Humanity got a similar wish granted when we learned how to turn brown stinky goo into magic.

Humanity got a similar wish granted when we learned how to turn brown stinky goo into magic .


Cheap, sterile and convenient, it changed our lives.

Cheap , sterile and convenient , it changed our lives .


But this wonder of technology got a little out of hand.

But this wonder of technology got a little out of hand .


Plastic has saturated our environment.


It has invaded the animals we eat and now it's finding its way into our bodies.

It has invaded the animals we eat and now it 's finding its way into our bodies .


What is plastic?


For most of our history, humans used stuff we found in nature to build the things we needed.

For most of our history , humans used stuff we found in nature to build the things we needed .


But the invention of plastic roughly 100 years ago completely changed our world.

But the invention of plastic roughly 100 years ago completely changed our world .


Plastic is made from polymers, long, repeating chains of molecule groups.

Plastic is made from polymers , long , repeating chains of molecule groups .


In nature, polymers exist everywhere.


But it's also possible to create them.

But it 's also possible to create them .


By breaking down crude oil into its components and rearranging them, we can form new synthetic polymers.

By breaking down crude oil into its components and rearranging them , we can form new synthetic polymers .


Synthetic polymers have extraordinary traits.

Synthetic polymers have extraordinary traits .


They are lightweight, durable and can be molded into almost any shape.

They are lightweight , durable and can be molded into almost any shape .


Not requiring time-consuming manual work, plastic can be easily mass-produced and its raw materials are available in vast amounts and incredibly cheaply.

Not requiring time - consuming manual work , plastic can be easily mass - produced and its raw materials are available in vast amounts and incredibly cheaply .


And so the golden era of plastics began.

And so the golden era of plastics began .


Bakelite was used for mechanical parts, PVC for plumbing, electric gears and cases, acrylic as a shatter-resistant alternative to glass and nylon for stockings and war equipment.

Bakelite was used for mechanical parts , PVC for plumbing , electric gears and cases , acrylic as a shatter - resistant alternative to glass and nylon for stockings and war equipment .


Today, almost everything is at least partly made from plastic.

Today , almost everything is at least partly made from plastic .


Plastic has long ceased to be a revolutionary material.

Plastic has long ceased to be a revolutionary material .


Instead, it became trash.


We don't think about this fact a lot.


Plastic just appears and goes away.


Unfortunately, it doesn't.


Since synthetic polymers are so durable, plastic takes between 500 and 1,000 years to break down.

Since synthetic polymers are so durable , plastic takes between 500 and 1,000 years to break down .


But somehow, we collectively decided to use this super-tough material for things meant to be thrown away.

But somehow , we collectively decided to use this super - tough material for things meant to be thrown away .


40% of plastics are used for packaging.

40 % of plastics are used for packaging .


In the US, packaging makes up one-third of all the waste that is generated annually.

In the US , packaging makes up one - third of all the waste that is generated annually .


Since its invention, we have produced about 8.3 billion metric tons of plastic, 335 million tons in 2016 alone.

Since its invention , we have produced about 8.3 billion metric tons of plastic , 335 million tons in 2016 alone .


More than 6.3 billion metric tons of plastic have become waste since 1907.

More than 6.3 billion metric tons of plastic have become waste since 1907 .


Piled up in one place, that makes a cube with a side length of 1.9 kilometers.

Piled up in one place , that makes a cube with a side length of 1.9 kilometers .


So, what did we do with all this waste?

So , what did we do with all this waste ?


9% was recycled.


12% burned.


But 79% of it is sticking around still.

But 79 % of it is sticking around still .


A lot ends up in the ocean, around 8 million tons a year.

A lot ends up in the ocean , around 8 million tons a year .


That's so much plastic that it will outweigh all the fish in the ocean by 2050.

That 's so much plastic that it will outweigh all the fish in the ocean by 2050 .


Because it's everywhere, marine animals keep getting trapped in plastic and swallowing it.

Because it 's everywhere , marine animals keep getting trapped in plastic and swallowing it .


In 2015 already, 90% of seabirds had eaten plastic.

In 2015 already , 90 % of seabirds had eaten plastic .


Many animals starve with stomachs full of indigestible trash.

Many animals starve with stomachs full of indigestible trash .


In 2018, a dead sperm whale washed up in Spain.

In 2018 , a dead sperm whale washed up in Spain .


He had eaten 32 kilos of plastic bags, nets and a drum.

He had eaten 32 kilos of plastic bags , nets and a drum .


While this is tragic and makes for great magazine covers, there's an even more widespread, invisible form of plastic.

While this is tragic and makes for great magazine covers , there 's an even more widespread , invisible form of plastic .


Microplastics are pieces smaller than 5 millimeters.

Microplastics are pieces smaller than 5 millimeters .


Some of them are used in cosmetics or toothpaste, but most result from floating waste that is constantly exposed to UV radiation and crumbles into smaller and smaller pieces.

Some of them are used in cosmetics or toothpaste , but most result from floating waste that is constantly exposed to UV radiation and crumbles into smaller and smaller pieces .


51 trillion such particles float in the ocean, where they are even more easily swallowed by all kinds of marine life.

51 trillion such particles float in the ocean , where they are even more easily swallowed by all kinds of marine life .


This has raised concerns among scientists, especially about health risks from the chemicals that are added to plastic.

This has raised concerns among scientists , especially about health risks from the chemicals that are added to plastic .


BPA, for example, makes plastic bottles transparent, but there's also evidence that it interferes with our hormonal system.

BPA , for example , makes plastic bottles transparent , but there 's also evidence that it interferes with our hormonal system .


DEHP makes plastics more flexible, but may cause cancer.

DEHP makes plastics more flexible , but may cause cancer .


It would be pretty bad if microplastics are toxic because they travel up the food chain.

It would be pretty bad if microplastics are toxic because they travel up the food chain .


Zooplankton eat microplastic.


Small fish eat zooplankton.


And they all land on our plate.


Microplastics have been found in honey, in sea salt, in beer, in tap water and in the household dust around us.

Microplastics have been found in honey , in sea salt , in beer , in tap water and in the household dust around us .


8 out of 10 babies and nearly all adults have measurable amounts of phthalates, a common plastic additive, in their bodies.

8 out of 10 babies and nearly all adults have measurable amounts of phthalates , a common plastic additive , in their bodies .


And 93% of people have BPA in their urine.

And 93 % of people have BPA in their urine .


There is little science about this so far, and right now it's inconclusive.

There is little science about this so far , and right now it 's inconclusive .


We need a lot more research before panic is justified.

We need a lot more research before panic is justified .


But it is safe to say that a lot of stuff happened that we didn't plan for.

But it is safe to say that a lot of stuff happened that we did n't plan for .


And we have lost control over plastic to a certain extent, which is kind of scary.

And we have lost control over plastic to a certain extent , which is kind of scary .


Unfortunately, it's a bit more complicated than that.

Unfortunately , it 's a bit more complicated than that .


Plastic pollution is not the only environmental challenge we face.

Plastic pollution is not the only environmental challenge we face .


Some of the substitutes we'd use for plastic have a higher environmental impact in other ways.

Some of the substitutes we 'd use for plastic have a higher environmental impact in other ways .


For example, according to a recent study by the Danish government, making a single-use plastic bag requires so little energy and produces far lower carbon dioxide emissions compared to a reusable cotton bag that you need to use your cotton bag 7,100 times before it would have a lower impact on the environment than the plastic bag.

For example , according to a recent study by the Danish government , making a single - use plastic bag requires so little energy and produces far lower carbon dioxide emissions compared to a reusable cotton bag that you need to use your cotton bag 7,100 times before it would have a lower impact on the environment than the plastic bag .


We're left with a complex process of trade-offs.

We 're left with a complex process of trade - offs .


Everything has an impact somehow, and it's hard to find the right balance between them.

Everything has an impact somehow , and it 's hard to find the right balance between them .


Plastic also helps solve problems that we don't have very good answers for at the moment.

Plastic also helps solve problems that we do n't have very good answers for at the moment .


Globally, one-third of all food that's produced is never eaten and ends up rotting away on landfills where it produces methane.

Globally , one - third of all food that 's produced is never eaten and ends up rotting away on landfills where it produces methane .


And the best way of preventing food from spoiling and avoiding unnecessary waste is still plastic packaging.

And the best way of preventing food from spoiling and avoiding unnecessary waste is still plastic packaging .


It's also important to note where the vast majority of the world's plastic pollution is coming from right now.

It 's also important to note where the vast majority of the world 's plastic pollution is coming from right now .


90% of all plastic waste entering the ocean through rivers comes from just 10 rivers in Asia and Africa.

90 % of all plastic waste entering the ocean through rivers comes from just 10 rivers in Asia and Africa .


The Yangtze in China alone flushes 1.5 million tons of plastic into the ocean each year.

The Yangtze in China alone flushes 1.5 million tons of plastic into the ocean each year .


Countries like China, India, Algeria or Indonesia industrialized at an impressive pace in the last few decades, transforming the lives of billions of people.

Countries like China , India , Algeria or Indonesia industrialized at an impressive pace in the last few decades , transforming the lives of billions of people .


This development was so fast that the garbage disposal infrastructure couldn't keep up with collecting and recycling all the new waste this broad.

This development was so fast that the garbage disposal infrastructure could n't keep up with collecting and recycling all the new waste this broad .


