Muadib
Paranormal Adept
INFLUX OF METEORITIC DUST
(Table 10, nos. 3, 36)
Other Links:
Meteorite Dust and the Age of the Earth
A detailed look at creationist fallacy.
Moon dust and the age of the solar system
The young-earth creationist organization, Answers in Genesis, says that meteorite dust arguments are flawed and should no longer used by creationists.
Morris and Parker (97) list two age calculations based on the influx of meteoritic dust to the Earth (“Too small to calculate”) and the Moon (200,000 years), referenced to Morris (92) and Slusher (116), respectively. Morris (92) argues that the age of the Earth cannot be great because if it were, there would be a thick layer of meteoritic dust on both the Earth and the Moon. Table 11 lists the data he uses. Morris’ values for the density of the dust and the area of the Earth are reasonable, and his slight exaggeration of the age of the Earth is unimportant to this discussion. The real problem is with his value for the influx of meteoritic dust from space, which Morris takes from Petterson (105).
Petterson (105) collected particulate matter from the top of Mauna Loa on the Island of Hawaii, using an air pump designed to sample smog. He analyzed the dust content in a known volume of air for the element nickel. Using a value of 2.5 percent for the nickel content of meteoritic material and assuming that all nickel in the atmospheric dust comes from space, he calculated that about 15 million tons of meteoritic dust falls on the Earth each year. Petterson (105) concluded that his calculation was an upper limit and, after evaluating all the available data, stated that a value of 5 million tons per year was more reasonable. Note that Morris (92) didn’t get Petterson’s upper limit of 15 million tons per year correct and that he completely ignored Petterson’s preferred value.
Although there is probably nothing fundamentally wrong with Petterson’s (105) measurements, his assumptions that nickel is a rare element in the Earth’s crust and in atmospheric dust, and that all the nickel can be attributed to dust from space, are incorrect. More significant is the fact that Petterson’s (105) measurements were made in 1957, the same year that the first satellite was launched. Since the late 1960s, much better and more direct measurements of the meteoritic influx to the Earth have been available from satellite penetration data. In a comprehensive review article, Dohnanyi (39) showed that the mass of meteoritic material impinging on the Earth is only about 22,000 tons per year, a value that would result in a layer only 8.1 centimeters thick in 4.55 billion years (Table 11). Other recent estimates of the mass of interplanetary matter reaching the Earth from space, based on satellite-borne detectors, range from about 11,000 to 18,000 tons per year (67); estimates based on the cosmic-dust content of deep-sea sediment are comparable (e.g., 11, 103). Thus, Morris (92) is off by a factor of more than 600. His conclusion about the thickness of dust on the Moon is likewise in error; he apparently neglects gravitational effects, which reduce the influx per unit area to the Moon by a factor of about 2.
Table 11: Comparison of Creationist and Scientific Versions of Meteoritic Dust on the Earth and the Moon. Following Morris (92), These Calculations are Based on the Highly Questionable Assumptions that the Influx of Dust has been Constant Throughout Geologic History and that No Erosion has Occurred
Creationist version (92)
Influx of dust to the Earth 14 × 106 tons/yr
Density of the dust 140 lb/ft3
Area of the Earth 5.5 × 1015 ft2
Age of the Earth 5 × 109 yr
RESULTS:
1) Layer on the Earth 182 ft (5048 cm) thick
2) Layer on the Moon at least as thick
Scientific version
Influx of dust to the Earth 4 × 10-9 g/cm2·yr (20,084 tons/yr)
Influx of dust to the Moon 2 × 10-9 g/cm2·yr (2,989 tons/yr)
Density of the dust 2.24 g/cm3 (140 lbs/ft3)
Area of the Earth 5.10 × 1018 cm2 (5.49 × 1015 ft2)
Area of the Moon‡ 1.52 × 1018 cm2 (1.63 × 1015 ft2)
Age of the Earth and the Moon 4.55 × 109 yr
RESULTS:
1) Layer on the Earth 8.1 cm thick
2) Layer on the Moon 4.1 cm thick
Slusher (116) likewise fails to avail himself of current knowledge on the subject and, instead, uses obsolete dust-influx estimates ranging from 3.6 million to 256 million tons per year. In addition, he advances the erroneous argument that the impact of meteoritic material and radiation from space should have created, by pulverization, a layer of regolith (“soil”) many miles thick if the Moon is 4.5 billion years old.
