10 results found containing all search terms.
... Science Frontiers ONLINE No. 77: Sep-Oct 1991 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Mercury: the impossible planet Mercury, largely hidden in the sun's glare, also conceals beneath its baked, cratered surface: (1 ) far more iron than solar-system theory allows; and (perhaps) (2 ) a dynamo that should not exist. Let us take the excess-iron problem first. Mercury's density is 5.44 (compared to earth's 5.52), so that it very likely contains much iron. Our moon, which resembles Mercury in size and external appearance, only has a density of 3.34, implying an altogether different origin. In the currently accepted ... Science Frontiers ONLINE No. 77: Sep-Oct 1991 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Mercury: the impossible planet Mercury, largely hidden in the sun's glare, also conceals beneath its baked, cratered surface: (1 ) far more iron than solar-system theory allows; and (perhaps) (2 ) a dynamo that should not exist. Let us take the excess-iron problem first. Mercury's density is 5.44 (compared to earth's 5.52), so that it very likely contains much iron. Our moon, which resembles Mercury in size and external appearance, only has a density of 3.34, implying an altogether different origin. In the currently accepted ...
Terms matched: 2 - Score: 214 - 15 May 2017 - URL: /sf077/sf077a03.htm
... Science Frontiers ONLINE No. 70: Jul-Aug 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Tilted Planetary Magnetic Fields The axis of the earth's magnetic field is tilted about 11 away from our planet's axis of rotation. This tilt is embarrassing to the reigning "dynamo theory," in which the axes of the magnetic field and rotation are presumed to be aligned. The situation is even worse with some the other planets; viz., Uranus with 60 and Neptune with 47 . Jupiter's tilt is 10 , while Saturn's is only 1 . Clearly, something is awry. Two possibilities are: (1 ) The dynamo theory is incorrect; or (2 ) The magnetic fields measured by spacecraft ... actually combinations of central, dynamocreated, dipole fields, which are aligned with the axes of rotation, and "other" dipole fields originating in the outermost portions of the planetary cores. If the latter solution to the dilemma is correct, we must account for the origin and disposition of these "other" dipoles. (Eberhart, J.; "Straightening the Magnetic Tilts of Planets," Science News, 137:294, 1990.) Reference. The anomalously titled magnetic fields of planets are cataloged in The Moon and the Planets. For details on this book, visit: here . From Science Frontiers #70, JUL-AUG 1990 . 1990-2000 William R. Corliss ...
Terms matched: 2 - Score: 154 - 15 May 2017 - URL: /sf070/sf070a04.htm
... . What is surprising is that the energy detected radiating from the two hot spots is all reradiated solar energy; that is, there seems to be no contribution at all from Mercury's core! If no heat is leaking out of Mercury's core, the core itself is very likely solid. If it is solid, it cannot establish convection cells and thus generate a magnetic field through dynamo action. But back in 1975, the Mariner 10 spacecraft radioed back that Mercury actually does possess a magnetic field, and a surprisingly large one at that. (Wilford, John Noble; "Theory of Mercury's Hot Poles Is Shown to Be a Fact," New York Times, June 13, 1990. Cr. J. Covey.) Comment. Something is clearly awry ... This inconsistency could mean that the dynamo theory presumed to be responsible for planetary magnetic fields is incorrect. Reference. Mercury's anomalous magnetic field is cataloged in section AHZ in our catalog: The Moon and the Planets. To order, visit: here . From Science Frontiers #71, SEP-OCT 1990 . 1990-2000 William R. Corliss ...