If politicians in Europe and the US want to address this issue, investing in infrastructure in developing countries is just as important as fighting plastic pollution at home with campaigns and redesigning products to minimize unnecessary plastic production.

If politicians in Europe and the US want to address this issue , investing in infrastructure in developing countries is just as important as fighting plastic pollution at home with campaigns and redesigning products to minimize unnecessary plastic production .


The bottom line is, as long as we don't address plastic pollution from a global perspective, we will not solve it.

The bottom line is , as long as we do n't address plastic pollution from a global perspective , we will not solve it .


Plastic pollution is a complicated problem.

Plastic pollution is a complicated problem .


We found a magic material and we had a really good time with it.

We found a magic material and we had a really good time with it .


But we need to be careful, or just like Midas, we'll end up in a world that we didn't wish for.

But we need to be careful , or just like Midas , we 'll end up in a world that we did n't wish for .


Your individual daily actions still have a huge impact.

Your individual daily actions still have a huge impact .


What you do matters.


Refuse disposable plastics.


Convince your friends and family to do the same.

Convince your friends and family to do the same .


Pressure companies and politicians to take the necessary steps to keep our oceans clean and our food safe.

Pressure companies and politicians to take the necessary steps to keep our oceans clean and our food safe .


Together we can beat plastic pollution.

Together we can beat plastic pollution .


This video was a collaboration with UN Environment and their Clean Seas campaign.

This video was a collaboration with UN Environment and their Clean Seas campaign .


If you want to take action to turn the tide on plastics, go to cleanseas.org and make your pledge.

If you want to take action to turn the tide on plastics , go to cleanseas.org and make your pledge .


For most of our history, human technology consisted of our brains, fire, and sharp sticks.

For most of our history , human technology consisted of our brains , fire , and sharp sticks .


While fire and sharp sticks became power plants and nuclear weapons, the biggest upgrade has happened to our brains.

While fire and sharp sticks became power plants and nuclear weapons , the biggest upgrade has happened to our brains .


Since the 1960s, the power of our brain machines has kept growing exponentially, allowing computers to get smaller and more powerful at the same time.

Since the 1960s , the power of our brain machines has kept growing exponentially , allowing computers to get smaller and more powerful at the same time .


But this process is about to meet its physical limits.

But this process is about to meet its physical limits .


Computer parts are approaching the size of an atom.

Computer parts are approaching the size of an atom .


To understand why this is a problem, we have to clear up some basics.

To understand why this is a problem , we have to clear up some basics .


A computer is made up of very simple components doing very simple things, representing data, the means of processing it, and control mechanisms.

A computer is made up of very simple components doing very simple things , representing data , the means of processing it , and control mechanisms .


Computer chips contain modules, which contain logic gates, which contain transistors.

Computer chips contain modules , which contain logic gates , which contain transistors .


A transistor is the simplest form of a data processor in computers, basically a switch that can either block or open the way for information coming through.

A transistor is the simplest form of a data processor in computers , basically a switch that can either block or open the way for information coming through .


This information is made up of bits, which can be set to either 0 or 1.

This information is made up of bits , which can be set to either 0 or 1 .


Combinations of several bits are used to represent more complex information.

Combinations of several bits are used to represent more complex information .


Transistors are combined to create logic gates, which still do very simple stuff.

Transistors are combined to create logic gates , which still do very simple stuff .


For example, an AND gate sends an output of 1 if all of its inputs are 1, and an output of 0 otherwise.

For example , an AND gate sends an output of 1 if all of its inputs are 1 , and an output of 0 otherwise .


Combinations of logic gates finally form meaningful modules, say for adding two numbers.

Combinations of logic gates finally form meaningful modules , say for adding two numbers .


Once you can add, you can also multiply, and once you can multiply, you can basically do anything.

Once you can add , you can also multiply , and once you can multiply , you can basically do anything .


Since all basic operations are literally simpler than first-grade math, you can imagine a computer as a group of seven-year-olds answering really basic math questions.

Since all basic operations are literally simpler than first - grade math , you can imagine a computer as a group of seven - year - olds answering really basic math questions .


A large enough bunch of them could compute anything from astrophysics to Zelda.

A large enough bunch of them could compute anything from astrophysics to Zelda .


However, with parts getting tinier and tinier, quantum physics are making things tricky.

However , with parts getting tinier and tinier , quantum physics are making things tricky .


In a nutshell, a transistor is just an electric switch.

In a nutshell , a transistor is just an electric switch .


Electricity is electrons moving from one place to another, so a switch is a passage that can block electrons from moving in one direction.

Electricity is electrons moving from one place to another , so a switch is a passage that can block electrons from moving in one direction .


Today, a typical scale for transistors is 14 nanometers, which is about eight times less than the HIV virus's diameter, and 500 times smaller than a red blood cell's.

Today , a typical scale for transistors is 14 nanometers , which is about eight times less than the HIV virus 's diameter , and 500 times smaller than a red blood cell 's .


As transistors are shrinking to the size of only a few atoms, electrons may just transfer themselves to the other side of a blocked passage via a process called quantum tunneling.

As transistors are shrinking to the size of only a few atoms , electrons may just transfer themselves to the other side of a blocked passage via a process called quantum tunneling .


In the quantum realm, physics works quite differently from the predictable ways we're used to, and traditional computers just stop making sense.

In the quantum realm , physics works quite differently from the predictable ways we 're used to , and traditional computers just stop making sense .


We are approaching a real physical barrier for our technological progress.

We are approaching a real physical barrier for our technological progress .


To solve this problem, scientists are trying to use these unusual quantum properties to their advantage by building quantum computers.

To solve this problem , scientists are trying to use these unusual quantum properties to their advantage by building quantum computers .


In normal computers, bits are the smallest units of information.

In normal computers , bits are the smallest units of information .


Quantum computers use qubits, which can also be set to one of two values.

Quantum computers use qubits , which can also be set to one of two values .


A qubit can be any two-level quantum system, such as a spin in a magnetic field or a single photon.

A qubit can be any two - level quantum system , such as a spin in a magnetic field or a single photon .


Zero and one are this system's possible states, like the photon's horizontal or vertical polarization.

Zero and one are this system 's possible states , like the photon 's horizontal or vertical polarization .


In the quantum world, the qubit doesn't have to be in just one of those.

In the quantum world , the qubit does n't have to be in just one of those .


It can be in any proportions of both states at once.

It can be in any proportions of both states at once .


This is called superposition.


But as soon as you test its value, say by sending the photon through a filter, it has to decide to be either vertically or horizontally polarized.

But as soon as you test its value , say by sending the photon through a filter , it has to decide to be either vertically or horizontally polarized .


So as long as it's unobserved, the qubit is in a superposition of probabilities for zero and one, and you can't predict which it will be.

So as long as it 's unobserved , the qubit is in a superposition of probabilities for zero and one , and you ca n't predict which it will be .


But the instant you measure it, it collapses into one of the definite states.

But the instant you measure it , it collapses into one of the definite states .


Superposition is a game-changer.


Four classical bits can be in one of two to the power of four different configurations at a time.

Four classical bits can be in one of two to the power of four different configurations at a time .


That's 16 possible combinations, out of which you can use just one.

That 's 16 possible combinations , out of which you can use just one .


Four qubits in superposition, however, can be in all of those 16 combinations at once.

Four qubits in superposition , however , can be in all of those 16 combinations at once .


This number grows exponentially with each extra qubit.

This number grows exponentially with each extra qubit .


20 of them can already store a million values in parallel.

20 of them can already store a million values in parallel .


A really weird and unintuitive property qubits can have is entanglement,

A really weird and unintuitive property qubits can have is entanglement ,


This means that when measuring just one entangled qubit, you can directly deduce properties of its partners without having to look.

This means that when measuring just one entangled qubit , you can directly deduce properties of its partners without having to look .


Qubit manipulation is a mind-bender as well.

Qubit manipulation is a mind - bender as well .


A normal logic gate gets a simple set of inputs and produces one definite output.

A normal logic gate gets a simple set of inputs and produces one definite output .


A quantum gate manipulates an input of superpositions, rotates probabilities, and produces another superposition as its output.

A quantum gate manipulates an input of superpositions , rotates probabilities , and produces another superposition as its output .


So a quantum computer sets up some qubits, applies quantum gates to entangle them and manipulate probabilities,

So a quantum computer sets up some qubits , applies quantum gates to entangle them and manipulate probabilities ,


What this means is that you get the entire lot of calculations that are possible with your setup all done at the same time.

What this means is that you get the entire lot of calculations that are possible with your setup all done at the same time .


Ultimately, you can only measure one of the results, and it will only probably be the one you want, so you may have to double-check and try again.

Ultimately , you can only measure one of the results , and it will only probably be the one you want , so you may have to double - check and try again .


But by cleverly exploiting superposition and entanglement, this can be exponentially more efficient than would ever be possible on a normal computer.

But by cleverly exploiting superposition and entanglement , this can be exponentially more efficient than would ever be possible on a normal computer .


So while quantum computers will probably not replace our home computers, in some areas they are vastly superior.

So while quantum computers will probably not replace our home computers , in some areas they are vastly superior .


One of them is database searching.


To find something in a database, a normal computer may have to test every single one of its entries.

To find something in a database , a normal computer may have to test every single one of its entries .


