Scientists Argue Over How Universe Will End

Summary

This script delves into the potential ultimate fates of our universe, focusing on the Big Rip and Big Freeze theories. It explains the universe's constant expansion, driven by dark energy and the mysterious phenomena of dark matter. The Big Rip suggests an accelerated expansion leading to the disintegration of matter and spacetime, while the Big Freeze envisions a universe reaching thermodynamic equilibrium, becoming inert. The script also touches on alternative theories like the Big Crunch and the speculative Big Slurp, emphasizing the ongoing quest to understand our universe's destiny.

Takeaways

• 🌌 The Big Bang marks the beginning of the universe, characterized by an event of high density and temperature that initiated its expansion.
• 🔍 Two leading theories for the universe's end are the Big Rip and the Big Freeze, offering different scenarios for the ultimate fate of the cosmos.
• 📐 The universe's constant expansion is driven by the energy from the Big Bang, with galaxies moving away from each other at increasing speeds.
• 🌌 Dark matter, an elusive cosmic phenomenon, influences gravitational fields and bends light, despite being invisible due to its non-interaction with light.
• 🔮 Dark energy, comprising about 68% of the universe, is a mysterious force causing the accelerated expansion of the universe and galaxies.
• 💥 The Big Rip theory suggests that dark energy will eventually overcome gravity, leading to the disintegration of matter and spacetime, resulting in the universe's complete destruction.
• 📅 According to a 2015 model, the Big Rip is predicted to occur around 22 billion years from now, should dark energy continue to strengthen.
• 🌐 The Big Freeze theory posits that the universe will reach a state of thermodynamic equilibrium, leading to a lack of energy for any action, effectively 'freezing' the universe.
• ❄️ In the Big Freeze scenario, the universe would expand until no new stars can form, leading to a state where no physical processes can occur due to energy depletion.
• 🔁 Some scientists propose the Big Crunch, where the universe's expansion reverses, potentially leading to a new cycle of Big Bangs and Big Crunches, or a Big Bounce.
• 💡 The most widely accepted theory is the Big Freeze, supported by the understanding of dark energy's influence on the universe's continued expansion without signs of contraction.

Q & A

What are the two leading theories for the ultimate fate of the universe mentioned in the script?

The two leading theories mentioned are the Big Rip Theory and the Big Freeze Theory.

What is the Big Rip Theory?

The Big Rip Theory suggests that the universe will continue to expand at an accelerated rate until dark energy becomes strong enough to deconstruct matter and even spacetime itself, ultimately tearing the universe apart into its basic components.

What is dark energy and how is it related to the expansion of the universe?

Dark energy is a mysterious force that makes up about 68% of the universe and is believed to be the cause of the universe's accelerated expansion. It can overwhelm gravitational and electromagnetic forces, causing objects in the universe to move apart.

What is dark matter and how does it affect the universe?

Dark matter is a type of matter composed of particles that do not interact with light, making it difficult to detect directly. It affects the universe by influencing gravitational fields and bending light, playing a crucial role in the structure of galaxies.

What is the approximate date given by the 2015 model for when the Big Rip might occur?

According to the 2015 model developed by Marcelo Disconzi and others, the Big Rip is likely to occur around twenty-two billion years from now.

What is the concept of 'cosmological viscosity' mentioned in the script?

Cosmological viscosity refers to the universe's resistance to expansion or contraction. It is different from the viscosity of liquids and is related to how easily the universe can expand to a near-infinite size.

What is the Big Freeze Theory and how does it differ from the Big Rip Theory?

The Big Freeze Theory, also known as the Heat Death of the universe, posits that the universe will continue to expand until all energy is evenly distributed, leading to a state of thermodynamic equilibrium where no action can occur due to the lack of energy. This is different from the Big Rip, which involves the universe being torn apart by dark energy.

What is entropy and how does it relate to the Big Freeze Theory?

Entropy is a measure of the degree of disorder or randomness in a system. In the context of the Big Freeze Theory, as the universe expands, entropy increases until it reaches its maximum value, leading to an even distribution of heat and energy and the cessation of all action.

What is the Big Crunch Theory and how does it compare to the other theories mentioned?