Terms matched: 2 - Score: 149 - 15 May 2017 - URL: /sf071/sf071a06.htm
... at Steens Mountain, when the field reversed 15.5 million years ago, the lava flows suggest that the field's axis was rotating 3-8 per day -- incredibly fast according to current thinking, in fact a thousand times faster than expected. The conundrum (one might call it a scientific impasse) arises because the flowing electrically conducting fluids that supposedly constitute the earth's dynamo would have to flow at speeds of several kilometers/hour. No one has ever contemplated molten rock moving at such speeds in the core! (Appenzeller, Tim; "A Conundrum at Steens Mountain," Science, 255:31, 1992. Lewin, Roger; "Earth's Field Flips Flipping Fast," New Scientist, p. 26, January 25, 1992. ... Could it be that the prevailing dynamo theory is incorrect? To make matters more interesting, it now seems that the paths taken by the reversing poles follow similar routes with each flip-flop. One preferred path is a band about 60 wide running northsouth through the Americas; the other path is 180 away cutting through east Asia and just west of Australia. The implication is that some unknown structure in the core somehow guides the reversing poles. (Anonymous; "A New Path to Magnetic Reversals," Eos, 72:538, 1991.) Reference. Additional doubts about the dynamo paradigm are expressed in EZF3 in our catalog: Inner Earth. For further information, visit: here . From Science Frontiers #80, MAR-APR 1992 . 1992-2000 William R. Corliss ...
Terms matched: 2 - Score: 143 - 15 May 2017 - URL: /sf080/sf080g13.htm
... close-packed in hexagons, because such a 'sigma' phase is anisotropic." But, asks Tromp, how and why did the core material assume this crystalline character? (Hecht, Jeff; "The Giant Crystal at the Heart of the Earth," New Scientist, p. 17, January 22, 1994.) Comment. How does this big iron crystal jibe with the dynamo theory of the earth's magnetic field? Could Tromp's "giant asymmetric crystal" produce a permanent magnetic field, thereby forcing the supposed dynamo to play second magnetic fiddle? From Science Frontiers #93, MAY-JUN 1994 . 1994-2000 William R. Corliss ...
Terms matched: 2 - Score: 133 - 15 May 2017 - URL: /sf093/sf093g12.htm
... a climate change and the beginning of a little ice age. The redistribution of water near the equator to ice at high latitudes alters the rotation rate of the crust and mantle of the Earth. If the sea-level change is sufficiently large ( 10 meters) and rapid (in a few hundred years), then the velocity shear in the liquid core disrupts the convective cells that drive the dynamo. The new convective cells that subsequently form distort and tangle the previous field, reducing the dipole component near to zero while increasing the energy in multipole components. Eventually a dipole is rebuilt by dynamo action, and the event is seen either as a geomagnetic reversal or as an excursion." (Muller, Richard A., and Morris, Donald E.; "Geomagnetic Reversals from Impacts ... the Earth," Geophysical Research Letters, 13:1177, 1986.) Comment. That the earth's field is generated by internal dynamo action is still a theory, although a widely accepted one. From Science Frontiers #49, JAN-FEB 1987 . 1987-2000 William R. Corliss ...
Terms matched: 2 - Score: 133 - 15 May 2017 - URL: /sf049/sf049p18.htm
... is radiated away. With Neptune's period now pegged at 16 hours by Voyager's measurements, the mixing-cooling theory is in trouble. The magnetic-field situation is in even worse shape. When planetary scientists found that Uranus' magnetic field was tilted 60 from the axis of rotation, they worried a bit but didn't think that this one exception would overthrow the favored dynamo theory of field generation. After all, the magnetic fields of Jupiter, Saturn, and earth are reasonably well-behaved. But Neptune's field is now found to be misaligned by 50 ! The confidence of the planetologists has now been shaken. What, if anything, is different about Neptune and Uranus? It may just be that we don't really know how the magnetic ... Science Frontiers ONLINE No. 66: Nov-Dec 1989 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Neptune Spins Too Fast And Its Magnetic Field Is Awry Some pre-Voyager theories about Neptune have been severely tried by the data trickling back to earth across the great gulf separating us from what is now the most distant planet. Before Voyager, Neptune's spin period was believed to be about 17 hours. This was just the spin rate needed by theorists to explain why Neptune radiates much more heat than Uranus. It seems that spin rate is related to the mixing of a planet's molten innards, which in turn affects the rate at which heat reaches the surface where it is radiated away. With Neptune's period now ...
