The universe is shrouded in mystery. No matter how much science uncovers about the universe, there always seems to be more to discover. What are some of the greatest mysteries in the universe and why have they gone unsolved?
How the Universe Was Born
The currently accepted model that describes the early moments of the universe is the Big Bang. While the Big Bang explains how the universe evolved during its earliest moments, it tells us nothing about how the universe came into existence. Was there anything before the Big Bang, or did the universe simply spring from nothing? As of yet, this remains one of physics’s biggest mysteries.
The reason why this question remains unsolved is due to the fact that the two theories that best describe our universe are at odds with one another. These two theories are general relativity and quantum mechanics. Relativity describes the universe on its largest scales, such as gravity and mass, while quantum mechanics describes the smallest aspects of our universe, such as atoms and subatomic particles. While these two theories work well on their own, scientists have yet to figure out how to unite the two under a single, unified theory. Until scientists figure that out, the origin of the universe will remain a mystery.
Inside Black Holes
There is perhaps no better example of mystery in our universe than black holes. A black hole is any object whose gravitational pull is so strong that not even light can escape past a certain point. Every black hole is surrounded by a region known as an event horizon, which is the boundary where the escape velocity of the black hole exceeds the speed of light. Since light cannot escape the event horizon, no information can exit the black hole. This means that no matter how hard we try, there is no way of knowing what happens beyond the event horizon, at least not directly. There is a chance that mathematical models may one day explain the inner workings of a black hole. Yet for that to happen, scientists will need to unite quantum mechanics and general relativity.
Life on Other Worlds
Ever since humanity awakened to the fact that the stars are other suns with their own planets, scientists have wondered about the possibility of life existing beyond the Earth. As of yet, the Earth is the only world known that has life. Given the sheer size of the universe and the number of stars and planets out there, it seems unlikely that our planet is the only one with life, yet we currently have no evidence of it. Discovering alien life would be no easy task, and since Earth life is the only form of life we know of, humans are subject to extreme bias when looking for aliens. However, technology has now advanced to the point where it is possible scientists could detect alien life in the near future if there is any to find. The reason why this question has remained unanswered for so long could come down to technological limitations.
How Did Life Begin?
While the question of alien life remains unanswered, there is another pressing question related to life: how did it get started? The fossil record and genetics have allowed us to peer deep into Earth’s history, painting an accurate picture of how life has evolved over the last 3.8 billion years. However, as of yet, it remains unknown exactly how life started.
At some point in Earth’s history, the right chemicals existed under the right conditions to allow for the development of RNA and DNA, leading to the first forms of life on this planet. How and where that happened remains a mystery. Since there is no way of going back in time and observing the origin of life, humans may never know for sure how life first started. Some form of an answer to this question may eventually come in the form of laboratory experiments that may one day be capable of synthesizing RNA and DNA from non-living materials.
How Will the Universe End?
The origin of the universe is one of its biggest mysteries, yet so is its end. The universe is currently 13.8 billion years old, and it will likely continue existing for trillions upon trillions of years more. Relative to how long the universe will likely exist, it is still very much in the early stages of the universe. The universe may one day end in a heat death long after the last stars have burned out, or perhaps the expansion of space will one day run in reverse, causing the universe to collapse inwards. While there are many good theories on how the universe will end, the information scientists do have is far too limited to know for certain.
Antimatter vs Matter
When matter first formed after the Big Bang, it emerged in two types: matter and antimatter. Models show that the universe should have created equal amounts of matter and antimatter, which would have destroyed one another and left a universe of pure energy. However, for reasons that remain unknown, the universe created slightly more matter than antimatter, allowing for the eventual formation of stars, galaxies, planets, and life. Exactly why the early universe had this discrepancy is a mystery, and according to most models, the universe should not exist in its current form. This could remain a mystery until better models are uncovered, or perhaps it has to do with how the universe came into existence.
A Mysterious Universe
The universe is full of mystery, and the questions listed above only scratch the surface of what remains unknown. As science and technology advance, our understanding of the universe will change. Perhaps at some point in the future, the answers to these and other questions will be as basic as knowing the Earth is round. For now, all we can do is continue to search for answers and uncover more about this mysterious universe.