The History of Life, I guess

From sharing the Earth with many other human species merely as hunter-gatherers trying to brave the elements to building rockets, creating the internet, and now with our eyes set on Mars, the history of humanity is one that's filled with determination, cooperation, and ingenuity. We have done so much more for ourselves than our ancestors could have ever imagined. Today, humans dominate contemporary life on Earth, but we haven't always been this powerful. So how did we get here? What's our story? This is the entire history of humanity in 10 minutes.

Our story begins around 200,000 years ago with the emergence of our species, Homo sapiens. At the time, we shared our world with several other human species or hominins. The most well-known are Homo erectus, the upright man, and Homo neanderthalensis, commonly referred to as neanderthals. The scientific consensus is that we all come from a common ancestor, the first species of hominins that evolved approximately 2.5 million years ago. The genes of these hominins suggest that they crossed paths and even occasionally inbred. Sadly, for the last 15,000 years, we've been the only human species to walk this Earth, which raises the question: What happened to the rest of us?

The scientific debate concerning the cause of extinction of all other human species is far from over. Some theories attribute their demise to rapid changes in the local climate, while others lean towards a more aggressive explanation, with mass graves and cracked skulls found at archaeological sites as backup evidence. Another possibility is that they didn't go extinct at all, but rather that we all merged into one species through interbreeding. Whatever the real course is, there's only one species of humans left today: Homo sapiens.

For many millennia, humans were just another link in the food chain, another stop in the circle of life, bipedal primates that were no more significant than other species participating in the ecosystem. So what changed? What allowed us to become the only known species to successfully migrate and adapt to a wide variety of ecosystems across our planet, fundamentally change global climate, and even venture into space? This development didn't happen overnight; it took tens of thousands of years. What exactly transpired is something that we'll never know for sure, but historians have generally agreed on a few major landmarks in our prehistory that stand out above all others.

Striding bipedal locomotion was novel for primates roaming the prehistoric African savannah, but though it did free up early humans' arms for other tasks, it didn't yet give them a significant edge over other species in their ecosystem for millions of years to come. What did forever change our place in the food chain, though, was the use of fire. The first evidence for hominin interactions with one of the most destructive forces of nature dates back to around 1.5 million years ago. We started out by adding fuel to naturally occurring fires to keep them burning. It would take us around another million years for us to start creating fires on our own, which enabled its habitual use. And once we figured it out, everything changed.

The mastery of fire by hominin species was extremely useful for many different reasons. We used it to provide warmth when the weather went cold, light when the sky turned dark, protection against predators and insects, and best of all, we used it to cook our meals. By cooking food, Richard Wrangham posits in his cooking hypothesis that our bodies required less energy for digestion, which allowed for more energy to be allocated to different functions of the brain. This, Wrangham believes, is what eventually led to the development of complex language.

According to Israeli scientist Yuval Noah Harari, though, it wasn't only our fiery ways that set Homo sapiens apart from all other species. He believes there was something else: the cognitive revolution. Around 70,000 years ago, we developed the capacity for large-scale collaboration through the ability to communicate complex information. The cause is uncertain, most likely a chance gene mutation, but the effect was unparalleled. Many species communicate to each other about an imminent threat or the desire to mate. But during the cognitive revolution, Harari argues that Homo sapiens started talking to each other about other members of the tribe and collective fictions like animus deities and spirits, which allowed even complete strangers to cooperate effectively. Who knew that gossiping would turn out to be one of our biggest strengths?

Even today, the functioning of our societies completely depends on our belief in collective fictions like human rights, the value of money, and the law. Such belief systems bind millions of people to each other and, back then, made it possible for Homo sapiens to conquer the world. This development of complex language allowed humans to move out of Africa into Europe and Asia, and eventually into Australia and America. The reason for this venture far away from home is unclear, but it was most likely environmental pressures, like severe droughts and lack of food, that pushed them out. Their migration was far from peaceful, though; due to hunting and competition for resources, it led to the extinction of a lot of endemic mammals.

Then, around 12,000 years ago, something incredible happened, theorized to have occurred in multiple different locations around the world simultaneously. Humans decided to start cultivating plants and breeding animals for food, essentially changing us from nomads to settlers, from hunter-gatherers to farmers. As a result, food supply stabilized, and acquiring nourishment wasn't a full-time occupation for every member of the tribe anymore. This allowed some members of the tribe enough time to specialize in other kinds of labor. We could now have artisans, warriors, and child caregivers.

With time, these settlements grew into cities, and cities into empires, often united under collective religious fictions. This ensued the development of culture, customs, traditions, and perhaps most importantly, written text. The emergence of written text distinguishes prehistory, defined by scholars as the period before written records, from history, defined as the period after. While prehistory is primarily based on interpretations from archaeological findings, our understanding of history is mostly dictated by written records. The oldest written records we found to date were discovered in Egypt and are estimated to be 5,000 years old. The ancient Egyptian and Mesopotamian civilizations are said to be the cradles of society as we know it.

Sadly, the human story would not be complete without some of the biggest atrocities the Earth has ever seen. While large-scale collaboration of humans under common beliefs led to some of our greatest achievements, it also had terrible consequences such as wars, genocide, and enslavement. Why does this unrivaled capacity for teamwork carry with it such a devastating power? The flip side of our collective fiction's potential to unite is its power to separate. Or rather, unite against competition for resources is a natural phenomenon, but it had never before been as organized and ruthless as under human civilization. The belief in, for instance, a deity, the divinity of a ruler, or national superiority became a strong enough motivator to wish death upon groups of people with opposing beliefs or different identities.

English philosopher Thomas Hobbes argues that humans are inherently self-interested and competitive, and that we can both control our brutish nature by subjecting ourselves to rigid authoritative bodies who maintain peace. Genevan philosopher Rousseau counters this by saying that we're not biologically wired to coexist in numerous groups and large-scale civilizations inevitably breed extreme inequality in social division and eventually collapse. He believes our good nature is corrupted by political and social institutions, which reward selfish desires that would have been kept in check by smaller-sized prehistoric communities of hunters and gatherers.

Either way, the intricate web of human interactions that constitutes contemporary society is unrecognizable and undeniably more complex compared to the way our genetically indistinguishable prehistoric ancestors organized themselves. This has led to issues beyond our control. We could fill dozens of videos with human accomplishments from the past few thousand years: from the construction of the pyramids to the invention of mathematics, from Greek politics to the morals of Confucianism, from Buddhist wisdom to Roman infrastructure. But looking at modern history, one development in particular stands out: the scientific revolution.

This method of systematic experimentation originated in Europe and radically changed our understanding of the universe, our planet, and ourselves. Empirical observations replaced superstitions as the framework we use to interpret the world around us. During the 18th century, also referred to as the Age of Enlightenment, religious doctrines were replaced by a thirst for reason in order to improve the human condition. Together with the flood of groundbreaking discoveries and innovations that resulted from this age came a reinterpretation of our relationship with nature. This is exemplified by French philosopher, scientist, and mathematician René Descartes, who a few centuries earlier claimed our progression in different scientific fields could and should make us masters and possessors of nature.

This paradigm shift, in combination with previously unimaginable technological advancement, gave rise to what is referred to as the industrial revolution and ushered into an era of not only unprecedented productivity and discovery but also unprecedented exploitation of the natural world and human labor. According to economic anthropologist Jason Hickel, the most important driver of this mass exploitation was an economic system that demands perpetual expansion. He argues that the rise of capitalism required the destruction of self-sufficient subsistence economies and the creation of artificial scarcity and cheap labor. An example of this were the enclosure acts, a series of acts proposed by the British Parliament between 1604 and 1914, in which the state essentially enclosed previously common land and converted it to private property. As a result, a lot of local people lost access to land that had been available to them for generations and were left with no other choice than to offer their labor to a landowner or move to the city.

