We've created a lot of black hole merch, spanning the whole range from somewhat bonkers to more serious.

We 've created a lot of black hole merch , spanning the whole range from somewhat bonkers to more serious .


This way, we get to explore a topic from different angles.

This way , we get to explore a topic from different angles .


And you get to continue having fun with black holes after this video ends.

And you get to continue having fun with black holes after this video ends .


What is the largest star in the universe?

What is the largest star in the universe ?


And why is it that large?


And what are stars anyway?


We begin our journey with Earth, not to learn anything, just to get a vague sense of scale.

We begin our journey with Earth , not to learn anything , just to get a vague sense of scale .


The smallest things that have some star-like properties are large gas giants or sub-brown dwarfs.

The smallest things that have some star - like properties are large gas giants or sub - brown dwarfs .


The transition towards stars begins with brown dwarfs, failed stars that are a huge disappointment to their mums.

The transition towards stars begins with brown dwarfs , failed stars that are a huge disappointment to their mums .


They have between 13 and 90 times the mass of Jupiter.

They have between 13 and 90 times the mass of Jupiter .


So even if we took 90 Jupiters and threw them at each other, although fun to watch, it wouldn't be enough to create a star.

So even if we took 90 Jupiters and threw them at each other , although fun to watch , it would n't be enough to create a star .


Interestingly, adding lots of mass to a brown dwarf doesn't make it much bigger, just its insides denser.

Interestingly , adding lots of mass to a brown dwarf does n't make it much bigger , just its insides denser .


This increases the pressure in the core enough to make certain nuclear fusion reactions happen slowly and the object glow a little.

This increases the pressure in the core enough to make certain nuclear fusion reactions happen slowly and the object glow a little .


So brown dwarfs are a sort of glowy gas giant that don't fit into any category very well.

So brown dwarfs are a sort of glowy gas giant that do n't fit into any category very well .


But we want to talk about stars, not failed wannabe stars, so let's move on.

But we want to talk about stars , not failed wannabe stars , so let 's move on .


Once large gas balls pass a certain mass threshold, their cores become hot and dense enough to ignite.

Once large gas balls pass a certain mass threshold , their cores become hot and dense enough to ignite .


Hydrogen is fused to helium in their cores, releasing tremendous amounts of energy.

Hydrogen is fused to helium in their cores , releasing tremendous amounts of energy .


Stars that do that are called main sequence stars.

Stars that do that are called main sequence stars .


The more massive a main sequence star is, the hotter and brighter it burns and the shorter its life is.

The more massive a main sequence star is , the hotter and brighter it burns and the shorter its life is .


Once the hydrogen burning phase is over, stars grow, up to hundreds of thousands of times their original size.

Once the hydrogen burning phase is over , stars grow , up to hundreds of thousands of times their original size .


But these giant phases only last for a fraction of their lifespan.

But these giant phases only last for a fraction of their lifespan .


So we'll be comparing stars at drastically different stages in their lives.

So we 'll be comparing stars at drastically different stages in their lives .


This doesn't make them less impressive, but maybe it's good to keep in mind that we'll be comparing babies to adults.

This does n't make them less impressive , but maybe it 's good to keep in mind that we 'll be comparing babies to adults .


The smallest real stars are red dwarfs, about 100 times the mass of Jupiter, barely massive enough to fuse hydrogen to helium.

The smallest real stars are red dwarfs , about 100 times the mass of Jupiter , barely massive enough to fuse hydrogen to helium .


Because they are not very massive, they are small, not very hot, and shine pretty dimly.

Because they are not very massive , they are small , not very hot , and shine pretty dimly .


They are the only stars in the main sequence that don't grow once they die, but sort of fizzle out.

They are the only stars in the main sequence that do n't grow once they die , but sort of fizzle out .


Red dwarfs are by far the most abundant type in the universe.

Red dwarfs are by far the most abundant type in the universe .


Because they burn their fuel very slowly, it lasts them up to 10 trillion years, a thousand times the current age of the universe.

Because they burn their fuel very slowly , it lasts them up to 10 trillion years , a thousand times the current age of the universe .


For example, one of the closest stars to Earth is a red dwarf star, Barnard's star, but it shines too dimly to be seen without a telescope.

For example , one of the closest stars to Earth is a red dwarf star , Barnard 's star , but it shines too dimly to be seen without a telescope .


We made a whole video on red dwarfs if you want to learn more.

We made a whole video on red dwarfs if you want to learn more .


The next stage are stars like our sun.


To say the sun dominates the solar system is not doing it justice, since it makes up 99.86% of all its mass.

To say the sun dominates the solar system is not doing it justice , since it makes up 99.86 % of all its mass .


It burns far hotter and brighter than red dwarfs, which reduces its lifetime to about 10 billion years.

It burns far hotter and brighter than red dwarfs , which reduces its lifetime to about 10 billion years .


The sun is 7 times more massive than Barnard's star, but that makes it nearly 300 times brighter with twice its surface temperature.

The sun is 7 times more massive than Barnard 's star , but that makes it nearly 300 times brighter with twice its surface temperature .


Let's go bigger.


Small changes in mass produce enormous changes in a main sequence star's brightness.

Small changes in mass produce enormous changes in a main sequence star 's brightness .


The brightest star in the night sky, Sirius, is two solar masses with a radius 1.7 times that of the sun, but its surface is nearly 10,000 degrees Celsius, making it shine 25 times brighter.

The brightest star in the night sky , Sirius , is two solar masses with a radius 1.7 times that of the sun , but its surface is nearly 10,000 degrees Celsius , making it shine 25 times brighter .


Burning that hot reduces its total lifespan by 4 times to 2.5 billion years.

Burning that hot reduces its total lifespan by 4 times to 2.5 billion years .


Stars close to 10 times the mass of our sun have surface temperatures near 25,000 degrees Celsius.

Stars close to 10 times the mass of our sun have surface temperatures near 25,000 degrees Celsius .


Beta Centauri contains two of these massive stars, each shining with about 20,000 times the power of the sun.

Beta Centauri contains two of these massive stars , each shining with about 20,000 times the power of the sun .


That's a lot of power coming from something only 13 times larger, but they'll only burn for about 20 million years.

That 's a lot of power coming from something only 13 times larger , but they 'll only burn for about 20 million years .


Entire generations of these blue stars die in the time it takes the sun to orbit the galaxy once.

Entire generations of these blue stars die in the time it takes the sun to orbit the galaxy once .


So is this the formula?


The most massive star that we know is R136a1.

The most massive star that we know is R136a1 .


It has 315 solar masses and is nearly 9 million times brighter than the sun.

It has 315 solar masses and is nearly 9 million times brighter than the sun .


And yet, despite its tremendous mass and power, it's barely 30 times the size of the sun.

And yet , despite its tremendous mass and power , it 's barely 30 times the size of the sun .


The star is so extreme and barely held together by gravity that it loses 321,000 billion tons of material through its stellar wind.

The star is so extreme and barely held together by gravity that it loses 321,000 billion tons of material through its stellar wind .


Stars of this sort are extremely rare because they break the rules of star formation a tiny bit.

Stars of this sort are extremely rare because they break the rules of star formation a tiny bit .


When supermassive stars are born, they burn extremely hot and bright, and this blows away any extra gas that could make them more massive.

When supermassive stars are born , they burn extremely hot and bright , and this blows away any extra gas that could make them more massive .


So the mass limit for such a star is around 150 times the sun.

So the mass limit for such a star is around 150 times the sun .


Stars like R136a1 are probably formed through the merger of several high-mass stars in dense star-forming regions and burn their core hydrogen in only a few million years.

Stars like R136a1 are probably formed through the merger of several high - mass stars in dense star - forming regions and burn their core hydrogen in only a few million years .


So this means they are rare and short-lived.

So this means they are rare and short - lived .


From here, the trick to going bigger isn't adding more mass.

From here , the trick to going bigger is n't adding more mass .


To make the biggest stars, we have to kill them.

To make the biggest stars , we have to kill them .


When main-sequence stars begin to exhaust the hydrogen in their core, it contracts, making it hotter and denser.

When main - sequence stars begin to exhaust the hydrogen in their core , it contracts , making it hotter and denser .


This leads to hotter and faster fusion, which pushes back against gravity and makes the outer layers swell in a giant phase.

This leads to hotter and faster fusion , which pushes back against gravity and makes the outer layers swell in a giant phase .


And these stars become truly giant indeed.

And these stars become truly giant indeed .


Only 30% more massive than the sun, it has swollen to about 84 times its radius.

Only 30 % more massive than the sun , it has swollen to about 84 times its radius .


Still, when the sun enters the last stage of its life, it will swell and become even bigger, 200 times its current radius.

Still , when the sun enters the last stage of its life , it will swell and become even bigger , 200 times its current radius .


In this final phase of its life, it will swallow the inner planets.

In this final phase of its life , it will swallow the inner planets .


And if you think that's impressive, let's finally introduce the largest stars in the universe, Hypergiants.

And if you think that 's impressive , let 's finally introduce the largest stars in the universe , Hypergiants .


Hypergiants are the giant phase of the most massive stars in the universe.

Hypergiants are the giant phase of the most massive stars in the universe .


They have an enormous surface area that can radiate an insane amount of light.

They have an enormous surface area that can radiate an insane amount of light .


Being so large, they're basically blowing themselves apart, as gravity at the surface is too weak to hold on to the hot mass, which is lifted away in powerful stellar winds.

Being so large , they 're basically blowing themselves apart , as gravity at the surface is too weak to hold on to the hot mass , which is lifted away in powerful stellar winds .