Considering that good satellite data on meteoritic influx were available before Morris (92) and Slusher (116) published their papers, they obviously have been highly selective in their choice of obsolete data. A more fundamental point, however, is that such calculations are based on faulty premises, including the erroneous assumptions that the meteoritic influx has remained constant for 4.5 billion years and that erosion is negligible, and thus are of no value in determining the age of the Earth or the Moon.
Finally, I have been unable to find the 200,000-year “age of the Earth” based on the accumulation of dust on the Moon (No. 36, Table 10) in Slusher’s (116) paper, nor can I find any data from which this result could have been obtained. Apparently, Morris and Parker (97) have credited Slusher (116) with a calculation that he did not do.
INFLUX OF MAGMA TO THE CRUST
(Table 10, no. 5)
Morris and Parker (97) list an age of 500 million years based on the “influx of magma from mantle to form crust.” This calculation, which appears in Morris (92), is based on the volume (0.2 km3/yr) of lava erupted by Paricutin Volcano in Mexico during the 1940s. Morris (92) notes that intrusive rocks are much more common than lava flows:
EFFLUX OF 4He INTO THE ATMOSPHERE
(Table 10, no. 8)
This age is referenced to a report by Cook (27), but the calculation was done by Morris (92), using data from Cook’s paper:
The helium balance in the atmosphere has been a subject of much study (76). Calculations show that at the present rates of production13, the entire atmospheric content of 4He and 3He could be supplied in about 2.3 million and 0.7 million years, respectively. Various mechanisms are known, however, by which helium escapes from the atmosphere into outer space.
At normal temperatures, the velocity of the average helium atom is less than the velocity required for escape from the Earth’s gravitational field. The elevated temperature in the exosphere, however, increases the kinetic energy of the helium atoms, so that some do escape. Calculations show that this mechanism could account for the escape of about half the 3He produced. Because 4 He is about a third heavier than 3He, however, thermal escape is probably insufficient by a factor of about 40 to account for the loss of 4He. The apparent inadequacy of thermal escape is the basis for Cook’s (27) report and Morris’ (92) calculation, but these authors have overlooked other mechanisms.
The most probable mechanism for helium loss is photoionization of helium by the polar wind and its escape along open lines of the Earth’s magnetic field. Banks and Holzer (12) have shown that the polar wind can account for an escape of 2 to 4 × 106 ions/cm2·sec of 4He, which is nearly identical to the estimated production flux of (2.5 ± 1.5) × 106 atoms/cm2·sec. Calculations for 3He lead to similar results, i.e., a rate virtually identical to the production flux. Another possible escape mechanism is direct interaction of the solar wind with the upper atmosphere during the short periods of lower magnetic-field intensity while the field is reversing. Sheldon and Kern (112) estimated that 20 geomagnetic-field reversals over the past 3.5 million years would have assured a balance between helium production and loss.
Calculations involving the helium balance in the atmosphere are complex because they are sensitive to solar activity, geomagnetic-field fluctuations, the rate of helium production from the Earth, and other factors. Although the helium-balance problem is not yet completely solved, it is clear that helium can and does escape from the atmosphere in amounts sufficient to balance production. The main problem is that the exact roles of the several known mechanisms are unknown. The helium balance of the atmosphere certainly is not a basis for calculating any reasonable estimate of the Earth’s age. Any attempt to do so (92) requires an unjustified oversimplification of a complex problem.
(Table 10, nos. 3, 36)
Other Links:
Meteorite Dust and the Age of the Earth
A detailed look at creationist fallacy.
Moon dust and the age of the solar system
The young-earth creationist organization, Answers in Genesis, says that meteorite dust arguments are flawed and should no longer used by creationists.
Morris and Parker (97) list two age calculations based on the influx of meteoritic dust to the Earth (“Too small to calculate”) and the Moon (200,000 years), referenced to Morris (92) and Slusher (116), respectively. Morris (92) argues that the age of the Earth cannot be great because if it were, there would be a thick layer of meteoritic dust on both the Earth and the Moon. Table 11 lists the data he uses. Morris’ values for the density of the dust and the area of the Earth are reasonable, and his slight exaggeration of the age of the Earth is unimportant to this discussion. The real problem is with his value for the influx of meteoritic dust from space, which Morris takes from Petterson (105).
Petterson (105) collected particulate matter from the top of Mauna Loa on the Island of Hawaii, using an air pump designed to sample smog. He analyzed the dust content in a known volume of air for the element nickel. Using a value of 2.5 percent for the nickel content of meteoritic material and assuming that all nickel in the atmospheric dust comes from space, he calculated that about 15 million tons of meteoritic dust falls on the Earth each year. Petterson (105) concluded that his calculation was an upper limit and, after evaluating all the available data, stated that a value of 5 million tons per year was more reasonable. Note that Morris (92) didn’t get Petterson’s upper limit of 15 million tons per year correct and that he completely ignored Petterson’s preferred value.
