Thursday, December 19, 2013

Winter Solstice night

December 21 is the Winter Solstice – the shortest day of the year - We hardly notice. but to our primitive ancestors the longest night marked the time when light begins to return.  

Stone Henge - England - Site of early Solstice celebrations

It must have been mysterious and frightening to see the light diminish in the days of autumn – and then start to slowly return.  

Here I want to include a variety of thoughts and recollections on the topic of light...

1.     “Let there be light – and there was light...”

2.     “Here comes the sun” George Harrison’s song is a perennial favorite of back packers, who wake from the cold night and welcome the warmth of sunlight each morning. High mountain marmots also welcome the sun with chirps and whistles. We share the goodness of the sun.

Oh the joy of the coming of the Sun

3.     As a child I recall travelling through dark farmlands at night and seeing far off pinpoints of light coming from far distant farm houses and then realizing that light could travel so far and still be bright in my eye.  It was a revelation to me as a child.

Now I experience the same wonder when I think of light traveling millions of years to reach my eye from distant stars! 

4.     “Darkness cannot drive out darkness: only light can do that. Hate cannot drive out hate: only love can do that.” ― Martin Luther King Jr., A Testament of Hope: The Essential Writings and Speeches

5.     When I studied physics I learned how unique light is – Our best scientific studies show that sometimes light behaves like waves of energy – similar to other natural wave phenomenon.  In other circumstances, light behaves like unique particles of energy called photons...these are not particles of matter but pure energy. Which is correct?  They both are...

Photons? Waves? Yes both!!

6.     “When the days get longer the cold gets stronger.” A farm adage I knew as a child...

7.     “We can easily forgive a child who is afraid of the dark; the real tragedy of life is when men are afraid of the light.” ― Plato

8.     Once on a day long trip into limestone caverns with cave exploring friends, we had carbide lanterns attached to the front of our hard hats. They sputtered and gave off a weak yellowish light.  To experience real darkness we turned the lights off for a few moments.  It was terrifying to be deep in a cave and be unable to see. The expression “we couldn’t see our hands in front of our eyes” is true. 

Eyes become accustomed to the low light when cave exploring

9.     Even light comes in different flavors depending on the vibrating wavelength of the light.  Red light is longest and Violet light the shortest wavelength.  But then us poor sorry human beings can only see part of the light spectrum– there are great spectra of colors more red than red and other colors more violet than violet.

10.My father taught me when I was about 9 how to strike steel  (like a piece of steel file) against a piece of flint (or quartz) to get a spark.  If you have a small piece of dry scorched cloth it can catch the spark and glow – with gentle breathing on the glow, it will catch fire and ignite splinters of wood and from that that can ignite a campfire.

Fire started with flint and steel

12.A glass prism does not attempt to hold on to the light but accepts all that enters and refracts each portion of the light according to its wavelength.  7 unique colors form when the white light is separated. Red. Orange, Yellow, Green, Blue, Indigo, Violet.  And here we think that white light is really white!

Raindrops in the sky refract light to my eye in a similar manner to the prism.

13.Human vision was once thought to be “rays of energy” that left the eye and illuminated the thing being seen.  Now we know that reflected light from an object passes through the lens of the eye and forms an actual image on the retina of the eye.  It is the brain that takes that image and inverts it so that we think we are seeing things right side up.  <>

14.It is better to light a candle than curse the darkness.  Eleanor Roosevelt

15.  All our food, all of our clothing, the cells of our bodies owe everything to photosynthesis.  The magic of photosynthesis is that it can capture sunlight energy and use it to make chemical bonds and complex molecules using Carbon Dioxide from the air, and Water from the soil.

The miracle of photosynthesis 

Happy solstice!  Enjoy the return of the light!

( Images this week are mostly form Google Image collection)