Pistol Star is 25 solar masses, but 300 times the radius of the sun, a blue hypergiant aptly named for its energetic blue starlight.

Pistol Star is 25 solar masses , but 300 times the radius of the sun , a blue hypergiant aptly named for its energetic blue starlight .


It's hard to say exactly how long Pistol Star will live, but probably just a few million years.

It 's hard to say exactly how long Pistol Star will live , but probably just a few million years .


Even larger than the blue hypergiants are the yellow hypergiants.

Even larger than the blue hypergiants are the yellow hypergiants .


The most well-studied is Rho Cassiopeia, a star so bright it can be seen with the naked eye although it's thousands of light-years from Earth.

The most well - studied is Rho Cassiopeia , a star so bright it can be seen with the naked eye although it 's thousands of light - years from Earth .


At 40 solar masses, this star is around 500 times the radius of the sun and 500,000 times brighter.

At 40 solar masses , this star is around 500 times the radius of the sun and 500,000 times brighter .


If the Earth were as close to Rho Cassiopeia as it is to the sun, it'd be incited and you would be very dead.

If the Earth were as close to Rho Cassiopeia as it is to the sun , it 'd be incited and you would be very dead .


Yellow hypergiants are very rare though, only 15 are known.

Yellow hypergiants are very rare though , only 15 are known .


This means they're likely just a short-lived intermediate state, as a star grows or shrinks between other phases of hypergiantness.

This means they 're likely just a short - lived intermediate state , as a star grows or shrinks between other phases of hypergiantness .


With red hypergiants, we reach the largest stars known to us, probably the largest stars even possible.

With red hypergiants , we reach the largest stars known to us , probably the largest stars even possible .


So who's the winner of this insane contest?

So who 's the winner of this insane contest ?


Well, the truth is, we don't know.


Red hypergiants are extremely bright and far away, which means that even tiny uncertainties in our measurements can give us a huge margin of error for their size.

Red hypergiants are extremely bright and far away , which means that even tiny uncertainties in our measurements can give us a huge margin of error for their size .


Worse still, red hypergiants are solar system-sized behemoths that are blowing themselves apart, which makes them harder to measure.

Worse still , red hypergiants are solar system - sized behemoths that are blowing themselves apart , which makes them harder to measure .


As we do more science and our instruments improve, whatever the largest star is will change.

As we do more science and our instruments improve , whatever the largest star is will change .


The star that is currently thought to be among the largest we've found is Stephenson 218.

The star that is currently thought to be among the largest we 've found is Stephenson 218 .


It was probably born as a main-sequence star a few tens of times the mass of the sun and has likely lost about half its mass by now.

It was probably born as a main - sequence star a few tens of times the mass of the sun and has likely lost about half its mass by now .


While typical red hypergiants are 1,500 times the size of the sun, the largest rough estimate places Stephenson 218 at 2,150 solar radii and shining with almost half a million times the power of the sun.

While typical red hypergiants are 1,500 times the size of the sun , the largest rough estimate places Stephenson 218 at 2,150 solar radii and shining with almost half a million times the power of the sun .


By comparison, the sun seems like a grain of dust.

By comparison , the sun seems like a grain of dust .


Our brains don't really have a way of grasping this kind of scale.

Our brains do n't really have a way of grasping this kind of scale .


Even at light speed, it would take you 8.7 hours to travel around it once.

Even at light speed , it would take you 8.7 hours to travel around it once .


The fastest plane on Earth would take around 500 years.

The fastest plane on Earth would take around 500 years .


Dropped on the sun, it would fill Saturn's orbit.

Dropped on the sun , it would fill Saturn 's orbit .


As it evolves, it will probably shed even more mass and shrink down into another, hotter hypergiant phase, accumulate heavy elements in its core,

As it evolves , it will probably shed even more mass and shrink down into another , hotter hypergiant phase , accumulate heavy elements in its core ,


This gas will then go on to form another generation of stars of all sizes, starting the cycle of birth and death again, to light up our universe.

This gas will then go on to form another generation of stars of all sizes , starting the cycle of birth and death again , to light up our universe .


Let's make this journey again, but this time without the talking.

Let 's make this journey again , but this time without the talking .


The universe is big.


There are many large things in it.


If you want to play a bit more with size stuff, we have good news.

If you want to play a bit more with size stuff , we have good news .


We've created our first app, Universe in a Nutshell, together with Tim Urban, the brain behind Wait But Why.

We 've created our first app , Universe in a Nutshell , together with Tim Urban , the brain behind Wait But Why .


You can seamlessly travel from the smallest things in existence, past the coronavirus, human cells and dinosaurs,

You can seamlessly travel from the smallest things in existence , past the coronavirus , human cells and dinosaurs ,


You can learn more about each object, or simply enjoy the sheer scale of it all.

You can learn more about each object , or simply enjoy the sheer scale of it all .


The app is inspired by the Scale of the Universe website by the Huang Twins that we spent a lot of time with when it came out years ago, and felt that it was finally time to create a Wait But Why and Kurzgesagt version.

The app is inspired by the Scale of the Universe website by the Huang Twins that we spent a lot of time with when it came out years ago , and felt that it was finally time to create a Wait But Why and Kurzgesagt version .


You can get it in your app store, there are no in-app purchases and no ads.

You can get it in your app store , there are no in - app purchases and no ads .


All future updates are included.


And since this is our first app, we'd love to hear your feedback, so we can improve it over time.

And since this is our first app , we 'd love to hear your feedback , so we can improve it over time .


If this sounds good to you, download the Universe in a Nutshell app now, and leave us a 5-star review if you want to support it.

If this sounds good to you , download the Universe in a Nutshell app now , and leave us a 5 - star review if you want to support it .


Kurzgesagt and all the projects we do are mostly funded by viewers like you.

Kurzgesagt and all the projects we do are mostly funded by viewers like you .


So if you like the app, we'll make more digital things in future.

So if you like the app , we 'll make more digital things in future .


Thank you for watching.


The future of humanity seems insecure.


Rapid climate change, political division, our greed and failings make it hard to look at our species with a lot of optimism, and so many people think our end is in sight.

Rapid climate change , political division , our greed and failings make it hard to look at our species with a lot of optimism , and so many people think our end is in sight .


But humans have always thought they lived in the end times.

But humans have always thought they lived in the end times .


Every generation assumes they're important enough to witness the apocalypse, and then life just goes on.

Every generation assumes they 're important enough to witness the apocalypse , and then life just goes on .


This is a problem because it leads to short-term thinking and prevents us from creating the best world for ourselves and our descendants.

This is a problem because it leads to short - term thinking and prevents us from creating the best world for ourselves and our descendants .


What makes this worse is that we may actually be living at an extremely critical moment in human history.

What makes this worse is that we may actually be living at an extremely critical moment in human history .


To understand why, let's look at the temporal window of humanity and ask, when will the last human be born, and how many people will there ever be?

To understand why , let 's look at the temporal window of humanity and ask , when will the last human be born , and how many people will there ever be ?


These sorts of estimates come with a lot of uncertainties, so please take them with a gigantic grain of salt.

These sorts of estimates come with a lot of uncertainties , so please take them with a gigantic grain of salt .


To get a sense of how many people there will be, let's see how many people have already lived.

To get a sense of how many people there will be , let 's see how many people have already lived .


Modern humans arose some 200,000 years ago.

Modern humans arose some 200,000 years ago .


They were uniquely good at making tools, telling stories, thinking abstractly, planning and working together in large groups beyond their close family.

They were uniquely good at making tools , telling stories , thinking abstractly , planning and working together in large groups beyond their close family .


Still, there were not that many of us.

Still , there were not that many of us .


Surpluses of food were scarce, survival was hard, life expectancy was low.

Surpluses of food were scarce , survival was hard , life expectancy was low .


It took us 150,000 years to grow to a population of 2 million.

It took us 150,000 years to grow to a population of 2 million .


Improvements were gradual and eventually led to the agricultural revolution, arguably the biggest change in our history.

Improvements were gradual and eventually led to the agricultural revolution , arguably the biggest change in our history .


This was when our numbers really started growing.

This was when our numbers really started growing .


It took 10,000 more years to get to 300 million.

It took 10,000 more years to get to 300 million .


But that increase was dwarfed by the industrial revolution.

But that increase was dwarfed by the industrial revolution .


In 1800, there were a billion of us.


The human population doubled in just 120 years, and then again in 50.

The human population doubled in just 120 years , and then again in 50 .


Today, we number around 8 billion.


In total, over the last 200,000 years, about 117 billion humans were born and lived, and 109 billion also died.

In total , over the last 200,000 years , about 117 billion humans were born and lived , and 109 billion also died .


Which means that about 7% of all humans that ever lived are alive right now, as many as were born in the first 150,000 years of human history.

Which means that about 7 % of all humans that ever lived are alive right now , as many as were born in the first 150,000 years of human history .


Every minute, 270 babies join the party.

Every minute , 270 babies join the party .


But there aren't just more people.


Never before have we been as healthy and well-off or lived longer.

Never before have we been as healthy and well - off or lived longer .


With growing living standards, our birth rates collapsed.

With growing living standards , our birth rates collapsed .


The UN estimates that around the year 2100, we will hit our population peak and there will be 125 million people born each year.

The UN estimates that around the year 2100 , we will hit our population peak and there will be 125 million people born each year .


It's pretty unlikely that birth rates will stay stable forever, but let's pretend to make our thought experiment simpler.

It 's pretty unlikely that birth rates will stay stable forever , but let 's pretend to make our thought experiment simpler .


How many people there will be in the future depends on when our species will die out.

How many people there will be in the future depends on when our species will die out .


And here, we find a lot of uncertainties.

