Hey there, curious minds! Have you ever wondered what will happen to the universe in the distant future? Well, buckle up because we’re about to explore some mind-blowing cosmic events that could spell the end of everything as we know it. But don’t worry, these events are billions of years away, so there’s plenty of time to enjoy the universe!
Imagine two galaxies, the Milky Way and Andromeda, on a collision course. Andromeda is our closest galactic neighbor, and it’s racing towards us at a speed of 110 kilometers per second. In about four billion years, these galaxies will merge into one. This kind of cosmic dance happens all the time in the universe, but it’s becoming rarer as galaxies drift apart due to the universe’s expansion.
Think of the universe like a giant slinky. It started expanding with a big push from the Big Bang, and it’s been stretching ever since. But what if gravity, the force that pulls everything together, eventually stops this expansion and reverses it? This scenario is called the Big Crunch. Galaxies would collide more frequently, stars and planets would be thrown out of orbit, and everything would be squished into a hot, dense state, similar to the universe’s early moments.
Now, let’s consider another possibility. In 1998, scientists discovered that the universe’s expansion is actually speeding up, thanks to a mysterious force called dark energy. Imagine throwing a ball into the air, and instead of falling back down, it keeps going faster and faster. That’s what’s happening with the universe.
As the universe expands, galaxies move farther apart, and eventually, they will disappear from our view. In a hundred billion years, the Milky Way will fade to black, and even black holes will evaporate. The universe will become a vast, empty space filled with dark energy, expanding forever—a slow death by loneliness.
But what if dark energy becomes even more powerful over time? Enter phantom dark energy, a force so strong it could tear apart galaxies, stars, planets, and even atoms. This scenario, known as the Big Rip, would unravel the very fabric of space itself. But don’t worry, if it happens, it won’t be for another 200 billion years!
There’s one more possibility that could happen at any moment, but it’s so fast you wouldn’t even notice. It’s called vacuum decay. The Higgs field, an energy field that fills the universe, could suddenly change, creating a bubble of new space with different rules. This bubble would expand at the speed of light, destroying everything in its path. But don’t fret; it’s highly unlikely to happen anytime soon.
Finally, what if the end isn’t really the end? Some theories suggest that our universe could be part of a cycle, where the end of one universe is the beginning of another. These ideas involve concepts like parallel universes and anti-universes. While we don’t have all the answers yet, exploring these possibilities adds meaning to our understanding of the universe.
Remember, all these scenarios are billions of years away, so there’s no need to panic. Instead, let’s stay curious and keep exploring the wonders of the cosmos!
If you’re fascinated by the universe and want to learn more about our planet, check out “Overview,” a show on PBS Digital Studios’ Science and Nature channel. It combines stunning drone footage with deep science storytelling to reveal the forces that shape our world. And guess what? I’m the narrator, so come join me on this exciting journey!
A big thank you to astrophysicist Katie Mack for inspiring this cosmic adventure. If you’re interested in her work, there are links available to learn more. And a huge shoutout to everyone supporting us on Patreon—your support helps us create these educational videos.
Until next time, keep exploring and stay curious!
Imagine you’re an astrophysicist! Use an online galaxy collision simulator to explore what happens when galaxies like the Milky Way and Andromeda collide. Observe the changes in star positions and galaxy shapes. Write a short report on your findings and how they relate to the concept of the Big Crunch.
Join a class debate on the effects of dark energy. Split into groups, with one side arguing for the Big Freeze scenario and the other for the Big Rip. Use evidence from scientific articles to support your arguments. Reflect on how these scenarios impact our understanding of the universe’s future.
Write a short story set in a future where one of the cosmic end scenarios occurs. Describe the impact on life and civilization. Share your story with the class and discuss how creative writing can help us understand complex scientific concepts.
Create an animation or comic strip illustrating the concept of vacuum decay. Use visuals to explain how a sudden change in the Higgs field could lead to a new universe. Present your work to the class and discuss the likelihood and implications of this scenario.
Conduct a research project on the theory of cyclic universes. Investigate concepts like parallel universes and anti-universes. Present your findings in a multimedia presentation, highlighting how these theories expand our understanding of the cosmos.
Sure! Here’s a sanitized version of the transcript:
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Hey smart people, Joe here! Now, I don’t want to alarm you, but the world is going to end. All of this—gone, poof! The sun will swell into a red giant, the oceans will boil away, and the planet will be scorched. Scientists are certain that all this will happen.
Now, on the bright side, this isn’t going to happen for four to five billion years. In a universe bigger than we can fathom, across eons of time, stars like the sun and planets like Earth blink out of existence all the time. But could all of it end? I mean everything—the whole universe? Yes, and it probably will.
