SPACE IS DARK

 THE DARK SPACE

In night, we wonder the light from the Moon and other Stars. If you are in the Light Pollution-Free environment, You can see the complete Milky-Way. But, we see more is DARK SPACE. What is the reason for the Dark Space? Let's see about it.

THE HUMAN EYE:

Before wee see about it, we want to know more about the color of our Eye. Our eyes can able to see only the VISIBLE SPECTRUM. This is 5% of the entire ELECTRO MAGNETIC SPECTRUM. There also present INFRARED, X-Rays, GAMMA RAYS, MICROWAVES, RADIOWAVES.

If we can able to see them, the nights and days are completely different to us. Our eyes are adjusted to see only the VISIBLE SPECTRUM. Our eyes has three different types of cones, L-Cone (large wavelength cones), M-Cone ( medium wavelength cones), S-Cone ( shorter wavelength cones). Things are visible to us is the color combination of Red, Blue and Green. The light reflected to an object only visible to us. Why lights are brighter? This is due to the Earth's atmosphere. It contains many dust particles, water droplets and molecules etc. Light takes 8 minutes to reach the Earth. That light scattered with the Earth's atmosphere and visible to us. Sun's light is of 7 colors. which is in the VISIBLE SPECTRUM. The shorter   wavelength (blue) is visible day time and evening the longer wavelength (red) is appear. We see only the objects that are visible to Our Eyes. But in night's, No light is reflected by an objects. Only mass objects like Galaxies, Stars, Planets and asteroids reflect light. Let's see about DARK.

SPACE IS NOTHING:

Space is Nothing. Torching light to an empty space, No objects will visible. Because no matter to reflect light. But many Stars present in Milky-Way and many Galaxies are present in the Observable Universe. Why didn't they visible? There are three answers for this question.

The first thing is, The Universe is FINITE. not infinite. The nights are converted into days, if the Universe is infinite. Because many Galaxies reflects light. So, Universe is Finite. Therefore the Universe is has an ENDING and a BEGINIG. This thing was said by the OLBERS PARADOX IN 18th century. He also proved that Universe is expanding. 

The Second thing is, No objects in the Universe (galaxies, stars, planets) are stable. They are moving by the expansion of Universe. For example, let's take M87, it is at a distance of 54 million Light Years from the Earth. Light takes 54 million years to reach the Earth's atmosphere which means The Black Hole what we see is PAST (54 million years ago). Let's take the Sun for more easy understanding. Light takes 8 minutes to reach the Earth surface. The Sun we seen is 8 minutes after from its original appearance. If the Sun is destroyed, We see it after 8 minutes. 

 The third thing is, The bigger distance of the object makes light more stretched. Stretching of Light result in change the wave length from blue to red. We can calculate the age of the Star by the color. But, to find the original color is difficult. 

THE CONCLUSION:

There are many objects that are invisible to us in Space. Because light of them is not reach our Earth. This is the reason for the DARK or At least  DARK to Human Eyes. We have to learn to enjoy the Beauty of DARKNESS.

Thanks for UNSIGNED.