This desire for economic expansion wasn't limited to the appropriation of the commons within national borders but is expected to have driven European colonization of most of the world. Oxford economist Kate Raworth argues that an economic system that depends on infinite growth is completely unsustainable, considering a planetary system with finite resources. If the global economy grows at 3% per year, which is relatively low, economic activity would double every 24 years. Since GDP growth is coupled to material and energy use, it significantly contributes to the climatic disruption and immense pressure on planetary boundaries that the productivity of the industrial revolution has brought with it. And while we have progressed further than ever in fields like healthcare, food production, or even astronomy, under this growth paradigm, Raworth suggests it's not essential to improving human welfare and scientific discovery. In her book Donut Economics, she puts forth that expanding the commons or public services, essentially reversing the privatization of the last few centuries, and a reinterpretation of the natural ecosystem and our place within it provide a stronger foundation for human life in nature to flourish.

Humanity's past is one that's filled with a lot of incredible achievements. Thousands of years have now passed since we first walked the Earth, and our world will be completely unimaginable to our prehistoric ancestors. But we must keep in mind that in our conquest for growth, we don't destroy the very thing that gave us life and an opportunity to thrive. We must take care of nature just as it took care of us in the past. Here's to humanity's future. Let's hope that as one, the ancient hominids would have been proud.

In the summer months of 1977, NASA launched two spacecraft: Voyager 1 and 2, on a planetary grand tour. Their mission: to study Jupiter, Saturn, Uranus, Neptune, and everything in between. But that was actually not the initial plan; they were only intended to fly to Jupiter and Saturn to examine both planets, their moons, and their surroundings. It was only after the mission had commenced that they realized a larger mission was indeed possible by remotely programming the onboard computers, and thus a mission extension was issued to include the far reaches of the solar system.

Astronomers had also observed that the planets in our solar system were approaching an optimal layout, which would allow the spacecraft to use what is called a gravitational assist—a planetary slingshot that allows spacecraft to pick up some orbital speed of the planet they're flying past. This sort of alignment takes place roughly once every 175 years and it proved crucial to the Voyager missions. It meant they could cover much larger distances and much higher speeds without carrying as much fuel, which could then be used to carry more instruments.

Lo and behold, the two Voyager spacecraft are now the furthest thing mankind has ever built. Within the first decade of the 21st century, both spacecraft had left the solar system, traveling millions of miles every single day. Even though the stars didn't, the planets certainly did. And on their way, they sent home some of the most breathtaking images of our planetary neighbors. These include the famous "Pale Blue Dot" image, where the Earth is barely a pixel against the stellar glow of the sun. These images were the first of their kind, and to imagine that they were taken using camera technology from the 1970s is truly remarkable.

To quote Rich Terrell, part of the imaging science team for the Voyager missions: "At the time, the biggest computers in the world were comparable to the kinds of things we have in our pocket today." And I'm not talking about your phone; I'm talking about your key fob. Of course, photos weren't the only gifts Voyager gave us. They were both decked with instruments to measure cosmic rays, plasma waves, magnetic fields, and other such data. More than four decades after launch, the Voyager spacecraft talk to us to this very day, shattering the initial mission timeline of only 5 years. But such incredible longevity has come at a cost. The cameras that captured those stunning images have been turned off, and less than half of all of the onboard instruments are still functional. The instruments are continuously being reprogrammed and managed to extend their performance as much as possible. But even with all that, NASA expects radio communication to cease completely by 2025. By then, the instruments will fail to produce sufficient heat to keep themselves warm against the numbing extremes of outer space. The machines will be too cold, and the signals too weak, and all the things that are onboard will slowly stop working—all but one.

The Voyager missions were unique in their ambitiousness and scale, but similar missions had been made in the past, most notably two spacecraft from the Pioneer program: Pioneer 10 and 11 were launched in 1972 and 1973, respectively, to carry out observations that would pave the way for the Voyager missions. Also on both spacecraft were two gold anodized plaques that carried a few graphic drawings meant to be read by a space-faring civilization. Carl Sagan, Frank Drake, and Linda Salzman were responsible for designing the Pioneer plaques and during the final stages of preparation of the Voyager missions, they were approached yet again, this time with the prospect of sending not just drawings but more elaborate messages that would attempt to tell humanity's story.

This was made possible from the use of phonograph records, the most advanced admission-appropriate encoding method at the time, which would weigh just as much as the Pioneer plaques but gives the ability to include much more information. As advanced as the phonograph records were, they only had a runtime of 30 minutes or so. Representing humanity was by itself a daunting task, but to do so in only 30 minutes was downright impossible. As with everything else in the industry of space exploration, boundaries had to be pushed and solutions had to be engineered. With some adjustments to the revolution rate of the disc, they were able to increase the runtime to 90 minutes.

After the hardware was figured out, the team had to decide what they wanted on the record. For all we know, we don't share languages with our interstellar brethren, nor do we share life experiences. What we do share, though, are facts of reality: physics, chemistry, and mathematics. In fact, that was the guiding principle for the curation of the messages on these plaques initially. But you have to wonder, if this is indeed a craft that might make it to another star or a planet, or an extraterrestrial, however slim that chance might be, is this all we want to say to them? Is this all they need to know about us, that we understand math? The team at NASA certainly didn't think so, and thus began the creation of music, language, and photos for humanity's very own mixtape.

The objective was to capture the human condition at every step of this mammoth task. The team tried to make sure that the contents of the record were as representative of Earth's population as possible, which is easier said than done. You see, back in the 1970s, music outside of your own demographic was barely accessible. You either had cassettes or you listened to the song on the radio—that's it. There was no Spotify, no internet, and when you liked what you heard, you had to go out and get the physical copy. And this is what the team did for the golden record. The musical curation was also especially important for its ability to communicate feelings. There is much more to human beings than perceiving and thinking; we are feeling creatures. However, our emotional life is more difficult to communicate, particularly to beings of very different biology. Music, it seems, was at least a credible attempt to convey human emotions.

On the record is music from Bach and Beethoven, chosen specifically to highlight the mathematical properties of music—a potentially universal phenomenon. They featured artists from ancient China, Bulgaria, Iran, Congo, Peru, and many more places as a desperate attempt to do justice to the diversity of the world's music. But human emotion is volatile and unpredictable. Amidst the chaos of organizing all this music, the abundance of choice, the copyright issues, and the inaccessibility of it all, Anne and Carl Sagan grew close to each other. On June 1st, 1977, in the final days of the curation process, Anne and Carl shouted a phone call about a chin music piece Anne had just discovered. By the end of the call, Anne and Carl had expressed their feelings for each other and even ended up proposing. The process of creating profound pieces of art had seemingly brought up a spontaneous love in both of them.

In the years after the Voyager missions, the two got married and actually spent the rest of their lives together. Meanwhile, Anne had also thought of a different way to communicate with extraterrestrials. She wondered if a sufficiently advanced civilization could decode our thoughts by taking a look at our brain waves recorded on an EEG machine. The idea was pitched to Carl, who then proceeded to choose Anne herself as the person whose brain waves should be recorded. The recording took place on June 3rd, 1977, just days after Anne and Carl had proposed to each other. While most of her mental itinerary consisted of global events, she couldn't help but think about her newfound love for Carl. "My feelings as a 27-year-old woman madly in love," they’re on that record, she says.