The Big Crunch Theory suggests that the universe's expansion will slow down and eventually reverse, causing everything to collapse into a singularity. This is in contrast to the Big Rip and Big Freeze Theories, which involve the universe expanding indefinitely.

What is the 'Big Slurp' or 'False Vacuum Decay' theory and how does it differ from other theories?

The Big Slurp or False Vacuum Decay theory is a complex quantum mechanics-based theory suggesting that a bubble of vacuum decay could expand at the speed of light, consuming the universe as we know it. Unlike other theories, it involves a sudden and unpredictable change rather than a gradual process.

Why is it important to consider the end of the universe, even though it is far in the future?

Considering the end of the universe helps us to better appreciate our existence and the universe we call home. It also drives scientific inquiry and understanding of the fundamental forces and phenomena that govern the cosmos.

Outlines

00:00

🌌 The Big Rip and Big Freeze Theories

This paragraph introduces two leading theories on the ultimate fate of the universe: the Big Rip and the Big Freeze. It explains the universe's ongoing expansion since the Big Bang and the role of dark matter and dark energy. Dark matter, invisible due to its non-interaction with light, influences gravitational fields, while dark energy, comprising 68% of the universe, drives the accelerated expansion. The Big Rip Theory suggests that dark energy will eventually overcome gravity, leading to the disintegration of all matter and spacetime. The paragraph also mentions a model developed in 2015 that predicts the Big Rip to occur in approximately 22 billion years.

05:02

🌗 Dark Energy's Dominance and the Big Rip Hypothesis

The second paragraph delves deeper into the concept of the Big Rip, exploring the potential for dark energy to increase in strength to the point where it can pull individual atoms apart. It discusses the universe's viscosity, which is low, suggesting a theoretical expansion to near-infinite size. However, the increasing strength of dark energy could lead to a scenario where celestial bodies, atoms, and even the fabric of space itself are torn apart, resulting in the universe's complete disintegration. The paragraph also contrasts the Big Rip with the Big Crunch and the Big Freeze, the latter being a state of thermodynamic equilibrium where no action can occur due to the even distribution of energy.

10:03

🔥 The Big Freeze and Other Theories on the Universe's End

This paragraph contrasts the Big Rip with the Big Freeze, which is characterized by the universe reaching a state of thermodynamic equilibrium where energy is evenly distributed, leading to a cessation of all activity. It explains the concept of entropy and how it would increase as the universe expands, eventually leading to a constant level of energy. The Big Freeze is likened to the Heat Death of the universe, where no new stars can form, and all existing energy is depleted. The paragraph also touches on the possibility of a Big Crunch, where gravity could reverse the expansion, leading to a potential Big Bounce and an endless cycle of universes. However, the prevailing view is that the universe will continue expanding, making the Big Freeze a more likely outcome.

💥 The Big Crunch and The Big Slurp Theories

The final paragraph discusses the Big Crunch theory, which suggests a reversal of the universe's expansion due to gravity, potentially leading to a new Big Bang and a cycle of universes. It also introduces the less conventional theory of the Big Slurp, or False Vacuum Decay, which involves a quantum field shifting from a high-energy state to a true vacuum, causing a bubble of vacuum decay that expands at light speed, engulfing the universe. While the exact nature of the universe's end remains uncertain, the paragraph emphasizes the importance of understanding these theories to appreciate our universe and the impermanence of all things.

Keywords

💡Big Bang

The Big Bang is the prevailing cosmological model for the observable universe's origin, suggesting that it began as a singularity and expanded rapidly. It is central to the video's theme as it sets the stage for discussing the universe's end. The script mentions it in the context of the universe's beginning, providing a contrasting backdrop for the potential end scenarios.

💡Big Rip Theory

The Big Rip Theory is one of the potential end-of-universe scenarios discussed in the script. It posits that the universe's expansion will continue to accelerate due to dark energy until it reaches a point where it overcomes all other forces, eventually tearing apart galaxies, stars, atoms, and even spacetime itself. The script uses this theory to illustrate a dramatic and extreme possibility for the universe's ultimate fate.

