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Sometimes the world feels boring. All the remote islands are visited, the arctic conquered, the dense jungles discovered. Except, there is still a place to explore: A wet deadly desert where mysterious creatures live in total darkness: The deep sea. Let us dive down.

For most of our history, the human population grew slowly. Until new discoveries brought us more food and made us live longer. In just a hundred years the human population quadrupled. This led to apocalyptic visions of an overcrowded earth. But the population growth rate actually peaked in the 1960s. Since then, fertility rates have crashed as countries industrialize and develop. World population is now expected to balance out at around 11 billion by the end of the century. But the big picture conceals the details.

The human immune system is the most complex biological system we know, after the human brain, and yet, most of us never learn how it works. Or what it is. Your immune System consists of hundreds of tiny and two large organs, it has its own transport network spread throughout your body. Every day it makes hundreds of billions of fresh cells. It is not some sort of abstract entity. Your immune system is YOU. Your biology protecting you from the billions of microorganisms that want to consume you and from your own perverted cells that turn into cancer. It's so manifold that it is impossible to cover in one video, so we’ll make a series looking at different aspects of it. Today, what happens when your body is invaded and your first lines of defenses are engaged in a fight for life and death?

A war has been going on for billions of years that breeds well armed monsters who struggle with other monsters for survival. Having no particular interest in us, most of them are relatively harmless, as our immune systems deal with their weapons handily. But there are exceptions. Naegleria fowleri is an amoeba that not only has developed a deadly taste for human brains but is also a match for our defenses and a guest in dramatic headlines. What happens when this monster enters your body?

Hidden in the microverse all around you, there is a merciless war being fought by the true rulers of this planet, microorganisms. Amoebae, protists, bacteria, archaea and fungi compete for resources and space. And then there are the strange horrors that are viruses, hunting everyone else. Not even being alive, they are the tiniest, most abundant and deadliest beings on earth, killing trillions every day. Not interested in resources, only in living things to take over. Or so we thought. It turns out that there are giant viruses that blur the line between life and death – and other viruses hunting them.

The largest things in the universe are black holes. In contrast to things like planets or stars they have no physical size limit, and can literally grow endlessly. Although in reality specific things need to happen to create different kinds of black holes, from really tiny ones to the largest single things in the universe. So how do black holes grow and how large is the largest of them all?

You are not a person, you are a planet, made of roughly 40 trillion cells. There is so much of you, that if your cells were human-sized, you would be as big as 20 Mount Everests. For your creepy-crawly inhabitants, this makes your body an ecosystem, rich in resources and warmth and space. A perfect place to move into and have a family. While some of these guests are welcome, most are not. Your immune system is the guardian of this planet, the force tasked with protecting yourself against the constant danger of invasion.

Everybody feels lonely sometimes. But only few of us are aware how important this feeling was for our ancestors - and that our modern world can turn it into something that really hurts us. Why do we feel this way and what can we do about it?

What would happen if we were to detonate a very very powerful nuclear weapon on the moon? Would the explosion knock its orbit towards earth, causing tidal waves and misery? Could the moon be destroyed, showering the earth in a rain of meteoric death?

Nuclear energy creates an uneasy feeling of danger for many people: ancient and dangerous minerals are concentrated to awaken seemingly unnatural powers, creating toxic elements that, if they escape, can and have killed people in horrible ways. How many people has nuclear energy killed and how?

For years, you have been asking us how we make our videos. So let’s finally talk about it! From research, writing the script, illustrating, to animating, narrating and composing music, a Kurzgesagt video takes roughly 1.200 hours to produce!

As you may have noticed, we like to blow stuff up on this channel. So when the International Red Cross approached us to collaborate on a video about nuclear weapons, we were more than excited. Until we did the research. It turned out we were a bit oblivious off the real impact of nuclear weapons in the real world, on a real city. And especially, how helpless even the most developed nations on earth would be if an attack occurred today. So hopefully this video demonstrates how extremely non fun a real world nuclear attack would be, without being to gruesome. This collaboration was a blast (no pun intended) and we want to say a huge thank you to the International Red Cross!