And here , we find a lot of uncertainties .


We are able to destroy ourselves through our own inventions, but we are also able to find solutions to avert catastrophic risk.

We are able to destroy ourselves through our own inventions , but we are also able to find solutions to avert catastrophic risk .


We can change the direction of planet-killer asteroids, but we've also invented nuclear weapons.

We can change the direction of planet - killer asteroids , but we 've also invented nuclear weapons .


We discovered antibiotics, but also carry diseases across the globe in a matter of days.

We discovered antibiotics , but also carry diseases across the globe in a matter of days .


Our industrial system gives us an incredible standard of living, but also change the atmosphere in the process.

Our industrial system gives us an incredible standard of living , but also change the atmosphere in the process .


It's very hard to say if human ingenuity will prolong or shorten our species' lifespan.

It 's very hard to say if human ingenuity will prolong or shorten our species ' lifespan .


If things go badly, our end could come suddenly.

If things go badly , our end could come suddenly .


But if we manage to avoid that, we could conceivably stick around for a long time.

But if we manage to avoid that , we could conceivably stick around for a long time .


So every day we don't destroy ourselves may mean life for an unfathomable number of humans.

So every day we do n't destroy ourselves may mean life for an unfathomable number of humans .


It depends on how far our species is going to expand.

It depends on how far our species is going to expand .


Scenario 1, Humans will never leave Earth.

Scenario 1 , Humans will never leave Earth .


If we stay on our home planet, a good metric to look at is the extinction rate of animals that we get from the fossil record.

If we stay on our home planet , a good metric to look at is the extinction rate of animals that we get from the fossil record .


The average lifespan of mammalian species is in the region of 1 million years, with some surviving up to 10 million years.

The average lifespan of mammalian species is in the region of 1 million years , with some surviving up to 10 million years .


Our close relative Homo erectus survived for about 1.9 million years.

Our close relative Homo erectus survived for about 1.9 million years .


Let's be conservative and assume that humans will survive for a million years, which leaves us 800,000 more years to dawdle away.

Let 's be conservative and assume that humans will survive for a million years , which leaves us 800,000 more years to dawdle away .


Assuming a stable birth rate of 125 million people each year, this means there are roughly 100 trillion humans waiting to be born.

Assuming a stable birth rate of 125 million people each year , this means there are roughly 100 trillion humans waiting to be born .


This would make everybody alive today only 0.008% of all people that will ever live.

This would make everybody alive today only 0.008 % of all people that will ever live .


Think about where this leaves you.


Instead of putting you at the end of the chaotic mess that was our past, it would mean you live at the very beginning of something big.

Instead of putting you at the end of the chaotic mess that was our past , it would mean you live at the very beginning of something big .


Doesn't this feel incredibly different?

Does n't this feel incredibly different ?


And now, consider that this may be an extremely pessimistic estimate.

And now , consider that this may be an extremely pessimistic estimate .


If we match the survival time of the most successful mammals, then our future numbers rise to 1.2 quadrillion people that have yet to be born.

If we match the survival time of the most successful mammals , then our future numbers rise to 1.2 quadrillion people that have yet to be born .


And even this seems far from our potential.

And even this seems far from our potential .


As the sun slowly gets hotter and brighter, Earth will remain habitable for about 500 million years, giving so many more potential people the chance to become actual people.

As the sun slowly gets hotter and brighter , Earth will remain habitable for about 500 million years , giving so many more potential people the chance to become actual people .


And now, let's begin to think big.


Scenario 2, Humans will leave Earth.


We went from humans worshipping the moon to humans walking on it, so who knows how much further we can go.

We went from humans worshipping the moon to humans walking on it , so who knows how much further we can go .


If we don't die out within the next few hundred years, ideas that seem outlandish right now become serious considerations.

If we do n't die out within the next few hundred years , ideas that seem outlandish right now become serious considerations .


If we believe that we have a chance of surviving for maybe millions of years, then we could expand onto the other planets or into our own artificial worlds.

If we believe that we have a chance of surviving for maybe millions of years , then we could expand onto the other planets or into our own artificial worlds .


Life needs three things, a surface, resources and energy.

Life needs three things , a surface , resources and energy .


Our sun provides energy for billions of years, and there is so much water and material floating in the asteroid and Kuiper belt that we could sustain many times our current population.

Our sun provides energy for billions of years , and there is so much water and material floating in the asteroid and Kuiper belt that we could sustain many times our current population .


Instead of living on planets, we could decide to construct our own artificial worlds and habitats.

Instead of living on planets , we could decide to construct our own artificial worlds and habitats .


With resources and energy so abundant, we could try out different types of society and ways of life.

With resources and energy so abundant , we could try out different types of society and ways of life .


An interconnected civilization spanning the solar system would create the basis of existence for an absurd number of individuals, orders of magnitude more than if we stick to Earth, even if we only existed for a few million years.

An interconnected civilization spanning the solar system would create the basis of existence for an absurd number of individuals , orders of magnitude more than if we stick to Earth , even if we only existed for a few million years .


This future doesn't have to be grim and dark as science fiction likes to paint it.

This future does n't have to be grim and dark as science fiction likes to paint it .


With quadrillions of people waiting to be born, we will have billions of doctors working on curing cancer, billions of problem solvers working on ending poverty, and billions of video game developers making life fun.

With quadrillions of people waiting to be born , we will have billions of doctors working on curing cancer , billions of problem solvers working on ending poverty , and billions of video game developers making life fun .


More humans may actually mean more progress.

More humans may actually mean more progress .


Another upside of leaving Earth and spreading out is that it becomes much harder for us to become extinct as you need a solar system-wide catastrophe to catch everybody.

Another upside of leaving Earth and spreading out is that it becomes much harder for us to become extinct as you need a solar system - wide catastrophe to catch everybody .


So aside from nearby supernovae or gamma-ray bursts, humanity would be relatively safe from extinction, maybe for billions of years.

So aside from nearby supernovae or gamma - ray bursts , humanity would be relatively safe from extinction , maybe for billions of years .


If we manage to survive for that long, slow evolution or genetic engineering might split us into multiple species, or we might intentionally keep ourselves the same as we are now.

If we manage to survive for that long , slow evolution or genetic engineering might split us into multiple species , or we might intentionally keep ourselves the same as we are now .


So to account for that, we'll just talk about people from now on, instead of humans.

So to account for that , we 'll just talk about people from now on , instead of humans .


Okay, now let's think really big.


Scenario 3, people leave the solar system.

Scenario 3 , people leave the solar system .


As enormous as the solar system is, it is just one star system among billions in the Milky Way.

As enormous as the solar system is , it is just one star system among billions in the Milky Way .


If future people can colonize, say, 100 billion stars, and live there for 10 billion years, with each generating 100 million births per year, then we can expect something like a hundred octillion lives to be lived in the future.

If future people can colonize , say , 100 billion stars , and live there for 10 billion years , with each generating 100 million births per year , then we can expect something like a hundred octillion lives to be lived in the future .


This is a one with 29 zeros.


We can spend this up as much as we like.

We can spend this up as much as we like .


The Andromeda Galaxy will merge with the Milky Way, adding another trillion stars for us to settle.

The Andromeda Galaxy will merge with the Milky Way , adding another trillion stars for us to settle .


Red dwarfs stay active for up to a trillion years, and future civilizations might even find energy for their habitats around black holes.

Red dwarfs stay active for up to a trillion years , and future civilizations might even find energy for their habitats around black holes .


A sufficiently advanced civilization of our descendants might even try to reach other galaxy groups.

A sufficiently advanced civilization of our descendants might even try to reach other galaxy groups .


While these numbers are mind-blowing, they may underestimate the number of unborn people by many orders of magnitude.

While these numbers are mind - blowing , they may underestimate the number of unborn people by many orders of magnitude .


If we divide the total energy available in a galaxy by the average energy needs of a single person, then we get a tridicillion potential lives.

If we divide the total energy available in a galaxy by the average energy needs of a single person , then we get a tridicillion potential lives .


Hopefully, what's become evident is that if we don't kill ourselves in the next few centuries or millennia, almost all humans that will ever exist will live in the future.

Hopefully , what 's become evident is that if we do n't kill ourselves in the next few centuries or millennia , almost all humans that will ever exist will live in the future .


We exist at a high point in human history, with incredible possibilities at our grasp.

We exist at a high point in human history , with incredible possibilities at our grasp .


What we do matters for all the people who do not exist yet.

What we do matters for all the people who do not exist yet .


So while it's not on vogue to think about humanity's long-term future with optimism, or to think about it at all, maybe this has given you a bit of perspective.

So while it 's not on vogue to think about humanity 's long - term future with optimism , or to think about it at all , maybe this has given you a bit of perspective .


If we screw up the present, so many people may never come to exist.

If we screw up the present , so many people may never come to exist .


Quadrillions of unborn humans are at our mercy.

Quadrillions of unborn humans are at our mercy .


Even if we go with fairly conservative estimates, the unborn are by far the largest group of people, and the most disenfranchised.

Even if we go with fairly conservative estimates , the unborn are by far the largest group of people , and the most disenfranchised .


Somebody who might be born in a thousand or even a million years deeply depends on us today for their existence.

Somebody who might be born in a thousand or even a million years deeply depends on us today for their existence .


This is why it's important to think about the distant future, and why our presence is so crucial, why it matters what we do today.

This is why it 's important to think about the distant future , and why our presence is so crucial , why it matters what we do today .


One day, the last human will be born.


We don't know when.


We're launching Kurzgesagt in six more languages.

We 're launching Kurzgesagt in six more languages .


If enough people watch our new channels, we can hopefully run them for many years to come.

