The following piece is published as part of our TLM Young Writers series, a dedicated section of The London Magazine‘s website which showcases the work of exceptional young talent aged between 13-21, from the UK and beyond.
Darkness and Paradoxes
Nighttime. Countryside. You look up at the sky and marvel at the brilliance of the stars, the multitude of galaxies, planets and all kinds of objects co-existing simultaneously. You wonder how it all began and why, but perhaps you save those questions for another night. You settle on choosing a different kind of mystery, a less theory-prone question: “Why is it dark at night?” The most ideal, logical answer would be “because the sun has set.” But it turns out the answer is a little more complicated than that.
In order to understand the answer, we have to encounter Olbers’ Paradox. It was faced by a 19th century German doctor and astronomer Heinrich Olbers, who named the puzzle after himself. As there are millions upon millions upon millions of stars in the Universe, when we look up at the sky, at any and every line of sight, we will find a star. There would not be any dark spaces in the sky left. So wouldn’t their combined light make the night brighter than the day? This would be the case if the observations about the Universe previous astronomers considered to be true were accurate.
Therefore, the darkness directly contradicts the three conclusions centuries of astronomers had drawn up about the Universe. Firstly, the static Universe implies that the Universe is unchanging and remains the same forever. Secondly, the homogenous Universe is the same in all directions. Thirdly, the Universe is infinite. So, the darkness reveals that one, or more, of these conclusions is incorrect.
It is a well-known fact that the Universe is expanding, growing exponentially, meaning it is constantly changing. This also insinuates that as the Universe expands, the distance between the nearest stars and the Earth is constantly increasing as well. Consequently, this means that the light emitted from outlying stars created directly after the Big Bang, at the time of the birth of the Universe, has not had enough time to reach us. Furthermore, as the light travels longer distances to reach us, this elongates the light’s wavelength, causing a process called redshift. This indicates that the light is moving towards the red end of the electromagnetic spectrum.
Eventually, redshift will lead to the light transferring from visible light to infrared, the region of the spectrum that humans cannot see. This expanse is known as the unobservable Universe. As a result, expansion contributes to the darkness, revealing that the Universe is dynamic and ever-changing and provides the reason as to why it is dark at night.
Leemar Sheriff is a fifteen year old student from London. She loves space, astronomy computer science, music and writing poems.
To discover more content exclusive to our print and digital editions, subscribe here to receive a copy of The London Magazine to your door every two months, while also enjoying full access to our extensive digital archive of essays, literary journalism, fiction and poetry.