It is time to reframe how we think about our past. We need a new year 0 for humanity. But which one should we choose and why?

Black hole stars may have been the largest stars to ever exist. They burned brighter than galaxies and were Larger than any star today or that could ever exist in the future. But besides their scale, what makes them special and weird is that deep inside, they were occupied by a cosmic parasite, an endlessly hungry black hole. How is that even possible?

66 million years ago, maybe on a Tuesday afternoon, life was the same as it had been the day before or a thousand years before or pretty much a million years before. Things were good for our feathered dinosaur buddies. Until a tiny, tiny detail in the sky changed.

What would happen if we were to detonate a very very powerful nuclear weapon on the moon? Would the explosion knock its orbit towards earth, causing tidal waves and misery? Could the moon be destroyed, showering the earth in a rain of meteoric death?

The future of humanity seems insecure. Rapid climate change, political division, our greed and failings make it hard to look at our species with a lot of optimism and so many people think our end is in sight. But humans always thought they lived in the end times. Every generation assumes they’re important enough to witness the apocalypse and then life just goes on. This is a problem because it leads to short term thinking and prevents us from creating the best world for ourselves and our descendants. What makes this worse is that we actually may live at an extremely critical moment in human history. To understand why, let us look at the temporal window of humanity and ask: When will the last human be born and how many people will there ever be?

Kurzgesagt is lying to you, in every video, even in this one. Because our videos distill very complex subjects into flashy ten minute videos and unfortunately, reality is, well, complicated. The question of how we deal with that, is central to what we do on this channel and something we think about a lot.

Food is arguably the best thing about being alive. No other bodily pleasure is enjoyed multiple times every day and never gets old. It is an expression of culture, our parents' love and a means of celebration or comfort. That’s why it hits a special nerve when we are told we should change what and how we eat to fight rapid climate change. One of the most delicious foods, meat, gets the worst press. It doesn’t help that the topic is really hard to properly research yourself and debates get emotional quickly. But clearly science can give us an answer! The reality is, well, it’s complicated. Let’s take a look at three climate arguments against meat that are used a lot and see what happens.

Since the Industrial Revolution, humans have released over 1.5 trillion tonnes of carbon dioxide or CO2 into the earth's atmosphere. In the year 2019 we were still pumping out around 37 billion more. That’s 50% more than the year 2000 and almost three times as much as 50 years ago. And it’s not just CO2. We’re also pumping out growing volumes of other greenhouse gases such as methane and nitrous oxide. Combining all of our greenhouse gases, we’re emitting 51 billion tonnes of carbon dioxide equivalents each year. And emissions keep rising – but they need to get down to 0!

In a very short amount of time the human population exploded and is still growing very fast. Will this lead to the end of our civilization?

Facebook just announced 8 billion video views per day. This number is made out of lies, cheating and worst of all: theft. All of this is wildly known but the media giant Facebook is pretending everything is fine, while damaging independent creators in the process. How does this work?

Absolutely everything you think about yourself and the universe could be an illusion. As far as you know, you are real and exist in a universe that was born 14 billion years ago and that gave rise to galaxies, stars, the Earth, and finally you. Except, maybe not.

In nearly every corner of the Earth, ants wage war against each other. Their weapons are what nature gave them. Some have strong armour, deadly stingers or sharp mandibles. And then there is this tiny, and not very impressive ant. But it rules the biggest empire any ant has ever built. A colony spanning continents and fighting wars that leave millions of casualties. Let’s take a look at this unlikely warrioress: Linepithema humile, the Argentine ant.

What if we could stop aging forever?

If you could decide today... how long do you want to live?