I’ve been thinking about the end of the universe a lot lately, and I know what you’re thinking: “Hey Joe, you okay?” Don’t worry, that’s not why. It’s because I’ve been reading this awesome book, “The End of Everything (Astrophically Speaking)” by my friend, astrophysicist Katie Mack. It is great, and I have never had more fun learning about how everything will cease to be forever.
The Big Crunch: This is Andromeda, a trillion stars whizzing around a supermassive black hole and the Milky Way’s closest galactic neighbor. It’s headed this way right now. Andromeda is currently around two and a half million light-years from Earth, but it is closing that distance at 110 kilometers per second. In about four billion years, the galaxies will start to merge into one.
Across the cosmos, galaxies collide on a regular basis, and we can see these collisions with powerful telescopes. We can even simulate these collisions on really big computers. However, these galactic mergers are becoming more rare because giant structures like galaxies are drifting farther apart.
Actually, galaxies are drifting apart because the universe is expanding, and that expansion all started with one big push—the Big Bang. Think of the universe like a slinky. It started here, and since that push, the space between each rung of the spring has been getting slightly bigger. That’s like neighboring galaxies.
The question is, will that initial push from the Big Bang eventually fizzle out? Thanks to gravity, everything is always attracting everything else. That’s why Andromeda and the Milky Way will one day collide. The farther apart two objects are, the weaker the gravitational attraction between them becomes, but it never reaches zero.
It seems like the gravity of everything in the universe should eventually pull it back in. So what happens if that expansion stops and goes in reverse? In a collapsing universe, the space between galaxies would get smaller and smaller. Collisions would become more frequent, stars and planets would be flung out of orbit, and black holes would ignite and merge, becoming even more massive.
During these galactic crashes, some new stars will be born, and some of them might even have time to develop life—if they’re not in the path of a sterilizing radiation beam. But eventually, all of these too will be destroyed by fire.
As the universe collapses, all of the energy that’s ever been emitted by every star or drawn into any black hole will be squished into a smaller space and squeezed into higher energy wavelengths. This concentrated radiation will become so intense that the temperature of space will rise until nuclear explosions rip stars and planets apart, leaving space full of hot plasma.
At this point, the universe resembles the early moments after the Big Bang. The temperatures and densities are so high we don’t actually have a way to describe them—except really, really hot.
But what if that crunch never happens? Well, today we think the universe isn’t likely to snap back on itself, but turns out that’s not such good news either.
When you throw a ball into the air, it slows down and falls back down. Everybody knows that. But in the early days of the universe, things were close together, and so gravitational attraction slowed the outward push of the expansion from the Big Bang. For a while, the expansion was slowing down, just like a falling ball.
However, in 1998, scientists discovered that about five billion years ago, the expansion of the universe started speeding up, and it’s still speeding up. It’s like what would happen if you threw a ball up in the air and it kept going faster in the same direction forever.
The bigger our universe gets, the faster it’s expanding. There’s some mysterious property of empty space pushing outwards in all directions, and we call this dark energy. The more empty space there is, the more dark energy, and the more it pushes.
Dark energy might be a source of energy that never runs out and that we find everywhere there’s empty space—something that astrophysicists and cosmologists call a cosmological constant. As the universe expands, it makes more empty space, which means more dark energy, and the expansion gets faster and faster.
On a nearby scale, other forces like gravity and electromagnetism are still strong enough to keep molecules together, our planet orbiting the sun, and our galaxy from falling apart. But the vast spaces between galaxies are dominated by dark energy.
The universe is already expanding faster than the speed of light, meaning that light emitted from galaxies beyond a certain point will always be moving away from us and will never reach Earth. As that expansion speeds up, closer and closer galaxies will be outrun, and they’ll disappear from our view.
Eventually, every galaxy will be alone in a dark universe. The stars already shining will burn out over billions of years. A hundred billion years from now, the Milky Way will dim and eventually fade to black. Even black holes will evaporate. There’s no fuel for new stars—just vast empty spaces left filled only with dark energy, expanding forever.
A slow death by loneliness lasting hundreds of billions of years. It could be worse, though. If dark energy actually gets more powerful over time, that would be really bad.
Meet phantom dark energy—it’s like dark energy on steroids. Phantom dark energy would not only expand the space between things but expand things themselves. Remember, in our universe today, fundamental forces are enough to hold things together even as dark energy expands the universe as a whole.
But phantom dark energy would be strong enough to overcome all of those other forces. It wouldn’t just push galaxies apart; it would push stars away from galaxies, planets away from stars, and eventually tear planets apart. Atoms, molecules, and particles would rip apart as phantom dark energy becomes stronger than the electromagnetic forces that hold them together.
In the final moments, the very fabric of space would be torn apart—a big rip. But don’t worry; if the big rip is coming, it’s not for like 200 billion years. So at this point, it might be nice to remind ourselves that both you and I will be gone by then.
