How did the Universe form?

1. How did the Universe form?

The Milky Way galaxy (sripfoto/Shutterstock)

The universe is infinite and mind-boggling, but how it all began is still a mystery and the number one question on the minds of many. Even StephenHawking, one of the greatest theoretical physicists, couldn’t pinpoint the answer. According to Reader’s Digest some experts wonder if the universe had a beginning or has always existed. 

The Big Bang may explain the universe’s evolution, but how it came into existence remains unknown. Was there something before the Big Bang, or did the universe appear out of nothing? According to WorldAtlas, the problem lies in the clash between two key theories—general relativity, which governs large-scale phenomena like gravity, and quantum mechanics, which rules the microscopic world. Until scientists bridge that gap, the universe’s true origins will remain one of physics’ biggest unsolved puzzles.

To understand how this happened, cosmologists use massive computer simulations, like the “Millennium Run” by scientists at Durham University, to virtually recreate the Universe. Sky At Night Magazine explains that researchers then compare these digital galaxies to the ones we see in space. Interestingly, one model fits the data well, suggesting that most of the Universe’s matter is made of dark particles that barely interact with regular atoms but are crucial in shaping galaxies.

2. What happens inside a black hole?

3D illustration depicting merging of black holes in deep space. (Image by Jurik Peter on Shutterstock)

Black holes have such intense gravity that light can’t escape, making their interiors a mystery. However, Stephen Hawking theorized that information isn’t trapped inside but lingers on the event horizon, technically making it accessible. As Reader’s Digest points out, this theory creates a paradox since the event horizon exists outside the black hole—keeping scientists scratching their heads.

World Atlas says that until scientists can unite quantum mechanics and general relativity, the true nature of what lies inside black holes will remain a puzzle. This challenge has stumped even the brightest minds in physics, as each theory works perfectly on its own, but breaks down when applied together.

According to Urbo Einstein’s theory of general relativity unlocked the mysteries of black holes, predicting they form when massive stars collapse. But what happens next? As a black hole gets smaller, it becomes infinitely dense, according to Einstein. However, scientists now think quantum physics is the key to truly understanding what happens at a black hole’s most extreme point.

3. How will the Universe end?

An artist’s depiction of the Earth on fire (muratart/Shutterstock)

Scientists have yet to figure out how the Universe will end, just as they can’t fully explain how it began. What they do know is that life on Earth won’t last forever. Our Sun, like all stars, will eventually die. As Reader’s Digest points out, the Universe’s ultimate fate hinges on unknowns like its shape and density.

According to Sky at Night Magazine, many astronomers believe that thanks to dark energy, the Universe’s expansion will never slow down or reverse, leaving it to keep expanding indefinitely. As a result, the Universe may outlive people, planets, and even stars.

Don’t worry, though. The Universe is not going to end anytime soon, according to World Atlas. The Universe is currently 13.8 billion years old, and it will likely continue to exist for trillions upon trillions of years. 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.

4. What is dark matter?

Dark matter in space (Artsiom P/Shutterstock)

Scientists believe most of the Universe is made up of dark matter, a mysterious substance that neither emits light nor energy. While they know what dark matter isn’t, they still can’t figure out what it is. Reader’s Digest says that until scientists crack this puzzle, the Universe’s fate will remain one of its biggest mysteries 

Given that dark matter makes up 95 percent of the Universe, you would think the mystery would be solved by now, but it hasn’t. According to Watch Mojo galaxies wouldn’t hold their shape without it, but we don’t know what it is, how it works, or why it’s so abundant.

For years, scientists thought dark matter might be made of WIMPs (Weakly Interacting Massive Particles), but these haven’t shown up in experiments like those at the Large Hadron Collider. Now, Science Focus reports researchers are looking at other candidates like the super-light axion or even primordial black holes from the Big Bang. 

5. How did life begin?

DNA double helix structure (Billion Photos/Shutterstock)

We’re not just talking about human life, but all life! Some scientists think Earth’s early conditions sparked life’s building blocks, while others suggest they came from outer space says that experts can’t even agree on whether science will find the answer.

The earliest evidence of life on Earth dates back about 3.7 billion years, yet Earth is over 4.5 billion years old. So, what sparked life after such a long gap? Scientists believe six chemical elements—carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur—are essential for life. But, according to WatchMojo, how they arrived on Earth and why they aren’t found in abundance on other planets in our solar system remains a mystery.

At some point, the right conditions allowed for the formation of RNA and DNA, sparking life, but exactly how and where this happened is still unknown. World Atlas suggests future lab experiments could someday help synthesize RNA and DNA from non-living materials, bringing us closer to an answer.

 6. Is there other intelligent life in the Universe?

Alien UFO sighting (Photo by Albert Antony on Unsplash)

This is a question we continually ask but have no answer. Even if life forms on just one planet out of every trillion, that would still mean about a billion life-bearing planets.  the question of extraterrestrial life may only be answered if we find it—perhaps on Mars, Europa, or Saturn’s moon Enceladus, where conditions may support microbial life.

While scientists have discovered exoplanets that seem suited for life, we still have no evidence of extraterrestrial intelligence Statistically, other intelligent species likely exist, but where are they? As Watch Mojo highlights, the vastness of space may mean they’ve gone extinct, or communication over such distances is simply impossible. Yet, the question of whether we’re truly alone remains one of humanity’s greatest mysteries.

In 1950, physicist Enrico Fermi asked, “Where is everybody?”—referring to the lack of alien contact, now known as the Fermi Paradox. Scientists have since suggested that if aliens exist, they should have reached Earth by now. As Science Focus explains, theories range from us being the first intelligent life to aliens passing us by. Despite years of searching, we’ve only explored a tiny part of the galaxy, leaving the question unanswered.