Everything You Need To Know About Death and the End of Times

what we do know is that death for most people is not lonely or at least it does not feel that way. Speaking of the Soul, this is one concept that science has not been able to figure out yet, or at least have some kind of explanation for. What was the number of near-death experiences associated with an out-of-body experience? It might be time to start rethinking whether it's something that can even be explained by science.

I once came across the story of a freshman in college who had just overdosed on sleeping meds. They flatlined in the ambulance and were declared legally dead for three minutes. However, they experienced everything in the ambulance, not from their own eyes but from a third-person view, an out-of-body experience. What was striking was that they saw the EMT who was trying to resuscitate them in the ambulance, minty green hair so distinct you couldn't miss it. After they were stabilized at the hospital three days later, they asked for this EMT. The EMT who they had seen while they were dead was a real person. The out-of-body experience they had won in the ambulance was filled with real memories of them lying down on the ambulance floor, machines beeping, and an EMT struggling to bring them back.

You hear things like this and you have to pause and wonder, do we really not have a soul? Whatever that may be, are we literally just made of random atoms and molecules responding to stimuli that Mother Nature throws at us? Or perhaps are we something more? These are the stories and experiences of the people who have managed to escape the permanence of death and have battle scars to show for it. However, for most, what is dead remains dead and so around one to two weeks later it's time to say our final goodbyes.

Much of what we know about human history is down to how we've buried our dead. From tombs to mummies, dead people have given us more information than the living left behind. The oldest known international burial site dates to around 10,000 years ago in Kafsa, Israel. The remains of the dead were put carefully in a coffin together with items such as garments, trinkets, and food, and these coffins were then placed carefully in a cave.

There was also evidence in this cave that the living painted the remains of the dead through parties and great feasts to honor their passing. People were buried in groups of families. This means that even as far back as ten thousand years ago, humanity understood the significance of death and the need to celebrate a life well-spent. To date, many different cultures do funerals differently. Most people sit together to reminisce about the life once lived, talking about all the good the person did while they were alive. Many religious organizations pray over the remains to give them a favorable outcome in the afterlife, but what that afterlife is is different for different people.

Abrahamic religions believe that your actions on this Earth determine where you spend eternity afterward. Families are encouraged to be strong in the face of death as we would all eventually be reconnected when we cross to the other side. For some other religions like Hinduism, what is dead shall be reborn. After the ceremonies and prayers, the bodies are buried or cremated and the living that are gathered disperse in a bid to heal from the hurt of losing someone. Even when we expect it, death is extremely painful because the idea of losing someone isn't the same as actually losing them and mourning the relationship that it once was.

Although we are fully aware that these things can happen and that they are part of the human experience, when we are faced with the harsh reality, the feeling of grief can be excruciating. The finality of death is its scariest attribute—the waking up one morning and realizing that everything we once had shared, experienced, they're all gone forever. The fact that all we will have of those experiences are memories—old memories we cannot recreate and new memories we cannot form. But more often than not, these experiences give us a new perspective on life. It reaffirms the reality of the brevity of life and gives us the courage to experience all that we can in the short time we have on this Earth.

It teaches us to be good people while we're alive because we won't be there to defend ourselves when the eulogies are being read about us as we lie in an open casket. And in the end, we're better equipped to help people going through the same thing because people are better comforted by others who have had a similar experience. Seeing someone just like you survive through their own loss gives you a sense of hope that maybe, maybe you too will be able to pull through. When you're sitting there staring at your loved one who is about to die, understand that death is normally known as painful and troubling for the person dying as it is for you.

For the next two hours, sit with them. Squeeze their hand in yours. Talk about all the beautiful things in life, about shared experiences, about their kids and pets, their lovers and friends. Talk about a life worth living till its last breath. Talk about a life well spent. Talk about death. The Earth will keep spinning, the birds will keep chirping, but eventually, everything has an end.

[Music] Ashes to ashes, dust to dust. From Sand we came to sand we'll return. No matter what we do, no matter how hard we try, one day we're living, the next we're clocking out for the long nap. We all know this, but still, the thought of death is extremely scary for most people. I think this is because, unlike most other things in life, we don't know anything about death. We don't know when we'll die, how we'll die, or even why we die. We don't know if death is the end or if it's only the beginning of something else. We just don't know.

However, thanks to statistics and probability, we might be able to predict how we're going to die. Most of the time, when we talk about death prevention, people think of locking the door to their houses, learning martial arts, or carrying around a weapon for self-defense. We try to protect ourselves from other people who might want to harm us, but in reality, the person most likely to kill you is you. The odds of dying by suicide are significantly higher than the odds of getting murdered because we're always in our heads. We're always aware of all the wrong we've ever done. We become judge, jury, and executioner in our own court case, and we sentence ourselves to punishments that we don't deserve.

Our mind keeps us in solitary confinement with soundproof doors so no one outside can ever hear us scream. Slowly, it drains life out until there's nothing left. With how common suicide is, it's surprising to see how some people still treat issues relating to mental health. The way we treat mental health overall has improved, yes, but there's still a long way to go. If someone came to you to tell you that they felt unsafe and they've been seeing someone around who might try to kill them, your first reaction probably wouldn't be, “Are you sure?” or “It's probably just all in your head, just don't think that way.”