Our home is burning. Rapid climate change is destabilizing our world. It seems our emissions will not fall quickly enough to avoid runaway warming and we may soon hit tipping points that will lead to the collapse of ecosystems and our civilization. While scientists, activists and much of the younger generation urge action, it appears most politicians are not committed to do anything meaningful while the fossil fuel industry still works actively against change. It seems humanity can’t overcome its greed and obsession with short term profit and personal gain to save itself. And so for many the future looks grim and hopeless. Young people feel particularly anxious and depressed. Instead of looking ahead to a lifetime of opportunity they wonder if they will even have a future or if they should bring kids into this world. It’s an age of doom and hopelessness and giving up seems the only sensible thing to do. But that’s not true. You are not doomed. Humanity is not doomed.

Electricity is all around us, all the time. It makes our lives easier, safer, more fun and most of us never think about it. But is there such a thing as too much electricity? Electronic devices emit an electromagnetic field, which is suspected to cause cancer. We read countless sources on this topic to summarize the results of the latest research for you.

What happens if make a huge pile from all 15,000 nuclear bombs and pull the trigger? And what happens if we make an even bigger pile?

Did you know that we could start building a Lunar Base today?

What causes addiction? Easy, right? Drugs cause addiction. But maybe it is not that simple.

We take a fair look at some of the best counter arguments for legalization and see how they hold up in review.

The universe is pretty big and very strange. Hundreds of billions of galaxies with sextillions of stars and planets and in the middle of it all there is earth, with you and us. But as enormous as the universe seems looking up, it seems to get even larger when you start looking down. You are towering over worlds within worlds, within worlds – each in plain sight and yet hidden from your experience. Let’s go on a journey – we’ll start in a park, about a thousand meters long, enough for a 15 minute walk. Every time we click a magic button, we’ll become a thousand times smaller. Ready? Let’s go.

In the 1970s thousands of Chickenheads rained from the sky in Europe, making foxes and other wildlife confused and very happy. Why? They were filled with a vaccine to fight the deadliest virus known to humanity – since the 1930s a rabies epidemic had been sweeping across wildlife populations in Europe and humans wanted to finally get rid of the virus once and for all. Rabies is named after Lyssa, the ancient Greek spirit of mad rage, and has been haunting us for at least 4000 years. It can turn animals into angry beasts and humans into zombies that fear water. But what makes Lyssa fascinating is not just how bizarre and deadly its infection is, but also how incredibly good it is at avoiding our defenses.

Is there a border we will never cross? Are there places we will never reach, no matter how hard we try? It turns out, there are. 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?

Getting rare materials from the ground into your phone is ugly. The mining industry is responsible for air and water pollution and the destruction of entire landscapes. But what if we could replace the mining industry on Earth with a clean process that can’t harm anyone? Well, we can. All we need to do is look up.

The sun. Smooth and round and peaceful. Except when it suddenly vomits radiation and plasma in random directions. These solar flares and coronal mass ejections, or CMEs can hit earth and have serious consequences for humanity. How exactly do they work, how bad could they be and can we prepare for them?

In September of 1940, an 18-year-old mechanic named Marcel Ravidat was walking his dog, Robot, in the countryside of Southwestern France when the dog disappeared down a hole. Robot eventually returned but the next day, Ravidat went to the spot with three friends to explore the hole. And after quite a bit of digging, they discovered a cave with walls covered with paintings, including over 900 paintings of animals, horses, stags, bison and also species that are now extinct, including a wooly rhinoceros. The paintings were astonishingly detailed and vivid with red, yellow and black paint made from pulverized mineral pigments that were usually blown through a narrow tube, possibly a hollowed bone, onto the walls of the cave. It would eventually be established that these artworks were at least 17,000 years old.

At this very second, you are on a narrow ledge between life and death. You probably don’t feel it, but there is an incredible amount of activity going on inside you. And this activity can never stop. Picture yourself as a slinky falling down an escalator moving upwards – the falling part represents the self replicating processes of your cells, the escalator represents the laws of physics, driving you forwards. To be alive is to be in motion but never arriving anywhere. If you reach the top of the escalator there is no more falling possible and you are dead forever. Somewhat unsettlingly, the universe wants you to reach the top. How do you avoid that and why are you alive?