If enough people watch our new channels , we can hopefully run them for many years to come .


This is where we need your help.


It takes us a lot of time, effort and, yes, money to translate our videos properly and run so many channels.

It takes us a lot of time , effort and , yes , money to translate our videos properly and run so many channels .


So, to make this sustainable, please help us spread the word.

So , to make this sustainable , please help us spread the word .


If you're native in one of these languages, share our videos on social media and tell your friends and family.

If you 're native in one of these languages , share our videos on social media and tell your friends and family .


Make people in your native language aware that it exists.

Make people in your native language aware that it exists .


This multi-language expansion is supported by Open Philanthropy, an organization that tries to do as much good as possible.

This multi - language expansion is supported by Open Philanthropy , an organization that tries to do as much good as possible .


They want to help us spread awareness of science and ideas for how you can help humanity thrive.

They want to help us spread awareness of science and ideas for how you can help humanity thrive .


Their values align with ours in many fundamental ways, so we're going to work with them on more projects in the future.

Their values align with ours in many fundamental ways , so we 're going to work with them on more projects in the future .


So, please help us spread the word.


And thank you for watching.


Humans can survive in this universe as long as we have an energy source.

Humans can survive in this universe as long as we have an energy source .


Unfortunately, the universe will die.


It will happen slowly, over many billions of years, but it will happen.

It will happen slowly , over many billions of years , but it will happen .


On a universal time scale, stars like our sun will be gone in no time.

On a universal time scale , stars like our sun will be gone in no time .


Luckily, there are places that will exist practically forever from a human perspective.

Luckily , there are places that will exist practically forever from a human perspective .


They could be humanity's last home right before the death of the universe.

They could be humanity 's last home right before the death of the universe .


What are these strange things and what happens when they finally die?

What are these strange things and what happens when they finally die ?


How long stars live varies drastically, depending on how massive they are.

How long stars live varies drastically , depending on how massive they are .


For example, really massive stars burn hot and fast, dying violently in supernova a few million years after birth.

For example , really massive stars burn hot and fast , dying violently in supernova a few million years after birth .


But they're the exception.


97% of all stars will end their existence as white dwarfs.

97 % of all stars will end their existence as white dwarfs .


There are two ways this can happen.


Small stars, so-called red dwarfs, burn out over trillions of years until they eventually quietly turn into white dwarfs.

Small stars , so - called red dwarfs , burn out over trillions of years until they eventually quietly turn into white dwarfs .


Medium-sized stars like our sun are more interesting.

Medium - sized stars like our sun are more interesting .


Imagine the sun as a huge pressure cooker that fuses hydrogen into helium in its core through its gravity.

Imagine the sun as a huge pressure cooker that fuses hydrogen into helium in its core through its gravity .


The fusion of elements releases extreme amounts of energy that pushes outwards and stabilizes the star, keeping it in a delicate balance.

The fusion of elements releases extreme amounts of energy that pushes outwards and stabilizes the star , keeping it in a delicate balance .


When the sun is old, the hydrogen in the core is exhausted and the sun will begin to burn helium into heavier elements.

When the sun is old , the hydrogen in the core is exhausted and the sun will begin to burn helium into heavier elements .


While doing so, it will shed its outer layers.

While doing so , it will shed its outer layers .


When this process is over, more than half of the sun's mass will be lost into space as a spectacular planetary nebula millions of kilometers across.

When this process is over , more than half of the sun 's mass will be lost into space as a spectacular planetary nebula millions of kilometers across .


What remains will be its former core.


A white dwarf is born.


While its former self was about 100 times its diameter, now it's only about as big as Earth, but still with about half of its former mass.

While its former self was about 100 times its diameter , now it 's only about as big as Earth , but still with about half of its former mass .


This means it's extremely dense.


A teaspoon of white dwarf is about as massive as a car.

A teaspoon of white dwarf is about as massive as a car .


Its surface gravity is over 100,000 times higher than Earth's.

Its surface gravity is over 100,000 times higher than Earth 's .


If you tried to land on it, you'd immediately be compressed into a steaming puddle.

If you tried to land on it , you 'd immediately be compressed into a steaming puddle .


Life around a white dwarf is very unlikely, but possible.

Life around a white dwarf is very unlikely , but possible .


Most of them that exist now were former stars that, well, died, which probably ruined any planets they once had.

Most of them that exist now were former stars that , well , died , which probably ruined any planets they once had .


But that's not all.


Since they are so small, a planet would need to orbit them about 75 times closer than Earth is to the sun to have liquid water.

Since they are so small , a planet would need to orbit them about 75 times closer than Earth is to the sun to have liquid water .


This proximity has up and downsides.


For one, it would tidally lock the planet, giving it a permanent day and permanent night.

For one , it would tidally lock the planet , giving it a permanent day and permanent night .


At the edges of these day and night zones, life could be possible.

At the edges of these day and night zones , life could be possible .


But white dwarfs have a very stable energy output, so they might actually be safer to live around than many red dwarfs.

But white dwarfs have a very stable energy output , so they might actually be safer to live around than many red dwarfs .


This is still speculation at this point, but if we could find a white dwarf with the right conditions to settle around, we could have a home for many billions of years.

This is still speculation at this point , but if we could find a white dwarf with the right conditions to settle around , we could have a home for many billions of years .


But why do they shine so much longer than other star types?

But why do they shine so much longer than other star types ?


White dwarfs are very, very hot, up to 40 times hotter than our sun, ranking among the hottest objects in the universe.

White dwarfs are very , very hot , up to 40 times hotter than our sun , ranking among the hottest objects in the universe .


But they are not incredibly active.


All the heat inside of them is trapped and has nowhere to go.

All the heat inside of them is trapped and has nowhere to go .


Only on its outer layer can it escape into space.

Only on its outer layer can it escape into space .


But space is mostly empty, so heat can't be transferred by conduction.

But space is mostly empty , so heat ca n't be transferred by conduction .


The only way energy can escape is by radiation.

The only way energy can escape is by radiation .


This is so inefficient that white dwarfs will take trillions of years to cool down, which may make them humanity's last refuge.

This is so inefficient that white dwarfs will take trillions of years to cool down , which may make them humanity 's last refuge .


They might be the last sources of light and energy in a dying universe.

They might be the last sources of light and energy in a dying universe .


According to some estimates, white dwarfs might shine as long as 100 billion billion years, 10 billion times longer than the universe has existed.

According to some estimates , white dwarfs might shine as long as 100 billion billion years , 10 billion times longer than the universe has existed .


Galaxies will have evaporated.


And only then will the first white dwarf turn into the first black dwarf.

And only then will the first white dwarf turn into the first black dwarf .


When this happens, the last hope for life will die off.

When this happens , the last hope for life will die off .


Black dwarfs will be inactive spheres with no energy left to give.

Black dwarfs will be inactive spheres with no energy left to give .


So cold that they'll be near the coldest possible temperature in the universe.

So cold that they 'll be near the coldest possible temperature in the universe .


So dark that they are practically invisible.

So dark that they are practically invisible .


The universe will enter its last stage, heat death, which will leave the universe unrecognizable.

The universe will enter its last stage , heat death , which will leave the universe unrecognizable .


We don't know for sure what will happen with black dwarfs in the end.

We do n't know for sure what will happen with black dwarfs in the end .


If the proton, one of the fundamental parts of atoms, has a limited lifespan, black dwarfs will slowly evaporate over many trillions of years.

If the proton , one of the fundamental parts of atoms , has a limited lifespan , black dwarfs will slowly evaporate over many trillions of years .


If the proton does not decay, black dwarfs will probably turn into spheres of pure iron via quantum tunneling over a timespan so obscenely gigantic that calling it forever is okay.

If the proton does not decay , black dwarfs will probably turn into spheres of pure iron via quantum tunneling over a timespan so obscenely gigantic that calling it forever is okay .


These iron spheres will then travel completely alone through a dark universe.

These iron spheres will then travel completely alone through a dark universe .


Nothing new will happen anymore.


While this may sound kind of dark, this is so far away that for our purposes today, it might as well not happen at all.

While this may sound kind of dark , this is so far away that for our purposes today , it might as well not happen at all .


It doesn't matter what happens in a billion trillion years.

It does n't matter what happens in a billion trillion years .


Right now, we happen to exist at an excellent time.

Right now , we happen to exist at an excellent time .


Our music is finally available on Spotify and iTunes.

Our music is finally available on Spotify and iTunes .


It's composed by our good friends at Epic Mountain, two guys with a studio who make music for a living.

It 's composed by our good friends at Epic Mountain , two guys with a studio who make music for a living .


You can check them out here and follow them on Facebook and Twitter.

You can check them out here and follow them on Facebook and Twitter .


And if you like our videos, please consider supporting us on Patreon.

And if you like our videos , please consider supporting us on Patreon .


It really would be extremely helpful.


If you need an excuse to delay work a little bit longer, here's a playlist with more space videos.

If you need an excuse to delay work a little bit longer , here 's a playlist with more space videos .


One day the last star will die and the universe will turn dark forever.

One day the last star will die and the universe will turn dark forever .


It will probably be a red dwarf, a tiny kind of star that's also one of our best bets to find alien life and might be the last home of humanity before the universe becomes uninhabitable.

It will probably be a red dwarf , a tiny kind of star that 's also one of our best bets to find alien life and might be the last home of humanity before the universe becomes uninhabitable .


So what do we know about them and why are they our last hope?

So what do we know about them and why are they our last hope ?


At least 70% of stars in the universe are red dwarfs.

At least 70 % of stars in the universe are red dwarfs .


They are the tiniest stars out there with only about 7-50% of the mass of our sun, not that much bigger than our planet Jupiter, which is still huge though.

