...Paddle Boarding in the Shadow of the Earth.
Just after sunset there is a beautiful phenomenon that we can clearly see in Santa Barbara thanks to generally clear skies and good views of the horizon. The blue band you see in the sky opposite the location where the sun recently set is actually the shadow of the earth. You can see it cast upon the atmosphere in the distance as the angle of the sunlight dips below the opposite horizon. The pink or purple layer above that is called the Belt of Venus or the anti-twilight arch, which is caused by a completely different phenomenon, a backscattering of the light from the already set sun. You could think of it as a reflection of the sunset that is happening further to the west of your location. Now isn't physics pretty? By the way, if you're more of a morning person you can see these effects just before sunrise too.