Everybody is familiar with the feeling that things are not as they should be. That you are not successful enough, your relationships not satisfying enough. That you don’t have the things you crave. 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. An antidote against dissatisfaction so to speak: Gratitude.

Neutron stars are one of the most extreme and violent things in the universe. Giant atomic nuclei, only a few kilometers in diameter but as massive as stars. And they owe their existence to the death of something majestic.

A war has been raging for billions of years, killing trillions every single day, while we don’t even notice. This war involves the single deadliest being on our planet: the bacteriophage.

Why should you care about the well-being of people half a globe away?

Everybody is talking about Measles – but what does the virus actually do in the body? Is it really so harmful that you need a vaccination? We go deep into the body of an infected person and see what Measles does and how the immune system reacts to it!

The observable universe is a big place that has been around for more than 13 billion years. Up to two trillion galaxies made up of something like 20,000 billion billion stars surround our home galaxy. In the milky way alone scientists assume there are some 40 billion earth like planets in the habitable zone of their stars. When we look at these numbers it is hard to imagine that there is nobody else out there.

Meat is a complicated issue. But also a delicious one. Let's talk about it.

Where are the limits of human technology? And can we somehow avoid them? This is where quantum computers become very interesting.

The universe is magnificent and vast. Hundreds of billions of galaxies, trillions of stars, and even more planets. If even the tiniest fraction are habitable, then the Universe should be teeming with life. And yet we see nothing, only vast emptiness. Where is everyone else? The answer to this riddle could be as exciting as it is creepy: we are early, born before almost all other life – but very soon this may change. Not only might aliens appear, they could quickly surround us. An irreversible competition for the universe might be about to begin.

Look around you. Where are you? Where is this place you are occupying? Somewhere in a room, maybe in a city on a continent on a planet orbiting a star in a galaxy among billions. But… where is all of that? While this may feel like a daft question, it turns out that the concept of an absolute position is something humans made up. In a nutshell, the universe is a big bag of space that has things in it. If someone removed all these things, the stars and planets and black holes and dust, there would just be empty space left. In empty space, the concept of having a position loses all meaning. Empty space is uniform, the same everywhere.

The desire to be free from the limits of the human experience is as old as our first stories. We exist in an endless universe, only bound by the laws of physics and yet, our consciousness is trapped in mortal machines made of meat. With the breathtaking explosion of innovation and progress, for the first time the concept of leaving our flesh piles behind and uploading our minds into a digital utopia seems possible. Even like the logical next step on our evolutionary ladder.

Nothing in the Universe is static. In the milky way, billions of stars orbit the galactic center. Some, like our sun, are pretty consistent, keeping a distance of around 30,000 light years from the galactic center, completing an orbit every 230 million years. This dance is not an orderly ballet - more like a skating rink filled with drunk toddlers. This chaos makes the galaxy dangerous. Our solar neighbourhood is constantly changing, with stars moving hundreds of kilometers every second. Only the vast distances between objects protect us from the dangers out there. But we might get unlucky in the future. At some point we could encounter a star going supernova. Or a massive object passing by and showering earth with asteroids. If something like this were to happen we would likely know thousands, if not millions of years in advance. But we still couldn’t do much about it. Unless… we move our whole solar system out of the way.

If humans want to expand into space, it will take us incredible amounts of energy. How do we do that? Easy: we will just use the sun’s energy by realizing the most ambitious construction project in history. This is how it works.

What are the principles behind Homeopathy and does it work?

How does fusion energy work and is it a good idea?

Black holes. Lets talk about them.

Where are all the aliens? The universe is too big and too old, why have we not met aliens yet? Do they live in computers? Were they wiped out by an ancient super intelligence? Or are we just to primitive to understand their motives? Whatever the answer is, it is incredibly important for our own future.