They are the tiniest stars out there with only about 7 - 50 % of the mass of our sun , not that much bigger than our planet Jupiter , which is still huge though .


They are also very dim.


It's impossible to see them with the naked eye.

It 's impossible to see them with the naked eye .


You've never seen one in the night sky.

You 've never seen one in the night sky .


Even with all our technology we can only clearly observe red dwarfs in our neighborhood.

Even with all our technology we can only clearly observe red dwarfs in our neighborhood .


Approximately 20 of the 30 stars close to Earth are red dwarfs.

Approximately 20 of the 30 stars close to Earth are red dwarfs .


Like all stars, red dwarfs fuse hydrogen into helium.

Like all stars , red dwarfs fuse hydrogen into helium .


But while more massive stars accumulate all the fused helium in their cores, red dwarfs stay convective, meaning that the helium and hydrogen constantly mix.

But while more massive stars accumulate all the fused helium in their cores , red dwarfs stay convective , meaning that the helium and hydrogen constantly mix .


So they use up their fuel incredibly slowly before they're extinguished.

So they use up their fuel incredibly slowly before they 're extinguished .


Red dwarfs burn so slowly that their average lifespan is between 1 and 10 trillion years.

Red dwarfs burn so slowly that their average lifespan is between 1 and 10 trillion years .


By comparison, the sun will survive for another 5 billion years.

By comparison , the sun will survive for another 5 billion years .


Because the universe is only 13.75 billion years old, not a single red dwarf has reached later development stages.

Because the universe is only 13.75 billion years old , not a single red dwarf has reached later development stages .


Every single one of the trillions that exist is still a baby.

Every single one of the trillions that exist is still a baby .


Speaking of babies, the smallest star in the entire universe is also a red dwarf because small red dwarfs are right on the verge of being a star at all.

Speaking of babies , the smallest star in the entire universe is also a red dwarf because small red dwarfs are right on the verge of being a star at all .


Just a tiny bit less hydrogen and they are mere brown dwarfs.

Just a tiny bit less hydrogen and they are mere brown dwarfs .


Since our sun will die one day, we'll eventually need to look for a new home.

Since our sun will die one day , we 'll eventually need to look for a new home .


And where there are habitable planets, there might also be aliens.

And where there are habitable planets , there might also be aliens .


The Kepler Space Observatory found that at least half of all red dwarfs host rock planets between half and four times the mass of our Earth.

The Kepler Space Observatory found that at least half of all red dwarfs host rock planets between half and four times the mass of our Earth .


Many of them are in the habitable zone, the area around a star where water can be liquid.

Many of them are in the habitable zone , the area around a star where water can be liquid .


But since red dwarfs burn at relatively cold temperatures, a planet would need to be really close to be hospitable.

But since red dwarfs burn at relatively cold temperatures , a planet would need to be really close to be hospitable .


For example, a planet this close to a star would probably be tidally locked, meaning the same side would always face it.

For example , a planet this close to a star would probably be tidally locked , meaning the same side would always face it .


This side would be incredibly hot, while the shadow side would be frozen, which makes it hard for life to develop.

This side would be incredibly hot , while the shadow side would be frozen , which makes it hard for life to develop .


Although a planet with a big enough ocean might be able to distribute the star's energy and create some kind of stability.

Although a planet with a big enough ocean might be able to distribute the star 's energy and create some kind of stability .


All the gravitational forces of the red dwarf could squeeze the planet and heat it up so much that it might lose all its water over time.

All the gravitational forces of the red dwarf could squeeze the planet and heat it up so much that it might lose all its water over time .


These planets could end up like Venus, a hot, burning hell.

These planets could end up like Venus , a hot , burning hell .


Another problem is that many red dwarfs vary in their energy output.

Another problem is that many red dwarfs vary in their energy output .


They can be covered in star spots that can dim their emitted light by up to 40% for months, which would cause oceans on planets to freeze over.

They can be covered in star spots that can dim their emitted light by up to 40 % for months , which would cause oceans on planets to freeze over .


At other times, they can emit powerful solar flares, sudden outbursts of energy incredibly powerful.

At other times , they can emit powerful solar flares , sudden outbursts of energy incredibly powerful .


These red dwarfs could double their brightness in minutes, which could strip away sizable portions of a planet's atmosphere and burn it, rendering it sterile.

These red dwarfs could double their brightness in minutes , which could strip away sizable portions of a planet 's atmosphere and burn it , rendering it sterile .


On the other hand, their extremely long lifespan is a big plus.

On the other hand , their extremely long lifespan is a big plus .


A red dwarf with just moderate levels of activity could be an amazing place for a planet that hosts life.

A red dwarf with just moderate levels of activity could be an amazing place for a planet that hosts life .


Life on Earth has existed for about 4 billion years, and we have about a billion years left before the sun becomes so hot that complex life on Earth will become impossible.

Life on Earth has existed for about 4 billion years , and we have about a billion years left before the sun becomes so hot that complex life on Earth will become impossible .


We will either die out or leave Earth and look for a new home.

We will either die out or leave Earth and look for a new home .


We could build a civilization for potentially trillions of years around a red dwarf with the right conditions.

We could build a civilization for potentially trillions of years around a red dwarf with the right conditions .


About 5% of the red dwarfs in the Milky Way may host habitable, roughly Earth-sized planets.

About 5 % of the red dwarfs in the Milky Way may host habitable , roughly Earth - sized planets .


That would be more than 4 billion in total.

That would be more than 4 billion in total .


But life may not even need a planet like Earth.

But life may not even need a planet like Earth .


Candidates for life around a red dwarf may be the moons of gas giants, also called super-Earths, really massive, rocky planets.

Candidates for life around a red dwarf may be the moons of gas giants , also called super - Earths , really massive , rocky planets .


All in all, there are an estimated 60 billion potentially habitable planets around red dwarfs, and that's in the Milky Way alone.

All in all , there are an estimated 60 billion potentially habitable planets around red dwarfs , and that 's in the Milky Way alone .


So red dwarfs might become really important for our survival in the future.

So red dwarfs might become really important for our survival in the future .


But everything has to die at some point, even red dwarfs.

But everything has to die at some point , even red dwarfs .


When in trillions of years the life of the last red dwarf in the universe is about to end, it will not be a very spectacular event.

When in trillions of years the life of the last red dwarf in the universe is about to end , it will not be a very spectacular event .


As its hydrogen runs out, it shrinks, becoming a blue dwarf burning out completely.

As its hydrogen runs out , it shrinks , becoming a blue dwarf burning out completely .


After its fuel is spent, it's transformed into a white dwarf, an object about as small as Earth, packed very densely and made of degenerate gases, mostly of helium-4 nuclei.

After its fuel is spent , it 's transformed into a white dwarf , an object about as small as Earth , packed very densely and made of degenerate gases , mostly of helium-4 nuclei .


Having no more source of energy, it will cool extremely slowly over trillions of years until it becomes its final form, a cold black dwarf.

Having no more source of energy , it will cool extremely slowly over trillions of years until it becomes its final form , a cold black dwarf .


White and black dwarfs are so fascinating that they deserve their own video.

White and black dwarfs are so fascinating that they deserve their own video .


Anyway, it's going to be a long time before the last stars in the universe vanish.

Anyway , it 's going to be a long time before the last stars in the universe vanish .


It's kind of uplifting to know that if humanity succeeds in venturing into space, we have plenty of time before the universe turns out the lights.

It 's kind of uplifting to know that if humanity succeeds in venturing into space , we have plenty of time before the universe turns out the lights .


Our videos are made thanks to your support on Patreon.com.

Our videos are made thanks to your support on Patreon.com .


If you want to help us make more of them, we really appreciate your support.

If you want to help us make more of them , we really appreciate your support .


The universe today is happy and healthy, with exciting things going on.

The universe today is happy and healthy , with exciting things going on .


But at some point, the night will turn dark.

But at some point , the night will turn dark .


Everything that once was will peacefully sleep forever.

Everything that once was will peacefully sleep forever .


But what is the last thing that will ever happen, and when will it be?

But what is the last thing that will ever happen , and when will it be ?


It turns out there is such a thing, and you probably haven't heard about it.

It turns out there is such a thing , and you probably have n't heard about it .


Let's travel to the end of the universe and look at the last thing.

Let 's travel to the end of the universe and look at the last thing .


After a messy birth, our universe was a sleepy baby, warm and dark, filled with swirling clouds of hot hydrogen and helium.

After a messy birth , our universe was a sleepy baby , warm and dark , filled with swirling clouds of hot hydrogen and helium .


The story of creation is a story of this gas and where it will end up.

The story of creation is a story of this gas and where it will end up .


Shortly after, the universe got busy making the first generation of stars.

Shortly after , the universe got busy making the first generation of stars .


They were massive and lived violent lives, forging new elements, only to release most of them when they blew up.

They were massive and lived violent lives , forging new elements , only to release most of them when they blew up .


Countless stars were born and refined the gas available in the universe, cycling matter around, each generation giving most of its gas and fresh elements to the next.

Countless stars were born and refined the gas available in the universe , cycling matter around , each generation giving most of its gas and fresh elements to the next .


But not all gas is returned.


Every time a new generation of stars forms, they also make more and more red dwarfs that burn slowly and live for trillions of years.

Every time a new generation of stars forms , they also make more and more red dwarfs that burn slowly and live for trillions of years .


When they die, they don't give their gas back to the universe, but turn it into white dwarfs.

When they die , they do n't give their gas back to the universe , but turn it into white dwarfs .


So red dwarfs lock up more gas forever.

So red dwarfs lock up more gas forever .


