Melting Mess
New details are emerging on how the melting poles could raise ocean heights [see "The Unquiet Ice"; SciAm, February 2008]. Researchers at the University of Toronto and Oregon State University suggest that the rise could be uneven around the world. They examined the West Antarctic ice sheet, which contains enough grounded ice to boost global sea levels by five meters if it splashed into the water. But such a huge redistribution of mass in Antarctica would reduce the gravitational pull in the area and shift the earth's rotation axis by 500 meters. Taking these and other factors into account, they figure that the seas will drop near Antarctica but rise in the Northern Hemisphere by an additional one to two meters above previous estimates. Gravitate toward the analysis in the February 6 Science.
Sensation Swirls
Those fingertip whorls aren't just good for gripping objects and identifying people; they also enable you to feel fine textures and tiny objects. French researchers constructed two mechanical sensors, one with a ridged end tip and another with a smooth one; they then ran them over various textured surfaces, measuring the vibrations picked up by the fingerprinted sensors. Each ridge magnified the frequency range well suited for detection by nerve endings in the skin called Pacinian corpuscles. The work, published online January 29 by Science, helps to explain how the sense of touch accurately informs our surroundings [see "Worlds of Feeling"; SciAm Mind, December 2004].
--Kate Wilcox
Forward with Stem Cells
Researchers at Northwestern University stopped and, in some cases, reversed the effects of early-stage multiple sclerosis, a disease in which the immune system attacks the central nervous system. The investigators removed from the bone marrow so-called hematopoietic stem cells, which resupply the body with fresh blood cells, then used drugs to destroy the patients' existing immune cells. Injected back into the patients, the stem cells apparently "reset" the body's defenses so that they do not mistakenly go after healthy tissue. The study, published online January 30 in the Lancet Neurology, involved only 21 patients, however, so more complete trials are needed to assess the approach.
Data on stem cell therapies in general should increase soon: the U.S. Food and Drug Administration approved in January the first human embryonic stem cell trial a decision long awaited by scientists [see "The Stem Cell Challenge"; SciAm, June 2004]. It will enable Geron Corporation in Menlo Park, Calif., to test embryonic stem cells on 10 patients with spinal cord injuries.
--Kate Wilcox
Mooned by the Moon
Some four billion years ago the far side of the moon may have faced Earth. Mark Wieczorek and Mathieu Le Feuvre of the Institute of Earth Physics in Paris propose that if the moon had always faced the same way, it would have more craters on its leading side, where it encountered heavy bombardment during the early years of the solar system [see "The New Moon"; SciAm, December 2003]. Younger craters follow this pattern, but older craters do not; they instead cluster on the trailing edge, suggesting that it was once in front. An asteroid or comet strike could have spun the moon 180 degrees to its current orientation. The journal Icarus posted the conclusion online on December 31, 2008.
--John Matson
This article was originally published with the title Updates.
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6 Comments
Add CommentOur precious 33 year old daughter has been diagnosed with MS. We certainly hope Ms Wilcox has found some positive news about this awful disease! Do ya need another pataient to test? May we offer my precious and loved Ashley? We want her cured--please consider her if you need more victims to test! We are totally serious and desperate. Thanks and Bless you, Elayne Powers
Reply | Report Abuse | Link to thisI seem to remember reading that all/most moons would get locked to it's planet in this way. Nothing to do with random orientations or asteroid strikes.
Reply | Report Abuse | Link to thisI found the link that explains why we always see the same face of the moon, and why, over deep time, the earth will eventually always show the same face to the moon.
Reply | Report Abuse | Link to thishttp://www.badastronomy.com/bad/misc/tides.html
Gravitation torque on the moon's slightly out of round shape is believed to hold it in autorotation. The same was believed to hold Mercury in autrotation about the sun until it was discovered that its rotation period is 58.65 days which is 2/3 of its revolution period of 87.97 days. A Mercury year is precisely half a day.
Reply | Report Abuse | Link to thisGravitational torque on the moon's slightly out of round shape is believed to hold it in autorotation. The same was believed to hold Mercury in autorotation about the sun until it was discovered that its rotation period is 58.65 days which is 2/3 (0.6667) of its revolution period of 87.97 days. A year is precisely half a day on Mercury since it exposes opposite faces to the sun on each revolution. It has no tilt to its axis and no seasons. One Venus day (117 Earth days) is 2/3 (0.665) of a Mercury day (175.94 Earth days). Now the rotation period of Venus is (243.17 Earth days) which is 2/3 (0.666) of an Earth Year (365.24 days). Moreover Venus is in retrograde rotation and every time it comes directly between the Earth and the sun it exposes the same face toward the Earth, even though exactly five Venus days have elapsed between such conjunctions. Mars is outside of Earth without direct resonances with other planets, however there are 666.8 Mars solar days of 24.6587 hours in a Mars year. It is an extraordinary coincidence that resonances such as these should arise with the terrestrial planets. There is no explanation for them in classical dynamical theory or in theories of planetary formation.
Reply | Report Abuse | Link to thisCurrent theories are based on the assumption of a continuous universe and there is very strong evidence that space and time are discontinuous. For example Zeno’s arrow would never reach the target if space and time could be infinitely divisible. In 1888 the mathematician Richard Dedekind showed that continuous space is not consistent with irrational numbers. In a discontinuous universe atoms are synchronously projected as a succession of independent space frames linked by light that together define space and time. Universals interact with particulars is such a way that the same ratio of 2/3 crops up, just as it does in quark theory. There is a structural reason for this.
Cyclical motions of suns, planets and galaxies introduce space frame skipping at their centers with respect to the peripheries. This necessarily implicates a small family of quantum forces to compensate and maintain a preponderance of synchronicity in the universe as a whole. For example these retard the rotation of the poles of the sun to 33 days while the equator rotates in 25 days, contrary to traditional physics, and the average is close to the revolution period of the moon about the Earth. The point here is that a discontinuous universe offers a new methodology to celestial dynamics, including earth science and the relation of the moon to the evolutionary process. You can find more in various articles at www.cosmic-mindreach.com, including one entitled Cosmology & System3. That ratio of 2/3 is structurally required by System 3.
Is the moniker "Weir" derived from weird? It is puzzling enough to me that Sol and our moon should have such similar apparent diameters in the sky that the latter can eclipse the former. This was a great mechanism for enticing early humans to think about the heavens. We made the sun and moon our earliest gods and for no reason at all they have the same apparent size in the sky and now we know that they rotate at the same 30-day average.
Reply | Report Abuse | Link to thisFrom General Relativity we understand that anytime two objects orbit each other in a vacuum, even though one object is much more massive than the smaller one every so many million years the world line of the larger object will lap over the world line of the smaller one, in effect indicating an "orbit" of the larger around the smaller object.
This is quite hard to visualize, especially in the case of the solar system because the sun in this very long scale sense "orbits" each of the planets individually. World lines appear like a dance of geodesic sine waves, incredibly intertwined but on fantastically different frequencies and amplitudes.
I claim that the Sun therefore "orbits" the Earth once every billion years or so, so maybe five times in our planet's history Ptolemy is correct concerning the sun going round our planet.
Morever, to the understanding of the ancients, a "day" was defined as the time it took for the sun to rise in the East, traverse the sky, do whatever it did to get back to its starting point and rise again the next morning. So, holding on to this understanding, the Genesis account of God creating the Earth in six days would be in the ball park, as it would mean six billion years give or take a couple billion.