Quantum algorithms need only the square root of that time, which for large databases is a huge difference.

Quantum algorithms need only the square root of that time , which for large databases is a huge difference .


The most famous use of quantum computers is ruining IT security.

The most famous use of quantum computers is ruining IT security .


Right now, your browsing, email, and banking data is being kept secure by an encryption system in which you give everyone a public key to encode messages only you can decode.

Right now , your browsing , email , and banking data is being kept secure by an encryption system in which you give everyone a public key to encode messages only you can decode .


The problem is that this public key can actually be used to calculate your secret private key.

The problem is that this public key can actually be used to calculate your secret private key .


Luckily, doing the necessary math on any normal computer would literally take years of trial and error.

Luckily , doing the necessary math on any normal computer would literally take years of trial and error .


But a quantum computer with exponential speedup could do it in a breeze.

But a quantum computer with exponential speedup could do it in a breeze .


Another really exciting new use is simulations.

Another really exciting new use is simulations .


Simulations of the quantum world are very intense on resources, and even for bigger structures such as molecules, they often lack accuracy.

Simulations of the quantum world are very intense on resources , and even for bigger structures such as molecules , they often lack accuracy .


Quantum simulations could provide new insights on proteins that might revolutionize medicine.

Quantum simulations could provide new insights on proteins that might revolutionize medicine .


Right now, we don't know if quantum computers will be just a very specialized tool, or a big revolution for humanity.

Right now , we do n't know if quantum computers will be just a very specialized tool , or a big revolution for humanity .


We have no idea where the limits of technology are, and there's only one way to find out.

We have no idea where the limits of technology are , and there 's only one way to find out .


This video is supported by the Australian Academy of Science, which promotes and supports excellence in science.

This video is supported by the Australian Academy of Science , which promotes and supports excellence in science .


Learn more about this topic and others like it at nova.org.au


It was a blast to work with them, so go check out their site.

It was a blast to work with them , so go check out their site .


Our videos are also made possible by your support on patreon.com.

Our videos are also made possible by your support on patreon.com .


If you want to support us and become part of the Kurzgesagt bird army, check out our Patreon page.

If you want to support us and become part of the Kurzgesagt bird army , check out our Patreon page .


Terrorism is very scary, especially when it happens close to home and not in some faraway place.

Terrorism is very scary , especially when it happens close to home and not in some faraway place .


Nobody likes to be afraid, and we were eager to make the fear go away, so we demanded more security.

Nobody likes to be afraid , and we were eager to make the fear go away , so we demanded more security .


In the last decade, it's become increasingly normal for civil liberties to be eroded and for government agencies to spy on citizens,

In the last decade , it 's become increasingly normal for civil liberties to be eroded and for government agencies to spy on citizens ,


Regardless of whether you're a fan of right or left-wing policies, this affects every one of us.

Regardless of whether you 're a fan of right or left - wing policies , this affects every one of us .


So we have to take a look at the data and ask ourselves honestly, has all of this actually made us safer?

So we have to take a look at the data and ask ourselves honestly , has all of this actually made us safer ?


In the aftermath of 9-11, the US government concluded that the law had not kept pace with technology.

In the aftermath of 9 - 11 , the US government concluded that the law had not kept pace with technology .


It created the Terrorist Surveillance Program, initially to intercept communications linked to Al-Qaeda.

It created the Terrorist Surveillance Program , initially to intercept communications linked to Al - Qaeda .


Officials were confident that if the program had been in place before 9-11, the hijackers could have been stopped.

Officials were confident that if the program had been in place before 9 - 11 , the hijackers could have been stopped .


But soon, the new powers were also used to prove guilt by association.

But soon , the new powers were also used to prove guilt by association .


The FBI used immigration records to identify Arab and Muslim foreign nationals in the US.

The FBI used immigration records to identify Arab and Muslim foreign nationals in the US .


On this basis, 80,000 individuals were required to register, another 8,000 were called in for FBI interviews, and more than 5,000 locked up in preventive detention.

On this basis , 80,000 individuals were required to register , another 8,000 were called in for FBI interviews , and more than 5,000 locked up in preventive detention .


Not one terrorist was found in what's been called the most aggressive national campaign of ethnic profiling since World War II.

Not one terrorist was found in what 's been called the most aggressive national campaign of ethnic profiling since World War II .


How commonplace it's since become for government agencies to collect and store the personal data of citizens was made plain by the leak of the Snowden documents in 2013.

How commonplace it 's since become for government agencies to collect and store the personal data of citizens was made plain by the leak of the Snowden documents in 2013 .


They showed how the NSA can demand information about users from firms like Microsoft or Google


So instead of focusing on criminals, governments are increasingly turning their attention to everyone.

So instead of focusing on criminals , governments are increasingly turning their attention to everyone .


But if you're looking for a needle in a haystack, adding more hay to the stack isn't going to make it any easier to find the needle.

But if you 're looking for a needle in a haystack , adding more hay to the stack is n't going to make it any easier to find the needle .


On the contrary, every recent success announced by the NSA has come from classic target surveillance.

On the contrary , every recent success announced by the NSA has come from classic target surveillance .


Despite high hopes, the NSA surveillance program has not stopped any major terror attack.

Despite high hopes , the NSA surveillance program has not stopped any major terror attack .


For instance, one of the Boston Marathon bombers was already a target of the FBI.

For instance , one of the Boston Marathon bombers was already a target of the FBI .


So what we need is not even more random data, but better ways to understand and use the information we have.

So what we need is not even more random data , but better ways to understand and use the information we have .


Spy agencies are also pushing to cripple encryption.

Spy agencies are also pushing to cripple encryption .


In early 2016, the FBI asked Apple to produce a backdoor program to disable the encryption of a terrorist's iPhone.

In early 2016 , the FBI asked Apple to produce a backdoor program to disable the encryption of a terrorist 's iPhone .


Apple publicly declined, not only because this tool could be used to permanently weaken the privacy of law-abiding citizens worldwide,

Apple publicly declined , not only because this tool could be used to permanently weaken the privacy of law - abiding citizens worldwide ,


A few weeks later, the FBI revealed that they had hacked the phone themselves, basically admitting that they lied to the public about the need for a backdoor.

A few weeks later , the FBI revealed that they had hacked the phone themselves , basically admitting that they lied to the public about the need for a backdoor .


Concerns about this are often met with the argument, if you have nothing to hide, you have nothing to fear.

Concerns about this are often met with the argument , if you have nothing to hide , you have nothing to fear .


But this reasoning only creates a climate of oppression.

But this reasoning only creates a climate of oppression .


Wanting to keep certain parts of your life private doesn't mean you're doing anything wrong.

Wanting to keep certain parts of your life private does n't mean you 're doing anything wrong .


Right now, we live in a democracy.


But imagine the damage the wrong person could do with all our data and such easy access to our devices.

But imagine the damage the wrong person could do with all our data and such easy access to our devices .


Anti-terrorism laws allow the authorities to investigate and punish non-terrorism related crimes more aggressively.

Anti - terrorism laws allow the authorities to investigate and punish non - terrorism related crimes more aggressively .


If you give law enforcement powerful tools, they will use them.

If you give law enforcement powerful tools , they will use them .


That's why democratic oversight is so important.

That 's why democratic oversight is so important .


Even if those tools and laws aren't used against you today, they might be tomorrow.

Even if those tools and laws are n't used against you today , they might be tomorrow .


France expanded its already extensive anti-terrorism laws by giving law enforcement greater powers to conduct house raids and place people under house arrest.

France expanded its already extensive anti - terrorism laws by giving law enforcement greater powers to conduct house raids and place people under house arrest .


Within weeks, evidence emerged that these powers were being used for unintended purposes such as quashing climate change protests.

Within weeks , evidence emerged that these powers were being used for unintended purposes such as quashing climate change protests .


The governments of Spain, Hungary and Poland have introduced more restrictive laws on the freedom of assembly and speech.

The governments of Spain , Hungary and Poland have introduced more restrictive laws on the freedom of assembly and speech .


Freedom of expression and the press in Turkey has been seriously undermined in the last few years with people sentenced to prison for criticizing the government.

Freedom of expression and the press in Turkey has been seriously undermined in the last few years with people sentenced to prison for criticizing the government .


None of this is effectively helping us fight terrorism.

None of this is effectively helping us fight terrorism .


The motivation behind this might be good, even noble, but if we let our elected governments limit our personal freedom, the terrorists are winning.

The motivation behind this might be good , even noble , but if we let our elected governments limit our personal freedom , the terrorists are winning .


What's worse, if we're not careful, we might slowly move towards a surveillance state.

What 's worse , if we 're not careful , we might slowly move towards a surveillance state .


The data is pretty clear.


The erosion of rights along with mass surveillance hasn't led to significant successes so far, but it has changed the nature of our society.

The erosion of rights along with mass surveillance has n't led to significant successes so far , but it has changed the nature of our society .


Terrorism is a complicated problem without simple solutions.

Terrorism is a complicated problem without simple solutions .


No security apparatus can prevent a few guys from building a bomb in their basement.

No security apparatus can prevent a few guys from building a bomb in their basement .


We should keep the principle of proportionality in mind.

We should keep the principle of proportionality in mind .


Creating master keys to enter millions of phones is not the same as searching a single house.

Creating master keys to enter millions of phones is not the same as searching a single house .


