Solstice morning Sun, at its lowest, burning a hole in the clouds over the bay.
Actually this was the morning after the solstice; so I reckon the Sun was higher than the previous morning by 24 arc seconds – about a hundredth of a degree. So that’s about a fiftieth of the Sun’s width.
In other words, the Sun’s altitude changes very little in the days around the solstice’ then the speed of change picks up.
This diagram shows the daily arcs of the Sun above the horizon for latitude 40 degrees north – at weekly intervals, starting with the date of the solstice, which is the lowest arc. And the Sun is drawn to the same scale, at noon. At eight in the morning, it wold be down near the left-hand end of the arc.
The top arc is for 8 weeks later, Feb 15. and the height of the arc will continue to increase more rapidly. So there is hope of sunshine on our skin and picnics by the sea.
Home planet department.
35 years after Union Carbide’s massive spill of poison gas at Bhopal in India, children are still being born with defects that make them unable to speak, stand, or eat without assistance; and the American and Indian governments are still protecting the corporations from taking responsibility.
Research by Erica Chenoweth shows that non-violent protests are twice as likely to succeed as violent conflicts. And those engaging a threshold of 3.5% of the population have never failed to bring about change.
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Does the rate of change of the angle of the sun continue to increase until the summer solstice?
Because of the spherical shape of the Earth, it seems that equidistant sun rays measured north to south would cover a larger portion of the earth as we travel from the equator to either of the poles.
In the north hemisphere (north of latitude 23.5) the sun’s rays would become less oblique as we go from winter to summer solstice, so it seems that the rate of change of the angle of the sun should increase until the summer solstice.
Not sure I know what you mean.
As the sun moves from December solstice to March equinox to June solstice, for a northern latitude the rays become less oblique, slowly at first, then faster, then more slowly again, till the change stops and reverses.
I’m just trying to make sense of why the rate of change of the path of the sun is not constant.
Here’s an answer to your question.
http://mypages.iit.edu/~maslanka/SolarGeo.pdf
Look especially at the graph “Yearly Variation in Declination”. Declination is the Sun’s angular distance north or south of the equator. Because variation in the Sun’s declination is a sine function, it changes most quickly when the declination is zero degrees at the equinoxes and most slowly when the Sun is at it’s maximum absolute declination, either north or south, at the solstices.
This document was prepared for engineers designing solar electric systems. The illustrations are very helpful, the underlying spherical geometry equations are provided, and there’s a link to a much more extensive reference.
Thank you. I printed the pages in your link and will digest them… looks like I’ll have to brush up on my trig. I’m also studying “Seasons” in the Astro calendar. Thanks again.
You’re welcome! I don’t understand spherical trigonometry equations, but the diagrams make sense by analogy to plane trigonometry.
Yuletide blessings! Thanks for the pictures, and thanks for the link to the story about the effectiveness of nonviolent protest. Howard Zinn’s book _A People’s History of the United States_ tells the story of abolitionists, labor organizers, anti-war activists, and common people who worked together to make better lives for themselves and their children. The book is an uplifting response to mainstream history which glorifies warfare, racism, and exploitation.
I don’t really notice a major difference in the Suns position until February but then it’s pretty obvious it’s getting lighter.yes bohpal was a leak of a host of toxic substances can’t remember what they all where but one was hydrogen chloride which is also called hydrochloric acid gas.nobody has ever really been brought to book over it yet people are still dying.
Happy belated winter Solstice to you and Tilly!