Saturday, March 30, 2013

Photos of Earth taken by Astronauts

I've included a few of the photos of earth taken by astronauts in the past -- but it has been a while.  So for today's posting I took a look at the portal website http://eol.jsc.nasa.gov/.

 


Cumulonimbus Cloud over Africa Perhaps the most impressive types of clouds are cumulonimbus.  These dynamic clouds form when warm, moist, and unstable air vigorously rises in the atmosphere. If sufficient atmospheric moisture is present, water droplets condense as the air mass encounters cooler air at higher altitudes.

As water in the rising air mass condenses and changes from a gas to a liquid state, it releases energy and further heats the surroundings, which further intensifies the convection process and causes the cloud to rise to an even higher altitude. An example of one of these vertical “tower clouds”  is visible in the astronaut photograph included above. If enough moisture is present to condense and heat the cloud mass through several convective cycles, a tower can rise to altitudes of approximately six miles (10 km) at high latitudes and to 12 miles (20 km) in the tropics.  The cloud formation process stops its upward convection when it encounters a region of the atmosphere known as the tropopause—the boundary between the troposphere and the stratosphere.

The tropopause is characterized by a strong temperature inversion. Beyond the tropopause, the air no longer gets colder as altitude increases. When the cloud formation reaches this atmospheric layer, the cloud tos flattens and spreads into an anvil shape, as illustrated by this astronaut photograph. The photo was taken from a  side angle, rather than looking straight down towards the Earth’s surface. The image was taken over western Africa near the Senegal-Mali border.  The image shows a fully formed anvil cloud with numerous smaller cumulonimbus towers rising near it. The high energy levels of these storm systems typically make them hazardous due to associated heavy precipitation, lightning, high wind speed,s and possible tornadoes.


The Colorado Plateau spans northern Arizona, southern Utah, northwestern New Mexico, and southwestern Colorado. This physiographic province is well known for its striking landscapes and broad vistas—an impression that is enhanced by the view from the orbital perspective of the International Space Station. This astronaut photograph highlights several prominent landforms including the Colorado River, dammed to form Lake Powell in 1963, crosses from east to west (which is left to right here because the astronaut was looking south; north is towards the bottom of the image). The confluence of the Colorado and San Juan Rivers is also visible. Sunglint—sunlight reflected off a water surface back towards the observer—provides a silvery, mirror-like sheen to some areas of the water surfaces.

The geologic uplift of the Colorado Plateau led to rapid down cutting of rivers into the flat sedimentary bedrock, leaving spectacular erosional landforms. One such feature, The Rincon, preserves evidence of a former meander bend of the Colorado River.

Snow cover blankets the higher elevations of Navajo Mountain, a large body of igneous rock that intruded into pre-existing sedimentary rock layers and bowed them upwards into a structural dome. Snow also caps the highland surface of the Kaiparowits Plateau (approximately 2,300 meters or 7500 feet in elevation). The bulk of Navajo Mountain and the Kaiparowits Plateau are within the state of Utah; the town of Page is located just south of the border in Arizona.


Himalayan Landscape The above photograph of Bhutan, taken by one of the Expedition 33 crew members aboard the International Space Station, shows a number of Himalayan peaks, glaciers and lakes.

Michigan, U.P., and Grand Marais Photos  When you go to the NASA website I list at the top of this posting, you can type in any location on earth into the search box.  The chances are that there is a photo in the archive.  There were many dozen pictures listed for Grand Marais.  Below I've included a few.  Look for the Grand Sable Dunes and Sable Lake.  The pictures were taken from different angles -- so for you GM faithfuls, have fun examining the perspectives.

 
 
 
In the above photo notice Caribou Island out in the middle of Lake Superior.  The island is located approximately 40 miles north of Grand Marais.
 
 
 
 
The color in the upper left corner of the above photos shows the sun's glint off the northern end of Lake Michigan.  The remainder of the photos below are of the Great Lakes.  A few show the Grand Marais area.  Some of the following photos show ice flows on the Great Lakes.
 
 
 
 
 
 
 

Fractal Geometry -- a Follow Up

It is amazing to me that of the  904 posts on this blog, the most visited is the one on Fractal Geometry.  Out of the nearly quarter million visits to this blog, nearly 19,000 have been to the September 8, 2011 posting.

I decided that since the first posting on fractal geometry only gave a little bit of background, that it is worth posting more detail as well as some more terrific photos.


Definition
Fractals are geometric figures -- just like rectangles, squares, and circles are geometric figures. They form in nature -- in fact  most objects in nature do not from in squares or triangles, but instead take the form of complicated geometric fractal shapes. 

Some refer to the result of the pattern as the fractal; others refer to the mathematical formula that determines the pattern as the fractal.  Mathematicians can create fractal sets that demonstrate self-similar patterns such as the Cantor dust image shown below.

 
Sometimes the mathematical process that a natural form develops is in part random, but does have a branching pattern that has a fractal element, such as seen in the two photos below.

 
 

Another way to think about what fractal really means is to compare the mathematics of fractal geometry with the process of measuring the length of a coastline. If you were to measure the shoreline of Lake Superior using a mile-long ruler, you would get an approximate measurement of the length of the shoreline.  Then, if you instead used a half-mile long stick to measure that same shoreline -- you would get a longer measurement because the shorter measurement stick would more efficiently measure some of the shoreline's sections.  If you then used a 1,000-foot stick to measure that same shoreline -- the length would again increase because you would be able to measure most every cove and inlet.  If you then used a yard stick to measure the circumference of Lake Superior's shoreline -- the length would again increase.  The accuracy of the measurement increases with the preciseness of the measurement length.  That is fractal.

