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Message: <blockquote data-quote="sam@" data-source="post: 7511502" data-attributes="member: 27411">Sailing Stones<a href="http://img522.imageshack.us/my.php?image=58858109.jpg" target="_blank"><img src="http://img522.imageshack.us/img522/6411/58858109.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>The mysterious moving stones of the packed-mud desert of Death Valley have been a center of scientific controversy for decades.Rocks weighing up to hundreds of poundshave been known to move up to hundreds of yards at a time.Some scientists have proposedthat a combination of strong winds and surface ice account for these movements.However, this theory does not explain evidence ofdifferent rocks starting side by sideand moving at different rates and in disparate directions.Moreover, the physics calculations do not fully support this theoryas wind speeds of hundreds of miles per hourwould be needed to move some of the stones.Columnar Basalt<a href="http://img80.imageshack.us/my.php?image=25911293.jpg" target="_blank"><img src="http://img80.imageshack.us/img80/5404/25911293.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>When a thick lava flow cools, it contracts verticallybut cracks perpendicular to its directional flow with remarkable geometric regularity- in most cases forming a regular grid of remarkable hexagonal extrusionsthat almost appear to be made by man.One of the most famous such examples isthe Giant's Causeway on the coast of Ireland (shown above),though the largest and most widely recognizedwould be Devil's Tower in Wyoming.Basalt also forms different but equally fascinating wayswhen eruptions are exposed to air or water.Blue Holes<a href="http://img294.imageshack.us/my.php?image=19955848.jpg" target="_blank"><img src="http://img294.imageshack.us/img294/93/19955848.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>Blue holes are giant and sudden drops in underwater elevationthat get their name from the dark and foreboding blue tone they exhibitwhen viewed from above in relationship to surrounding waters.They can be hundreds of feet deepand while divers are able to explore some of themthey are largely devoid of oxygen that would support sea lifedue to poor water circulation - leaving them eerily empty.Some blue holes, however, containancient fossil remains that have been discovered, preserved in their depths.Red Tides<a href="http://img340.imageshack.us/my.php?image=32959476.jpg" target="_blank"><img src="http://img340.imageshack.us/img340/9792/32959476.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>Red tides are also known as algal blooms- sudden influxes of massive amounts of colored single-cell algaethat can convert entire areas of an ocean or beach into a blood red color.While some of these can be relatively harmless,others can be harbingers of deadly toxinsthat cause the deaths of fish, birds and marine mammals.In some cases, even humans have been harmed by red tidesthough no human exposure are known to have been fatal.While they can be fatal,the constituent phytoplankton in ride tides are not harmful in small numbers.Ice Circles<a href="http://img228.imageshack.us/my.php?image=75223623.jpg" target="_blank"><img src="http://img228.imageshack.us/img228/1434/75223623.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>While many see these apparently perfect ice circlesas worthy of conspiracy theorizing,scientists generally accept that they are formedby eddies in the water that spin a sizable piece of ice in a circular motion.As a result of this rotation,other pieces of ice and flotsam wear relatively evenly at the edges of the iceuntil it slowly forms into an essentially ideal circle.Ice circles have been seen with diameters of over 500 feetand can also at times be foundin clusters and groups of different sizes as shown above.Mammatus Clouds<a href="http://img196.imageshack.us/my.php?image=60584839.jpg" target="_blank"><img src="http://img196.imageshack.us/img196/8427/60584839.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>True to their ominous appearance,mammatus clouds are often harbingersof a coming storm or other extreme weather system.Typically composed primarily of ice,they can extend for hundreds of miles in each directionand individual formations can remain visibly staticfor ten to fifteen minutes at a time.While they may appear forebodingthey are merely the messengers- appearing around, before or even after severe weather.Fire Rainbows<a href="http://img30.imageshack.us/my.php?image=16803138.jpg" target="_blank"><img src="http://img30.imageshack.us/img30/2797/16803138.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>A circumhorizontal fire rainbow arc occurs ata rare confluence of right time and right place for the sun and certain clouds.Crystals within the clouds refract lightinto the various visible waves of the spectrumbut only if they are arrayed correctly relative to the ground below.Due to the raritywith which all of these events happen in conjunction with one another,there are relatively few remarkable photos of this phenomena.Sinkholes<a href="http://img338.imageshack.us/my.php?image=33543523.jpg" target="_blank"><img src="http://img338.imageshack.us/img338/935/33543523.