But there’s one scenario that might be less far off. It could happen any time; it could be happening right now, but it destroys everything so fast you wouldn’t feel it. It all starts with a bubble—it’s like a self-destruct button for the universe, setting off a wave of apocalypse moving at the speed of light.
How could that happen? Something called vacuum decay. The Higgs field is a sort of energy field that permeates all of space. It surrounds us and penetrates us; it binds the galaxy together. The Higgs field sets the rules for physics on the scale of particles—like what particles exist, how they interact with each other, and what their masses are.
Atoms, molecules, and everything else exist because the Higgs field has a particular value. If that value were slightly different, it could scramble all of that up. In fact, it was like this in the early universe; the Higgs field had a different value, and there were different particles with different rules.
The Higgs field is pretty stable; it’s settled down here at a low energy. But there is a small chance that an ultra-high energy explosion, the evaporation of a black hole, or a quantum event could kick the Higgs field to some lower value. This would create a sort of bubble in the Higgs field—a new kind of space with different rules—and this bubble would zip through the universe at the speed of light, ripping particles apart and swallowing everything in the bubble.
If it hit you, you’d be gone before your brain knew anything happened. Once this bubble destroys everything, the space inside it collapses into a black hole.
But don’t worry; there’s no way that we could trigger vacuum decay ourselves. The universe might, though.
Don’t lose hope, though! We have one more scenario. What if the end isn’t the end? There is another option. Other more recent theories point to cycling universes, where the end of one is the beginning of another. These theories involve ideas like anti-universes or parallel fabrics of space-time.
But they would mean that an end really isn’t an end at all. As we learn more, all of these theories may change, and we may even find some new ones. Understanding our universe so deeply that we could one day figure out its ultimate fate, as well as ours, adds meaning to a universe that we know won’t last forever.
And besides, none of this will happen for a very long time—like at least tens of billions of years, maybe more than a hundred billion. I guess unless it’s vacuum decay.
Stay curious!
Hey everyone! Are you feeling a little stuck inside? Then you should check out “Overview,” a brand new show on PBS Digital Studios’ Science and Nature channel. “Overview” combines mesmerizing, beautiful drone footage with deep science storytelling to reveal all the things that shape our planet from a bird’s-eye view—literally!
Go over to Tara, subscribe, and oh, did I mention that I’m the narrator? Yeah, you get to hear me tell you these stories. Go watch them!
What are you still doing here? I want to say a huge thank you to my friend Katie Mack. This really is a great book, and she helped make this video possible. There are links down in the description if you’d like to learn more about her awesome astrophysics work.
And as always, I’d like to say a huge thank you to everyone who supports the show on Patreon. Your support means everything to us; it helps us make these videos and add a little bit of meaning to this universe that we know won’t last forever. There are links down in the description if you’d like to join our community.
See you next time!
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Feel free to let me know if you need any further modifications!
Universe – The universe is the vast, all-encompassing space that includes everything that exists, from the smallest particles to the largest galaxies. – Scientists study the universe to understand its origins and the laws that govern it.
Galaxies – Galaxies are massive systems composed of stars, stellar remnants, interstellar gas, dust, and dark matter, bound together by gravity. – The Milky Way is the galaxy that contains our solar system.
Expansion – Expansion in astronomy refers to the increase in distance between parts of the universe over time, as observed in the movement of galaxies away from each other. – The expansion of the universe is a key piece of evidence for the Big Bang theory.
Gravity – Gravity is the force of attraction between objects with mass, which pulls them toward each other. – Gravity is what keeps the planets in orbit around the Sun.
Dark Energy – Dark energy is a mysterious form of energy that is hypothesized to be responsible for the accelerated expansion of the universe. – Dark energy makes up about 68% of the universe, yet it remains largely unexplained.
Black Holes – Black holes are regions in space where the gravitational pull is so strong that nothing, not even light, can escape from them. – Scientists use telescopes to study the effects of black holes on nearby stars and gas.
Vacuum Decay – Vacuum decay is a theoretical event in which a lower-energy vacuum state could cause the universe to collapse into a different state. – Although vacuum decay is a theoretical concept, it raises questions about the stability of our universe.
Stars – Stars are luminous spheres of plasma held together by gravity, undergoing nuclear fusion reactions in their cores. – The Sun is the closest star to Earth and provides the energy necessary for life.
Planets – Planets are celestial bodies that orbit a star, are spherical in shape, and have cleared their orbital path of other debris. – Earth is the third planet from the Sun in our solar system.
Cosmic – Cosmic refers to anything related to the universe or cosmos, especially beyond Earth’s atmosphere. – Cosmic radiation is a type of energy that comes from outer space and can affect astronauts in orbit.