More gas is locked forever in other remains of dead stars, neutron stars and black holes, which is bad as it reduces the material available for new stars.

More gas is locked forever in other remains of dead stars , neutron stars and black holes , which is bad as it reduces the material available for new stars .


Today, the universe is a great home for us and will remain so for billions of years.

Today , the universe is a great home for us and will remain so for billions of years .


But most of the gas has been used up or trapped.

But most of the gas has been used up or trapped .


Over 90% of the stars that will ever be born have been born already.

Over 90 % of the stars that will ever be born have been born already .


To get to the last thing to ever happen, all other things need to happen first.

To get to the last thing to ever happen , all other things need to happen first .


The next few hundred billion years will be fun and a great time for galactic exploration.

The next few hundred billion years will be fun and a great time for galactic exploration .


But step by step, large stars and stars like our sun will die out.

But step by step , large stars and stars like our sun will die out .


Eventually, almost all the stars will be red dwarfs slowly dying.

Eventually , almost all the stars will be red dwarfs slowly dying .


In a few trillion years, the cosmic gas will finally have run out.

In a few trillion years , the cosmic gas will finally have run out .


About 88% of the mass of every galaxy will be white dwarfs, 2% neutron stars and black holes, and about 10% gas giants, and sad brown dwarf losers.

About 88 % of the mass of every galaxy will be white dwarfs , 2 % neutron stars and black holes , and about 10 % gas giants , and sad brown dwarf losers .


White dwarfs are the corpses of old stars, not much bigger than Earth, but on average as massive as half our sun, some even much more.

White dwarfs are the corpses of old stars , not much bigger than Earth , but on average as massive as half our sun , some even much more .


This makes them the third densest objects in the universe, after neutron stars and black holes.

This makes them the third densest objects in the universe , after neutron stars and black holes .


Since they used to be active stars, their surface can be as hot as 150,000 degrees.

Since they used to be active stars , their surface can be as hot as 150,000 degrees .


White dwarfs are dim, hot, dense spheres, and they're the ones that don't do anything anymore.

White dwarfs are dim , hot , dense spheres , and they 're the ones that do n't do anything anymore .


But eventually, even white dwarfs will die because they're slowly losing their heat.

But eventually , even white dwarfs will die because they 're slowly losing their heat .


It takes at least 10 trillion years, more than 700 times longer than the current age of the universe.

It takes at least 10 trillion years , more than 700 times longer than the current age of the universe .


As they do their cooling down, the universe around them will irreversibly grow dark, as more and more white dwarfs burn out and turn into dead husks, black dwarfs.

As they do their cooling down , the universe around them will irreversibly grow dark , as more and more white dwarfs burn out and turn into dead husks , black dwarfs .


Over trillions and trillions of years, every object in every galaxy is eventually either ejected into the void, or its orbit decays and it will fall into the central black hole and be destroyed.

Over trillions and trillions of years , every object in every galaxy is eventually either ejected into the void , or its orbit decays and it will fall into the central black hole and be destroyed .


In about a quintillion years, all galaxies have evaporated and every object is on its own,

In about a quintillion years , all galaxies have evaporated and every object is on its own ,


Still, there are things that will happen.

Still , there are things that will happen .


Black holes are dying, slowly.


They'll fizzle away by emitting Hawking radiation, until they're so small that they die in a final flash of light.

They 'll fizzle away by emitting Hawking radiation , until they 're so small that they die in a final flash of light .


This will take about a googol years, 10 to the power of 100 years, until the last supermassive black hole dies.

This will take about a googol years , 10 to the power of 100 years , until the last supermassive black hole dies .


Maybe some living beings could have survived around black holes, but even this science fiction option ends now.

Maybe some living beings could have survived around black holes , but even this science fiction option ends now .


After this unsettling amount of time, we're not even close to the end.

After this unsettling amount of time , we 're not even close to the end .


Now is the time of the black hole.


It turns out there's some weird physics going on inside the dead husk of stars.

It turns out there 's some weird physics going on inside the dead husk of stars .


A black dwarf is a sphere the size of Earth, as massive as a star, but almost as cold as absolute zero.

A black dwarf is a sphere the size of Earth , as massive as a star , but almost as cold as absolute zero .


Stars stay alive because of their intense heat in their cores.

Stars stay alive because of their intense heat in their cores .


So why do black dwarfs not collapse into a black hole?

So why do black dwarfs not collapse into a black hole ?


What keeps them together?


Deep inside a black dwarf, matter is squeezed to densities millions of times greater than anything we see on Earth.

Deep inside a black dwarf , matter is squeezed to densities millions of times greater than anything we see on Earth .


The pressure is so great that electrons can't combine with nuclei to form atoms.

The pressure is so great that electrons ca n't combine with nuclei to form atoms .


Instead, matter is weird, degenerate.

Instead , matter is weird , degenerate .


The nuclei are compressed by the weight of the star, locked into a rigid lattice, while the electrons form a plasma between them.

The nuclei are compressed by the weight of the star , locked into a rigid lattice , while the electrons form a plasma between them .


And these electrons hold the star together.

And these electrons hold the star together .


We're simplifying, but imagine matter as a subway train and electrons as passengers.

We 're simplifying , but imagine matter as a subway train and electrons as passengers .


If there are empty seats, passengers spread out because they care a lot about their personal space.

If there are empty seats , passengers spread out because they care a lot about their personal space .


But as a black dwarf is so incredibly dense, this is like squishing more and more passengers into our train.

But as a black dwarf is so incredibly dense , this is like squishing more and more passengers into our train .


Gravity is pushing in, trying to collapse it.

Gravity is pushing in , trying to collapse it .


The passengers are forced to sit and stand close together, which they hate.

The passengers are forced to sit and stand close together , which they hate .


And so the passengers, our electrons, try to push out against gravity as hard as they can.

And so the passengers , our electrons , try to push out against gravity as hard as they can .


This way, the electrons that are having a horrible time in the crowded train that's the black dwarf, hold up the star.

This way , the electrons that are having a horrible time in the crowded train that 's the black dwarf , hold up the star .


Everything else in the universe may have crumbled already, but these tiny particles push against each other, until the end of time.

Everything else in the universe may have crumbled already , but these tiny particles push against each other , until the end of time .


Simplifying a lot, when particles get close enough, sometimes they can jump at each other and fuse together.

Simplifying a lot , when particles get close enough , sometimes they can jump at each other and fuse together .


This happens constantly in stars because of their intense heat.

This happens constantly in stars because of their intense heat .


It's one of the key reasons stars can fuse elements into new ones.

It 's one of the key reasons stars can fuse elements into new ones .


But it also happens at a temperature near absolute zero.

But it also happens at a temperature near absolute zero .


This is the final step to creating the last interesting thing to ever happen in our universe.

This is the final step to creating the last interesting thing to ever happen in our universe .


Here, in this lone black dwarf, something fantastic occurs.

Here , in this lone black dwarf , something fantastic occurs .


Nothing happens for a trillion years.


Can you imagine that?


Two carbon nuclei combined by quantum tunneling to become magnesium.

Two carbon nuclei combined by quantum tunneling to become magnesium .


Another 100 trillion years pass.


It happens again.


Oh, two oxygen nuclei combine into silicon.

Oh , two oxygen nuclei combine into silicon .


As eons pass, the nuclei in the frozen black dwarf slowly combine.

As eons pass , the nuclei in the frozen black dwarf slowly combine .


And these take even longer to fuse, but given enough time, they eventually will.

And these take even longer to fuse , but given enough time , they eventually will .


Remember the breathtaking amount of time it took for a supermassive black hole to evaporate?

Remember the breathtaking amount of time it took for a supermassive black hole to evaporate ?


That's a brief moment in comparison to what's going on here.

That 's a brief moment in comparison to what 's going on here .


The difference between a second and trillions of years has lost its meaning.

The difference between a second and trillions of years has lost its meaning .


Over a time so absurd that it has no name, nuclei keep fusing into heavier elements.

Over a time so absurd that it has no name , nuclei keep fusing into heavier elements .


Until, when silicon nuclei fuse, they form nickel-56.

Until , when silicon nuclei fuse , they form nickel-56 .


Nickel-56 is radioactive, which means it's unstable.

Nickel-56 is radioactive , which means it 's unstable .


And when it eventually decays and turns into iron, it emits two positrons, antimatter electrons.

And when it eventually decays and turns into iron , it emits two positrons , antimatter electrons .


And these two positrons find two electrons and annihilate them and themselves.

And these two positrons find two electrons and annihilate them and themselves .


Remember how the uncomfortable electrons produce the pressure to hold the star together?

Remember how the uncomfortable electrons produce the pressure to hold the star together ?


Destroying the electron means fewer friends to help them hold up the star.

Destroying the electron means fewer friends to help them hold up the star .


Losing an electron does not give them more space to scratch their butts, it just makes gravity squeeze harder, the walls closing in on those that remain.

Losing an electron does not give them more space to scratch their butts , it just makes gravity squeeze harder , the walls closing in on those that remain .


In the case of the most massive black dwarfs, this is catastrophic.

In the case of the most massive black dwarfs , this is catastrophic .


Bit by bit, the black dwarf turns into a sphere of iron, and more electrons are annihilated.

Bit by bit , the black dwarf turns into a sphere of iron , and more electrons are annihilated .


For at least 10 to the power of 1,000 years, almost but not quite forever,  there's no visible change in the entire universe.

For at least 10 to the power of 1,000 years , almost but not quite forever , there 's no visible change in the entire universe .


And then, finally, the last thing to ever happen, happens.

And then , finally , the last thing to ever happen , happens .


The black dwarf has lost one too many electrons.