Terms matched: 2 - Score: 133 - 15 May 2017 - URL: /sf066/sf066a05.htm
... rocks are not faithful recorders of the main geomagnetic field. Should this be actually so, the whole field of paleomagnetism, including plate tectonics, is undermined, for it depends upon similar measurements. The earth's molten core can change rapidly, at least in some regions, in response to forces still unrecognized. This, of course, is not really a satisfying "explanation." The dynamo theory of the origin of the geomagnetic field is incorrect. (Coe, R.S ., et al; "New Evidence for Extraordinarily Rapid Change of the Geomagnetic Field during a Reversal," Nature, 374:687, 1995. Merrill, Ronald T.; "Principle of Least Astonishment," Nature, 374:674, 1995.) Reference. More puzzles of the ... field are provided in: Inner Earth. For details, visit: here . From Science Frontiers #101 Sep-Oct 1995 . 1995-2000 William R. Corliss ...
Terms matched: 2 - Score: 116 - 15 May 2017 - URL: /sf101/sf101g11.htm
... from its rest position, the restoring force becomes nonlinear; i.e ., not proportional to the displacement. At some combination of displacement and driving frequency, a region of chaos may develop, in which theory is powerless to tell what is going to happen next. "It is not just the behavior of pendulums that has sprung this surprise. Systems as diverse as simple electrical circuits, dynamos, lasers, chemical reactions and heart cells behave in an analogous way and the implications extend far beyond these examples -- to matters such as weather forecasting, populations of biological species, physiological and psychiatric medicine, economic forecasting and perhaps the evolution of society." (Tritton, David; "Chaos in the Swing of a Pendulum," New Scientist, p. 37, July 24 ... fixtures of physics labs, to say nothing of grandfather clocks. It is now widely recognized that pendulums can behave chaotically; that is, unpredictably. As the pendulum bob swings farther away from its rest position, the restoring force becomes nonlinear; i.e ., not proportional to the displacement. At some combination of displacement and driving frequency, a region of chaos may develop, in which theory is powerless to tell what is going to happen next. "It is not just the behavior of pendulums that has sprung this surprise. Systems as diverse as simple electrical circuits, dynamos, lasers, chemical reactions and heart cells behave in an analogous way and the implications extend far beyond these examples -- to matters such as weather forecasting, populations of biological species, physiological and psychiatric medicine ...
Terms matched: 2 - Score: 112 - 15 May 2017 - URL: /sf047/sf047p20.htm
... on the western slope of the Sangre de Cristos, northwest of Mount Blanca and south of the Sand Dunes, we heard the sounds in 1970. Two or three nights in succession, it 'cranked up' after midnight and subsided shortly before dawn. It wasn't really loud enough to hear over conversation - but definitely sounded like a motor of some sort, with a suggestion of a dynamo-type whine to it. And others had said that it sometimes seems even louder with an ear to the ground. One could easily imagine (Adam's emphasis) the sound was coming from beneath the surface, but whether it did or not remains purely speculative." The report referenced below contains similar observations from Texas, New Jersey, New York, Pennsylvania, California, Puerto ... Science Frontiers ONLINE No. 69: May-Jun 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Machine-like underground noises On SF#68, we reported on the "English hums." One theory is that these particular humming sounds emanate from turbines in Britain's network of buried natural gas pipelines. It seems, though, that similar subterranean sounds are heard in many places where buried pipelines are unlikely. Mainstream scientists care little for such phenomena; and the following data were collected by an independent researcher. Yakima Indian Reservation, Washington. Statement by W.J . Vogel, Chief Fire Control Officer: "In September 1978 the sound of underground turbines or engines was heard at Sopelia Tower at the southern boundary of the ...
Terms matched: 2 - Score: 112 - 15 May 2017 - URL: /sf069/sf069g11.htm
