Saturday, July 25, 2015

Looking Inward

Early July, for the first time since December 1972 when Apollo 17 astronauts made the stunningly beautiful and transformational Blue Marble photographs, DSCOVR returned its first image of the sunlit face of Earth.

Following a million miles journey to the L1 Lagrange Point, the DSCOVR satellite positioned its gaze back toward Earth.
The medieval notion of the earth put man at the center of everything.
Archibald MacLeish
Lagrange Points L1 - L5
Lagrange points are positions in an orbital configuration of two large bodies, like the Sun and Earth, where a small object like a satellite, pulled by the gravity of the large bodies, maintains a stable position.
Too close to the Sun, DSCOVR moves toward the Sun. Too close to Earth, DSCOVR moves Earthward.
Images from DSCOVR are made using NOAA's imaging instrument dubbed EPIC for Earth Polychromatic Imaging Camera.
If you could see the earth illuminated when you were in a place as dark as night, it would look to you more splendid than the moon.
Galileo Galilei
Sunlit side of Earth
acquired July 6, 2015 by DSCOVR

To see the earth as it truly is, small and blue and beautiful in that eternal silence where it floats, is to see ourselves a riders on the earth together, brothers on that bright loveliness in the eternal cold—brothers who know now they are truly brothers.
Archibald MacLeish

REFERENCES

Saturday, July 18, 2015

Aeolian Dunes

Le Musée de Sainville
Aeolus was the keeper of the winds in Greek mythology.
Wind-driven transport and deposition of sand is called an "aeolian process".
Aeolian processes occur in deserts and on beaches, or wherever there are granular materials and strong enough winds to move the particles.


The transport of sand is a function of particle size and wind velocity.
“Air, I should explain, becomes wind when it is agitated.”
Lucretius (99 BC – c. 55 BC), On the Nature of Things
Sand blowing off a dune crest is shown in an image below of the Kelso Dunes.

image by Mark A. Wilson

Sand is moved by the wind via
  • Suspension (fine particles);
  • Saltation (the skipping of medium-sized particles); or
  • Creep (the rolling or sliding large-sized particles).
The deposition of sand happens as
  • Sand sheets;
  • Ripples; or
  • Dunes.
Sand sheets are gently undulating sandy areas. Ripples occur when wind blows surface materials into crests and troughs. The long axes of the crests and troughs are perpendicular to the direction of the wind.

image by Charles O'Rear

Dunes are accumulations of sand blown into mounds or ridges. The windward side of a dune has a gentle slope. The lee side, or the downwind portion of the dune, has a steeper avalanche slope called a slip face or Barchan dune.




REFERENCES

Saturday, July 11, 2015

Fleeting Flora

Earth laughs in flowers is an oft quoted phrase plucked from a line of the poem Hamatreya by Ralph Waldo Emerson.

Removed from the context of the poem, the phrase evokes a magnificently poetic personification of Earth's flora.

Within the context of the poem, earth laughs in flowers assumes a different meaning.

Emerson chides the long-deceased settlers of Concord for their braggadocio and for having a sense of ownership over the flora and fauna.
Where are these men? Asleep beneath their grounds:
And strangers, fond as they, their furrows plough.
Earth laughs in flowers, to see her boastful boys
Earth-proud, proud of the earth which is not theirs;
Who steer the plough, but cannot steer their feet
Clear of the grave.
He mocks the boastful boys with the image of flowers laughing at their hubris.

Keenly aware life is fleeting as compared to the longevity of Earth, Emerson asks,
Where are these men?
Emerson foreshadows the Earth-Song poem within this poem. In the Earth-Song part of the poem, Emerson places humankind in the fitting perspective of an Earth that endures and Stars that abide.
Earth-Song

   "Mine and yours;
    Mine, not yours.
    Earth endures;
    Stars abide—

The personification of Earth's flora is curious particularly upon close inspection of a flower. A flower is, foremost, an intricately specialized reproductive system.
The flower is the poetry of reproduction. It is an example of the eternal seductiveness of life.Jean Giraudoux
A flowering plant is aptly called an angiosperm. We assign the constituent parts of a flower with female ♀ and male ♂ gendered functions. Perhaps one purpose of labeling the constituent parts as such is to understand plant reproduction in a similar context to human reproduction.

Lillium Stamens by JJ Harrison

The gendered constituents of a flower, labeled 1-5 (image above), are:
  1. Stigma is the tip of a style adapted to trap and receive pollen. The stigma germinates the pollen grain containing male reproductive cells.
  2. Style is a tube on top of the ovary where ovules are produced. Ovules eventually develop into the fruit and seeds.
  3. Stamens are the pollen-producing reproductive organs. A stamen has an anther that produces pollen and a filament that supports it. The pollen consists of the male reproductive cells that fertilize ovules.
  4. ♂Filament is the slender stalk of a stamen that supports the anther (where the pollen develops).
  5. Tepal is the outer part (petals).

Emerson's Concord settlers seemed enchanted by material possessions. Perhaps the settlers failed to appreciate the irony that death would turn them into "a lump of mould". Emerson's Concord settlers became part of the land they possessed.



REFERENCES

Saturday, July 4, 2015

Sound Tuning

Our nervous system relies on data collection organs dedicated to each sense. Humans seem most acquainted to the world through visual input. Sound, smell, taste, and touch sometimes require a greater allocation of our attention to appreciate what the non-visual senses add to the mosaic of perception.
Sound comes to us as sensory and perceptual events both sequential and ongoing. Distinguishing and appreciating sounds in nature is a matter of attention and practice.
― GrokEarth, Sound and Soundscape
Listening requires attuning to the specifics of the incoming data, distinguishing foreground and background, tuning to pitch and frequency, and experiencing sound in all its symphonic or cacophonic fullness.
In every sound, the hidden silence sleeps.
Dejan Stojanovic
Nature Sound Map and Wild Sanctuary offer collections of natural sound samples ranging from bubbling mudpots to groaning icebergs, and whale sounds.

Bubbling Mudpot

A mudpot is an acidic hot spring in a geothermal area. The sound of mudpots comes from bubbling gases exiting the viscous slurry of mud. Artist's Paint Pots is geothermal area in Yellowstone with large mudpots. Listen to the sound of a mud pot and steam vent recorded in the Artist's Paint Pots:



Iceberg Sounds

Icebergs creak, squeal, and groan as they scrape against each other. The movements that generate the sounds are caused by shifting tides and small waves under the ice shelf. Listen to iceberg sounds recorded in Terre Adélie, Antarctica:



Whale Vocalization

Whales and other marine mammals depend on sound for communication. Whales vocalize to communicate because sight and smell are less effective in the ocean. Listen to humpback whale vocalizations recorded in the south Pacific ocean near the Tongan islands:



Biophonies and geophonies are the signature voices of the natural world, and as we hear them, we're endowed with a sense of place, the true story of the world we live in.
Bernie Krause, TED talk

REFERENCES

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