suchandra Posted February 1, 2008 Report Share Posted February 1, 2008 In chapter 2 of Light of the Bhagavata it says, "obedience is the first law of discipline. The people have become disobedient to the laws of God, and therefore neither rain nor wealth is equally distributed." In the New Scientist January 2008 we find an interesting article below how modern science considers, "there must be a real secret what actually happens within a rain cloud". Since I never heard Vaishnava preachers mention this, could be there is a real secret. Although in almost all secrets, it is ultimately Krishna who is involved. "This knowledge is the king of education, the most secret of all secrets...." BG 9.1 Cracking the puzzle of how raindrops form Mark Anderson sticks his head in a cloud CONTRARY to what it says in the song, the rain in Spain does not stay mainly in the plain. It falls mostly in the mountainous regions of Cantabria and Asturias. Ask meteorologists why, and they will explain that the prevailing winds pick up moisture over the Atlantic, and that when this moist air hits Spain's northern mountain ranges it is forced up to higher altitudes, where the moisture condenses to form clouds, and then rain. So far so good - except that it's only half an answer. Not all clouds produce rain, and if you ask those same meteorologists why, after a few hand waving explanations they will probably confess that they don't really know. While the mechanisms of cloud formation are well understood, no one knows for certain what makes some clouds produce rain and others not. Models of what happens inside a cloud take into account general data like wind speed and the air's humidity, but fudge the inner mechanics of clouds. There is a lot of room for improvement, and solving the mystery will not only help improve climate models, but could improve the reliability of cloud seeding as a way to induce rain (New Scientist, 16 April 2007, p 4o). To estimate the chances of rain, meteorologists and climate modellers have to fall back on observations of which types of clouds tend to produce rain and which do not, says Steve Derbyshire, a weather modeller at the UK's Meteorological Office in Exeter. What modellers like Derbyshire would love is a clean model that explains the precise physics of raindrop formation. There is no shortage of ideas: at least four competing alternatives have been put forward, but until now we have not had the data to conclusively rule any of them in or out. That may be about to change, thanks to the most comprehensive study of cloud formation so far, which has just been completed. The conditions necessary for clouds to form are well understood. Air temperature drops with altitude, so as warm damp air rises and cools, the moisture it carries condenses onto specks of dust or soot, tiny salt crystals and other microscopic particles floating about called cloud condensation nuclei (CCNs) just as moisture in your breath condenses on a cold day. The droplets created when water molecules condense spontaneously onto CCNs can grow to around to micrometres in diameter in under 5 minutes. And that's where the mystery begins. For some reason, these tiny droplets sometimes but not always continue growing, swelling up to a million times their original volume in around 3o minutes. Droplets that grow this big, typically 1 to 2 millimetres in diameter, become too heavy to be held suspended in the cloud by updraughts and so fall to the ground as rain. But what causes this sudden and rapid growth of droplets in some clouds, and why is the process absent in others? Crucial stage The answer may lie in a crucial early stage in droplet growth. At first, the droplets that condense onto CCNs can easily gather more water molecules as they condense out of the cooling cloud. But once the droplets reach a diameter of around 10 micrometres, even a small increase in size means adding many millions of water molecules. Relying purely on condensation to grow the droplets becomes like filling an Olympic swimming pool one cup at a time - a very slow process. It can take days for condensation alone to produce raindrops, says Sonia Lasher-Trapp, an atmospheric physicist at Purdue University in Indiana. However, once droplets reach approximately 4o micrometres, the problem disappears as they now have a significant chance of colliding and amalgamating with one another. "We call that stage collision and coalescence, and once that process gets going, you get rain very quickly," says Lasher Trapp. So the crux of the mystery is this: what makes some droplets bridge the gap and grow from 10 to 4o micrometres? Four main hypotheses have been proposed to explain this. The first of these was developed in 1973 by Hendrik Tennekes of Pennsylvania State University and John Woods, then at the University of Southampton in the UK. They calculated that turbulence inside a cloud might crash droplets together faster and more efficiently than simple cloud models, and their successors now suggest that turbulence lowers the bar for collision and coalescence closer to 10 micrometres, eliminating the 10 to 4o micrometre gap altogether. Yet turbulence may only be part of the story. In 1982, David Johnson of the Illinois State Institute of Natural Resources suggested that just a few 4o micrometre droplets could be enough to trigger a rainstorm. His idea relies on the fact that large aerosol particles, several micrometres in diameter, are known to exist in the