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>Sinkholes are one of the world's scariest natural phenomena.Over time, water erodes the soil under the planet's surfaceuntil in some cases, quite suddenly,the land above gives way and collapses into the earth.Many sinkholes occur naturallywhile others are the result of human intervention.Displacing groundwater can open cavitieswhile broken pipes can erode otherwise stable subterranean sediments.Urban sinkholes, up to hundreds of feet deephave formed and consumed parts of city blocks, sidewalks and even entire buildings.Penitentes<a href="http://img256.imageshack.us/my.php?image=98599113.jpg" target="_blank"><img src="http://img256.imageshack.us/img256/6427/98599113.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>Named after peak-hooded New Mexican monks (lower right above),penitentes are dazzling naturally-forming ice bladesthat stick up at sharp angles toward the sun.Rarely found except at high altitudes,they can grow up taller than a human and form in vast fields.As ice melts in particular patterns,'valleys' formed by initial melts leave 'mountains' in their wake.Strangely, these formations ultimately slow the melting processas the peaks cast shadows on the deeper surfaces belowand allow for winds to blow over the peaks, cooling them.Lenticular Clouds<a href="http://img514.imageshack.us/my.php?image=80602351.jpg" target="_blank"><img src="http://img514.imageshack.us/img514/6110/80602351.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>Ever wonder the truth about UFOs?Avoided by traditional pilots but loved by sailplane aviators,lenticular clouds are masses of cloudwith strong internal uplift that can drive a motorless flyer to high elevations.Their shape is quite often mistakenfor a mysterious flying object or the artificial cover for one.Generally, lenticular clouds are formedas wind speeds up while moving around a large land object such as a mountain.Light Pillars<a href="http://img17.imageshack.us/my.php?image=74763598.jpg" target="_blank"><img src="http://img17.imageshack.us/img17/8146/74763598.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>Light pillars appear as eerily upright luminous columns in the sky,beacons cast into the air above without an apparent source..These are visible when light reflects just right off of ice crystalsfrom either the sun (as in the two top images above)or from artificial ground sources such as street or park lights.Despite their appearance as near-solid columns of light,the effect is entirely created by our own relative viewpoint.Sundogs<a href="http://img268.imageshack.us/my.php?image=77051494.jpg" target="_blank"><img src="http://img268.imageshack.us/img268/8752/77051494.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>Like light pillars, sundogs are the product of light passing through crystals.The particular shape and orientation of the crystalscan have a drastic visual impact for the viewer,producing a longer tail and changing the range of colors one sees.The relative height of the sun in the skyshifts the distance the sundogs appear to be on either side of the sun.Varying climactic conditions on other planets in our solar systemproduce halos with up to four sundogs from those planets' perspectives.Sundogs have been speculated about and discussed since ancient timesand written records describing the various attributes of our sundate back the Egyptians and Greeks.Fire Whirls<a href="http://img196.imageshack.us/my.php?image=27646326.jpg" target="_blank"><img src="http://img196.imageshack.us/img196/2971/27646326.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>Fire whirls (also known as fire devils or tornadoes)appear in or around raging fireswhen the right combination of climactic conditions is present.Fire whirls can be spawned by other natural eventssuch as earthquakes and thunderstorms,and can be incredibly dangerous,in some cases spinning well out of the zone of a fire itselfto cause devastation and death in a radius not even reached by heat or flame.Fire whirls have been known to be nearly a mile high,have wind speeds of over 100 miles per hourand to last for 20 or more minutes.Orange Moons<a href="http://img293.imageshack.us/my.php?image=93809950.jpg" target="_blank"><img src="http://img293.imageshack.us/img293/4628/93809950.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></a>This last phenomena is something most people have seen before- beautiful orange moon hanging low in the sky.But what causes this phenomena- and, for that matter, does the moon have a color at all?When the moon appears lower on the horizon,rays of light bouncing off ithave to pass through a great deal more of our atmospherewhich slowly strips away everything but yellows, oranges and reds.The bottommost image above is true to the hues of the moonbut has enhanced colors to more clearly show the differences in shadethat illustrate the mixed topography and minerologythat tell the story of the moon's surface.Looking at the colors in combination with the cratersone can start to trace the history of impactsand consequent material movements across the face of our mysterious moon.</blockquote>

Verification: Hata thunen beduwama keeyada? (60 bedeema thuna)

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