Although there is probably nothing fundamentally wrong with Petterson’s (105) measurements, his assumptions that nickel is a rare element in the Earth’s crust and in atmospheric dust, and that all the nickel can be attributed to dust from space, are incorrect. More significant is the fact that Petterson’s (105) measurements were made in 1957, the same year that the first satellite was launched. Since the late 1960s, much better and more direct measurements of the meteoritic influx to the Earth have been available from satellite penetration data. In a comprehensive review article, Dohnanyi (39) showed that the mass of meteoritic material impinging on the Earth is only about 22,000 tons per year, a value that would result in a layer only 8.1 centimeters thick in 4.55 billion years (Table 11). Other recent estimates of the mass of interplanetary matter reaching the Earth from space, based on satellite-borne detectors, range from about 11,000 to 18,000 tons per year (67); estimates based on the cosmic-dust content of deep-sea sediment are comparable (e.g., 11, 103). Thus, Morris (92) is off by a factor of more than 600. His conclusion about the thickness of dust on the Moon is likewise in error; he apparently neglects gravitational effects, which reduce the influx per unit area to the Moon by a factor of about 2.
Table 11: Comparison of Creationist and Scientific Versions of Meteoritic Dust on the Earth and the Moon. Following Morris (92), These Calculations are Based on the Highly Questionable Assumptions that the Influx of Dust has been Constant Throughout Geologic History and that No Erosion has Occurred
Creationist version (92)
Influx of dust to the Earth 14 × 106 tons/yr
Density of the dust 140 lb/ft3
Area of the Earth 5.5 × 1015 ft2
Age of the Earth 5 × 109 yr
RESULTS:
1) Layer on the Earth 182 ft (5048 cm) thick
2) Layer on the Moon at least as thick
Scientific version
Influx of dust to the Earth 4 × 10-9 g/cm2·yr (20,084 tons/yr)
Influx of dust to the Moon 2 × 10-9 g/cm2·yr (2,989 tons/yr)
Density of the dust 2.24 g/cm3 (140 lbs/ft3)
Area of the Earth 5.10 × 1018 cm2 (5.49 × 1015 ft2)
Area of the Moon‡ 1.52 × 1018 cm2 (1.63 × 1015 ft2)
Age of the Earth and the Moon 4.55 × 109 yr
RESULTS:
1) Layer on the Earth 8.1 cm thick
2) Layer on the Moon 4.1 cm thick
Slusher (116) likewise fails to avail himself of current knowledge on the subject and, instead, uses obsolete dust-influx estimates ranging from 3.6 million to 256 million tons per year. In addition, he advances the erroneous argument that the impact of meteoritic material and radiation from space should have created, by pulverization, a layer of regolith (“soil”) many miles thick if the Moon is 4.5 billion years old.
If a layer, say 0.0004 inch thick of pulverized matter, is formed per year, then, in 10,000 years a layer about four inches in depth would be produced; in 100,000 years a layer of 40 inches; in 1,000,000 years a layer of 3.3 feet; in 4,500,000,000 years a layer about 28 miles in depth would be formed. (116, p. 42)
He apparently fails to realize, however, that once a layer of pulverized material is formed, repeated impacts primarily will stir the existing layer rather than increase its thickness. As Dutch (41) has pointed out, Slusher’s (116) argument is equivalent to arguing that if a farmer plows his field to a depth of 20 centimeters each spring, in 100 years he (and his successors) will have plowed to a total depth of 20 meters.Considering that good satellite data on meteoritic influx were available before Morris (92) and Slusher (116) published their papers, they obviously have been highly selective in their choice of obsolete data. A more fundamental point, however, is that such calculations are based on faulty premises, including the erroneous assumptions that the meteoritic influx has remained constant for 4.5 billion years and that erosion is negligible, and thus are of no value in determining the age of the Earth or the Moon.
Finally, I have been unable to find the 200,000-year “age of the Earth” based on the accumulation of dust on the Moon (No. 36, Table 10) in Slusher’s (116) paper, nor can I find any data from which this result could have been obtained. Apparently, Morris and Parker (97) have credited Slusher (116) with a calculation that he did not do.
