The purpose of this website is to share the appreciation of sunsets, one of the best things in life.

This is the Science Page explaining some of the basic physics behind the appearance of sunsets.

A sunset is the moment at which the sun disappears below the horizon in the west. 
Technically, it would be the moment at which the Earth's rotation has caused the sun to be hidden from our view.
Sunrises are measured from the moment the sun is first seen and sunsets are measured from the moment the sun is last seen.  Therefore there is slightly more daylight than night in every day.  The phenomena of watching a sunset starts long before the sunset itself.  It may also last long after the sunset depending on a variety of factors:

The color of sunsets is determined by a complex variety of factors.
Sunsets tend to be more colorful than sunrises due to the amount of dust and activities stirred up during the day. 
The timing of sunsets is largely a factor of your latitude and longitude.  In the northern hemisphere the earliest sunset is actually before the winter solstice and the latest sunset is after the summer solstice.
Due to the Earth’s axial tilt, the sun sets in the northwest in the summer months between the March and September equinox.  The sun sets in the southwest in the winter months between September and March.
 

The colors of the sky are explained by the phenomena of 2 main types of light disturbances:

1. Rayleigh Scattering –
-         Shorter wavelength light collides with particles (atoms) much smaller than the wavelength of the light, usually gases.
-         Rayleigh scattering of sunlight in clear atmosphere is the main reason the sky appears blue.
-         This scattering produces colors of blue, violet, and green
2. Mie Scattering –
-         Light collides with dust, smoke, ash or any particle larger than a wavelength.
-         Produces reds, orange, peach, pink, purples
-         When larger spherical particles scatter electromagnetic radiation
-         Red hues in the sky are caused by Mie Scattering.

 

 

 

 

 

 

 

 

 

 

Air generally scatters the short-wavelength light more so than longer wavelength light (such as red).   Therefore, during most of the day we see blue light waves.  Later in the day, as the sun sets, light comes in nearly tangent to the Earth’s surface.  This extends the lights path through the atmosphere scattering a greater amount of blue light leaving more red light. 


 
 Comparison of the scattering efficiency of different wavelengths of light

The position of the sun at the exact time every day will change throughout the year.  If you viewed the sun each day at the same throughout the year, it would follow a pattern like this:
 

 

 





 

We would like to offer the simple word of caution that you should be careful when viewing the sun. 
Conflicting reports describe the consequences of prolonged viewing of the sun.
We are not advocating prolonged viewing of the sun. 

Our belief is that what you think about tends to happen. 
If you believe sunsets will hurt your eyes then they will.
If you believe sunsets are beautiful then they are.
 

   The sun is about 92,955,000 miles from Earth, and the distance varies throughout the year.  However that distance is from center to center so the actual distance from surface to surface (if you were traveling there) is not quite as far.  It's closer to 92.5 million miles.  The sun is more than 100 times larger than Earth but has a mass more than 332,000 times larger than Earth.  The sun is very dense.

   However, each the day sun radiates 5 million tons of pure energy, so it is getting lighter each day.  The sun is the primary source of energy on Earth.  The sun averages about 6,000 degrees Celsius or 11,000 degrees Fahrenheit.  The sun takes approximately 1 Earth month to rotate once on its axis. 

   The Sun is the star at the center of our solar system.  In comparison to other stars in the universe it is an average sized star.  The sun accounts for greater than 99% of the solar system's mass.  Energy from the sun supports almost all life on Earth. 

   The sun is primarily made up of hydrogen and helium with trace amounts of other elements.  The sun, like most stars, generates energy by nuclear fusion of hydrogen nuclei into helium.  These stars maintain a state of hydrostatic equilibrium, neither contracting nor expanding over time.  There are greater than 100 million stars like this in our galaxy.  However, our sun is brighter than 85% of stars in our galaxy. 

   As we on Earth are orbiting the sun, the sun orbits the center of the Milky Way galaxy.  Our sun is approximately 26,000 light-years from the galactic center.  It makes its complete orbit around the galactic center every 250ish million years.     

   We are currently traveling in our galaxy through the Local Interstellar Cloud in a low density zone of diffuse high temperature gas. 

   Size is all relative.  Something is only large or small if it is compared to another thing.  However, we can clearly see that the Earth is small in comparison to the sun.  And we can see that the sun is very small in comparison to the galaxy.  And the galaxy is small in comparison to the universe. 

   Is it really that hard to believe that anything is possible if you are in harmony with the universe?