Why Is It Dark In Space

Why is the night sky dark.

Why is it dark in space. The color black usually signals the absence of light. It s perplexed many astronomers since the time of sir edmond halley of comet fame in the 17th century. A few hundred thousand years after the big bang when the first light was able to leap out into space everything in every direction was as bright as the surface of a star.

Space is black to our perception because there are few molecules of matter that can reflect or scatter light like our atmosphere on earth. It had a start date and printed somewhere on the underside of a far off nebula or some solid stardust it just as definitively has a sell by. Astronomers now realize that the universe is not infinite.

Astronomers determine distances to 18 dwarf galaxies. But inside the solar system space is filled with light. Light usually travels straight ahead in a line unless it reflects off of something or.

Universe today has another explanation. Why is space black. Hubble looks at light and dark in the universe.

Although the idea of a finite universe explains why earth s sky is dark at night other causes work to make it even darker. Clearly there s something wrong with the simple calculation and a big clue about what it is came in the 1920s when astronomers discovered that the universe is. A finite universe that is a universe of limited size even one with trillions and trillions of stars just wouldn t have enough stars to light up all of space.

So we know that the universe is expanding and if you subscribe to the big bang theory we know it is not infinite in age or size. That s because although starlight gets fainter with distance a simple calculation shows the fading is cancelled out by the ever increasing numbers of stars with distance and should therefore leave space ablaze with light.