INFLUX OF MAGMA TO THE CRUST
(Table 10, no. 5)
Morris and Parker (97) list an age of 500 million years based on the “influx of magma from mantle to form crust.” This calculation, which appears in Morris (92), is based on the volume (0.2 km3/yr) of lava erupted by Paricutin Volcano in Mexico during the 1940s. Morris (92) notes that intrusive rocks are much more common than lava flows:
… so that it seems reasonable to assume that at least 10 cubic kilometers of new igneous rocks are formed each year by flows from the earth’s mantle.
The total volume of the earth’s crust is about 5 × 109 cubic kilometers. Thus, the entire crust could have been formed by volcanic activity at present rates in only 500 million years, which would only take us back into the Cambrian period. On the other hand, all geologists would surely agree that practically all the earth’s crust had been formed billions of years before that time. The uniformitarian model once again leads to a serious problem and contradiction. (92,p. 157)
But the “uniformitarian model” of which Morris (92) is so critical is a product of Morris (92), not science. He has pulled the value of 10 km3/yr from thin air, assumed that this fictitious rate has been constant over time, and neglected erosion, sedimentation, crustal recycling, and the fact that the injection of magma into the crust is a highly nonuniform process about which little is known. Morris’ (92) calculation is worthless.The total volume of the earth’s crust is about 5 × 109 cubic kilometers. Thus, the entire crust could have been formed by volcanic activity at present rates in only 500 million years, which would only take us back into the Cambrian period. On the other hand, all geologists would surely agree that practically all the earth’s crust had been formed billions of years before that time. The uniformitarian model once again leads to a serious problem and contradiction. (92,p. 157)
EFFLUX OF 4He INTO THE ATMOSPHERE
(Table 10, no. 8)
This age is referenced to a report by Cook (27), but the calculation was done by Morris (92), using data from Cook’s paper:
Consequently the maximum age of the atmosphere, assuming no original helium in the atmosphere, would be
As a matter of fact, Henry Faul (Faul, 1954) has cited evidence that the rate of efflux of helium into the atmosphere … is about 100 times greater than the value used by Cook. This in turn would reduce the age of the atmosphere down to several thousand years! (92, p. 151)
The values in this calculation are the content of 4He in the present atmosphere (3.5 × 1015 g) and the estimated total efflux (1020 g) from the Earth’s crust and mantle throughout geologic time (5 × 109 years). Morris’ (92) calculation is based on the assumption that all the helium released into the atmosphere would be retained, an assumption known to be false.As a matter of fact, Henry Faul (Faul, 1954) has cited evidence that the rate of efflux of helium into the atmosphere … is about 100 times greater than the value used by Cook. This in turn would reduce the age of the atmosphere down to several thousand years! (92, p. 151)
The helium balance in the atmosphere has been a subject of much study (76). Calculations show that at the present rates of production13, the entire atmospheric content of 4He and 3He could be supplied in about 2.3 million and 0.7 million years, respectively. Various mechanisms are known, however, by which helium escapes from the atmosphere into outer space.
At normal temperatures, the velocity of the average helium atom is less than the velocity required for escape from the Earth’s gravitational field. The elevated temperature in the exosphere, however, increases the kinetic energy of the helium atoms, so that some do escape. Calculations show that this mechanism could account for the escape of about half the 3He produced. Because 4 He is about a third heavier than 3He, however, thermal escape is probably insufficient by a factor of about 40 to account for the loss of 4He. The apparent inadequacy of thermal escape is the basis for Cook’s (27) report and Morris’ (92) calculation, but these authors have overlooked other mechanisms.
The most probable mechanism for helium loss is photoionization of helium by the polar wind and its escape along open lines of the Earth’s magnetic field. Banks and Holzer (12) have shown that the polar wind can account for an escape of 2 to 4 × 106 ions/cm2·sec of 4He, which is nearly identical to the estimated production flux of (2.5 ± 1.5) × 106 atoms/cm2·sec. Calculations for 3He lead to similar results, i.e., a rate virtually identical to the production flux. Another possible escape mechanism is direct interaction of the solar wind with the upper atmosphere during the short periods of lower magnetic-field intensity while the field is reversing. Sheldon and Kern (112) estimated that 20 geomagnetic-field reversals over the past 3.5 million years would have assured a balance between helium production and loss.
Calculations involving the helium balance in the atmosphere are complex because they are sensitive to solar activity, geomagnetic-field fluctuations, the rate of helium production from the Earth, and other factors. Although the helium-balance problem is not yet completely solved, it is clear that helium can and does escape from the atmosphere in amounts sufficient to balance production. The main problem is that the exact roles of the several known mechanisms are unknown. The helium balance of the atmosphere certainly is not a basis for calculating any reasonable estimate of the Earth’s age. Any attempt to do so (92) requires an unjustified oversimplification of a complex problem.