💡Big Freeze Theory

The Big Freeze Theory, also known as the Heat Death of the universe, is another hypothesis for the universe's end. It suggests that as the universe expands, it will reach a state of thermodynamic equilibrium where energy is evenly distributed, leading to no more heat or light energy production. The script explains this as a state where the universe would be so still that no physical processes could occur, contrasting with the Big Rip's violent end.

💡Dark Matter

Dark matter is a form of matter hypothesized to account for gravitational effects that are not explained by observable matter alone. In the script, dark matter is described as being crucial to the universe's structure, existing throughout and influencing gravitational fields, yet being incredibly difficult to detect due to its non-interactive nature with light.

💡Dark Energy

Dark energy is a mysterious form of energy that is believed to permeate all of space and is responsible for the universe's accelerated expansion. The script explains that dark energy is a key factor in both the Big Rip and Big Freeze theories, as its strength and effects determine the universe's ultimate fate, either by tearing everything apart or causing a state of equilibrium.

💡Expansion of the Universe

The expansion of the universe refers to the ongoing increase in the distance between galaxies, which has been occurring since the Big Bang. The script discusses this concept as the foundational process that could lead to either the Big Rip or Big Freeze, depending on the influence of dark energy.

💡Entropy

Entropy, in the context of the Big Freeze Theory, is a thermodynamic measure of disorder or randomness in a system. The script explains that as the universe expands, entropy increases, leading to a state where energy is evenly distributed and no new heat is produced, signifying the end of action and heat production in the universe.

💡Thermodynamic Equilibrium

Thermodynamic equilibrium is a state where the energy distribution is uniform throughout a system, with no net flow of energy. The script uses this concept to describe the end state of the universe in the Big Freeze Theory, where no further physical processes can occur due to the even spread of energy.

💡Big Crunch

The Big Crunch is a cosmological hypothesis suggesting that the expansion of the universe will eventually slow down and reverse, leading to a collapse back into a singularity. The script briefly mentions this as an alternative to the Big Rip and Big Freeze, but notes that it is less likely due to the lack of evidence for a deceleration in the universe's expansion.

💡Cosmological Viscosity

Cosmological viscosity, as discussed in the script, is a theoretical property of the universe that would determine its resistance to expansion or contraction. The script explains that a low viscosity suggests the universe could expand to near-infinite size, which is a key factor in the potential occurrence of the Big Rip.

💡False Vacuum Decay

False Vacuum Decay, also whimsically referred to as The Big Slurp, is a theoretical scenario in which a bubble of true vacuum forms and expands at the speed of light, converting the false vacuum of our universe into a lower energy state. The script describes this as a highly uncertain and contentious theory, but one that could result in the end of the universe as we know it.

Highlights

Scientists and cosmologists have long discussed the origins of the universe, known as the Big Bang.

Two leading theories about how the universe will end are the Big Rip Theory and the Big Freeze Theory.

The universe is constantly expanding due to the energy from the Big Bang.

Dark matter and dark energy play crucial roles in the expansion of the universe.

Dark matter affects gravitational fields and bends light, although it cannot be directly detected.

Dark energy, comprising roughly 68% of the universe, is linked to its expansion.

The Big Rip Theory suggests that the universe will eventually be torn apart by dark energy.

Marcelo Disconzi and colleagues developed a new model of the Big Rip theory in 2015.

According to Disconzi's model, the Big Rip is likely to occur around 22 billion years from now.

The Big Rip would deconstruct matter and spacetime itself, leaving nothing behind.

The Big Freeze Theory predicts a state where the universe reaches thermodynamic equilibrium.

In the Big Freeze, energy would be evenly distributed, preventing any new actions or heat production.

The Big Freeze is also referred to as the Heat Death of the universe.

Most scientists agree that the Big Freeze is the most likely outcome due to the continued expansion of the universe.

There is also a less widely accepted theory called The Big Slurp or False Vacuum Decay.

The Big Slurp involves a bubble of vacuum decay expanding at the speed of light, ending the universe as we know it.

Understanding the potential end of the universe helps us appreciate the current state of our universe.

