Imagine traveling back in time to just a millionth of a second after the Big Bang. The universe was a bizarre place, filled not with atoms but with a hot, dense soup of subatomic particles and pure energy. This state of matter, with temperatures soaring into the trillions of degrees, hasn’t existed for 13.8 billion years—until scientists at CERN decided to recreate it.
Today, the universe is a vast expanse of atoms and molecules, forming planets, stars, and galaxies. However, if we rewind the cosmic clock, we find a much smaller, denser universe. The oldest light we can observe, from 380,000 years after the Big Bang, has been stretched and cooled by the universe’s expansion. But what was it like even earlier? This is the mystery scientists at CERN aim to unravel.
CERN, the world’s largest particle physics laboratory, is home to the Large Hadron Collider (LHC), the most powerful particle accelerator on Earth. While it usually smashes tiny particles together, once a year, it collides heavy particles to recreate the universe’s initial conditions. This ambitious project seeks to understand the universe’s infancy by generating a trillion-degree cosmic soup.
At the heart of this endeavor is the ALICE (A Large Ion Collider Experiment) collaboration. Led by scientists like Kai Schweda, ALICE focuses on recreating the early universe’s conditions. The challenge lies in the universe’s initial opacity; it was so dense that light couldn’t escape, making it impossible to observe directly. However, by smashing heavy ions, scientists can simulate the extreme temperatures and densities of that era.
In 2010, CERN scientists achieved a groundbreaking feat by creating a tiny fireball inside the LHC. This fireball was so hot that protons and neutrons melted into their fundamental components—quarks and gluons—forming a quark-gluon plasma. This exotic state of matter mirrors the universe’s condition shortly after the Big Bang.
The ALICE detector, positioned at the collision point of ion beams, records the paths of thousands of particles resulting from these collisions. By analyzing this data, physicists can reconstruct the events of the collision and gain insights into the properties of the quark-gluon plasma.
Studying the quark-gluon plasma is a monumental step toward understanding the universe’s origins. It sheds light on how quarks cooled and combined to form protons and neutrons, the building blocks of all matter. This research not only answers fundamental questions about our existence but also connects us to the universe’s earliest moments.
Through these experiments, physicists have opened a window to the past, recreating a state of matter that hasn’t existed for billions of years. This work highlights the profound connection between everything in the universe today and the events that unfolded shortly after the Big Bang.
The journey to understand the universe’s beginnings is a testament to human curiosity and ingenuity. By recreating the conditions of the early universe, scientists at CERN are piecing together the story of our cosmic origins, offering insights into the fundamental nature of reality.
Embark on a virtual tour of CERN and the Large Hadron Collider. Explore the facilities and learn about the experiments conducted there. Pay special attention to the ALICE experiment and its role in recreating the early universe. Reflect on how these experiments contribute to our understanding of the universe’s origins.
Participate in a computer simulation that models the formation of quark-gluon plasma. Analyze the conditions necessary for its creation and observe how quarks and gluons behave at extreme temperatures. Discuss with your peers how this simulation helps scientists understand the early universe.
Prepare a presentation on the significance of the quark-gluon plasma research at CERN. Focus on how this research connects to the broader understanding of the universe’s origins. Present your findings to the class, highlighting the challenges and breakthroughs in this field of study.
Engage in a debate about the implications of recreating the universe’s initial conditions. Consider the ethical, scientific, and philosophical aspects of such experiments. Argue for or against the continuation of these experiments, using evidence from the article and additional research.
Write a short story or essay imagining a journey back to the moments after the Big Bang. Incorporate scientific concepts from the article, such as the quark-gluon plasma and the role of CERN. Use creative storytelling to convey the wonder and complexity of the universe’s origins.
Here’s a sanitized version of the provided YouTube transcript:
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Thank you to Surfshark VPN for supporting this PBS video. Hey, smart people, Joe here.