atmosphere. Droplets formed by condensation on these oversized CCNs have a headstart, and so can reach the 4o-micrometre threshold more quickly. "It's a nice, simple idea. If you've got big particles, you make raindrops quickly," says Lasher-Trapp. But she points out there's a flaw in this model. When it rains, larger particles drop out of the clouds faster, so the amount of rain they can be responsible for creating is small. In 2000, Alexei Korolev and George Isaac of the Meteorological Service of Canada in Toronto revived an older model, nicknamed the entrainment model. They calculated that the tops of some clouds sweep up parcels of cold, dry air so abruptly that they create turbulence and thus the conditions for extra condensation and coalescence. Korolev and Isaac calculated that this can produce enough 4o micrometre cloud droplets to start the runaway formation of rain. But this still fails to explain how rain is produced in large cumulus clouds. Another model was put forward in 2005, when Raymond Shaw and Alex Kostinski of Michigan Technological University suggested a new twist an Johnson's giant aerosol idea. Although there's only a tiny chance of two to micrometre droplets colliding, Shaw and Kostinski calculated that it only takes a few such droplets to collide and merge for larger droplets to form that will, in turn, start the runaway train of collision and coalescence. "To form rain, you don't need all the droplets to collide with each other. Only a few are needed to get this process going," says Shaw. To help determine which model, or combination of them, is right, Bjorn Stevens of the University of California, Los Angeles, has launched the Rain In Cumulus over the Ocean (RICO) project, which aims to be the most exhaustive empirical study of warm rain to date. He plans to analyse the movement of water droplets in clouds in minute detail, and from that work out what is really going on in rain clouds. Between November 2006 and January 2007, RICO researchers studied clouds forming over a 20,000 square kilometre patch of the Caribbean sea around Antigua and Barbuda. Three research airrraft were flown through the study region, which measured the variation in droplet size within the clouds and also dropped hundreds of lightweight GPS enabled beacons to study air currents within them. Members of the team operating from ships used radar to build up accurate profiles of water density in the clouds, and the movement of droplets in them. On land, there were more radar stations and aerosol measurement sites. Finally, RICO tapped into visual and infrared spectroscopic measurements made from NASA's Terra satellite. (see Diagramm, above) These measurements should at last allow researchers to distinguish between the various models of rain formation. "RICO will allow us to advance the art of cloud simulation to the point where we can begin to quantitatively evaluate these ideas," says Stevens. If, for example, the giant aerosol model is valid, there will be more rain an days when a lot of large aerosols are present in the atmosphere. Things are not looking good for it, as preliminary analysis of the RICO data shows no evidence for such a link. Ruling out the others will be less straightforward, though, and will require more sophisticated analysis of the data. Observations from RICO have even suggested a new twist an existing models. "We saw clouds forming in the debris or wake of old clouds, and that was new to us," says Stevens, describing how particles from evaporating clouds were observed being consumed and turned into a new cloud as a pulse of warm, moist air rose from the sea. It is possible that can initiate rain making, he suggests, as this recycling is likely to cause droplets from the parent clouds to combine and grow. So far, though, it has yet to be borne out by observation. Whichever theory wins out will have to explain both how raindrops form and why they sometimes fail to form "You'd like a theory that can form rain relatively quickly, but on the other hand can still allow for all those clouds we know and love that don't form rain," says Stevens. Understanding the behaviour of water droplets at the micrometre scale, crucial as it is, will never provide the whole story, however. A complete theory of rain formation will have to take into account everything from submicrometre aerosols to wind and convection currents within and around clouds, right up to the interaction of weather fronts hundreds of kilometres wide. The mass of data collected by RICO will be relevant to all these factors, but at the same time its sheer volume will pose a problem for researchers. There will be far too many measurements for the computational model to cope with, Lasher-Trapp says, so modellers will have to select representative phenomena at each significant size scale. If the puzzle of raindrop formation can be solved, the conclusions will reach beyond meteorology. The cooling effect of small, puffy cumulus clouds as they reflect sunlight is linked to the sizes of the droplets they contain. So understanding how raindrops form should help answer crucial questions about how the climate might change in the years ahead. "In a future climate that might be warmer, can we expect clouds to help us out?" asks Lasher-Trapp. "Or might it go the other way and help warm Earth even more?" Mark Anderson is a science writer based in Northampton, Massachusetts Quote Link to comment Share on other sites More sharing options...