The black dwarf has lost one too many electrons .


It can no longer support its immense mass and goes into an uncontrolled collapse, a supernova.

It can no longer support its immense mass and goes into an uncontrolled collapse , a supernova .


It first implodes, and then explodes as bright as a galaxy and fills the empty universe with light again.

It first implodes , and then explodes as bright as a galaxy and fills the empty universe with light again .


A beautiful moment nobody will get to enjoy.

A beautiful moment nobody will get to enjoy .


And then, as quickly as it began, it's all over.

And then , as quickly as it began , it 's all over .


That was the last thing that will ever happen.

That was the last thing that will ever happen .


The universe may now be truly dead.


But don't be bummed out about it.


This is so far away in the future that forever hardly describes it.

This is so far away in the future that forever hardly describes it .


Today, the universe is the best place it could be for us.

Today , the universe is the best place it could be for us .


And you can sleep tight tonight, knowing the last interesting thing that will ever happen is forever long away.

And you can sleep tight tonight , knowing the last interesting thing that will ever happen is forever long away .


Imagine the excitement of a trip to the museum or an amazing theme park, but delivered to your doorstep with everything you need neatly packed inside.

Imagine the excitement of a trip to the museum or an amazing theme park , but delivered to your doorstep with everything you need neatly packed inside .


There are different lines designed for kids of all ages and interests, so there's something for everyone.

There are different lines designed for kids of all ages and interests , so there 's something for everyone .


Like us, KiwiCo spends a ridiculous amount of time on fine-tuning each crate.

Like us , KiwiCo spends a ridiculous amount of time on fine - tuning each crate .


Every one of their 2,000 available projects took more than 1,000 hours to develop by experts and is tested by kids.

Every one of their 2,000 available projects took more than 1,000 hours to develop by experts and is tested by kids .


We really liked the KiwiCo Tinker Crate line, which gives you a hands-on engineering project with all of the educational and instructional information you need to complete the project at home.

We really liked the KiwiCo Tinker Crate line , which gives you a hands - on engineering project with all of the educational and instructional information you need to complete the project at home .


We might also have decided to just keep some of them around the office and not hand the extras to any kids we know.

We might also have decided to just keep some of them around the office and not hand the extras to any kids we know .


If you want to try out KiwiCo and get the best deal, click on the link in the info box or use the code KURZFESAGT to get 50% off your first month.

If you want to try out KiwiCo and get the best deal , click on the link in the info box or use the code KURZFESAGT to get 50 % off your first month .


Or if you want to try it out first, they also offer individual crates in the KiwiCo store.

Or if you want to try it out first , they also offer individual crates in the KiwiCo store .


At Kurzgesagt, we love to spark curiosity.

At Kurzgesagt , we love to spark curiosity .


And we love to work with companies that share this goal.

And we love to work with companies that share this goal .


The moons of Mars explained.


Mars has two moons, Phobos and Deimos.

Mars has two moons , Phobos and Deimos .


They are really tiny.


Although, tiny is a matter of opinion.

Although , tiny is a matter of opinion .


Their surface areas are close to some of the smallest states on Earth, like Luxembourg and Malta.

Their surface areas are close to some of the smallest states on Earth , like Luxembourg and Malta .


Although Phobos and Deimos are in no way lightweight, in reality their gravitational pull isn't even strong enough to bring them into spherical form,

Although Phobos and Deimos are in no way lightweight , in reality their gravitational pull is n't even strong enough to bring them into spherical form ,


so they look more like huge potatoes than moons.

so they look more like huge potatoes than moons .


The most popular theory of their origin is that they were once part of the asteroid belt until Jupiter's massive gravity kicked them out of it, so Mars could catch them.

The most popular theory of their origin is that they were once part of the asteroid belt until Jupiter 's massive gravity kicked them out of it , so Mars could catch them .


Phobos orbits Mars at an average distance of 9,400 km once every 7.5 hours.

Phobos orbits Mars at an average distance of 9,400 km once every 7.5 hours .


It's on a collision course and gets 2 meters closer to Mars every year.

It 's on a collision course and gets 2 meters closer to Mars every year .


In 50 to 100 million years, it will either be ripped to pieces by Mars' gravity and be transformed into a beautiful ring, or it will crash into Mars.

In 50 to 100 million years , it will either be ripped to pieces by Mars ' gravity and be transformed into a beautiful ring , or it will crash into Mars .


The energy released in this collision would kill everything on the small planet, so if there are humans on Mars by then, they should build very strong bunkers.

The energy released in this collision would kill everything on the small planet , so if there are humans on Mars by then , they should build very strong bunkers .


Smaller Deimos, on the other hand, is slowly escaping Mars.

Smaller Deimos , on the other hand , is slowly escaping Mars .


Eventually, it will fly off into space and leave a lonely red planet behind.

Eventually , it will fly off into space and leave a lonely red planet behind .


So, in a few hundred million years, Mars will be moonless and on its own, unless it manages to catch itself another asteroid.

So , in a few hundred million years , Mars will be moonless and on its own , unless it manages to catch itself another asteroid .


Neutron stars are the densest things that are not black holes.

Neutron stars are the densest things that are not black holes .


In their cores, we might find the most dangerous substance in existence.

In their cores , we might find the most dangerous substance in existence .


Or it could teach us about how the universe began.

Or it could teach us about how the universe began .


To understand how extreme strange matter really is, we first need to get a few basics.

To understand how extreme strange matter really is , we first need to get a few basics .


What is a neutron star?


And how does strange matter break the rules of the universe?

And how does strange matter break the rules of the universe ?


To get all of this into one video, we'll grossly oversimplify a few things, but we'll provide you with further reading if you want more details.

To get all of this into one video , we 'll grossly oversimplify a few things , but we 'll provide you with further reading if you want more details .


A neutron star is what remains after a very massive star explodes in a supernova.

A neutron star is what remains after a very massive star explodes in a supernova .


When this happens, the star's core collapses under its own gravity with such a strong inward force that it squeezes nuclei and particles together violently.

When this happens , the star 's core collapses under its own gravity with such a strong inward force that it squeezes nuclei and particles together violently .


Electrons are pushed into protons, so they merge and turn into neutrons.

Electrons are pushed into protons , so they merge and turn into neutrons .


All the nothing inside of atoms is suddenly completely filled with particles that really don't want to be close to each other, but have no choice.

All the nothing inside of atoms is suddenly completely filled with particles that really do n't want to be close to each other , but have no choice .


They desperately push back against gravity, against the collapse.

They desperately push back against gravity , against the collapse .


If gravity wins, they will become a black hole.

If gravity wins , they will become a black hole .


If they win, they become a neutron star.

If they win , they become a neutron star .


This makes neutron stars like giant atomic nuclei the size of a city, but holding the mass of our sun.

This makes neutron stars like giant atomic nuclei the size of a city , but holding the mass of our sun .


And here, things get weird.


The environment in the core of neutron stars is so extreme that the rules of nuclear physics change.

The environment in the core of neutron stars is so extreme that the rules of nuclear physics change .


And this could lead to a strange and extremely dangerous substance.

And this could lead to a strange and extremely dangerous substance .


But let's not get ahead of ourselves.


We first need to know the rules before we learn how they can be broken.

We first need to know the rules before we learn how they can be broken .


Protons and neutrons, the particles making up the nuclei of atoms, are made up of smaller particles called quarks.

Protons and neutrons , the particles making up the nuclei of atoms , are made up of smaller particles called quarks .


Quarks really don't want to be alone.


They are what we call confined.


You can try to separate them, but the harder you pull, the harder they try to pull themselves back together.

You can try to separate them , but the harder you pull , the harder they try to pull themselves back together .


If you use a lot of energy, they just use this energy to create new quarks.

If you use a lot of energy , they just use this energy to create new quarks .


Quarks only exist together as the building blocks of other particles and have never been observed by themselves.

Quarks only exist together as the building blocks of other particles and have never been observed by themselves .


They come in many types, but only two appear to make stable matter.

They come in many types , but only two appear to make stable matter .


The up and down quarks found in protons and neutrons.

The up and down quarks found in protons and neutrons .


All other quarks seem to decay away quickly.

All other quarks seem to decay away quickly .


But this may be different inside neutron stars.

But this may be different inside neutron stars .


The forces operating in their cores are so extreme that they are actually similar to the universe shortly after the Big Bang.

The forces operating in their cores are so extreme that they are actually similar to the universe shortly after the Big Bang .


Neutron star cores are like fossils, which can let us peer back in time to the beginning of everything.

Neutron star cores are like fossils , which can let us peer back in time to the beginning of everything .


So learning how quarks behave inside a neutron star is a way of understanding the very nature of the universe itself.

So learning how quarks behave inside a neutron star is a way of understanding the very nature of the universe itself .


One hypothesis is that inside a neutron star core, protons and neutrons de-confine.

One hypothesis is that inside a neutron star core , protons and neutrons de - confine .


All the particles crammed shoulder to shoulder dissolve and melt into a sort of bath of quarks.

All the particles crammed shoulder to shoulder dissolve and melt into a sort of bath of quarks .


Uncountable numbers of particles become one giant thing made purely from quarks.

Uncountable numbers of particles become one giant thing made purely from quarks .


A star made from this is called a quark star, though from the outside it may not look any different than a regular neutron star.

A star made from this is called a quark star , though from the outside it may not look any different than a regular neutron star .


Now we can finally talk about the most dangerous substance.

Now we can finally talk about the most dangerous substance .


If the pressure inside a quark star is great enough, it may get stranger.

If the pressure inside a quark star is great enough , it may get stranger .


In the cores of neutron stars, some of the quarks may be converted into strange quarks.