The universe is unbelievably big – trillions of stars and even more planets. So… there just has to be life out there, right? But where is it? Why don’t we see any aliens? Where are they? And more importantly, what does this tell us about our own fate in this gigantic and scary universe?

Do we need nuclear energy to stop climate change? More and more voices from science, environmental activists and the press have been saying so in recent years – but this comes as a shock to those who are fighting against nuclear energy and the problems that come with it. So who is right? Well - it is complicated.

What is the largest star in the Universe? And why is it that large? And what ARE stars anyway?

Black holes might create infinite universes while destroying time and space. Everything in existence could be black holes, all the way down. We might live inside a black hole that is inside a black hole, that is inside a black hole. But let’s start at the beginning and build a black hole out of air.

58 of you watching this video right now will not be alive next week. And it’s not because of some freak accident or rare disease. It’s because of everyday actions you probably think are harmless. Let’s save your life today by looking at what is most likely to kill you next week – so you can avoid it.

Never before in human history have we been richer, more advanced or powerful. And yet we feel overwhelmed in the face of rapid climate change. It seems simple on the surface. Greenhouse gases trap energy from the Sun and transfer it to our atmosphere. This leads to warmer winters, harsher summers. Dry places become drier and wet places wetter. Countless ecosystems will die while the rising oceans swallow coasts and the cities we build on them. So why don’t we just like… prevent all of that? Well, it’s complicated.

A ruthless murder was committed! Someone killed the dinosaurs and we have the murderer! Witnesses say that an Everest-sized asteroid hit Earth, devastated the planet and caused a mass extinction. A simple, fascinating and convincing explanation. Or… is it?

We often assume that advanced technology will make it easy for aliens to colonize space. But what if space exploration is always difficult, no matter how advanced you are? Let’s travel back in human history, to the colonization of Oceania over 5000 years ago, to find parallels between ancient explorers and extraterrestrial civilizations.

You’ve got trillions of viruses inside you – right now! But these aren’t the viruses you fear. Some of them are your body’s secret protectors, keeping deadly bacteria in check and even killing cancer cells. But what happens when they turn against you? Let's look at the wild world of the human virome.

In 2022 nearly half of Americans expected a civil war in the next few years, one in five now believes political violence is justified. And it is not just the US but around the world. People increasingly see themselves as part of opposing teams. There are many different reasons for this, but one gets blamed a lot: social media. Social media divides us, makes us more extreme and less empathetic, it riles us up or sucks us into doom scrolling, making us stressed and depressed. It feels like we need to touch grass and escape to the real world. New research shows that we might have largely misinterpreted why this is the case. It turns out that the social media internet may uniquely undermine the way our brains work but not in the way you think.

Time travel is possible. In fact, you’ve been doing it since the day you were born. But what if we told you there’s a way to hack the universe and manipulate time itself? We just have to do two simple things to make it happen: 1. Make a lot of physicists grumpy. 2. Shoot one twin through space against their will, while the other chills on Earth. Let's go!

Exercising doesn’t help you lose weight. In fact, it barely changes your daily calorie burn. Welcome to the workout paradox! Let’s dive into the science of how your body actually handles calories and sabotages your best efforts to burn them.

You may think you have free will and can choose what you do, but this might be an illusion. Your body is made up of particles that blindly follow the laws of physics, with every outcome already predetermined. So, you might not have any free will at all. Is free will an illusion, or does it exist? Which philosophical camp is right?

Could aliens destroy us from light years away? Another day at Kurzgesagt Labs, where we answer the most important questions with science. Today: how might civilizations wage war across light years? What kind of devastating weapons could they use and what would they look like?

Your tattoos are inside your immune system, literally. With each very tasteful piece of art, you kick start a drama with millions of deaths, grand sacrifices and your immune system stepping in to protect you from yourself. Let us get under your skin with our newest video.

What do you know about the Moons of Mars? Nothing? They are super cool (and strange), promise.