In most countries, the law already permits a wide range of actions, including targeted surveillance.

In most countries , the law already permits a wide range of actions , including targeted surveillance .


To take full advantage of this existing potential, we need better international cooperation and more effective security and foreign policies.

To take full advantage of this existing potential , we need better international cooperation and more effective security and foreign policies .


Let us not, out of fear, destroy what we are most proud of.

Let us not , out of fear , destroy what we are most proud of .


Everybody is familiar with the feeling that things are not as they should be.

Everybody is familiar with the feeling that things are not as they should be .


That you're not successful enough.


Your relationship is not satisfying enough.

Your relationship is not satisfying enough .


That you don't have the things you crave.

That you do n't have the things you crave .


Pop culture, advertising and social media make this worse by reminding you that aiming for anything less than your dream job is failure.

Pop culture , advertising and social media make this worse by reminding you that aiming for anything less than your dream job is failure .


You need to have great experiences constantly, be conventionally attractive, have a lot of friends and find your soulmate and that others have all of these things and are truly happy.

You need to have great experiences constantly , be conventionally attractive , have a lot of friends and find your soulmate and that others have all of these things and are truly happy .


And of course a vast array of self-improvement products implies that it's all your fault for not working hard enough for yourself.

And of course a vast array of self - improvement products implies that it 's all your fault for not working hard enough for yourself .


In the last two decades researchers have been starting to investigate how we can counteract these impulses.

In the last two decades researchers have been starting to investigate how we can counteract these impulses .


The field of positive psychology emerged.

The field of positive psychology emerged .


While cognitive behavioral therapy was developed to change negative feelings.

While cognitive behavioral therapy was developed to change negative feelings .


Scientists began to ask why are some people happier and more satisfied than others and are there ways to apply what they're doing right to the rest of us.

Scientists began to ask why are some people happier and more satisfied than others and are there ways to apply what they 're doing right to the rest of us .


In this video we want to talk about one of the strongest predictors of how happy people are, how easily they make friends and how good they are at dealing with hardship.

In this video we want to talk about one of the strongest predictors of how happy people are , how easily they make friends and how good they are at dealing with hardship .


While gratitude may sound like another self-improvement trend preached by people who use hashtags,

While gratitude may sound like another self - improvement trend preached by people who use hashtags ,


what we currently know about it is based on a body of scientific work and studies.

what we currently know about it is based on a body of scientific work and studies .


We'll include them in the description.

We 'll include them in the description .


Gratitude can mean very different things to different people in different contexts.

Gratitude can mean very different things to different people in different contexts .


It's a character trait, a feeling, a virtue and a behavior.

It 's a character trait , a feeling , a virtue and a behavior .


You can feel grateful towards someone who did something for you, for random events like the weather or even for nature or fate and it's wired into our biology.

You can feel grateful towards someone who did something for you , for random events like the weather or even for nature or fate and it 's wired into our biology .


How gratitude connects us to each other.

How gratitude connects us to each other .


The predecessor of gratitude is probably reciprocity.

The predecessor of gratitude is probably reciprocity .


It likely evolved as a biological signal that motivates animals to exchange things for their mutual benefit


When your brain recognizes that someone's done something nice for you, it reacts with gratitude to motivate you to repay them.

When your brain recognizes that someone 's done something nice for you , it reacts with gratitude to motivate you to repay them .


This gratitude makes you care about others and others care about you.

This gratitude makes you care about others and others care about you .


This was important because as human brains got better at reading emotions, selfish individuals were identified and shunned.

This was important because as human brains got better at reading emotions , selfish individuals were identified and shunned .


It became an evolutionary advantage to play well with others and build lasting relationships.

It became an evolutionary advantage to play well with others and build lasting relationships .


For example, if you were hungry and someone else showed you where to find tasty berries, you felt gratitude towards them and a bond to return the favor in the future.

For example , if you were hungry and someone else showed you where to find tasty berries , you felt gratitude towards them and a bond to return the favor in the future .


When you repaid them, they felt gratitude towards you.

When you repaid them , they felt gratitude towards you .


This brought your ancestors closer together and forged bonds and friendships.

This brought your ancestors closer together and forged bonds and friendships .


So early forms of gratitude were biological mechanisms that modified your behavior towards cooperation which helped humans to dominate Earth.

So early forms of gratitude were biological mechanisms that modified your behavior towards cooperation which helped humans to dominate Earth .


But over time, gratitude became more than just an impulse to play fair.

But over time , gratitude became more than just an impulse to play fair .


Scientists found that gratitude stimulates the pathways in your brain involved in feelings of reward, forming social bonds and interpreting others' intentions.

Scientists found that gratitude stimulates the pathways in your brain involved in feelings of reward , forming social bonds and interpreting others ' intentions .


It also makes it easier to save and retrieve positive memories.

It also makes it easier to save and retrieve positive memories .


Even more, gratitude directly counteracts negative feelings and traits like envy and social comparison, narcissism, cynicism and materialism.

Even more , gratitude directly counteracts negative feelings and traits like envy and social comparison , narcissism , cynicism and materialism .


As a consequence, people who are grateful no matter what for tend to be happier and more satisfied.

As a consequence , people who are grateful no matter what for tend to be happier and more satisfied .


They have better relationships, an easier time making friends,

They have better relationships , an easier time making friends ,


they sleep better, tend to suffer less from depression, addiction and burnout and are better at dealing with traumatic events.

they sleep better , tend to suffer less from depression , addiction and burnout and are better at dealing with traumatic events .


In a way, gratitude makes it less likely that you'll fall into one of the psychological traps modern life has set for you.

In a way , gratitude makes it less likely that you 'll fall into one of the psychological traps modern life has set for you .


For example, gratitude measurably counters the tendency to forget and downplay positive events.

For example , gratitude measurably counters the tendency to forget and downplay positive events .


If you work long and hard for something, actually getting it can feel daft and empty.

If you work long and hard for something , actually getting it can feel daft and empty .


You can find yourself emotionally back where you started and try to achieve the next biggest thing, looking for that satisfaction instead of being satisfied with yourself.

You can find yourself emotionally back where you started and try to achieve the next biggest thing , looking for that satisfaction instead of being satisfied with yourself .


Or imagine being lonely and wanting to have more friends.

Or imagine being lonely and wanting to have more friends .


You actually might have someone or even multiple people who want to hang out, but you might feel that this is not enough, that you're a loser and feel bad about yourself.

You actually might have someone or even multiple people who want to hang out , but you might feel that this is not enough , that you 're a loser and feel bad about yourself .


So you might turn down their attempts to hang out and become more lonely.

So you might turn down their attempts to hang out and become more lonely .


If you feel grateful for your relationships instead, you might accept invitations or even take the initiative.

If you feel grateful for your relationships instead , you might accept invitations or even take the initiative .


In the best case, gratitude can trigger a feedback loop.

In the best case , gratitude can trigger a feedback loop .


Positive feelings lead to more pro-social behavior, which leads to more positive social experiences that cause more positive feelings.

Positive feelings lead to more pro - social behavior , which leads to more positive social experiences that cause more positive feelings .


This is a commom experience after serious hardship, like chemotherapy for example.

This is a commom experience after serious hardship , like chemotherapy for example .


Life can feel amazing after a crisis is over.

Life can feel amazing after a crisis is over .


The smallest things can be bottomless sources of joy, from being able to taste, to just sitting in the sun or chatting with a friend.

The smallest things can be bottomless sources of joy , from being able to taste , to just sitting in the sun or chatting with a friend .


Objectively, your life is the same or maybe even slightly worse than before, but your brain compares your present experiences with the times when life was bad and reacts with gratitude.

Objectively , your life is the same or maybe even slightly worse than before , but your brain compares your present experiences with the times when life was bad and reacts with gratitude .


So in a nutshell, gratitude refocuses your attention towards the good things you have.

So in a nutshell , gratitude refocuses your attention towards the good things you have .


And the consequences of this shift are better feelings and more positive experiences.

And the consequences of this shift are better feelings and more positive experiences .


While it is great to know these things, is there actually a way for you to feel more of it?

While it is great to know these things , is there actually a way for you to feel more of it ?


The ability to experience more or less gratitude is not equally distributed.

The ability to experience more or less gratitude is not equally distributed .


You have what's known as trait gratitude, that determines how much you are able to feel it.

You have what 's known as trait gratitude , that determines how much you are able to feel it .


It depends on your genetics, personality and culture.

It depends on your genetics , personality and culture .


This discovery made scientists wonder if they could design exercises that change your trait gratitude and lead to more happiness.

This discovery made scientists wonder if they could design exercises that change your trait gratitude and lead to more happiness .


Let's start with important caveats.


It's not yet entirely clear to what degree gratitude can be trained or how long the effects last.

It 's not yet entirely clear to what degree gratitude can be trained or how long the effects last .


There are no magic pills for happiness.

There are no magic pills for happiness .


Life is complicated.


On some days it feels like you're in control of yourself and on others you feel like you're not.

On some days it feels like you 're in control of yourself and on others you feel like you 're not .


And this is okay.


Also, sometimes pursuing happiness can make you more unhappy if you put too much pressure on yourself.

Also , sometimes pursuing happiness can make you more unhappy if you put too much pressure on yourself .


Gratitude should also not be seen as a solution to depression or a substitute for professional help.