Transcripts

Scientists and cosmologists have long  discussed the origins of the universe,  

an expansion that occurred when high density  and temperatures created an event that we know  

as the Big Bang. So, with that knowledge of how  all this got started, perhaps it’s only natural  

to be curious as to how it’ll all come to an end. As it stands, two of the leading theories as to  

how the universe will eventually be destroyed are  known as the Big Rip Theory and the Big Freeze  

Theory. Both of these provide potential answers  for what may end up being the ultimate fate of  

our universe, but that then begs the question:  which one is more likely? Well, in order to  

figure that out, we need to first understand  what each of these theories actually entails! 

Let’s start off with the Big Rip theory.  Physicists trying to understand what the  

end of the universe will look like have  described this as one potential outcome.  

But in order to understand it, we need to first  go over a few important bits of context. Firstly,  

as you may or may not already know, the universe  as we know it is constantly expanding. Over time,  

the distance between parts of the universe is  steadily increasing, and has been since the  

Big Bang thanks to the energy of that event. Due to this constant expansion, the galaxies  

that exist outside of our own are gradually moving  away from us; those further away move faster. But  

that doesn’t mean that these galaxies are moving  through space from one part to another. Instead,  

they are moving in space, the space that they  inhabit is also expanding. In other words,  

the universe encompasses everything that exists  – our own galaxy and others – and everything is  

gradually spreading itself thinner and thinner. Now, the second piece of context is the existence  

of dark matter and dark energy. Those terms  might sound familiar if you’re a big science  

fiction fan, but these aren’t just cool-sounding  words that authors throw into their space stories.  

Dark matter is arguably one of the most  important cosmic phenomena in the universe,  

and yet it is surprisingly difficult to study  – because it’s incredibly hard to detect. 

This is because dark matter is composed  of particles that do not absorb, reflect,  

or emit light, hence its name. Thanks to this,  it cannot be detected or even seen directly. So,  

how do scientists know it’s even there? Well,  that’s done by observing the effects dark  

matter has on the objects in the universe that  we can observe. It collects around every galaxy,  

affecting gravitational fields and bending  light. While everything within the universe  

is composed of matter, dark matter  also exists all across the universe,  

woven into the very fabric of space itself. Dark energy, however, is not as well understood.  

It’s a mystery, with roughly 68% of the universe  comprised of dark energy. This is known because  

dark energy’s primary effect is directly linked  to the expansion of the universe. According to  

current theories on the subject, dark energy  is what causes space and the galaxies within  

that space to gradually move apart on such a  small scale that it is almost undetectable. 

Dark energy has long been thought to just be  an inherent property of space, however, this  

mysterious force is still not fully understood.  All we need to know for the purposes of this  

explanation is that dark energy can overwhelm  gravitational and electromagnetic forces, hence  

why it causes the objects in the universe and  the space containing them to keep moving apart. 

So, in short, the universe is constantly  expanding, and that is largely due to the  

effects of dark energy. Of course, we’re  simplifying things here, these concepts  

are exceedingly complex and there’s still a lot  more research that needs to be done into the exact  

nature of dark energy. With all that in mind, what  exactly is the Big Rip? Well, given the universe  

is continually expanding at an accelerated rate,  the theory states that eventually, the universe  

will hit a limit where this force will begin to  deconstruct matter and even spacetime itself. 

Essentially, the universe would be broken down  into its basic components, and the gravitational  

forces between objects would also be pulled apart  by the continuous rapid expansion. Eventually,  

the entire universe would be ripped  to shreds on every conceivable level.  

This includes everything from galaxies to stars,  planets, individual atoms, and even time itself,  

eventually leaving nothing left, hence the name  the Big Rip. And R.I.P. to all of existence. 

While this might sound more akin to something  from a science-fiction movie, Marcelo Disconzi,  

assistant professor of mathematics at  Vanderbilt University in Tennessee,  

along with physics professors Thomas Kephart and  Robert Scherrer, developed a new model of the Big  

Rip theory in 2015. Using this model, they were  even able to give an approximate date of when the  

Big Rip is likely to occur. Make sure to mark your  calendars for it everyone, it should be arriving  

around twenty-two… billion years from now. According to Disconzi, in order for the Big  

Rip to occur, dark energy will first need to  become stronger than the force of gravity,  

until it becomes powerful enough to cause single  atoms to separate. In the Big Rip model from 2015,  

he began by examining the viscosity of the  universe, in other words, how sticky the universe  

is, and how resistant it is not only to expanding  but also potentially contracting too. If the  

universe is constantly expanding outwards, will it  ever reach a point where it springs back inwards? 