Climate Change is just too much. There is never any good news. Only graphs that get more and more red and angry. Almost every year breaks some horrible record, from the harshest heat waves to the most rapid Glacier melt. It’s endless and relentless. We have known for decades that rapid Climate Change is being caused by the release of Greenhouse Gases. But instead of reducing them, in 2019 the world was emitting 50% more CO2 than in the year 2000. And emissions are still rising. Why is that? Why is it so hard to just stop emitting these gases?

Here in the Kurzgesagt labs we test very important ideas to see what happens when you blow things up or play with black holes. Many of you suggested that we look into an idea that sounds reasonable: Shooting nuclear waste into space. It is one of those concepts that seems like an easy fix for one of the main problems with nuclear energy. But it turns out this idea is not just bad but horribly bad and it gets worse the longer you think about it.

Supernovae are the most powerful explosions in the universe, unleashing enough energy to outshine galaxies. We have no real metaphor for their power – if the sun were to magically go supernova it would feel like you were being hit by the energy of a nuclear explosion, every second. For weeks. While supernovae are the engines of creation, forging the elements that enable life, they also burn sterile whole regions of galaxies. So what would happen if one hit earth?

Mr. President! Nuclear missiles will strike our country in 14 minutes. I know it’s your first day in office so I’m going to walk you through it, but you’re the only one who can authorize our nuclear retaliation in response and you’ve only got a few minutes to make a decision!

Every two years one million Japanese disappear, China’s population will halve by the end of the century, the median age in Italy has reached 48. All around the world birth rates are crashing – Is humanity dying out? What is going on and how bad is it?

What is outside of the universe? We know that the universe had a beginning 14 billion years ago and that it has been expanding ever since. But something that is expanding should also have an edge, right? What would you see if you went there?

So what is the difference between you and a rock? This seems like an easy, even stupid question. But even the smartest people on Earth have no idea where to draw the line between living and dead things. Which leads to mind-blowing implications. What is life after all? And is death really a thing? Let's look into it together.

Mars is a disappointing hellhole lacking practically everything we need to stay alive. It looks like we’ll only ever have small crews spend a miserable time hidden underground. Except, we could terraform it into a green new world. But to solve the planet’s problems, we first need to make it worse and turn it into oceans of lava with gigantic lasers.

Black holes can destroy everything – but can they be destroyed? What happens if we push physics to the absolute limits, maybe even break it and the universe in the process? Let’s create a tiny black hole, about the mass of our moon, in the Kurzgesagt Labs and try to rip it apart.

The Moon might be much bigger than you think it is.

If Neptune didn't catch Triton we might have another Dwarf Planet in our Solar system -- maybe even another Planet or double system. We show how this could have happened.

What does the Ebola virus actually do in your body? Why is it so dangerous and why does it kill so many people? We take a look at the apocalyptic war that rages in the body after an infection by the Ebola virus and the soldiers fighting.

Friends make life good. They provide the scaffolding that makes it not just bearable but fun. They give us a sense of meaning and purpose and are a source of security, self esteem and happiness. Almost nothing predicts how happy you will be as how connected you feel and a lack of social connection is associated with a number of diseases and a shorter life. But maybe you have scrolled through your phone, unsure who to call to go to a movie with, to celebrate with or ask for comfort. You may realize that you don’t have enough friends and feel lonely. And it is not just you. Disconnectedness and loneliness are widespread. Many people want more close friends but don’t know how to get them.

Vaccines are one of our best tools to prevent dangerous diseases, but they come with side effects. So would it be safer not to vaccinate?

A breathtaking scientific revolution is taking place – biotechnology has been progressing at stunning speed, giving us the tools to eventually gain control over biology. On the one hand solving the deadliest diseases while also creating viruses more dangerous than nuclear bombs, able to devastate humanity. What is going on?