Gratitude should also not be seen as a solution to depression or a substitute for professional help .


It can only be a piece of the puzzle.


It's not the solution to the puzzle itself.

It 's not the solution to the puzzle itself .


The easiest gratitude exercise with the most solid research behind it is gratitude journaling.

The easiest gratitude exercise with the most solid research behind it is gratitude journaling .


It means sitting down for a few minutes, one to three times a week and writing down five to ten things you're grateful for.

It means sitting down for a few minutes , one to three times a week and writing down five to ten things you 're grateful for .


It might feel weird at first, so start simply.

It might feel weird at first , so start simply .


Can you feel grateful for a little thing, like how great coffee is or that someone was kind to you?

Can you feel grateful for a little thing , like how great coffee is or that someone was kind to you ?


Can you appreciate something someone else did for you?

Can you appreciate something someone else did for you ?


Can you reflect on which things or people you would miss if they were gone and be grateful that they're in your life?

Can you reflect on which things or people you would miss if they were gone and be grateful that they 're in your life ?


We're all different, so you'll know what works for you.

We 're all different , so you 'll know what works for you .


And that's it really.


It feels almost insulting, like things shouldn't be that simple.

It feels almost insulting , like things should n't be that simple .


But in numerous studies, the participants reported more happiness and a higher general life satisfaction after doing this practice for a few weeks.

But in numerous studies , the participants reported more happiness and a higher general life satisfaction after doing this practice for a few weeks .


And even more, studies have found changes in brain activity some months after they ended.

And even more , studies have found changes in brain activity some months after they ended .


Practicing gratitude may be a real way to reprogram yourself.

Practicing gratitude may be a real way to reprogram yourself .


This research shows that your emotions are not fixed.

This research shows that your emotions are not fixed .


In the end, how you experience life is a representation of what you believe about it.

In the end , how you experience life is a representation of what you believe about it .


If you attack your core beliefs about yourself and your life, you can change your thoughts and feelings, which automatically changes your behavior.

If you attack your core beliefs about yourself and your life , you can change your thoughts and feelings , which automatically changes your behavior .


It's pretty mind-blowing that something as simple as self-reflection can hack the pathways in our brain to fight dissatisfaction.

It 's pretty mind - blowing that something as simple as self - reflection can hack the pathways in our brain to fight dissatisfaction .


Being a human is hard, but it doesn't need to be as hard.

Being a human is hard , but it does n't need to be as hard .


And if you actively look, you might find that your life is much better than you thought.

And if you actively look , you might find that your life is much better than you thought .


If you're curious and want to try out gratitude, we made a thing.

If you 're curious and want to try out gratitude , we made a thing .


Please note that you don't need to buy anything from anyone to practice gratitude.

Please note that you do n't need to buy anything from anyone to practice gratitude .


All you need is paper, a pen, and five minutes.

All you need is paper , a pen , and five minutes .


Having said that, we've made a Kurzgesagt gratitude journal based on studies we've read,

Having said that , we 've made a Kurzgesagt gratitude journal based on studies we 've read ,


It's structured in a way that might make it a bit easier to get into the habit of gratitude journaling.

It 's structured in a way that might make it a bit easier to get into the habit of gratitude journaling .


There are short explanations and reflections to mix it up and make it more interesting.

There are short explanations and reflections to mix it up and make it more interesting .


We've also made it as pretty as we could.

We 've also made it as pretty as we could .


This video continues the unofficial series of more personal, introspective videos from optimistic nihilism to loneliness and now gratitude.

This video continues the unofficial series of more personal , introspective videos from optimistic nihilism to loneliness and now gratitude .


We don't want to be a self-help channel, so we'll keep this sort of video at roughly one per year.

We do n't want to be a self - help channel , so we 'll keep this sort of video at roughly one per year .


We hope they're helpful to some of you.

We hope they 're helpful to some of you .


Thank you for watching.


It's hard to get to space.


As much as we all wish there were an easy and affordable way to see our planet floating in the dark, right now the only way is to become an astronaut or a billionaire.

As much as we all wish there were an easy and affordable way to see our planet floating in the dark , right now the only way is to become an astronaut or a billionaire .


But there is a concept that might make it possible while serving as the starting point for the exploration of the universe, the space elevator.

But there is a concept that might make it possible while serving as the starting point for the exploration of the universe , the space elevator .


How exactly does it work?


To understand how a space elevator will get us into space, we must first understand what an orbit is.

To understand how a space elevator will get us into space , we must first understand what an orbit is .


Being in orbit basically means falling towards something but moving fast enough to miss.

Being in orbit basically means falling towards something but moving fast enough to miss .


If you throw a ball on earth, it makes an arc through the air and then hits the ground.

If you throw a ball on earth , it makes an arc through the air and then hits the ground .


In space, gravity makes you move much the same way,

In space , gravity makes you move much the same way ,


but if you move sideways fast enough, the curvature of the earth makes the ground fall away beneath you as fast as gravity pulls you towards it.

but if you move sideways fast enough , the curvature of the earth makes the ground fall away beneath you as fast as gravity pulls you towards it .


So to enter earth's orbit, rockets have to go up and sideways fast.

So to enter earth 's orbit , rockets have to go up and sideways fast .


By contrast, a space elevator taps into energy from the earth's rotation to get the cargo going fast.

By contrast , a space elevator taps into energy from the earth 's rotation to get the cargo going fast .


Imagine a child spinning a toy on a rope with an ant on the child's hand.

Imagine a child spinning a toy on a rope with an ant on the child 's hand .


As the ant climbs out along the rope, it starts to move faster and faster as it ascends.

As the ant climbs out along the rope , it starts to move faster and faster as it ascends .


Compared to rockets, with cargo launched on an elevator, you only need to provide the energy to go up.

Compared to rockets , with cargo launched on an elevator , you only need to provide the energy to go up .


Fast sideways movement comes free with the earth's rotation.

Fast sideways movement comes free with the earth 's rotation .


But a space elevator would, without a doubt, be the single largest and most expensive structure ever built by humans.

But a space elevator would , without a doubt , be the single largest and most expensive structure ever built by humans .


So is it worth it?


It all comes down to costs.


Rockets burn a huge amount of rocket fuel just to get a small amount of cargo into space.

Rockets burn a huge amount of rocket fuel just to get a small amount of cargo into space .


At current prices, it costs about $20,000 to put 1kg of payload into space.

At current prices , it costs about $ 20,000 to put 1 kg of payload into space .


That's $1.3 million for the average human, $40 million for your car.

That 's $ 1.3 million for the average human , $ 40 million for your car .


This immense cost is one of the major limitations of human spaceflight.

This immense cost is one of the major limitations of human spaceflight .


Even with advancing technology, this cost isn't likely to be comparable with the price of an airline ticket any time soon.

Even with advancing technology , this cost is n't likely to be comparable with the price of an airline ticket any time soon .


A space elevator would solve this problem.

A space elevator would solve this problem .


After construction, a space elevator is projected to reduce the cost 100-fold to $200 per kilogram.

After construction , a space elevator is projected to reduce the cost 100 - fold to $ 200 per kilogram .


If an inexpensive space elevator costs $20 billion, then we'll recoup our losses after launching only 1,000 tons.

If an inexpensive space elevator costs $ 20 billion , then we 'll recoup our losses after launching only 1,000 tons .


So what would a space elevator look like in real life?

So what would a space elevator look like in real life ?


A space elevator has four major components.

A space elevator has four major components .


The elevator part of the space elevator is the tether and the climber.

The elevator part of the space elevator is the tether and the climber .


It extends from the surface of the Earth to space.

It extends from the surface of the Earth to space .


The climber is like a conventional elevator carriage, a chamber that works its way up and down the tether.

The climber is like a conventional elevator carriage , a chamber that works its way up and down the tether .


At the base would be an anchor, pinning the tether to the Earth, along with a port for climbers.

At the base would be an anchor , pinning the tether to the Earth , along with a port for climbers .


At the top is the counterweight, which holds up the tether.

At the top is the counterweight , which holds up the tether .


The tether is held tight like a rope and supported from above by the tension from the counterweight.

The tether is held tight like a rope and supported from above by the tension from the counterweight .


At the counterweight could be a space station, a launching point for all missions from the spaceport elevator.

At the counterweight could be a space station , a launching point for all missions from the spaceport elevator .


But can we actually build one?


It's hard to say.


The biggest challenge is the tether.


It needs to be light, affordable, and more stable than any material we can produce right now.

It needs to be light , affordable , and more stable than any material we can produce right now .


There are promising materials like graphene and diamond nanothreads, but even they may not be strong enough.

There are promising materials like graphene and diamond nanothreads , but even they may not be strong enough .


And aside from being incredibly strong, the tether would also have to withstand atmospheric corrosion, radiation, and micrometeorite and debris impacts.

And aside from being incredibly strong , the tether would also have to withstand atmospheric corrosion , radiation , and micrometeorite and debris impacts .


Additionally, it takes several days to climb the elevator.

Additionally , it takes several days to climb the elevator .


How do we power the climber?


It requires a lot of energy to go up.


Do we need a nuclear reactor on our elevator carriage?

Do we need a nuclear reactor on our elevator carriage ?


Or do we beam it power from the ground with a super-powered laser?

Or do we beam it power from the ground with a super - powered laser ?