In the cores of neutron stars , some of the quarks may be converted into strange quarks .


Strange quarks have bizarre nuclear properties, and they are heavier, and for the lack of a better word, stronger.

Strange quarks have bizarre nuclear properties , and they are heavier , and for the lack of a better word , stronger .


If they turn up, they could create strange matter.

If they turn up , they could create strange matter .


Strange matter might be the ideal state of matter.

Strange matter might be the ideal state of matter .


If this is the case, we have a problem.

If this is the case , we have a problem .


It might be infectious.


Every piece of matter it touches might be so impressed by its stability that it would immediately turn it into strange matter too.

Every piece of matter it touches might be so impressed by its stability that it would immediately turn it into strange matter too .


Protons and neutrons would dissolve and become part of the quark bath which frees energy and creates more strange matter.

Protons and neutrons would dissolve and become part of the quark bath which frees energy and creates more strange matter .


The only way to get rid of it would be to throw it into a black hole.

The only way to get rid of it would be to throw it into a black hole .


But then again, who cares?


All of it is inside neutron stars.


they spew out tremendous amounts of their insides, some of which could include little droplets of strange matter called strangelets.

they spew out tremendous amounts of their insides , some of which could include little droplets of strange matter called strangelets .


Strangelets are as dense as the core of a neutron star.

Strangelets are as dense as the core of a neutron star .


They could be really small, maybe even subatomic, but even the largest strangelets wouldn't be any bigger than a rocket.

They could be really small , maybe even subatomic , but even the largest strangelets would n't be any bigger than a rocket .


These strangelets would drift through the galaxy for millions or billions of years until they meet a star or planet by chance.

These strangelets would drift through the galaxy for millions or billions of years until they meet a star or planet by chance .


If one were to strike Earth, it would immediately start converting it into strange matter.

If one were to strike Earth , it would immediately start converting it into strange matter .


The more it converts, the more it would grow.

The more it converts , the more it would grow .


Ultimately, all of the atoms making up Earth would be converted.

Ultimately , all of the atoms making up Earth would be converted .


Earth would become a hot clump of strange matter the size of an asteroid.

Earth would become a hot clump of strange matter the size of an asteroid .


If a strangelet strikes the Sun, it would collapse into a strange star, eating through it like fire through a dry forest.

If a strangelet strikes the Sun , it would collapse into a strange star , eating through it like fire through a dry forest .


This would not change the Sun's mass much, but it would become way less bright, so Earth would freeze to death.

This would not change the Sun 's mass much , but it would become way less bright , so Earth would freeze to death .


And like a tiny virus, we'd have no way to see a strangelet coming.

And like a tiny virus , we 'd have no way to see a strangelet coming .


Worse still, some theories suggest strangelets are more than common, outnumbering all stars in the galaxy.

Worse still , some theories suggest strangelets are more than common , outnumbering all stars in the galaxy .


These strangelets could have formed very early after the Big Bang, when it was as hot and dense as a neutron star core everywhere.

These strangelets could have formed very early after the Big Bang , when it was as hot and dense as a neutron star core everywhere .


They might be clumping around the gravity of galaxies as the universe expanded and evolved.

They might be clumping around the gravity of galaxies as the universe expanded and evolved .


Strangelets could even be so numerous and massive that they might actually be the dark matter we suspect holds galaxies together.

Strangelets could even be so numerous and massive that they might actually be the dark matter we suspect holds galaxies together .


This is speculation, and the Earth and Sun and planets haven't been consumed in a wildfire of strangelets in the past few billion years,

This is speculation , and the Earth and Sun and planets have n't been consumed in a wildfire of strangelets in the past few billion years ,


so the odds seem good that it won't happen any time soon.

so the odds seem good that it wo n't happen any time soon .


Understanding these strange objects today may be the key to understanding the birth of our universe and why it grew to look the way it does now.

Understanding these strange objects today may be the key to understanding the birth of our universe and why it grew to look the way it does now .


When scientists first started playing with magnets and wires and thinking about electrons, they had no idea how technology would evolve in the next hundred years.

When scientists first started playing with magnets and wires and thinking about electrons , they had no idea how technology would evolve in the next hundred years .


The scientists thinking about the cores of neutron stars and strange matter today may be setting up humans for a future beyond our wildest imaginations.

The scientists thinking about the cores of neutron stars and strange matter today may be setting up humans for a future beyond our wildest imaginations .


Time will tell.


So while you're waiting to see if the universe gets destroyed, you might still want to find out more about it.

So while you 're waiting to see if the universe gets destroyed , you might still want to find out more about it .


We've got you.


Our friends from Brilliant can be your insight into a whole world of science, black holes and all.

Our friends from Brilliant can be your insight into a whole world of science , black holes and all .


Brilliant is a website that helps you tackle science in a practical way, with interactive problem-solving courses and daily challenges in maths, logic and engineering.

Brilliant is a website that helps you tackle science in a practical way , with interactive problem - solving courses and daily challenges in maths , logic and engineering .


Each problem gives you all the tools you need to crack complex topics all by yourself.

Each problem gives you all the tools you need to crack complex topics all by yourself .


It's learning by doing, but with your brain instead of your hands.

It 's learning by doing , but with your brain instead of your hands .


Use your curiosity to get to the bottom of puzzles and courses about things like classical mechanics, astronomy, gravitational physics and much more.

Use your curiosity to get to the bottom of puzzles and courses about things like classical mechanics , astronomy , gravitational physics and much more .


If you click the link in the description or visit brilliant.org/nutshell, you can sign up for free and learn more things than you can imagine.

If you click the link in the description or visit brilliant.org/nutshell , you can sign up for free and learn more things than you can imagine .


And there's an extra perk for Kurzgesagt viewers.

And there 's an extra perk for Kurzgesagt viewers .


The first 688 people to use the link get 20% off their annual membership, which lets you view all the daily problems in the archives and unlock every course.

The first 688 people to use the link get 20 % off their annual membership , which lets you view all the daily problems in the archives and unlock every course .


Brilliant helps you end your day a little smarter.

Brilliant helps you end your day a little smarter .


You might get hooked on the experience.

You might get hooked on the experience .


GMOs are one of the most controversial areas of science.

GMOs are one of the most controversial areas of science .


Genetic engineering is used in many fields, but even though medical applications like GM insulin are widely accepted, the debate heats up when it comes to food and agriculture.

Genetic engineering is used in many fields , but even though medical applications like GM insulin are widely accepted , the debate heats up when it comes to food and agriculture .


Why is that? Why is the same thing treated so differently?

Why is that ? Why is the same thing treated so differently ?


Let's try to get to the bottom of this and explore the facts, the fears and the future of GMOs.

Let 's try to get to the bottom of this and explore the facts , the fears and the future of GMOs .


Humans have been genetically modifying plants and animals for thousands of years.

Humans have been genetically modifying plants and animals for thousands of years .


Maybe a few of your crops had very good yields, maybe one of your wolves was especially loyal.

Maybe a few of your crops had very good yields , maybe one of your wolves was especially loyal .


So you did the smart thing and bred the plants and animals that had traits beneficial to you.

So you did the smart thing and bred the plants and animals that had traits beneficial to you .


Traits are just an expression of genes.

Traits are just an expression of genes .


So with each generation, those genes got more pronounced.

So with each generation , those genes got more pronounced .


After thousands of years, almost every single plant and animal around us is vastly different from its pre-domesticated state.

After thousands of years , almost every single plant and animal around us is vastly different from its pre - domesticated state .


If humans have been changing genes for millennia, what makes a so-called genetically modified organism or GMO different?

If humans have been changing genes for millennia , what makes a so - called genetically modified organism or GMO different ?


Selective breeding is basically hoping for lucky hits.

Selective breeding is basically hoping for lucky hits .


Genetic engineering eliminates this factor.

Genetic engineering eliminates this factor .


We can choose the traits we want, make fruit grow bigger, immune to pests and so on.

We can choose the traits we want , make fruit grow bigger , immune to pests and so on .


So why are people concerned about them?

So why are people concerned about them ?


Let's start with one of the most common objections to GMOs.

Let 's start with one of the most common objections to GMOs .


There is a method that might guarantee complete prevention but is a big anti-GMO argument by itself.

There is a method that might guarantee complete prevention but is a big anti - GMO argument by itself .


The idea is that they could produce sterile plants requiring farmers to buy new seeds every year.

The idea is that they could produce sterile plants requiring farmers to buy new seeds every year .


The very concept of this, however, caused a public outcry, stopping the technology being put to use.

The very concept of this , however , caused a public outcry , stopping the technology being put to use .


This brings us back to the unintentional spreading of engineered DNA.

This brings us back to the unintentional spreading of engineered DNA .


There have been cases of GMOs growing where they weren't planted and traces of modified genes found in foreign crops.

There have been cases of GMOs growing where they were n't planted and traces of modified genes found in foreign crops .


But GM plants can't run wild entirely.

But GM plants ca n't run wild entirely .


Many crops pollinate themselves, and all crops have to be related to mingle.

Many crops pollinate themselves , and all crops have to be related to mingle .


There are also cultural methods like buffer zones to keep unintentional crossing at a minimum.

There are also cultural methods like buffer zones to keep unintentional crossing at a minimum .


But if it's possible in principle that a GMO could unintentionally cross with a non-GMO, there's actually a more important question.

But if it 's possible in principle that a GMO could unintentionally cross with a non - GMO , there 's actually a more important question .


Is food that comes from GM crops different to food from non-GM crops?

Is food that comes from GM crops different to food from non - GM crops ?


This question has been a major concern from the very beginning.

This question has been a major concern from the very beginning .