Referred to as ‘cosmological viscosity,’  this is considerably different from how  

we understand the viscosity of liquids. This  is normally measured by how quickly a liquid  

can move through a small opening – the  thicker and more viscous something is,  

the slower it typically moves. Disconzi was able  to determine that the universe’s viscosity is  

quite low, which means it could theoretically  expand to a near-infinite size. However,  

then the dark energy comes into the mix. If dark energy increases in strength the  

more the universe expands, and the universe  continues to expand, then Disconzi’s hypothesis  

states that this will eventually lead to  dark energy becoming strong enough to pull  

individual atoms apart. After all, for the Big Rip  to occur, dark energy needs to win its battle with  

the force of gravity. So, if the Big Rip theory  is correct, then this could be how it happens: 

After gradually getting further and further  apart, the space that lies between galaxies would  

become nearly infinite. Individual stars have  drifted away from their galaxies by this point,  

while planets and everything on them would  also be torn apart. These planets would also  

have drifted away from the stars surrounding  them, as would the moons from said planets.  

Celestial bodies would explode as they themselves  were pulled apart by the effects of dark energy. 

On a microscopic level, molecules and atoms would  also split as the forces keeping them together  

would be ripped open. Electrons would be pulled  away from atoms, all the way down to quarks,  

the theoretical smallest subatomic particles. If anything smaller exists, then that, too,  

would be pulled apart. This would eventually  reduce the universe to its bare components,  

until it would, in all likelihood, be unable  to withstand the immense pressure created.  

At that point, if you had somehow managed to  stick around for that long, you could witness  

the very fabric of space glitching as it, too,  began to rip itself apart. Reality would become  

reminiscent of the time before the Big Bang when  there was quite literally nothing in existence. 

So, that was the Big Rip, in a nutshell. So  long, universe, we hardly knew you. However,  

the Big Rip isn’t a certainty. That’s not to say  we can avoid the inevitable end of the universe,  

but there are other predicted models for  the eventual demise of all existence. 

One of these is the Big Crunch, which  suggests that the constant expansion  

of the universe will eventually begin  to slow down rather than accelerate,  

eventually causing everything to implode,  collapsing in on itself into a singularity.  

Think of the Big Bang, but in reverse. And then, there’s the much-anticipated Big Freeze,  

so crank up your thermostat and get ready for an  ice age bigger than you could possibly imagine. 

Except, despite what the name suggests, the Big  Freeze isn’t everything in the universe dropping  

to the same low temperature. Instead, it would be  a new continuous state wherein the universe itself  

would be so still that nothing could physically  happen. If you thought that the entire universe  

being slowly pulled apart by dark energy was a  sour note to go out on, then this possible outcome  

is even more of a bleak end to the universe. According to the Big Freeze theory, as the  

universe expands, one day, all the energy in the  universe will become evenly distributed. This  

would lead to what is called a thermodynamic  equilibrium, essentially a constant level of  

thermodynamic energy across the entire universe.  Thermodynamics, for those of you who don’t know,  

is the science that deals with the  transfer of energy from one place to  

another. Energy can take on many different  forms, and in particular for thermodynamics,  

kinetic energy and potential energy, which  are both related to movement or action. 

So, thermodynamics examines the  relationships between these action  

forms of energy and the heat produced by action. One of the key principles of thermodynamics is  

entropy. This refers to the idea that everything  in the universe eventually moves from a state of  

disorder to order, so think of entropy as the  way in which we measure that shift. According  

to the Big Freeze theory, entropy would increase  as the universe expands, and this would continue  

until it reaches its maximum value. That would  mean that all of the heat and energy would be  

evenly distributed, staying at a level that  remains constant across the entire universe. 