The mechanisms of evolution explained in one video. The theory of evolution explains how the enormous variety of life could come into existence. How it is possible for primitive life forms to spawn the millions of different creatures, that exist today. Unfortunately, evolution is often misunderstood, because it's mechanisms seem counter intuitive.

Learn about the role of the sea in global warming.

Nuclear war, cat gifs and reddit? Wait, what?

Most Conspiracy Theories are stupid. By the power of the internet they spread like wildfire and often poison discussions. But there is hope – we developed a way to debunk conspiracies in just a few seconds…

The Egg, a story by Andy Weir, animated by Kurzgesagt. This video was more than 2 years in the making and is a little bit different than the others on this channel. We hope you like it.

For the fifth time, we present to you the Human Era Calendar for the year 12,021 – this time it is all about the journey of humanity, beginning tens of thousands of years ago, leading into the revolution of agriculture, to ancient high civilizations and the beginning of modern times, culminating in a vision for our future. You can get the limited Edition now until we sell out and then never again. As always the calendar features 12 illustrated pages printed on high quality paper in Europe and the US. And this year the cover is especially shiny. The calendar will look great on your wall and let you dream about a glorious future. We truly have come far as a species!

The Universe is incredibly big and seems full of potential for life, with billions of habitable planets. If an advanced civilization had the technology to travel between the stars, at just 0.1% of the speed of light, It could colonize our galaxy in roughly 100 million years. Which is not that long given the billions of years the milky way has existed – so in principle any spacefaring civilization should be able to spread rapidly over huge sectors of the galaxy. And yet we see nothing, hear nothing, the universe seems empty. Devoid of others. This is the Fermi Paradox, which we have discussed in more detail in other videos. Confronted with the seemingly empty universe, humanity faces a dilemma. We desperately want to know if we are alone in the Milky Way. We want to call out and reveal ourselves to anyone watching but that could be the last thing we ever do. Because maybe the universe is not empty. Maybe it’s full of civilizations but they are hiding from each other. [...]

At its height, the Roman Empire was home to about 30 % of the world’s population, and in many ways the pinnacle of human advancement. Rome became the first city in history to reach one million inhabitants and was a center of technological, legal, and economic progress. An empire impossible to topple, stable and rich and powerful. Until it wasn’t anymore. First slowly then suddenly, the most powerful civilization on earth collapsed. If this is how it has been over the ages, what about us today? Will we lose our industrial technology, and with that our greatest achievements, from one dollar pizza to smartphones or laser eye surgery? Will all this go away too?

We need to have an honest conversation about smoking: The problem with smoking is that it is way more than just a physical addiction. Smoking creates a temporary problem and offers an instant solution. Once your brain is used to nicotine, for up to 72 hours you are itchy,nervous and stressed – but one drag and instantly, you feel really good. It also helps you focus and take breaks during work, while suppressing your appetite. So why is it such a bad idea?

Fever feels bad. So we take medication to suppress it – but is this a good idea? It turns out fever is one of the oldest defenses against disease. What exactly is a fever, and how does it make your immune defense stronger? Should you take a pill to combat it?

We’ve found a new planet, home to octillions of the most extreme beings living in the most absurd and deadly hellscape. In absolute darkness, crushed by the weight of mountains, starved of oxygen, cooked alive, bathed in acid, salt or radiation. And yet, they live for thousands, perhaps millions of years! It turns out, this planet is not in space – it is inside the crust of Earth! This is the deep biosphere and we basically learned that it exists yesterday. Its volume is at least twice as large as all the Earth’s oceans, home to more microbes than the rest of the entire planet.Their total biomass is more than 20 times greater than all humans, livestock, and animal wildlife. Let’s descend into this mad, deadly world where none of the rules we thought are mandatory for life apply.

Leaving earth to find new homes in space is an old dream of humanity and will sooner or later be necessary for our survival. The planet that gets the most attention is Mars, a small, toxic and energy poor planet that just about seems good enough for a colony of depressed humans huddled in underground cities. But what if we think bigger? What if we take Venus, one of the most hostile and deadly places in the solar system and turn it into a colony? Not by building lofty cloud cities, but by creating a proper second earth? It might be easier than you think.