Also on the record is an audio essay that starts with sounds from volcanoes, thunder, and other such natural phenomena, and ends with more modern creations such as the liftoff of the Saturn V rocket. It's intended to chronologically tell the story of our civilization purely by sound. The record also features greetings from 55 different languages, including the now-famous line from Carl Sagan's own son, Nick. You may have heard it before: "Hello from the children of planet Earth." The records also carried 115 images encoded in analog form. Some of the images are technical in nature, describing constants and demonstrating the scale of things, but a lot of them are seemingly arbitrary images. What they could mean is anybody's guess, and maybe that's why they're important. You see, a critical aspect of the human experience is our ability for abstraction—to feel something in a piece of art or a photo and to find meaning where there's apparently none to be found.

This picture, for example, of a girl in the supermarket, is a very ordinary picture at first glance. She is shown eating some fruit she picked up while she's still in the shopping aisles, presumably without having paid for them yet. Something you're not supposed to do. The photo ends up capturing the subtle mischief and the joy that comes with doing something like that. Meanwhile, these photos capture the intrigue of someone looking at an X-ray of their hand, the determination to make it to the finish line, and the focus of a teacher and his disciple. These photos convey all of these things, or they convey none of them. It really is for the viewer to decide, but that's what it's really about—to provide an avenue for exploration into the human psyche.

The multifaceted contents of the record certainly captured some of the most beautiful aspects of our life on this planet—expressions of love, breathtaking symphonies, you name it. But intentionally or not, the records also capture some of the not-so-beautiful aspects, ones that are nonetheless human. For example, Sagan recalls that in trying to get permission to include the greetings from the UN delegates, he came to the disappointing realization that almost all of them were men. The production team also has numerous accounts of licensing issues when trying to collect the music. You would expect an opportunity to send your song and immortalize it in the process would be the ultimate form of advertisement for any label—a no-brainer. But it was far from that. NASA, meanwhile, refused to include images of explosions, even though they are part of the lives of a lot of people in war-torn countries, in fear that it may be perceived as hostile and offensive. Carl and his team then offered to include the photo of a nude couple that they hoped was non-offensive and showed a critical aspect of human lives: reproduction. NASA famously turned that down in fears of a negative public reaction, and instead went with a silhouette version of the image.

Anne and Carl's love story is certainly a captivating one, but less known is the fact that Anne was engaged to Tim Ferriss at the time, and Carl was married to Linda Salzman. In the midst of all this, some had found love and some had lost it. There's nothing on the record that directly points to these events, but the fact that these things, so earthy in their disposition, were nonetheless part of the larger process that makes the golden records that much more genuine. These stories are destined to live on for millennia, just like the records themselves. The gold-plated copper disc will be protected by an electroplated aluminum cover that is supposed to last for at least the next billion years. It's a practically infinite shelf life. By then, the sun will have expanded to the point that its heat no longer nourishes life on Earth, but rather destroys it. The pale blue dot will have been reduced to a charred cinder. But then again, a billion years is, after all, just a billion years. The golden records too will perish, just like its very own makers.

I like the golden record because it highlights the scope for sentimental value in otherwise technical pursuits. The immensity of space means that the Voyager spacecraft are not likely to be met with another planet in 10 to the 20 years. Of course, it might be detected before then by a technologically capable entity, but even that has infinitesimal odds. What then is the true purpose of the golden records? Looking back at the project, Brian Oliver, recognized as a pioneer in our search for extraterrestrial life, said, "There's only an infinitesimal chance that the plaque will ever be seen by a single extraterrestrial, but it will certainly be seen by billions of terrestrials. In fact, its real function, therefore, is to appeal to and to expand the human spirit and to make contact with extraterrestrial intelligence—a welcome expectation of mankind."

I constantly find myself looking at the pictures on the record and those that Voyager took and wonder what could have been if they were to be made today. We could have much higher definition cameras and significantly more storage. We could have sent so much more. But then I feel our limitations were for the best. Perhaps it was good that we were restricted by those 90 minutes, by those 115 images. The inability to say everything that we wanted to means that we had to be intentional with every pixel, every syllable. It forced us to say some things out loud and leave others unsaid, in our own very human way.

The latrine, the porcelain throne, the Oval Office toilets. Do I really need to say anything here? Before toilets, we would literally use buckets or just went into the forest or peed on a tree or something. We didn't really have any efficient way of getting rid of our waste. We would take all of this filth and go dump it into the closest river, and then later that same day go and get water to drink from that same river or even try and bathe in it. Luckily, it only took tens of millions of people dying from disease until we realized, "Hey, maybe we're doing something wrong."

On top of toilets themselves, and toilet paper—that's also really important—the sewer system and subsequently water treatment plants have become some of the most important things in almost every major city on the planet. There are some things in life that we just don't notice, but in reality, they have shaped and molded the foundation of the very society we live in today. Without them, your life would probably fall apart. So here are some inventions that changed the world.

Being able to refrigerate food is something that is heavily slept on. Without this, feeding a population of almost 8 billion people would be nearly impossible. Food will spoil much faster and would in turn make it cost much more. Your bills at restaurants would no longer be $50 to $60, but upwards of $1,000 or even more. This would also mean fewer people would be able to afford good and nutritious food. Diets would change, and your food sources would be much more limited. Life expectancy would drop, and your time on this planet would slowly run out.

We're really, really lucky that everyone on the planet uses the same units of time, though: like seconds, hours, days, and so on. Imagine if we all had different definitions for what these were and how utterly impossible it would be to keep track of anything. "I have an appointment at 2:30 today." "Oh, which 2:30?" Speaking of appointments, I had an eye doctor appointment a couple of days ago, and it made me realize that I would be completely screwed if eyeglasses weren't a thing. Now, my vision isn't the worst, which I'm grateful for, but you never truly understand how bad your vision is until you realize reading something from 10 feet away is harder than understanding quantum mechanics.

Even just a thousand years ago, if you had bad eyesight, you didn't really have any options to fix it. Glasses gave people with terrible vision a get-out-of-jail-free card of sorts. It gave them an extension to continue doing things, to continue creating and building the things that we use today, to continue learning about us and the universe we live in. Imagine if Einstein couldn't get glasses and just gave up on everything he did—that would suck. So thank you, glasses; you've saved us many times.

If this were still survival of the fittest, a lot of us would have been wiped out a long time ago. Thermostats and temperature control in general are just unbelievable. We can just set the temperature of a car, a house, or an entire skyscraper to a specific degree on command. We use cars and buses and trains on the daily, but it's become just a routine part of our life. Modern transportation in general is actually super overlooked. Traveling is much faster than it has ever been, but we genuinely take it for granted.

Sure, being on a cramped airplane seat for 5 hours to travel across the country sucks, but it's a lot better than riding on a horse for a week or getting sick from just being in the back of a carriage. And this is just talking about airplanes; cars are just as crazy. Despite there being tons of terrible drivers, almost any competent person can get into a car, which is just a few thousand pounds of metal, press two or three pedals, and move at nearly 100 mph. In the best scenario, you can drive thousands of miles without getting into a crash or hurting yourself or someone else in the process.

Compare this to traveling across the country hundreds of years ago where many times you wouldn't even survive the journey. Cars are one of the most useful things ever created and are yet so simple to use. With self-driving cars becoming more and more capable, eventually, in however many years, driving will be just as safe as airplane flights—which sounds kind of weird. The odds of you dying in a car crash is about 1 in 100, but the odds of you dying in an airplane crash: 1 in 5 million. Driver error and the pure volume of cars and risk while driving is enough to shoot up your odds of dying. But fully autonomous self-driving cars will take out this large risk factor. Both old and young people who are capable of driving will be able to be mobile. It will revolutionize travel the way Ubers and taxis have—except this time they'll be fully autonomous. Cars could be designed differently to accommodate for sleeping or to be more social.