Think about it as being perfectly, evenly, and  very thinly spread so that no one part of the  

universe has any more potential energy than  another part. This would ultimately decrease  

the temperature, not because things were  getting colder but because no heat energy  

would be produced from action. This is why the  Big Freeze is also referred to as the Heat Death  

of the universe, because you need energy  for action to occur, and with no action,  

no new heat can be produced as a result. Essentially, in this outcome, the universe  

would continue to expand thanks to the inflating  effects of dark energy. In theory, it would  

inevitably become so vast that the supplies of  gasses would also be spread thin, so thin that  

no new stars can form. No new stars means no heat  and light energy. With nothing new being born as  

the universe continues to expand, everything  would essentially grind to a halt. It would  

all ‘freeze,’ and nothing would be able to happen  due to the lack of energy left in the universe. 

So, when all’s said and done, which of these  unpleasant outcomes is more likely to be the  

definitive end of the universe? Well, that all  depends on who you ask. Different scientists  

ascribe to different theories, with some  of the more optimistic hoping for a Big  

Crunch. In that outcome, the expansion of the  universe would not only eventually slow down,  

but would also end up reversing, with gravity  pulling everything back towards… well, everything  

else. This would lead to stars, planets, and  entire galaxies crashing into each other,  

destroying all life in an explosive fashion. But as the universe contracts, its heat and  

density would increase until… boom! The Big Crunch could, in essence,  

cause the Big Bang to be recreated, if the  universe condenses into a singularity. Some  

scientists refer to this as the Big Bounce,  theorizing this would create an entirely new  

universe in the place of our old one. This would  begin a brand new cycle of this second universe  

expanding up until the point where it contracts,  and then another Big Crunch and Big Bang happen,  

leading to another Big Bounce. This means that our  universe could just be one in an ongoing endless  

cycle of universal destruction and creation. However, most scientists are in agreement that the  

universe is going to keep expanding, and with no  signs of it contracting again, so the Big Crunch  

is unlikely to be the outcome we get. The most  widely accepted of the theories is that the Big  

Freeze will occur as a result of the universe’s  continued expansion. This is, in large part,  

thanks to the existence of dark energy. It’s unlikely that gravity will ever  

become strong enough to counteract the inflating  effect of dark energy, and if gravity is weaker,  

then it can’t pull the universe back inwards  to collapse in on itself for the Big Crunch. 

There is one more, slightly contentious theory  about how the universe could end, a theory is  

known rather whimsically as The Big Slurp, and  less whimsically as False Vacuum Decay. This  

theory is particularly strange and complex, as  it delves deep into quantum mechanics. In short,  

what you need to understand is that we  exist within a field of energy known as  

the Higgs Field. Ever heard of the Higgs  Boson Particle? This is the same Higgs. 

You also need to understand that, under the  current laws of physics, any system will  

try to become stable, which it does by moving  from a state of high energy to a state of low  

energy. When a quantum field stabilizes into its  lowest state of energy, it becomes a true vacuum. 

The reason this is relevant to our  current discussion is that the Higgs  

Field is believed to be a false rather  than true vacuum. And if even one tiny  

part of space slips from a high energy to a low  energy state, it would cause a bubble of vacuum  

decay that expands at the speed of light,  “slurping” the rest of our universe into it. 

What would happen in that bubble of vacuum  decay? Well, we’re not entirely sure. The  

only thing that is certain is that the  universe as we know it would be over. 

Although, it’s worth noting that the  exact nature of how the universe will  

end is still highly uncertain. All anyone can  agree on is that it’s certainly a long way off. 

So, that begs the question, why think about it  at all? Well, learning more about the universe,  

and gaining a better understanding about its  inevitable end might seem like an exercise in  

futility. After all, none of us are likely to live  to see it. But if anything, what should be gleaned  

from all this is a better appreciation for all  parts of this universe that we call home. And a  

reminder that, some things might seem like they’re  going to be here forever, but they won’t always. 

Now watch “Incredible Things We Still Don't  Understand About Our Universe” Or look at  

“Why Astronauts Were Almost Trapped On  The Moon Forever (Apollo 11 Landing)”