The Night Sky Is Dark
The temperature of the Earth is an equilibrium value arising from the balance between heat received from the Sun and heat radiated into space. If the night sky were not dark less heat would flow to it, and the Earth temperature would rise. The night sky is dark because the universe is not eternal and uncreated, and because the universe is expanding. Let us examine this point in greater detail.
Here and there stars punctuate the darkness. Ancient peoples thought the number of stars was limited to those they could see. There are about 3 000 bright stars visible to the unaided eye. Modern telescopes reveal that our galaxy alone has 100 000 million stars. In the known universe there are about the same number of galaxies. With so many stars, why is the night sky not lit up from east to west and north to south?
Here and there stars punctuate the darkness. Ancient peoples thought the number of stars was limited to those they could see. There are about 3 000 bright stars visible to the unaided eye. Modern telescopes reveal that our galaxy alone has 100 000 million stars. In the known universe there are about the same number of galaxies. With so many stars, why is the night sky not lit up from east to west and north to south?