And where do we get the raw materials for a 36,000 kilometer long tether?

And where do we get the raw materials for a 36,000 kilometer long tether ?


Do we make it on Earth and launch it into space, or do we make it in space and lower it down to the Earth?

Do we make it on Earth and launch it into space , or do we make it in space and lower it down to the Earth ?


Could asteroid mining be the answer?


Put simply, there are still some major technological hurdles to overcome.

Put simply , there are still some major technological hurdles to overcome .


And a space elevator is not without risk.

And a space elevator is not without risk .


Should the tether break, it would collapse in spectacular style.

Should the tether break , it would collapse in spectacular style .


If it breaks near the anchor, the force exerted by the counterweight will cause the entire elevator to rise up, ascending into space.

If it breaks near the anchor , the force exerted by the counterweight will cause the entire elevator to rise up , ascending into space .


Should it break near the counterweight, the tether will fall, wrapping around the world and whipping the end off.

Should it break near the counterweight , the tether will fall , wrapping around the world and whipping the end off .


The resulting debris in orbit could pose serious problems to future spaceflight.

The resulting debris in orbit could pose serious problems to future spaceflight .


If we build a space elevator on Earth, we have to do it right the first time.

If we build a space elevator on Earth , we have to do it right the first time .


For these reasons, some experts have proposed first building a space elevator on the Moon.

For these reasons , some experts have proposed first building a space elevator on the Moon .


The Moon's gravity is much weaker than the Earth's, so a flimsier but existent material like Kevlar could serve as a tether.

The Moon 's gravity is much weaker than the Earth 's , so a flimsier but existent material like Kevlar could serve as a tether .


Even with all these challenges, the payoff of having a working space elevator would be immense.

Even with all these challenges , the payoff of having a working space elevator would be immense .


It might be the first step to truly becoming a spacefaring civilization.

It might be the first step to truly becoming a spacefaring civilization .


Maybe we will never build a space elevator, but in trying to do so, we might learn an awful lot.

Maybe we will never build a space elevator , but in trying to do so , we might learn an awful lot .


And when it comes to the exploration of the universe, there can't be too many dreams of a glorious future.

And when it comes to the exploration of the universe , there ca n't be too many dreams of a glorious future .


What is the true nature of the universe?

What is the true nature of the universe ?


To answer this question, humans come up with stories to describe the world.

To answer this question , humans come up with stories to describe the world .


We test our stories and learn what to keep and what to throw away.

We test our stories and learn what to keep and what to throw away .


But the more we learn, the more complicated and weird our stories become.

But the more we learn , the more complicated and weird our stories become .


Why did we come up with it?


And is it correct?


To understand the true nature of reality, we looked at things up close and were amazed.

To understand the true nature of reality , we looked at things up close and were amazed .


We thought they were the final layer of reality, until we smashed them together really hard and discovered things that can't be divided anymore.

We thought they were the final layer of reality , until we smashed them together really hard and discovered things that ca n't be divided anymore .


But now we had a problem.


They're so small that we could no longer look at them.

They 're so small that we could no longer look at them .


Think about it.


What is seeing?


To see something, we need light, an electromagnetic wave.

To see something , we need light , an electromagnetic wave .


This wave hits the surface of the thing and gets reflected back from it into your eye.

This wave hits the surface of the thing and gets reflected back from it into your eye .


The wave carries information from the object that your brain uses to create an image.

The wave carries information from the object that your brain uses to create an image .


So you can't see something without somehow interacting with it.

So you ca n't see something without somehow interacting with it .


Seeing is touching.


This is not a problem with most things.

This is not a problem with most things .


But particles are very, very, very small.

But particles are very , very , very small .


Visible light just passes over them.


We can try to solve this by creating electromagnetic waves with more and much smaller wavelengths.

We can try to solve this by creating electromagnetic waves with more and much smaller wavelengths .


But in quantum physics, shorter wavelengths means more energy.

But in quantum physics , shorter wavelengths means more energy .


So when we touch a particle with a wave that has a lot of energy, it gets a kick.

So when we touch a particle with a wave that has a lot of energy , it gets a kick .


By looking at a particle, we change it.

By looking at a particle , we change it .


In quantum physics, we cannot know where a particle is and where it's going with absolute precision.

In quantum physics , we can not know where a particle is and where it 's going with absolute precision .


This fact is so important that it has a name.

This fact is so important that it has a name .


So what does a particle look like then?

So what does a particle look like then ?


What is its nature?


We don't know.


If we look really hard, we can see a blurry sphere of influence, but not the particles themselves.

If we look really hard , we can see a blurry sphere of influence , but not the particles themselves .


We just know they exist.


But if that's the case, how can we do any science with them?

But if that 's the case , how can we do any science with them ?


We did what humans do and invented a new story, a mathematical fiction.

We did what humans do and invented a new story , a mathematical fiction .


We decided that we would pretend that a particle is a point in space.

We decided that we would pretend that a particle is a point in space .


Any electron is a point with a certain electric charge and a certain mass, all indistinguishable from each other.

Any electron is a point with a certain electric charge and a certain mass , all indistinguishable from each other .


This way, physicists could define them and calculate all of their interactions.

This way , physicists could define them and calculate all of their interactions .


This can be made precise in quantum field theory, and this solved a lot of problems.

This can be made precise in quantum field theory , and this solved a lot of problems .


All of the standard model of particle physics is built on it, and it predicts lots of things very well.

All of the standard model of particle physics is built on it , and it predicts lots of things very well .


Some quantum properties of the electron, for example, have been tested and are accurate up to 0.000000000000002%.

Some quantum properties of the electron , for example , have been tested and are accurate up to 0.000000000000002 % .


So while particles are not really points, by treating them as if they were, we get a pretty good picture of the universe.

So while particles are not really points , by treating them as if they were , we get a pretty good picture of the universe .


Not only did this idea advance science, it also led to a lot of real-world technology we use every day.

Not only did this idea advance science , it also led to a lot of real - world technology we use every day .


But there's a huge problem, gravity.


In quantum mechanics, all physical forces are carried by certain particles.

In quantum mechanics , all physical forces are carried by certain particles .


But according to Einstein's general relativity, gravity is not a force like the others in the universe.

But according to Einstein 's general relativity , gravity is not a force like the others in the universe .


If the universe is a play, particles are the actors, but gravity is the stage.

If the universe is a play , particles are the actors , but gravity is the stage .


To put it simply, gravity is a theory of geometry, the geometry of space-time itself, of distances which we need to describe with absolute precision.

To put it simply , gravity is a theory of geometry , the geometry of space - time itself , of distances which we need to describe with absolute precision .


But since there is no way to precisely measure things in the quantum world, our story of gravity doesn't work with our story of quantum physics.

But since there is no way to precisely measure things in the quantum world , our story of gravity does n't work with our story of quantum physics .


When physicists tried to add gravity to the story by inventing a new particle, their mathematics broke down.

When physicists tried to add gravity to the story by inventing a new particle , their mathematics broke down .


And this is a big problem.


If we could marry gravity to quantum physics and the standard model, we would have the theory of everything.

If we could marry gravity to quantum physics and the standard model , we would have the theory of everything .


So very smart people came up with a new story.

So very smart people came up with a new story .


They asked, what is more complex than a point, a line, or a string?

They asked , what is more complex than a point , a line , or a string ?


String theory was born.


What makes string theory so elegant is that it describes many different elementary particles as different modes of vibration of the string.

What makes string theory so elegant is that it describes many different elementary particles as different modes of vibration of the string .


Just like a violin string vibrating differently can give you a lot of different notes, a string can give you different particles.

Just like a violin string vibrating differently can give you a lot of different notes , a string can give you different particles .


Most importantly, this includes gravity.

Most importantly , this includes gravity .


String theory promised to unify all fundamental forces of the universe.

String theory promised to unify all fundamental forces of the universe .


This caused enormous excitement and hype.

This caused enormous excitement and hype .


String theory quickly graduated to a possible theory of everything.

String theory quickly graduated to a possible theory of everything .


Unfortunately, string theory comes with a lot of strings attached.

Unfortunately , string theory comes with a lot of strings attached .


Much of the maths involving a consistent string theory does not work in our universe with its three spatial and one temporal dimensions.

Much of the maths involving a consistent string theory does not work in our universe with its three spatial and one temporal dimensions .


String theory requires ten dimensions to work out.

String theory requires ten dimensions to work out .


So string theorists did calculations in model universes, and then tried to get rid of the six additional dimensions and describe our own universe.

So string theorists did calculations in model universes , and then tried to get rid of the six additional dimensions and describe our own universe .


But so far, nobody has succeeded and no prediction of string theory has been proven in an experiment.

But so far , nobody has succeeded and no prediction of string theory has been proven in an experiment .


So string theory did not reveal the nature of our universe.

So string theory did not reveal the nature of our universe .


One could argue that in this case, string theory really isn't useful at all.

One could argue that in this case , string theory really is n't useful at all .


Science is all about experiments and predictions.

Science is all about experiments and predictions .


If we can't do those, why should we bother with strings?

If we ca n't do those , why should we bother with strings ?


It really is all about how we use it.


Physics is based on maths.


Two plus two makes four.


This is true no matter how you feel about it.

This is true no matter how you feel about it .


And the maths in string theory does work out.

And the maths in string theory does work out .


That's why string theory is still useful.

That 's why string theory is still useful .