Sure, you could take a short plane ride a couple of hours, or you could have an overnight car ride for cheaper. But this is all speculation—maybe I'll talk about this some other time. At any moment in time, you can know exactly where you are on the planet within a single meter! Shout out to Google Maps! One day, some Google employee just said, "What if we drove a van down every street on the entire planet?" And then they actually did it! But also, you can get directions from your current location to anywhere on the planet. On top of that, you can also get the traffic conditions, detours, and other information that might prove to be useful along the way.

But also, it knows where you're going, which direction you're headed, and can give you pictures of the exact location you're heading to. On top of all that, you can also get local restaurants, stores, parks, gas stations, and much more while you're driving. And even after all that, there's one thing that makes it amazing: it's completely free! If you have a phone, you have a map that can take you to almost any specific spot on the entire Earth and show you exactly what it will look like when you get there. And we take it for granted every day.

Transistors—they're everywhere and outnumber humans by far! For perspective, there are about 200 billion stars in our galaxy, about 100 trillion cells in our body, and over 1 quadrillion ants in the world—but transistors outnumber all three of these combined! There have been nearly three sextillion transistors made since they were invented. Transistors are basically switches: on is one, off is zero. Electronics have currents! Picture them as cars on a street. Transistors operate as a stop light. When the light is green or the transistor is on, the cars can pass through the intersection, no problem. When the light is red or the transistor is off, they can't. Now scale this up to billions of transistors in a single device, and you can perform complex tasks like a smartphone can. These things allow you, speed drives, to have more storage than the computers that took us to the moon, and they can fit in your pocket! That kind of speaks for itself. Transistors are getting smaller and smaller year after year. As of right now, the smallest transistors come in at around 5 nanometers, or about 10 atoms wide. You would not have modern electronics without these!

Cameras are built to preserve snapshots of time. It's a copy of something that happened in the real world. We can look at anything and decide to preserve it and keep it for the rest of eternity. Imagine all the memories, all the special moments that were lost to history before cameras were invented. It only takes a few seconds to take out your phone, open the camera app, and snap a picture. You could do it in a single breath, but on the other hand, the first photograph ever taken took 8 hours! The speed at which we can save these single moments is unreal. We can take pictures of some of the largest things in the universe that are trillions of miles away, and at the same time, we can take pictures of the smallest things known to man.

Cars, video games, cameras—you buy all of this modern technology with money, and money itself is a simple invention that changed everything. Before, we used to trade things: "You want the loaf of bread I have? I have a chicken to trade you!" The chicken could stay alive for however long you can keep it, but that loaf of bread will start to mold within a week or so. We needed a way to place value on something without one end getting an unfair trade—something that holds value that isn't cigarettes or bars of gold. Money, fortunately, doesn't appreciate in value most of the time. It's something we use every day, and now it actually runs our lives. Without it, you'll probably die—oops!

Alphabets have single-handedly shaped modern civilization. Without them, languages wouldn't—and couldn't—exist. It allowed us to evolve from grunting at each other and pointing our fingers to actually being able to create cohesive sentences and convey our ideas. It allows us to time travel, in a way. Write down your ideas, make a book, mass-produce it, and if it's good enough, people in 100 years will still be reading it, using the same language you're using today. It might be a little bit different, though. These letters hold all the information and knowledge that we've accumulated over thousands of years. Just learn how each of these letters sound and what words they form when combined, and you can learn almost anything.

All of this information needs to be stored somewhere. Search engines are blessings in disguise. There's so much information on the internet that you couldn't even view all of it even if you wanted to. It's amazing how quickly you can Google something and have it search through billions and billions of results, finding you exactly what you want most of the time. Math is the language of the universe. It's not always used to talk to one another, but rather explain everything around us. Math didn't just come out of thin air; we discovered and crafted equations and formulas to explain everything we know. But even more interesting is that math is forever incomplete. It's been proven that there is no way to prove every possible statement about math, so there will always be more to learn—forever.

But with math comes another question: Is math an invention or a discovery? Numbers and variables are just human constructs used to give order to the world. All of math that we figured out was always there; we just needed someone to discover it. We needed a way to put these universal truths into the language that we built. Picture it like this: If humans had named a tree "tree," it would still exist; it just wouldn't be called a tree. Electricity always existed; we just didn't understand it. But now with light bulbs, batteries, and everything else we do!

Fun fact: Telescopes are basically just tubes of mirrors. Make one big enough, and you can see galaxies tens of billions of light-years away—effectively looking back in time at a younger universe. But in order for these things to be made, you need glass! Literally just heat up sand to a high enough temperature and you can make glass. Without glass, there's no telescopes, no chemistry, no medicine, no airplanes, no buildings—none of that! The world would be a lot more difficult to navigate, or even to just live in.

The global mailing service is one of the most impressive feats of the past 100 years. Before 1900, mail could take anywhere from a few weeks to a few months to get delivered. But today, you can ship almost anything from anywhere on the planet across the world in a single day. The fact that you can send a single piece of paper from, let's say, a house in the middle of Kansas in the United States to a random town in Russia, and despite the distance, despite the fact that your single piece of paper will pass through tens or even hundreds of people, travel thousands of miles, it will arrive. Life can suck, trust me, I get it. But so many inventions that changed the way the world works came within the last 200 years or so. You could have been born in the 1400s and had to deal with the plague, but you weren't. You're alive now, with airplanes and toothbrushes and never-ending amounts of water whenever you want it. Most things in this video were invented within the last couple hundred years. There's so much more that's going to be invented and discovered even within the next couple of decades. So thanks everyone for figuring stuff out—I owe you one.

If I told you right now that humans are perfect organisms and that in our mothers' wombs we first are fish who then develop into amphibians, then reptiles, then birds, then primates, before finally becoming what we know as human, I'm sure you'd look at me like I've gone insane. And I have, but that's besides the point. Just as recently as 1811, because of the works of scientist Johann Friedrich Meckel, everybody thought that was true. And this is because science is transient. What we once hold as truth quickly fades away upon closer inspection, and looking back, we can only laugh at ourselves for the scientific facts we once held dear to our hearts.

Some other times, these aren't even actual scientific facts; they're just very popular opinions that all of us have collectively agreed to be true, even though they are in fact not. These are all the times we were wrong. Not everything Meckel said was wrong, though. In fact, he was the first scientist to correctly predict that embryos have gill slits on their neck that closely resemble gills, at least. However, unlike what he suggested, we don't pass through a fish phase in our mother's wombs. These slits are most likely due to the fact that both humans and fish share a common ancestor and some DNA, and not because we're trying to attain some kind of biological perfection. I mean, who are we kidding? We're far from perfect. But for a long time, scientists believed this to be true.

Well, until the late 19th century when Charles Darwin's theory of evolution started to gain traction. We realized that a linear series of evolution in our mother's womb was completely illogical. The theory of evolution is one that has been completely riddled with lots of false claims and ideas that are simply not true. In reality, evolution is a very difficult subject to research because of the limited amount of possible information available. As a result, a lot of times, all we're left with are hypotheses, some of which are brilliant and others not so much.

For a long time, scientists believed that all of life was aquatic until one day, many millions of years ago, a brave fish dared to walk on land, starting with very short periods on dry ground. The fish started spending more and more time on land, and gradually, its gills got replaced with lungs and it became amphibian. Then the amphibians became reptiles, who became birds, who became mammals. And while the scientists got the process of evolution right, that one brave fish was not the first animal to step on land. The Earth was rich with insects, funguses, and was bubbling with life before that fish ever came into the picture.

