial sources. Patterson knew that the nickel values were 'contaminated' by terrestrial imput and was only looking for a ballpark figure. Since the amount of contamination was unknown he ignored it to come up with a theoretical maximum value, not an accurate one. However since at that stage it was all there was to work with, it was a worthwhile endevour.
Shedlovsky and Paisley (1966) obtained an influx rate of <100,000 tones per year by measuring the concentration of iron in the stratosphere.
Barker and Anders (1968) measured iridium and osmium in deep sea sediments. These elements are orders of magnitude less abundant in the earth's crust that nickel and so the terrestrial contamination problem would be correspondingly less. They came up with a value of between 100,000 tones and 8000 tones per year for the dust influx. This confirmed Leavasta and Mellis's work in that not only was the spherule data indicating a much lower influx, but the nickel values were substantially contaminated by terrestrial sources. It had to be, if the 14 million tons was correct, Antarctica would be dark with accumulated dust!
Since the late sixties much better and more accurate figures are available thanks to direct measurements in space. These show the influx rate to be about 22,000 tons per year (Dohnanyi 1972). More recent measurement put the figure even lower, at between 11,000 - 18,000 tons per year (Hughes 1975).
Now, using a figure of 22,000 tons per year, realizing that the Moon's gravity and area is less than the Earth's, we get (From Dalrymple 1984):
- Influx: 22,000 tons/yr
- Density: 140lb/ft^3
- Area ofMoon: 1.63x 10^15 ft^2
- Age of Moon: 4.6 billion years
- Layer: 1.6 inches (4.1 cm)
Claims that the lack of Moon dust imply a recent Earth are bogus. The Moon dust arguement has even been refuted by the ICR.
References
Barker, J.L. & Anders. E. (1968) Accretion rate of cosmic matter from iridium and osmium contents of deep sea sediments. Geochim. et Cosmochim. Acta, 32: 627-645.
Dalrymple, G.B. (1984) How old is the Earth? A reply to "scientific" creationism. Proceedings, 63rd Annual Meeting of the Pacific devision, American Association for the Advancement of Science, 1(2) 66-131.
Dohnanyi, J.S. (1972) Interplanetary objects in review: statistics of their masses and dynamics. Icarus, 17: 1-48.
Hughes, D.W. (1975) Cosmic dust influx to the Earth. Space Research XV: 531-539.
Laevasta, T. & Mellis, O. (1955) Transactions of the American Geophysical Union, 36: 385.
Morris, H.M. (1974) Scientific creationism (Public School Edition). Creation-Life Publ., San diego, California. 217 pp.
Morris, H.M. & Parker, G.E. (1982) What is creation science? Creation-Life Publ., San diego, California. 306 pp.
Patterson, H. (1960) Cosmic spherules and meteoric dust. Scientific American, 202: 123-132.
Patterson, H. & Rotchi, H. (1951) The nickel content of deep-sea deposits. Geochimica et Cosmochimica Acta, 2: 81-90.
Shedlovsky, J.P. & Paisley, S. (1966) On the meteoric component of stratospheric aerosols. Tellus, 18: 499-503.
The Receding Moon
A common argument is that since the Moon is receding from the Earth at a rate approaching 6 inches per year, extrapolating backwards indicates that the Moon would have been inside the Earths Roche limit (and thus destroyed) about 2 billion years ago. Thus the Earth-Moon system cannot have been in existence 2 billion years ago. This is wrong because a uniformitarian application of the recession rate is incorrect. The rate at which the Moon recedes is connected with the tides on the Earth. The gravitations interaction of the Moon with the tides causes the Earths rotation to slow. To conserve the energy of the Earth-Moon system, the excess is transfered to the Moon, pushing it into a higher orbit. The current rate is considered to be high because the spin of the Moon and the tides are thought to be nearly synchronous. In the past, the movement of the continents interrupted this, leading to a much lower rate of recession. Evidence from rythmic tidelites and fossil coral 'clocks' support the view that the number of days in a year was higher in thegeological past - in line with a faster spinning Earth then.