weallshineon Posted November 10, 2008 Report Share Posted November 10, 2008 Interesting what you wrote, I found the following in the same Amazing Book Light of the Bhāgavata by His Divine Grace A. C. Bhaktivedanta Swami Prabhupāda The moon, or Candraloka, is one of the four important places of residence for the demigods. Beyond Mānasa Lake is Sumeru Mountain. On the eastern side of this mountain is the planet Devadhānī, where Indra resides. On the southern side is the planet known as Saṁyamanī, where Yamarāja resides. On the western side is the planet known as Nimlocanī, the residence of Vāyu, the demigod who controls the wind. And on the northern side of the mountain is the moon, which is also known as Vibhāvarī. All these various planets are within the universe in which our planet is situated. Persons who are too materialistic always engage in sense enjoyment. Such persons worship the material demigods and goddesses to fulfill their material desires. They are fond of performing many yajñas to propitiate the various demigods and the forefathers in heaven. Such persons are automatically promoted to the moon, where they enjoy soma, a celestial beverage. The moon is too cold for the inhabitants of this earth, and therefore ordinary persons who want to go there with earthly bodies are attempting to do so in vain. Merely seeing the moon from a distance cannot enable one to understand the real situation of the moon. One has to cross Mānasa Lake and then Sumeru Mountain, and only then can one trace out the orbit of the moon. Besides that, no ordinary man is allowed to enter that planet. Even those admitted there after death must have performed the prescribed duties to satisfy the pitās and devas. Yet even they are sent back to earth after a fixed duration of life-on the moon. Men with developed consciousness, therefore, do not waste time making excursions, real or imaginary, to the moon. Such intelligent persons do not endeavor to achieve temporary sense enjoyment. Rather, they apply their conserved energy for the sake of spiritual cultivation. They discharge religious duties for the satisfaction of the Supreme Lord, and not for personal sense enjoyment. The signs of such exceptional devotees of the Lord are that they are unattached to material enjoyment, contented, pure in heart, attached to devotional service, free from affection for temporary things, and devoid of false ego. According to Vedic injunctions, such great personalities ultimately attain the place where the Supreme Personality of Godhead predominates and where there is no death, no birth, no old age, and no disease. On the way to these spiritual planets, such personalities pass through the sun line called arcir-mārga. And on the way they can see all the planets between here and the spiritual world. Quote Link to comment Share on other sites More sharing options...
ranjeetmore Posted November 10, 2008 Report Share Posted November 10, 2008 Yeah and when they bathe in viraja and approach goloka,Sri krsna,Sri radha and their eternal sva-amsas as well as vibhinna amsas are all waiting with smiles and open arms just to embrace you....Just imagine...finally getting to see Goloka Actually !!! Radhe!Radhe ! Quote Link to comment Share on other sites More sharing options...
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