Another hypothesis that we all seem to collectively get wrong is where humans come from. If I asked you right now, you'd most likely tell me that we evolved from chimpanzees, our closest living relatives. But while the second half of that statement is true, the first half is completely false. We didn't evolve from chimpanzees. Yes, we evolved from apes; however, we did not evolve from any apes living today. Monkeys, chimps, and gorillas all evolved from a common ancestor: the so-called great apes that lived in Africa around 7 million years ago. It was around that time in the evolutionary chain that we split. So although chimpanzees are our closest living relatives, we're further apart on the family tree than a lot of us think.

Our much closer relatives, albeit now extinct, are the Neanderthals. Modern humans split from Neanderthals just around 500,000 years ago. But even these guys certainly come with their own controversy. For a long time, scientists believed that Neanderthals and humans never lived together, with some believing that Neanderthals evolved into humans. But again, that's not true. Archaeologists have since found ancient human skeletons that prove that modern humans and Neanderthals coexisted for thousands of years. In fact, they didn't just coexist; they actually made it, which is why most humans living outside of Africa have anywhere between 1 to 4% of Neanderthal DNA still in them today.

When we start talking about the theory of evolution in ancient humans, we can't help but talk about dinosaurs. You know those giant, scary, lizard-looking things from Jurassic Park? The ones that have earth-like tones, lizard-like scales, and roars more earth-shattering than that of a lion? Well, in reality, dinosaurs were none of those things I just mentioned. First, dinosaurs are more closely related to birds than lizards. In fact, every single living bird today is a modern-day dinosaur—a descendant of theropods, a species of ancient dinosaurs. And because they're birds, they mostly had feathers covering their scaly skin. Fossil evidence has shown that a lot of Tyrannosaurus rex had feathers, which means that even the great T. rex probably had a few as well, mostly on its head and tail.

Dinosaurs also never ran fast because they always had to have one leg on the ground. They could only get to around 25 mph, which is still pretty scary because, well, one, they're massive, and two, the average speed of a human is 15 mph. But if you're Usain Bolt, you've got nothing to worry about. You can outrun these guys any day! And let's be honest, have you ever heard any bird roar? Yeah, me neither! Which is why a recent scientific study has shown that the T. rex most likely hooted, or made deep-throated, booming sounds like the emu—not a trembling roar like a giant lion.

It's funny when you think about it. Now, we can forgive ourselves for getting these details wrong. After all, all of these things happened tens of millions of years ago before any of us ever existed. But if you look much closer in time, you'll see a lot of things we get wrong every day—even things that are as simple as George Washington's teeth. In 1789, when George Washington was inaugurated as president, he only had one natural tooth left. But because the president needed an amazing smile, he wore dentures. Now, in reality, these dentures were made from hippopotamus ivory, brass, and gold. But for some reason, we like to believe they were made from wood. Why we believe that, I have no idea.

But it's not too late to change our minds. According to the Merriam-Webster Dictionary, a person who often changes their beliefs or behaviors in order to please others or to succeed is called a chameleon. But are chameleons really chameleons? This definition is derived from the assumption that chameleons change the color of their skin to match their surroundings, most likely to camouflage. And while there are animals that excel at using this tactic, like the octopus, the chameleon is not one of those animals. In reality, most chameleon species can only change from green to brown and back to green. And they don't change color to blend into their surroundings; they do it to regulate their body temperature. When the chameleon is cold, it becomes darker to absorb more heat, and when it's hot, it turns pale to reflect more heat so it can cool down. There is one species of chameleon that can change into any color, though, and that's the panther chameleon. But even those guys don't do it to match their surroundings; their flamboyant display of colors helps them fend off against males competing for territory and also to attract females. I mean, isn't that why we all buy designer in the first place—to impress each other?

Speaking of fancy, who else was taught that diamonds are made from coal? Sorry, but that's not true at all. It's a terribly common misconception. In fact, most of the diamonds that have been dated were found to be older than even the very first plants that appeared on Earth. And because you need trees to make coal, it's impossible for coal to produce diamonds when diamonds existed long before the material that makes coal even existed. Anyway, NASA researchers have even found a number of nanodiamonds in meteorites. Nanodiamonds are diamonds that are just a few nanometers in diameter. Simple enough, they're too tiny to be considered gems, but it's still pretty cool that you can have these precious objects just floating around in space. Still, it makes you question why we deem them as so precious when, in reality, they're extremely abundant in our universe. There are planets in space where it literally rains diamonds!

Anyway, of course, these asteroids are floating because there's no gravity in space, right? Well, unfortunately, wrong. There is gravity in space! It's what holds the moon in orbit around the Earth, and the Earth, close together around the sun, with all the other planets. It's just that as you get further away from the Earth, the Earth's gravitational pull on you weakens and other gravitational forces begin to take priority. But in reality, everything in space is falling in every direction imaginable all the time. The only reason it seems as if you're floating and not falling is because space is very large and, most importantly, very empty—at least compared to Earth. For instance, on Earth, if you were to—and I really, really don't recommend it—jump off a building, you could feel the strong winds on your face; you would see the ground appearing closer and closer. You can tell that you're falling quite easily, and in just a few seconds of impact, you're on the ground, because the distance between the height you fell from and where you landed isn't that much. In space, there is no air, so there's no whooshing sound to accompany your fall, and because it's so large, it takes you anywhere from a few hours to many years to land on one surface when you fall from another. So it feels like you're floating, but you're not; you're falling really, really slowly. And that's because of gravity.

One of man's most important discoveries—we're talking about the story behind gravity—wasn't preserved carefully, but the version almost all of us have heard has not been reserved at all. The old tale goes that Newton was tired from all the many failed experiments he had in his career, tired and frustrated. He sat under a tree to rest his head, and as he sat, a ripe apple fell down from the tree and hit him on the head. In a Eureka moment, he discovered one of the most important forces in physics—gravity! But the truth is much less dramatic than that. In reality, Isaac Newton was observing the apples falling from the tree of their own accord when he discovered that there must be a force behind. He wasn't sitting under the tree, and an apple certainly didn't fall on his head.

You see, sometimes I understand why we make up some of these stories. They help make us feel better about ourselves when we believe that some of humanity's greatest achievements couldn't have happened without a huge slice of luck. We can keep hope alive for our own share of luck, our own piece of the apple pie. It's the same with the story of Albert Einstein. We all heard growing up about how he failed in class but still went on to become one of the greatest physicists the world has ever seen. But that's just not true at all! Einstein always excelled in school; he didn't learn to read late in life, and he most likely didn't have a learning disability. Our teachers must have told us these stories to make us feel good about ourselves—give us hope that even if we have rough starts in school, we could still become geniuses later in life if we worked hard. And while there are a thousand examples of this exact theory, Einstein simply wasn't one of them.

Aristotle is one of the greatest philosophers to have ever lived and was the first true scientist. He practically invented formal logic, and he described and explored the different scientific disciplines and their relationships to one another. But for all the good he did, there was one thing he got terribly, terribly wrong: he claimed that the Earth was at the center of the universe. I mean, why wouldn't he? Most things you observe point to this exact conclusion. Now, while Aristotle wasn't the first to say this, he championed the fight. He claimed that using logic, he had found this to be 100% true and wouldn't back down from his argument. It took the work of Galileo, almost two millennia later, to discover that the sun was at the center of the solar system and not our Earth.