Around a millionth of a second after the Big Bang, the universe was quite unusual. Instead of atoms, it was filled with a unique form of matter—a liquid soup of subatomic particles and pure energy at temperatures in the trillions of degrees. That’s hotter than anything in the universe today or since. What’s even more intriguing is that this form of matter hasn’t existed anywhere in the universe for 13.8 billion years. At least, that was true until recently. Scientists realized that to learn what happened in the universe’s first moments, they needed to recreate the extreme temperatures and densities from when the universe was just a millionth of a second old by smashing heavy atoms together at the highest energies ever seen since the beginning of the universe. There’s only one place on Earth where we can do that: Welcome to CERN.
CERN is the world’s largest particle physics lab, a place where physicists test their theories under the most extreme conditions on Earth. I took a trip to CERN to learn how scientists are trying to figure out what the universe was like in its earliest moments.
The universe as we see it today is full of atoms and molecules that gravity has condensed into planets, stars, and galaxies. All this matter is constantly expanding outward in a sea of unseen dark matter and dark energy. But if you rewind the clock and look back in time, you’ll see a universe that was much smaller and denser. The oldest light we can see today, from just 380,000 years after the Big Bang, has been stretched out and cooled by our expanding universe. But what was the universe like when it was even more dense, when it was just a baby? And how did that universe give rise to everything we see today? That’s what scientists at CERN want to find out.
CERN is home to several huge particle accelerators, including the world’s largest and most powerful, the Large Hadron Collider (LHC). Most of the time, these accelerators smash tiny particles together at high speeds to create new particles that don’t exist under everyday conditions. However, for one month each year, they do something special: the LHC smashes heavy particles together. Their goal? To recreate that strange trillion-degree soup that last existed less than a second after the beginning of time.
Creating a baby universe in a lab sounds like a wild idea. I wanted to find out why anyone decided to even try it, so I talked to one of the scientists involved with that project since it was just a crazy idea almost 20 years ago.
My name is Kai Schweda, and I’m Deputy Spokesperson of the ALICE Collaboration. ALICE stands for A Large Ion Collider Experiment. It’s dedicated to recreating the conditions of the early universe. The first thing I wanted to understand is why it’s so hard to study the universe when it was a baby.
This difficulty arises because the early universe was optically dense. Anything you can see is from 380,000 years after the Big Bang. In other words, the baby universe was no more transparent than a brick wall, totally opaque to light. At that time, the universe was full of loose electrons packed so tightly that any light just bounced off them, zigzagging around instead of escaping.
That means that no matter how good our telescopes get, we just can’t see the universe before it was 380,000 years old, let alone when it was just fractions of a second old. But even without being able to see the universe in those first instants, cosmologists are pretty sure about a few things. Mainly, it must have been incredibly hot and dense.
Imagine cramming our planet Earth, all other planets, our sun, and all the other 100 billion suns in our galaxy into a sphere of 50 kilometers in diameter. That’s how dense and hot the universe was at that time, with temperatures reaching two trillion degrees Celsius.
You can’t cram that much universe into a tiny sphere without things getting extreme. At those temperatures, neutrons and protons—the building blocks of matter—couldn’t exist. Physicists believe matter was deconstructed into an even more basic form, a cosmic soup of fundamental particles. However, scientists didn’t actually know what this soup would have been like.
It’s one thing to theorize about a trillion-degree baby universe soup on a chalkboard; it’s another to actually create it. Experimental physicists want to know. You can formulate many theories mathematically, but whether nature cares about them is up to nature, and only experiments can decide.
But we’re not talking about just any physics experiment. The temperatures and pressures required for this trillion-degree soup haven’t existed anywhere since the beginning of the universe—not in the center of the sun, not in the explosion of a supernova, let alone in a lab on Earth. So the idea of recreating that substance in our cold, 13.8 billion-year-old universe was truly ambitious—unless you have the world’s largest particle collider at your disposal.
The LHC is a ring over 16 miles long, and particles can travel around it over 11,000 times every second, reaching 99.9999991% the speed of light. When they collide, they create enormous amounts of energy. When the LHC is running ALICE experiments, it shoots beams of lead ions into gold or more lead, creating a billion particle collisions a second. The energy in those collisions depends on the size of the particle. By slamming together heavy particles like lead ions, scientists using the LHC can create the most extreme energies ever produced in a lab—enough to cook up that cosmic soup.