Self-Similarity
To have a fractal pattern, there has to be self-similarity.   In life, we use the word "similar" to mean that things have at least something in common.  In geometry, the term "similarity" is very specific and precise.  Geometric figures are similar if they have the same exact shape, although the size of the shape can change.  So the two triangles shown below that have different shapes are not really similar from a mathematical point of view.  But the two squares shown below are similar.

 
 

Mathematics can play even more of a role in self-similarity.  The two shapes must have the same similar shape, but one shape can be a different proportion as determined by a ratio, or scale factor.  The corresponding sides must be mathematically linked while the corresponding angles must remain of equal measure.  For example, the second rectangle on the right below is twice as high and twice as wide as the rectangle on the left.  Both rectangles are similar.

Notice in the picture below that there are several different sizes of equilateral triangles that make up a large triangle.  If you magnify any of the small triangles, you get back to the original big triangle! In other words, this object is self similar. Self similarity is an important property of fractal objects.

 
Now for some intricate fractal geometry images.  Enjoy.
 
 
 
 
Fractal limestone crystals....
 
 
Fractal Romanescu....
 
 
Fractal honey crystals....
 
 
Fractal copper crystals....
 
 
Fractal broccoli...
 
 
Fractals carved in stone....
 
 
Fractal peacock...
 
 
Fractal cactus...
 
 
Fractal octopus...
 
 

 CITES:
http://math.rice.edu/~lanius/fractals/iter.html
http://commons.wikimedia.org/wiki/File:Julia_set_(highres_01).jpg
http://commons.wikimedia.org/wiki/File:Mandel_zoom_12_satellite_spirally_wheel_with_julia_islands.jpg
http://commons.wikimedia.org/wiki/File:Grotte_du_Grand_Roc_-_Fractal_limestone_crystals_-_20090923.jpg
http://commons.wikimedia.org/wiki/File:Crystallized_honey.jpg
http://commons.wikimedia.org/wiki/File:DLA_Cluster.JPG
http://commons.wikimedia.org/wiki/File:Fractal_Broccoli.jpg
http://commons.wikimedia.org/wiki/File:Romanescu.JPG
http://commons.wikimedia.org/wiki/File:Fractals_in_stone.JPG
http://commons.wikimedia.org/wiki/File:Peacock_Closeup.jpg
http://commons.wikimedia.org/wiki/File:Cactus_-_close_up_(6843283770).jpg
http://commons.wikimedia.org/wiki/File:Cooked_Octopus.jpg

Friday, March 29, 2013

New Picture of the Universe

The European Space Agency just released a new map detailing the oldest light in the universe.  To produce this montage, they used images generated during a 15 month period from the Planck Space Telescope.   These images recorded the cosmic microwave background (CMB) — what is essentially the dim glow of radiation that is found throughout all of space. Upon review of the data, it seems to provide more support for the Big Bang theory.  The data also seems to indicate that there is more matter in the universe than previously thought and that the universe is possibly older than we thought.  The newly released montage image of the universe is basically a heat map.  The reds and oranges show warmer temperatures, while light and dark blues represent cooler temperatures. 


The Planck satellite was launched in May of 2009, reaching its orbit by February 2010, when the satellite immediately started its all-sky survey. On 21 March 2013, the mission's all-sky map of the cosmic microwave background was released. 




The mission has the following objectives:

  • To provide high resolution detections of both the total intensity and polarization of the primordial cosmic microwave background radiation.
  • To create a catalogue of galaxy clusters.
  • To observe, measure, and study the Milky Way.
  • To study our Solar System including the planets, asteroids, comets, etc. 

  • Planck represents an advance over previous measurement satellites in several respects:
    • It has three times higher resolution.
    • It has ten times the sensitivity.
    • It observes in 9 frequency bands rather than 5.

     
    A comparison of the images from Planck compared with the previous two satellites is shown below.


     
     
    The COBE satellite was the first to measure the cosmic microwave background radiation in 1992. The resolution was very low and the results more or less vague, as can be seen in the comparison image below (COBE vs Planck).

     
    

     Planck's new numbers
    • 4.9% of the universe contains normal matter - atoms, the stuff from which we are all made
    • 26.8% of the universe is dark matter - the unseen material holding galaxies together
    • 68.3% of the universe is dark energy - the mysterious component accelerating cosmic expansion.  The number for dark energy is lower than previously estimated
    • The new age of the universe is now estimated at 13.82 billion years,  This number was calculated from the data, which indicates a slower expansion than previously thought.

    CITES:
    NASA/JPL-Caltech/ESA
    http://en.wikipedia.org/wiki/Planck_(spacecraft)
    http://www.bbc.co.uk/news/science-environment-21866464

    Thursday, March 28, 2013

    Agate Detail

    For today's blog posting I grabbed some close up detail photos of the pictures from my agate book.

    Lake Superior shadow agate...

     
    Lake Superior Peeler....
     
     
    Lake Superior Plume agate....
     
     
    Lake Superior sagenite agate....
     
     
    Lake Superior copper replacement agate....
     
    Lake Superior agate...
     
     
    Montana dry head agate...
     
     
    Oregon Priday agate...
     
     
    Texas moss agate...
     
     
    Australia Queensland agate...
     
     
    Canadian Thunder Bay agate...
     
     
    Mexican crazy lace agate...
     
     
    Mexican agate...
     
     
    Lake Superior agate...
     
     
     
    If you are reading this and you have been thinking about signing up for the Online Rockhounding Adventures but have not done so, maybe this reminder with a discount offer will help.  Email me at karen@agatelady.com and mention BLOG DISCOUNT to receive a discount.