Still, people didn't believe him. In fact, they ostracized him. And this is just one of the many times that we as humans have overemphasized our importance. In the movie Lucy, Morgan Freeman says this in a room full of students: "It is estimated most human beings only use 10% of their brain's capacity. Imagine if we could access 100%!" Interesting things begin to happen. While it's fun to think that humans are capable of a whole lot more if we could just find a way to tap into that remaining 90%, the reality is far less exciting. Most of the brain is active almost all the time. While they might not be actively used or thinking, they're working busily doing other things, like keeping you alive—kind of important.

Think about it. The brain is just 3% of the body's weight, but it uses 20% of the body's energy. To burn through that much energy, you would have to be doing something right. Even though we get it wrong most of the time, it's fun to explore the world around us. We will continue to make assumptions about everything we see, and chances are most of it will be wrong. But that's a good thing, because if we never know what's wrong, we can never know what's truly right.

The entire universe, every electron, proton, atom, every star, and galaxy, was born out of a singularity that brought about our whole existence: the Big Bang. An isolated moment in space and time created something out of nothing. For eons, we didn't know much about the universe, but through advancements in science and technology, we're now able to travel back in time right to the point just after the Big Bang to finally piece together its entire story. And in the next 10 minutes, I'll be sharing that story with you.

To be able to understand the history of our universe, we have to start at the beginning of time. Time and time itself were born with the Big Bang. Contrary to what its name might suggest, the Big Bang was not an explosion. It can more precisely be described as the rapid expansion of space and time in all directions, releasing immense amounts of radiation. In 1964, two American astronomers, Robert Wilson and astrophysicist Arno Penzias, stumbled upon a cryptic message traveling from the moment of creation itself. Their antenna in New Jersey picked up an odd buzzing sound that puzzled them. After eliminating all possible sources of interference, Wilson and Penzias figured out that they had just discovered the cosmic microwave background, or CMB—the thermal echo of the universe's explosive birth and the most crucial piece of evidence for the Big Bang.

Thanks to this ancient message, we know our universe came into existence 13.7 billion years ago, and it immediately began expanding at an exponential rate. This is known as the inflation epoch. When it was less than a blink of an eye old—like a billionth of a trillionth of a second old—our universe underwent an astounding growth spurt faster than the speed of light. Within a fraction of a second, it doubled in size at least 90 times. But as it expanded, the energy released became more diluted. In just 3 minutes, the universe had cooled down enough to allow the first particles of matter to form, and the first light elements were created. Neutrons and protons began colliding with each other and formed hydrogen, helium, and lithium. Though the particles were formed, the intense heat from the moment of creation made it too hot for light to shine, and so our universe was plunged into a cosmic dark age.

For hundreds of millions of years, space was desolate and devoid of any planets, galaxies, or stars. Then the age of reionization began, and light finally emerged from the darkness with the birth of the universe's first stars, known as population III stars. These are believed to be made of the only ingredients available in the universe at the time: hydrogen, helium, and lithium. These stars are time capsules rich with information about our universe's earliest days, and with the James Webb Space Telescope, we can now look into them with greater detail than ever before.

About 1 billion years after the Big Bang, galaxies began to appear, and there are two theories on how they first came into existence. The first suggests that big clouds of gas and dust collapsed under their own gravitational pull, allowing stars to form and eventually galaxies. The second, which has gained momentum in recent years, suggests that galaxies formed when small lumps of matter kept clumping and swirling together until they eventually grew to the size we're familiar with today.

Our galaxy, the Milky Way, is roughly 13.6 billion years old and contains between 100 to 400 billion stars, spanning about 100,000 light-years across. Astronomers are still working on charting the spiral structure of our galaxy. Although using infrared images from NASA's Spitzer Space Telescope, we've discovered that it is dominated by two arms wrapping off the ends of a central band of stars. Stars and galaxies are still being created to this day, and astronomers estimate that there could be as many as 2 trillion galaxies spiraling through the black ocean of our universe.

4.5 billion years ago, a dense cloud of interstellar gas and dust kept swirling together as gravity pulled more and more material into the center. The pressure in the core was so great that hydrogen atoms began to form to make helium, releasing immense amounts of energy. This process eventually gave birth to the star we see every morning when we wake up—our sun. Once the sun was formed, the matter surrounding it clustered into spheres and fell into its gravitational pull, creating the planets in our solar system. The giant planets—Jupiter, Saturn, Uranus, and Neptune—were the first to circle the sun as it began emitting its light. The smaller planets—Mercury, Venus, Mars, and our very own Earth—formed.

Our planet just happened to orbit the sun in what scientists call the Goldilocks zone—the perfect temperature and distance from the sun to allow for liquid water to exist. Somewhere between 60 to 175 million years after our solar system was born, a Mars-sized planet collided with Earth, and the post-impact debris morphed together to give us our moon. Talk about upcycling! Life in our universe seems to be far from inevitable. Everywhere we point our telescopes, we end up seeing the same thing: bright nebulae, star clusters, and ominous galaxies that all look desolate and lifeless. But when it comes to our home planet, the story is very different.

Life on Earth first appeared 3.7 billion years ago, but how it sprung into existence is still a hot topic of debate. Many believe the first living organisms were microscopic microbes that left signals of their presence in rocks. Others think life started in a primordial soup deep in the ocean through vents and the seabed, where the interaction between water and rocks provided enough chemical energy to allow the first unicellular organisms to emerge. Whichever side of the argument you're on, though, the one thing that's certain is that the Earth was teeming with life long before we showed up. We came onto the cosmic scene just around 6 million years ago—a long time for sure, but minuscule when compared to the 13.7 billion year lifespan of the universe.

Although our early ancestors joined the party late, we've moved quicker than we could have ever imagined. In just a short span of time, we've gone from hunter-gatherers to cosmic explorers, preparing to create a base on the moon's surface. Our telescopes now allow us to see further than we've ever been able to before, and our questions are bigger than we've ever dared to ask. But even with all the tools available to us, there are things in the universe that are still shrouded in mystery. Around 85% of our universe is made up of a mysterious substance that we have never seen. In 1933, Swiss astronomer Fritz Zwicky measured the visible mass of a cluster of galaxies and found that it was too small to prevent these galaxies from escaping the gravitational pull of the cluster. He concluded that something must be acting like glue, holding the cluster together—that mysterious substance we now describe as dark matter.

A completely invisible material that fills up our universe and acts as an astronomically potent super glue. Without dark matter, the behavior of stars, planets, and galaxies would just not make sense, and our universe would not have evolved the way it has. And then there's dark energy—the strange force that is pulling our universe apart at an ever-increasing speed. Just like dark matter, dark energy is invisible, but its powerful effects are largely felt. Lift off of the Space Shuttle Discovery with the Hubble Space Telescope, our window on the universe. In 1920, Edwin Hubble discovered that the universe is not static but is still expanding. And in 1998, the telescope named after the astronomer proved him right—and even more—that the universe was expanding at an accelerated rate. We have since discovered that dark energy is the reason for this expansion and also why stars and galaxies recede away from each other.

While much about the formation of the universe and its evolution has been theorized and plotted on the cosmic timeline, there are still enduring questions to be answered. With telescopes like Webb, we continue to hunt for the elusive dark matter, as well as look back into our universe to understand the evolution of stars and the formation of galaxies. Our quest also includes searching the cosmos in hopes of finding life forms to share our existence with. During the search, we've discovered exoplanets that orbit around a star outside of our solar system. Based on NASA's Kepler Space Telescope imagery, we can confidently assume that every star in the universe has at least one planet orbiting around it. In our galaxy of hundreds of billions of stars, it's believed that there are trillions of exoplanets, yet we've only discovered around 3,900 of them. A little more than four light-years away, Proxima Centauri is the closest of these exoplanets, but scientists have their eyes on bigger things with the TRAPPIST-1 star system.

