Olber's Paradox: The reason why space is dark
If the universe is populated by a colossal multitude of stars that emit an immense amount of light, why is it that the night sky of space is still completely black? An intricate inquisition that lingers in the minds of thousands of curious individuals. The same inquisition that Heinrich Olbers, a German astronomer had in 1823. Being aware that the universe is infinite and that a colossal number of stars co-exist in the universe, he wondered why the light emitted by these stars failed to fill the night sky of space causing it to be as bright as the surface of a star. This inquisition was then labelled ‘Olber’s Paradox.’
The only person with a reasonable elucidation for this Paradox at that time was Edgar Allen Poe, a raven poet with an unwavering passion for science who immersed himself in physics shortly after his wife’s death. He suggested that the universe was not old enough for the light of stars to aluminate the night sky. While there were many errors in this suggestion, the concept behind it made a lot of sense. He also suggested that the universe was created from the explosion of a single primordial particle and accurately predicted the big bang an entire century before the big bang theory was correctly discovered.
Later when technological advancements and modernization came into the picture, the Paradox was solved by Edwin Hubble, the inventor of the Hubble telescope. He observed that the spectrums of all the stars he looked at through the telescope appealed to be slightly red, indicating that the light emitted by them was being stretched out. The wavelengths of light he detected from stars in different galaxies overtime was stretching and moving further and further away. This meant that the space light was travelling through is expanding. The universe is expanding.
Hubble’s discovery also deduces that light from galaxies closer to us is not moving further away from us as fast light from galaxies away from us. The further away a celestial body is located from us, the quicker the space between it and us is stretching out. This means that light from stars aluminating space in the future is not possible.
When the universal theory was altered from believing the universe was static to believing it was expanding, it provided a solution for Olber’s Paradox – space is expanding faster than light can travel.
The speed of light is fixed and the expansion of space causes the light’s wavelength to stretch further into infrared, weakening the light and making it unable to reach the range of our visibility. In addition to this, space is also not filled with a sufficient amount of gas for light to reflect off of.
