Notable landmarks in Pittsburgh include the Cathedral of Learning, the Philadelphian, the Point State Park, and the USS Requin.
Sunset
Twilight
Darkness
Most people know that sunset is the time when the sun goes down. But did you know that the sun doesn't actually set? Instead, Earth rotates into darkness, giving us the illusion that the sun is setting. So what causes sunset?
Well, it's a combination of things. The Earth's atmosphere scatters sunlight in every direction, but blue and violet light are scattered more than other colors. This is why the sky is usually blue during the daytime. As the sun gets lower in the sky, the atmosphere becomes thicker and more dense.
This scattering of sunlight happens to a greater extent, and we see red and orange light more than blue and violet light. That's why sunset is usually a beautiful red or orange color. So next time you see sunset, remember that you're actually seeing Earth rotate into darkness!
Pittsburgh, Pennsylvania is located in the Northeastern United States. The city lies at the confluence of the Monongahela and Allegheny Rivers in the Allegheny Mountains. The city is also adjacent to the much larger city of Philadelphia. Pittsburgh is the county seat of Allegheny County, and has a population of 305,593 as of the 2010 census.
Pittsburgh is located in western Pennsylvania, in the Anthracite coal region. The city is home to the University of Pittsburgh, Duquesne University, and Carlow University. The city also has two medical centers, UPMC and Children's Hospital of Pittsburgh of UPMC.
Pittsburgh has a humid continental climate, with cold, wet winters and hot, humid summers. The city experiences significant snowfall, with an average of thirty-seven inches per year.
Notable landmarks in Pittsburgh include the Cathedral of Learning, the Philadelphian, the Point State Park, and the USS Requin.
}As the sun sets, the sky slowly grows dark. For many people, this is a time to relax and wind down for the day. But have you ever wondered exactly when it gets dark? The answer may surprise you.
Did you know that darkness actually begins long before the sun sets? As the sun gets lower in the sky, its light has to travel through more atmosphere. This filters out some of the blue light, making the sun look redder. At the same time, shadows get longer and darker. So by the time the sun finally dips below the horizon, darkness has already begun to fall.
Of course, not all places on Earth experience darkness at the same time. Near the equator, the sun sets and rises almost directly overhead. This means that there is less of a difference between daytime and nighttime. Closer to the poles, however, the sun stays low in the sky for much of the year. This leads to longer periods of darkness during wintertime.