Imagine that you want to build a cruise ship, but you only have blueprints for a small rowing boat.

Imagine that you want to build a cruise ship , but you only have blueprints for a small rowing boat .


There are plenty of differences.


But both things are fundamentally the same.

But both things are fundamentally the same .


So by studying the rowing boat blueprints, you might still learn something about how to build a cruise ship eventually.

So by studying the rowing boat blueprints , you might still learn something about how to build a cruise ship eventually .


With string theory, we can try to answer some questions about quantum gravity that have been puzzling physicists for decades,

With string theory , we can try to answer some questions about quantum gravity that have been puzzling physicists for decades ,


String theory may point us in the right direction.

String theory may point us in the right direction .


When used in this spirit, string theory becomes a precious tool for theoretical physicists and help them discover new aspects of the quantum world and some beautiful mathematics.

When used in this spirit , string theory becomes a precious tool for theoretical physicists and help them discover new aspects of the quantum world and some beautiful mathematics .


So maybe the story of string theory is not the theory of everything.

So maybe the story of string theory is not the theory of everything .


But just like the story of the point particle, it may be an extremely useful story.

But just like the story of the point particle , it may be an extremely useful story .


We don't yet know what the true nature of reality is, but we'll keep coming up with stories to try and find out until one day, hopefully, we do know.

We do n't yet know what the true nature of reality is , but we 'll keep coming up with stories to try and find out until one day , hopefully , we do know .


This video was supported by the Swiss National Science Foundation and realized with the scientific advice of Alessandro Sfondrini.

This video was supported by the Swiss National Science Foundation and realized with the scientific advice of Alessandro Sfondrini .


Is there a border we will never cross?


Are there places we will never reach, no matter how hard we try?

Are there places we will never reach , no matter how hard we try ?


Even with sci-fi technology, we are trapped in a limited pocket of the universe and the finite stuff within it.

Even with sci - fi technology , we are trapped in a limited pocket of the universe and the finite stuff within it .


How much universe is there for us and how far can we go?

How much universe is there for us and how far can we go ?


If you look at the night sky, you might assume it will be there forever.

If you look at the night sky , you might assume it will be there forever .


Stars are born and die again in a cycle that feels endless.

Stars are born and die again in a cycle that feels endless .


Take the Milky Way.


The answer is around three.


95% of all the stars that will ever exist in the universe have already been born, and we live at the tail end of the age of star formation.

95 % of all the stars that will ever exist in the universe have already been born , and we live at the tail end of the age of star formation .


We are at the beginning of the end of the universe as we know it.

We are at the beginning of the end of the universe as we know it .


The formation of new stars will continue to slow down.

The formation of new stars will continue to slow down .


But there's more.


It turns out that the universe is rushing away from us.

It turns out that the universe is rushing away from us .


The Milky Way is not alone.


Together with the Andromeda galaxy and more than 50 dwarf galaxies, it forms the Local Group, a region of space about 10 million light years in diameter, our galactic neighborhood.

Together with the Andromeda galaxy and more than 50 dwarf galaxies , it forms the Local Group , a region of space about 10 million light years in diameter , our galactic neighborhood .


Hundreds of galaxy groups like the Local Group make up the Laniakea supercluster, which itself is only one of a myriad of superclusters.

Hundreds of galaxy groups like the Local Group make up the Laniakea supercluster , which itself is only one of a myriad of superclusters .


In total, there are around 2 trillion galaxies that make up the current observable universe.

In total , there are around 2 trillion galaxies that make up the current observable universe .


Unfortunately, even if we could travel at light speed, around 94% of the galaxies we can see are already unreachable for us forever.

Unfortunately , even if we could travel at light speed , around 94 % of the galaxies we can see are already unreachable for us forever .


Let this number sink in for a moment.


The simple fact that there's a limit for us and that there is so much universe that a human will never be able to touch is kind of frightening.

The simple fact that there 's a limit for us and that there is so much universe that a human will never be able to touch is kind of frightening .


Why are all of these galaxies out of reach already?

Why are all of these galaxies out of reach already ?


Well, it all has to do with why there are galaxies in the first place, the Big Bang.

Well , it all has to do with why there are galaxies in the first place , the Big Bang .


We're simplifying here, but in a nutshell, about 10 to the power of minus 36 seconds after the Big Bang, the young universe was a very small bubble of energy.

We 're simplifying here , but in a nutshell , about 10 to the power of minus 36 seconds after the Big Bang , the young universe was a very small bubble of energy .


It wasn't completely uniform, though.

It was n't completely uniform , though .


Some parts of it were a tiny, tiny bit denser than others, which had massive consequences.

Some parts of it were a tiny , tiny bit denser than others , which had massive consequences .


In a process called cosmic inflation, the observable universe expanded rapidly, from the size of a marble to trillions of kilometers in a trillionth of a second.

In a process called cosmic inflation , the observable universe expanded rapidly , from the size of a marble to trillions of kilometers in a trillionth of a second .


That was so fast that all those tiny differences in density were stretched from subatomic distances into galactic distances,

That was so fast that all those tiny differences in density were stretched from subatomic distances into galactic distances ,


After that short but powerful inflation ended, gravity began trying to pull everything back together.

After that short but powerful inflation ended , gravity began trying to pull everything back together .


Inside the denser pockets, gravity emerged victorious, and so over time, they grew into groups of galaxies like the one we live in today.

Inside the denser pockets , gravity emerged victorious , and so over time , they grew into groups of galaxies like the one we live in today .


The local group is our pocket of the universe.

The local group is our pocket of the universe .


But at larger scales outside the denser pockets, the expansion of space never stopped.

But at larger scales outside the denser pockets , the expansion of space never stopped .


This means that our local group is surrounded by a lot of stuff, but none of those structures and galaxies are gravitationally bound to us.

This means that our local group is surrounded by a lot of stuff , but none of those structures and galaxies are gravitationally bound to us .


The more the universe expands, the larger the distance between us and the other gravitational pockets becomes.

The more the universe expands , the larger the distance between us and the other gravitational pockets becomes .


Even worse for us, the expansion of the universe is accelerating.

Even worse for us , the expansion of the universe is accelerating .


We don't know why this happens, so we came up with the concept of dark energy.

We do n't know why this happens , so we came up with the concept of dark energy .


You can imagine it like an invisible effect that speeds up the expansion of the universe.

You can imagine it like an invisible effect that speeds up the expansion of the universe .


We'll explain these concepts in more detail in another video, though.

We 'll explain these concepts in more detail in another video , though .


For now, all you need to know is that the universe is expanding faster and faster.

For now , all you need to know is that the universe is expanding faster and faster .


This expansion means that there's a cosmological horizon around us.

This expansion means that there 's a cosmological horizon around us .


Everything beyond it is traveling faster relative to us than the speed of light.

Everything beyond it is traveling faster relative to us than the speed of light .


So everything that passes the horizon is irretrievably out of reach forever, and we will never be able to interact with it again.

So everything that passes the horizon is irretrievably out of reach forever , and we will never be able to interact with it again .


In a sense, it's like a black hole's event horizon, but all around us.

In a sense , it 's like a black hole 's event horizon , but all around us .


94% of the galaxies we can see today have already passed it and are lost to us forever.

94 % of the galaxies we can see today have already passed it and are lost to us forever .


Wait, if we can't interact with them, how come we can still see them?

Wait , if we ca n't interact with them , how come we can still see them ?


Well, the way we're able to see something is via light, and although the speed of light is the fastest way to travel through the universe,

Well , the way we 're able to see something is via light , and although the speed of light is the fastest way to travel through the universe ,


it needs time to get from one place to another.

it needs time to get from one place to another .


Every second light reaches us from trillions of galaxies that have passed the horizon because when their light was emitted, they were much closer to us.

Every second light reaches us from trillions of galaxies that have passed the horizon because when their light was emitted , they were much closer to us .


We are looking at their ancient past and see their ancient positions.

We are looking at their ancient past and see their ancient positions .


So the observable universe is much larger than the universe we can actually interact with.

So the observable universe is much larger than the universe we can actually interact with .


In a sense, the universe is pulling off a great show for us, showing us things that are out of reach forever.

In a sense , the universe is pulling off a great show for us , showing us things that are out of reach forever .


We have no idea what these galaxies look like today, and we will never know.

We have no idea what these galaxies look like today , and we will never know .


But we will be able to observe them for a long time as their light hits our telescopes.

But we will be able to observe them for a long time as their light hits our telescopes .


Interestingly, this means that currently the observable universe still appears to be growing,

Interestingly , this means that currently the observable universe still appears to be growing ,


as more and more light released by super distant galaxies billions of years ago is arriving at our doorsteps.

as more and more light released by super distant galaxies billions of years ago is arriving at our doorsteps .


Still, all the pockets of the universe outside the local group will one day pass our cosmological horizon.

Still , all the pockets of the universe outside the local group will one day pass our cosmological horizon .


Once they do, their light won't be able to reach us anymore, and from our perspective, they will fade away into darkness.

Once they do , their light wo n't be able to reach us anymore , and from our perspective , they will fade away into darkness .


Every second of your life, 60,000 stars pass the horizon.

Every second of your life , 60,000 stars pass the horizon .


Since you started watching this video, around 22 million stars have moved out of our reach forever.