This star system is home to seven planets, all roughly the size of Earth, orbiting around a red dwarf around 40 light-years away. Our space telescopes, ground telescopes, and best scientists are working to try and understand whether any of these planets have the right ingredients for life to spring into existence. I made an entire video on what it would be like to live on one of these planets, the only one that scientists believe could possibly hold life. Whether we succeed in this mission is a story that will be written in the universe's future, one that will either propel us forward toward the understanding of the cosmos and our place in it or will leave us pondering our lonely existence.

Our universe is currently 93 billion light-years wide, filled with trillions of galaxies and 1 septillion stars—that's 24 zeros—and it's still expanding. Through the vastness of space, sometime in the distant future, it's estimated that our Milky Way will collide with the neighboring Andromeda galaxy. Because, though the universe is expanding, galaxies are receding away from each other, and the proximity of the two galaxies will make the collision inevitable. Don't worry, though; we'll be long gone before that happens. 100 billion years into the future, galaxies will disappear, and eventually, our universe will be populated by black holes ravenously eating away all that is in their way, as a new dark age sets upon our universe. Astronomers believe that its fate is bound to end the same way that it began. With time, space will begin contracting again; the universe will shrink in size until one day, it devolves back into the singularity that started it all—a sort of Big Crunch reversal that will bring things full circle and leave behind an emptiness aching to be filled. And then, who knows? Bang!

4.18. This number is the reason that you're alive right now. Under normal conditions, that's how many joules of energy you need to raise the temperature of a gram of water by 1° C, also known as the specific heat capacity of water. This value, this property of water—it's special! You see, if this value were any different, life as we know it would not exist. If it were higher, more energy would be needed to raise the temperature of water; the amount of water that evaporates into the atmosphere would reduce, and that means so would rainfall. This also means that there would be a greater difference between the temperature of air near land and the air near water. The resulting changes in pressure would lead to changes in the wind speed; temperatures would significantly drop, and species would slowly go extinct. On the other hand, if the heat capacity were lower than it is now, water would evaporate much quicker, and it would no longer be able to regulate the temperature of the Earth as it does now. It would rain all the time; crops would die, and again, species would slowly go extinct. 4.18, it seems, is just the right amount of energy.

This just-rightness is seen in other aspects of life on Earth too, including where it sits in the solar system! Too close to the sun and the water would just boil away before it could form; too far, and it would just freeze. But all these properties are in some way, shape, or form related to water, and so it's no wonder then that the search for life anywhere in space is essentially a search for water. And we've found it—lots of it, actually! You see, hydrogen is the most abundant element in the universe, and oxygen is the third most abundant. In between them is helium, which doesn't really react with much. So when the conditions are appropriate, water can be formed.

And given the scale of it all and how old the universe is, you'd imagine that there must be some planets in an Earth-like distance from their respective stars to allow for the formation of liquid water and by extension, life. Dr. Frank Drake attempted to answer this very question in 1961 using the Drake equation. He used factors like the average rate of star formation, how many of those stars could have planets, how many of those planets might develop intelligent life forms that could possibly communicate, and so on. Instead of the entire universe, Drake focused only on our galaxy, which is huge, and for practical limitations of speed and time, really the only thing we should worry about anyway.

Understandably, these inputs are all assumptions, and as such, the output of this equation is also an assumption. Depending on who and when you ask, the result of the Drake equation could be anything from a small number that is barely greater than zero to a number in the tens of millions. Our intuition tells us that if that number were somewhere in between that range, the Milky Way should be beaming with advanced civilizations making interplanetary journeys with regularity. Just the Milky Way—one of the trillions out there is so incredibly large that, even with astronomically low odds, you would expect to find at least some other civilizations.

To give you a sense of how large it is, modern humans have been around for nearly 200,000 years, and in that time, at its incredible speed, we've traveled the complete width of the Milky Way only twice! Okay, so let's run through this: The Milky Way has a lot of stars, and a lot of those stars have a lot of planets, and a lot of those planets should have a lot of water, and a lot of those planets have been around a lot longer than Earth—so therefore, they should have a head start compared to Earth. So that must mean that there are civilizations a lot more advanced than ours. We should have all the tools they need to communicate with us. If that's the case, there's just one problem: where is everybody?

That's the question Enrico Fermi asked in 1950 using a similar line of reasoning that I just talked about. Fermi was confused as to why we hadn't already come in contact with aliens, considering how abundant they should have been—known more popularly as the Fermi paradox. This question draws attention to the discrepancy between the supposed high likelihood of civilizations out there and the lack of observational evidence to prove their existence. To this day, 70 years after Fermi's equation, even with the scientific advancements that we've made, we are yet to receive any signals from civilizations other than our own. So really, where is everybody?

Nearly 50 years after Fermi asked his famous question, an economist named Robin Hanson figured that just as humanity had done in the past, we may have just been asking the wrong question all along. He felt that instead of sticking to the assumption that the universe should be filled with life forms like our own, we should accept what the evidence is telling us: that life is exceedingly rare, and that Earth is the only planet we know that has it, and that we should use that information to understand why we're here and how long we might have.

Well, if that's the case, Hanson argued, then there must be something wrong with the typical steps of reasoning that lead to the incorrect perception of life's abundance. Either one or more of these steps are wrong, or one or more of these steps are so incredibly improbable that life elsewhere is practically impossible, and thus the idea of the Great Filter was born—a hindrance that is so immense in its complexity and improbability that we are quite literally the only species to ever get past it. It's perfectly possible that the Great Filter was whatever initiated abiogenesis—the creation of life from non-living simple organic compounds. After all, it's a process that runs counter to the laws of thermodynamics and that it involves molecules to spontaneously arrange themselves in an ordered life-giving manner. It would be like a cold cup of water just naturally going hot, which by the way is physically possible—only unimaginably unlikely. Things like that just don't happen. Hot things go cold, and things tend towards disorder.

So, life never really should have formed. The Great Filter could also be the formation of complex cell organisms, or it could be the first proper replication of DNA that allowed for just enough mutation that would eventually sow the seeds for evolution. Or it could be the collision of Earth with a protoplanet named Theia that led to the creation of the moon, and with it, a reliable axis and a stable climate for life to flourish. It could be any number of things, really—I don't know.

Regardless, if we were to assume that the Great Filter was indeed in our past, it would explain why we are the only ones remaining and why the rest of the universe seems so utterly dead. But it would also say that we have done it—we've made it past the Great Filter! Everyone gets a pat on the back, and that's really it. But what if the Great Filter is ahead of us? What if the universe was indeed beaming with life just as we expected it to, but something simply kept filtering or killing civilizations one after another, which is why no one has really reached out to us? And more importantly, what if we're next?

Given the general lack of evidence regarding other planets and why they don't have life, a filter in the future could be just as likely as one in the past—if not more likely. So what are some of the possible filters that could possibly wipe out life as we know it? As it turns out, the abundance of galaxies that we point to when we search for other forms of life may just be the very reason why they don't exist. Our neighboring galaxy, Andromeda, is a mere 2.5 million light-years away from us, but scientists predict that it's getting closer. In about 4 billion years, it might collide with the Milky Way. These collisions are common enough in cosmic time scales that they're important!