Atoms are very weird. Wrapping your head around exactly how weird, is close to impossible – how can you describe something that is SO removed from humans experience? But then again, they kind of make up everything, so let us try anyways.

Banks are a riddle wrapped up in an enigma. We all kind of know that they do stuff with money we don’t understand, while the last crisis left a feeling of deep mistrust and confusion. We try to shed a bit of light onto the banking system. Why were banks invented, why did they cause the last crisis and are there alternatives?

Nuclear energy might be a failed experiment. In over sixty years the technology has not only failed to keep its promise of cheap, clean and safe energy, it also caused major catastrophes and enabled more nuclear weapons while the nuclear waste problem is still not solved.

Cancer is a creepy and mysterious thing. While we tried to understand it, to get better at killing it, we discovered a biological paradox that remains unsolved to this day: large animals seem to be immune to cancer. Which doesn’t make any sense – the bigger a being, the more cancer it should have. To understand why, we first need to take a look at the nature of cancer itself.

Let us explore the scientific mystery of what would happen to you, if Earth suddenly turned into gold! The “Midaspocalypse”, based on the ancient tale of King Midas who was cursed so everything he touched turned into gold.

The current crisis in Iraq explained in under 5 minutes.

We live in the most peaceful time in human history. Wait, what? Seriously? That can't be right, there are more wars than ever! Well, no and they're killing fewer and fewer people, even though the world population is at an all-time high... and the numbers prove it! We explain how we came to this conclusion, and why war might... go away.

We are so used to some things that we stopped wondering about them. Like light. What is light? Some kind of wavy thing, right? Kind of.

In 2023, Kurzgesagt has existed for 10 years (which is insanely long in internet years). We are among the largest sciencey channels on Youtube and still a bit of a black box to people. So let us talk about ourselves in three parts: Our backstory, how we finance our work, and the values of Kurzgesagt!

The universe today is happy and healthy, with exciting things going on – but at some point the night will turn dark. Everything that once was, will peacefully sleep forever. But what is the last thing that will ever happen? Let's travel to the end of the universe…

A nuclear bomb is the most devastating explosion ever created. One bomb can end tens of thousands of lives immediately and hundreds of thousands through the radioactive aftermath. However, the worst part comes afterward: a nuclear winter that might kill billions, potentially leading to the complete collapse of our civilization. In a nuclear winter, there are no winners – only starving losers. How exactly does it work and what would it look like?

The white death has haunted humanity like no other disease following us for thousands, maybe millions of years. In the last 200 years it killed a billion people – way more than all wars and natural disasters combined. Even today it’s the infectious disease with the highest kill count. But what is this horrible disease?

There are cosmic snipers firing at random into the unvierse. What are they and what happens if they hit us?

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. It was one of the greatest wins of our species over the ancient powers of nature, all made possible by… cows.

Earth is 4.5 billion years old - which is approximately the same amount of time it took us to create this video. We’ve scaled the complete timeline of our Earth’s life into our first animated movie! Every second shows about a million years of the planet’s evolution. Hop on a musical train ride and experience how long a billion years really is. It’s the perfect background for your next party, a great way to take a break from studying, or a fascinating companion while you’re on the go … and our celebration of 10 years of kurzgesagt.

Is your future already written? Do your past, present, and future all exist right now? Surprisingly, the answer could be yes. Let's take a look at what time is and how it works – in our first video of the year!

Nuclear Energy is a controversial subject. The pro- and anti-nuclear lobbies fight furiously, and it's difficult to decide who is right. So we're trying to clear up the issue - in this video we discuss how we got to where we are today, as the basis for discussion.

The last star in the universe will be a red dwarf. Red dwarfs in general might be great places to look for aliens – or planets for humans to find a new home after our solar system has died.

What happens if we bring the sun to earth? No, seriously.