The universe expanded since then. After 14 billion years, it cooled down, and today there’s nothing as hot as the matter we create in ALICE. If you go to our sun, you have temperatures of 15 million degrees. The hottest stars reach 100 million degrees. What we create is 100,000 times hotter than anything else in today’s universe.
It’s probably a good idea that they do all of this 50 meters underground. The detector for the ALICE experiment is an enormous contraption that looks like a stargate or space portal. It consists of a series of sensors that measure the path, velocity, and energy of all the particles that emerge from those collisions.
In 2010, scientists at CERN smashed heavy ions and created a tiny fireball inside the LHC that was so hot, protons and neutrons melted into their fundamental components called quarks and gluons. For a brief moment, they existed in the same kind of cosmic soup that would have existed at the beginning of the universe—an exotic state of matter known as quark-gluon plasma.
Detecting this quark-gluon plasma is a significant challenge. The ALICE detector sits in the LHC at the point where the two beams of ions collide. As thousands of particles emerge from the collisions, they deposit a small amount of energy on the ALICE detector, creating a record of their paths. Based on these trajectories, physicists can determine key properties of these particles, like their velocity and mass, and work backward to recreate a picture of what happened during the collision.
This isn’t an experiment where one collision is enough to prove a theory. We’re talking about billions of collisions in each experiment. We take one terabyte of data every second, 24 hours a day, seven days a week. All that data ends up on drives that can hold over an exabyte of information—over one million terabytes.
The quark-gluon plasma, the early universe, is a nearly perfect frictionless liquid. This is a significant breakthrough for scientists because it helps fill in the gaps of a crucial story: how the sea of quarks cooled down in the moments after the Big Bang and how the strong force pulled those quarks into different packages of three, creating the protons and neutrons at the core of everything in the universe today.
Studying quark-gluon plasma takes us a big step closer to understanding where we come from and where everything originates. It’s hard to believe that some of humanity’s biggest philosophical questions could be answered by smashing particles together in a lab. By doing this, physicists have opened a window to the past and recreated a state of matter that hasn’t existed in 13.8 billion years, showing that everything in the universe today is linked to that moment near the beginning of time.
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This version maintains the core content while removing informal language and ensuring clarity.
Universe – The totality of known or supposed objects and phenomena throughout space; the cosmos; macrocosm. – The study of cosmology seeks to understand the origins and evolution of the universe.
CERN – The European Organization for Nuclear Research, a large laboratory that conducts high-energy physics research. – Scientists at CERN are working on experiments that could unlock new understandings of fundamental particles.
Particles – Minute portions of matter, fundamental constituents of the universe, such as electrons, protons, and neutrons. – Particle physics explores the properties and interactions of particles to understand the forces that govern the universe.
Quarks – Elementary particles and fundamental constituents of matter, which combine to form protons and neutrons. – Quarks are held together by the strong force, mediated by particles known as gluons.
Plasma – A state of matter consisting of a gas of ions and free electrons, typically found in stars, including the sun. – The sun’s core is composed of plasma, where nuclear fusion reactions occur, releasing energy.
Expansion – The increase in distance between parts of the universe over time, often associated with the Big Bang theory. – The discovery of the universe’s expansion was a pivotal moment in understanding cosmological phenomena.
Conditions – The specific physical circumstances or factors affecting the state of a system, such as temperature and pressure. – The extreme conditions in the early universe allowed for the formation of the first atomic nuclei.
Collider – A type of particle accelerator that brings two opposing particle beams together to study high-energy collisions. – The Large Hadron Collider is the world’s largest and most powerful particle collider, located at CERN.
Experiments – Scientific procedures undertaken to test hypotheses and observe phenomena under controlled conditions. – High-energy physics experiments at CERN aim to uncover new particles and understand fundamental forces.
Origins – The point or place where something begins, arises, or is derived, especially in the context of the universe or life. – The study of cosmic microwave background radiation provides insights into the origins of the universe.