Since you started watching this video , around 22 million stars have moved out of our reach forever .


that still leaves us with 6% that is technically in reach, which is still a ton of stuff.

that still leaves us with 6 % that is technically in reach , which is still a ton of stuff .


They are still moving away, but slow enough that we could physically reach them.

They are still moving away , but slow enough that we could physically reach them .


Although the chances are shrinking with every second that passes.

Although the chances are shrinking with every second that passes .


Everything that's more than around 5 million light years away is moving away from us.

Everything that 's more than around 5 million light years away is moving away from us .


But the closest galaxy groups are receding the slowest, so there is a time window to jump galaxy groups.

But the closest galaxy groups are receding the slowest , so there is a time window to jump galaxy groups .


The challenge is extreme though, even for type 3 civilizations.

The challenge is extreme though , even for type 3 civilizations .


Even at the speed of light, a trip to the Mafi group, the closest pocket of galaxies outside the local group, would take 11 million years.

Even at the speed of light , a trip to the Mafi group , the closest pocket of galaxies outside the local group , would take 11 million years .


If some sort of super motivated, super advanced civilization takes this challenge on, its potential sphere of influence could expand to hundreds or thousands of galaxies.

If some sort of super motivated , super advanced civilization takes this challenge on , its potential sphere of influence could expand to hundreds or thousands of galaxies .


Although, as time passes and the universe grows, they would be separated forever.

Although , as time passes and the universe grows , they would be separated forever .


It's pretty safe to assume that humans will not make this journey, at least not with technologies that are even remotely on the horizon.

It 's pretty safe to assume that humans will not make this journey , at least not with technologies that are even remotely on the horizon .


For us, the local group is most likely the largest structure that we will ever be a part of.

For us , the local group is most likely the largest structure that we will ever be a part of .


Just traveling between the stars would be an achievement of epic proportions.

Just traveling between the stars would be an achievement of epic proportions .


We would already be incredibly successful if we were to colonize our cosmic backyard, which accounts for 0.0000000000001% of the observable universe.

We would already be incredibly successful if we were to colonize our cosmic backyard , which accounts for 0.0000000000001 % of the observable universe .


As dark energy pushes the rest of the universe away from us, the local group will become more tightly bound.

As dark energy pushes the rest of the universe away from us , the local group will become more tightly bound .


All its galaxies, big and small, will merge together to form one giant elliptical galaxy with the unoriginal name, Milkdromeda, in a few billion years.

All its galaxies , big and small , will merge together to form one giant elliptical galaxy with the unoriginal name , Milkdromeda , in a few billion years .


This process might even smash huge gas clouds together and re-spark star formation for some time.

This process might even smash huge gas clouds together and re - spark star formation for some time .


And this new light will be very welcome, because at some point, the galaxies outside Milkdromeda will be so far away that they become too faint to detect.

And this new light will be very welcome , because at some point , the galaxies outside Milkdromeda will be so far away that they become too faint to detect .


Once this happens, no information outside of the local group will reach us ever again.

Once this happens , no information outside of the local group will reach us ever again .


The universe will recede from view.


A being born in the far future in Milkdromeda will think that the universe consists of nothing but its own galaxy.

A being born in the far future in Milkdromeda will think that the universe consists of nothing but its own galaxy .


When they look far into empty space, they will only see more emptiness and darkness.

When they look far into empty space , they will only see more emptiness and darkness .


They won't see cosmic background radiation, and they won't be able to learn about the Big Bang.

They wo n't see cosmic background radiation , and they wo n't be able to learn about the Big Bang .


They may have no way of knowing what we know today, the nature of the expanding universe, when it began, and how it will end.

They may have no way of knowing what we know today , the nature of the expanding universe , when it began , and how it will end .


They might think the universe is static and eternal.

They might think the universe is static and eternal .


Milkdromeda will be an island in the darkness, slowly getting darker and darker.

Milkdromeda will be an island in the darkness , slowly getting darker and darker .


Still, with its trillion stars, the local group is certainly a big enough playground to entertain humanity for a while.

Still , with its trillion stars , the local group is certainly a big enough playground to entertain humanity for a while .


After all, we still haven't figured out how to leave our solar system, and we have dozens of billions of years at the very least to explore our galaxy.

After all , we still have n't figured out how to leave our solar system , and we have dozens of billions of years at the very least to explore our galaxy .


And we have the incredible luck to exist at the perfect moment in time to see not only our future, but also our most distant past, just by looking into the night sky.

And we have the incredible luck to exist at the perfect moment in time to see not only our future , but also our most distant past , just by looking into the night sky .


As isolated as the local group is, it is our home.

As isolated as the local group is , it is our home .


And it really is a spectacular place.


You might have noticed that we sorta already made this video a few years ago, but the original had a regrettable mistake.

You might have noticed that we sorta already made this video a few years ago , but the original had a regrettable mistake .


In it, we said it would be physically impossible to ever leave the local group to reach other galaxy groups.

In it , we said it would be physically impossible to ever leave the local group to reach other galaxy groups .


But our travel limit is actually much larger, as we showed in this video.

But our travel limit is actually much larger , as we showed in this video .


It's not physically impossible to go further, but just extremely unlikely that it'll ever happen.

It 's not physically impossible to go further , but just extremely unlikely that it 'll ever happen .


So, why did we leave the video up?


Well, it has to do with the nature of the mistake.

Well , it has to do with the nature of the mistake .


We talked to astrophysicists, and they thought it didn't matter.

We talked to astrophysicists , and they thought it did n't matter .


The parts they considered important were correct, and they thought we should just leave it and move on.

The parts they considered important were correct , and they thought we should just leave it and move on .


So with that feedback, we decided to spare the video.

So with that feedback , we decided to spare the video .


But since 2016, and really thanks to you birbs, we were able to grow Kurzgesagt and add fact-checkers to the team,

But since 2016 , and really thanks to you birbs , we were able to grow Kurzgesagt and add fact - checkers to the team ,


We can't avoid making mistakes from time to time, but we can work hard on getting better, and this video kept bugging us.

We ca n't avoid making mistakes from time to time , but we can work hard on getting better , and this video kept bugging us .


So, we finally decided to replace it, not just re-upload, but remake it better and longer, and add fun universe facts to make it worthwhile.

So , we finally decided to replace it , not just re - upload , but remake it better and longer , and add fun universe facts to make it worthwhile .


We'll leave the old video up, but pin a comment and change the title.

We 'll leave the old video up , but pin a comment and change the title .


If you want to support us and our sometimes exhausting, but hopefully worthwhile methods, you can watch, share, and click the bell, and get something from our shop.

If you want to support us and our sometimes exhausting , but hopefully worthwhile methods , you can watch , share , and click the bell , and get something from our shop .


Inspired by this video's topic, we created a Milky Way poster, and a local group poster, and we're working on a series about the entire universe.

Inspired by this video 's topic , we created a Milky Way poster , and a local group poster , and we 're working on a series about the entire universe .


Visit our shop for more sciency and Kurzgesagt-y products, designed with love, and produced with care.

Visit our shop for more sciency and Kurzgesagt - y products , designed with love , and produced with care .


In any case, thank you for watching.


Few of the monsters that evolution created have been so successful at hurting us as the Variola virus, responsible for smallpox.

Few of the monsters that evolution created have been so successful at hurting us as the Variola virus , responsible for smallpox .


The carnage it caused was so terrible and merciless that it compelled humankind for the first time to act truly globally.

The carnage it caused was so terrible and merciless that it compelled humankind for the first time to act truly globally .


It was one of the greatest wins of our species over the ancient powers of nature, all made possible by... cows.

It was one of the greatest wins of our species over the ancient powers of nature , all made possible by ... cows .


Variola is a virus, a tiny machine that only seeks to reproduce itself.

Variola is a virus , a tiny machine that only seeks to reproduce itself .


Evidence of it has been found in Egyptian mummies and in writing from India and China as old as 3000 years.

Evidence of it has been found in Egyptian mummies and in writing from India and China as old as 3000 years .


1300 years ago, smallpox killed up to a third of Japan's population.

1300 years ago , smallpox killed up to a third of Japan 's population .


By the 1600s, it was one of the major causes of death worldwide.

By the 1600s , it was one of the major causes of death worldwide .


In late 18th century Europe, it killed 400,000 a year.

In late 18th century Europe , it killed 400,000 a year .


Every third person who went blind did so because of this virus.

Every third person who went blind did so because of this virus .


Even in the 20th century, a hot second ago in history, it still killed at least 300 million people.

Even in the 20th century , a hot second ago in history , it still killed at least 300 million people .


Smallpox is an abusive monster that returns over and over and over again, killing, maiming and disrupting societies.

Smallpox is an abusive monster that returns over and over and over again , killing , maiming and disrupting societies .


How could Variola be so incredibly deadly for so long and how could we have forgotten its horror so quickly?

How could Variola be so incredibly deadly for so long and how could we have forgotten its horror so quickly ?


In 2023, there are only two laboratories left where the living virus is officially stored for research.

In 2023 , there are only two laboratories left where the living virus is officially stored for research .


Which is certainly a good idea because what could possibly go wrong?

Which is certainly a good idea because what could possibly go wrong ?


Let's say that through an unfortunate series of events, the virus got out and you got infected.

Let 's say that through an unfortunate series of events , the virus got out and you got infected .


What would happen to you?


How smallpox kills?