And although the likelihood of planets colliding with each other is exceedingly rare, given the distances between stars and planets, other massive objects might interfere with the effect of gravity of Earth or whatever planet humanity is on. When Andromeda and the Milky Way galaxy collide, this might pluck them out of the orbit they were in and jettison them out into the emptiness of space, where life simply ceases to exist. Extrapolate this possibility far enough, and you have a possible explanation as to why life is so rare: the cosmic commonality of galactic collisions keeps destroying life before it can take an intergalactic form. We've just been lucky so far.

But you might think that galactic collisions are super rare and still in the distance! So how about we focus on something more close to home—something more recent instead? In 1989, millions of people in Quebec woke up to heaters that were no longer working and a city that was completely out of power. In one of the rare and extreme cases of coronal mass injections (or simply solar storms), Quebec's entire power grid failed after 90 seconds of this geomagnetic storm from the sun. Effects were felt in other parts of North America and beyond, as radio signals were jammed, satellite measurements went haywire, and elevators stalled. Each of these solar storms can carry well over 100,000 times the energy of today's nuclear arsenal, so they're not to be taken lightly.

But typically, these storms are distributed over the entire volume of space around the sun, so by the time it reaches Earth, most of it simply dies out. The Quebec-style outage is certainly rare; scientists only predict such storms once every 100 years. But one only needs to think of a world where we rely on electricity more than we do now. Not just our phones, but our cars, planes, and even the military run on electricity. This is why these solar storms are classified as high-impact, low-frequency risks. They don't happen often, but when they do, they can be catastrophic!

On February 15, 2013, a dash cam in a car captured what is perhaps one of the most iconic space-related videos of recent times: known as the Chelyabinsk meteor, it had entered into the Earth's atmosphere undetected and, due to its high velocity and shallow angle, had turned into a bright, brilliant streak of light that was at one point brighter than the sun before atmospheric entry. This 20-meter-wide object was believed to have had the energy of a bomb that is roughly 30 times more powerful than the one detonated in Hiroshima. It injured nearly 1,500 people and damaged over 7,000 buildings from shock waves of the initial explosion.

New evidence keeps emerging about the extinction-level threat that asteroids possess. You would think that with such a strong presence in pop culture and wisdom from the leading scientists of the world, the modern world would be much more aware of a threat than ever before. But we're actually pretty underprepared for such an event! Initial plans included nuking the asteroid, but that would in turn lead to smaller radiation-bathed chunks falling back onto Earth—a genius idea there, boys! Another strategy could be to fly a ship to the asteroid to create enough of an impact to shift its trajectory, but a 2019 paper from Johns Hopkins University suggested the asteroids are stronger and harder to destroy than previously thought. Given a large enough asteroid, none of these measures may be enough to save life as we know it!

I chose these events specifically because they're all things that have already happened (albeit at a smaller scale) and continue to happen on a regular basis, galactically speaking. And while extinction-level events are rare and very unlikely in the generations to come, we must remember that if life can sprout from improbabilities, it can end with them too. These are just some of the ways civilization can meet its end. Everything from social media to a global pandemic to civilization itself could be hypothesized as the Great Filter that awaits us as humanity's final test.

But as always, there's some fundamental flaws with the idea of a Great Filter and the definitions of life it relies upon. Our sample size is one; this one data point is all we have ever known. How can we say with such confidence that a life form, advanced or otherwise, would even bother to explore beyond the comforts of its own home? Just because we exhibit colonial tendencies does not necessarily mean it has to be a universal phenomenon. And what if life just is different elsewhere? What if, instead of water, life lives off ammonia or methane or another such solvent? And the life that develops in it is fundamentally different from our own? Our current definitions of life are simply too specific to be able to incorporate all the possibilities hidden in the vastness of space.

The idea of the Great Filter is shrouded in such deep improbabilities and such extreme extrapolations that it is sometimes hard to pay attention. It is one of the more hypothetical topics out there, with so much simply based on speculation. There might as well be no Great Filter. After all, the improbability of our existence may not be because of one or two steps in the line of reasoning, but because the entire process is one life-nourishing coincidence after another. The Great Filter seeks to remind us about how lucky we are—lucky to be here at this very moment out of the billions of years for which the universe has existed, lucky to have come this far and be so aware of our place in reality, and lucky to realize how fine-tuned the universe seems to be for you and me to live in it. From the position of our galaxy to the exact values of the natural constants, one after another—from water's abundance to its specific heat capacity, 4.18.

Okay, all flight controllers, go for landing...

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July 20th of 2019 marked the 50th anniversary of mankind's most treacherous journey when Apollo 11 astronauts Neil Armstrong and Buzz Aldrin first touched the lunar surface. Over half a billion people around the world—20% of the Earth's population at the time—sat eagerly in front of their televisions as they watched the crew descend from the lunar module and take the most famous steps in history: "That's one small step for man..." The story of Apollo 11 is one of the most important events in the entire history of humanity—it's one that will be remembered for thousands of years to come. But this grainy television footage only tells part of the story. The technological complexity of the mission, alongside a risk that very few people on the planet were willing to take—very few actually understand how difficult this mission really was and how many things could have, and almost did, go wrong.

Apollo 11—its three crew members: Commander Neil Armstrong, lunar module pilot Buzz Aldrin, and Command Module pilot Michael Collins. On July 16th, 1969, they launched from Kennedy Space Center at 9:32:00 AM EST atop a Saturn V rocket, the most powerful machine ever built by humans. When John F. Kennedy made his proclamation to go to the moon before the decade was out in 1962, this left NASA only 7 years to conceptualize and create a rocket that could push humans to the moon. The end result was the Saturn V rocket. The behemoth stood at over 364 feet tall and weighed upwards of 6.2 million pounds when fully fueled. It included multiple stages, just as modern rockets do, but from this 111,000 kg machine, this is the only thing that would return to the Earth.

It's one thing to build a skyscraper; it's a whole different task trying to lift it off the ground, which is why it took over nearly 8 million pounds of thrust in order to get the Saturn V into the sky! As of 2019, it remains the tallest, heaviest, and most powerful rocket ever used by mankind. "T-minus 15 seconds. Guidance is internal. 12... 11... 10... 9... Ignition sequence start! 6... 5... 4... 3... 2... 1... Zero! All engines running!"

We have liftoff!

Thirty-two minutes into the flight, the first stage burn from the rocket lasts around 3 minutes to get the rocket clear from the launchpad and into the sky. It then detaches and falls to the ocean from about 30 miles up. The second stage burn then begins and continues for another 6 minutes to push the astronauts into space. After that, the S-IVB, third and final stage of the rocket burn begins and gets Apollo 11 into their correct orbit around the Earth. One and a half Earth orbits later, around 2 hours and 45 minutes after liftoff, the third stage of the Saturn V reignites for a second burn that lasts around 5 minutes, forcing Apollo 11 out of the Earth's gravity in an event called the translunar injection. The crew is now hurtling towards the moon at nearly 7 miles per second. But their job isn't done just yet.

The transposition and docking maneuver begins. The Apollo 11 spacecraft consisted of three main modules: the Command and Service Module Columbia, where the astronauts would spend most of their journey, served as the main quarters for the astronauts. It was a place they could work and live, except it was only the size of an average car. There's a single button inside the Command Module that, once pressed, will essentially blast away the panels that were once used to protect the lunar module. Once this happens, the Command Module uses small thruster rockets to separate the spacecraft. The Command Module pilot Michael Collins would then rotate 180 degrees and dock with the lunar module.

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The newly joined spacecraft then separates from the third stage of the rocket. They're now in the configuration needed to enter lunar orbit. From sitting on the launchpad at Cape Canaveral to reconfiguring