Instead, you would probably get the person to a place where they feel safe and away from their potential attacker. So why is it that when it comes to mental health issues that are more likely to kill us, we aren't as kind to one another? We tell people to stop sulking and just be happy, as if there's a light switch in their head that they can simply click on and off to control their emotions. We tell them that they aren't being strong enough, as if they can fight the demons in their head with their bare hands. We need to start treating people in serious mental health crises the same way we would treat people that are about to get murdered.

Instead of telling them to be happy or be strong, let's help get them to a place where they feel safe because, in reality, when someone is murdered, it's a guy who opens his door and just gets shot. But when it’s suicide, he is also the one who knocks. When he knocks, we need to figuratively lock our doors, learn martial arts, and carry around a weapon for self-defense. This can include things like taking some time off to clear your head and just breathe, doing mindfulness practices like meditation, and of course seeking actual professional help.

While we're not the ones doing the job, dying by murder is surprisingly unlikely. However, if you will get murdered, you'll most likely be killed by someone you know rather than a stranger. Most murders are carried out with a gun. It's one of man's deadliest inventions, and to be lethal with it, you don't need to have much skill, prior training, or physical strength. You don't need to know how to shoot or need to have shot before, just pull the trigger and you'll cause a lot of damage.

This is why gun control is an issue that so many people talk about. Some people argue that bad guys are going to get guns anyway, so the good guys need to be able to own one too to protect themselves. But in reality, how do you know who's a good guy and who's a bad guy? How do you tell that a good guy who gives you a gun today won't turn out to be a bad guy tomorrow? We also don't consider the fact that there are three different ways a gun can kill you. You can get shot by it, it can fire by accident, or you can use it to put an end to it all yourself.

If you don't own a gun, you can only die in one of these three ways: you can get shot. But if you do own a gun, you immediately open yourself up to the other two, increasing your odds of dying by a gunshot drastically. According to statistics from the CDC, 14,542 people died from gunshot-related homicides in 2019 alone. That number might seem like a lot. However, it pales in comparison to the number of people who died of suicide by gunshot: twenty-three thousand eight hundred and fifty-four people.

For each time a gun is used in self-defense, it's also used in 11 suicide attempts, seven murders and assaults, and four accidental fires. With stats like these, it almost makes you wonder why people want multiple weapons capable of doing things like this. Since we arrived on this planet, humans have been trying to increase their lifespan. We learned the best foods to eat for strength and rejuvenation. We learned what not to eat for a healthier life, and best of all, we created medication. We learned how to use drugs and other forms of medicine to help treat, cure, and prevent our diseases.

One of the most important drugs we created are pain relievers. Our body does a very good job at healing itself when we have a cut, a tear, or even broken bones. If given enough time, the body repairs itself with new cells and tissue. But the pain we feel before or while that healing happens can be very excruciating. With pain relievers, we can reduce this pain drastically to the point where we can keep going on with our daily activities while the injury heals.

In 1775, opioids became a legal pain-relieving medicine, and in the 1860s, it was used to treat troops during the Civil War. However, something unexpected happened. Many of the soldiers that were treated with opioids became addicted to them, and in that moment, what was designed to heal us would soon also be able to kill us. Today, opioid overdoses account for 1 in 92 deaths in America. You're more likely to die from an opioid overdose than you are to die from a car crash, a gunshot fire, or smoke or even a natural disaster. In New York alone, about 3,000 people die yearly from an opioid overdose.

Now, I'm sure you're wondering, if this stuff is so lethal, why is it still so easily accessible? Well, if you don't already know, Big Pharma is used to collectively describe the global pharmaceutical industry. They're responsible for producing our medicine, which is a good thing, but these are companies, and companies are designed to make the most money, not for the general good of the public. Opioids tend to make a lot of money, so they convinced everyone that opioids are essential, even though there are non-opioid painkillers that are much safer and not as addictive.

But there's still more. Diseases like diabetes and HIV are deadly killers when mismanaged, but when properly managed with the right medication, people can lead a long and relatively healthy life even with them. However, this medication is extremely expensive for most people. Currently, it is estimated that 463 million people are living with diabetes all over the world, but unfortunately, a lot of these people are going to die because they simply cannot afford insulin. If you live in America, you don't have to worry about HIV as much. However, if you live in sub-Saharan Africa, you are at more risk. If you live in Eswatini, whose population is 27% HIV positive, you might want to be extra careful on whose bed you lie.

As an American, however, there is one thing that you definitely need to worry about: obesity. If you're an American adult watching this video right now, there's a one in three chance that you're medically obese. Obesity is an American epidemic that isn't talked about enough. Well, it is, but most people tend to just shrug it off. With a predominantly sugary diet and the biggest fast-food chains in the world, it's not surprising that over 36% of Americans are obese.

And obesity isn't just a cosmetic concern. It puts you at risk of health problems, heart disease, high blood pressure, diabetes, and even cancer. Obesity is generally caused by eating too much and moving too little, so you would think eating too little and moving too much should solve the issue. And while for the most part, it does, if you do this, you're going to die of nutritional deficiencies. Although a lot more attention is given to obesity, obesity and nutritional deficiencies cause almost the same number of deaths.

In 2017, 7,740 people in America died of obesity. In the same year, 7,846 people died from nutritional deficiencies. Nutritional deficiencies are sometimes caused by eating disorders like anorexia, although they can affect anyone. As a young woman, you are most at risk. This is in part because the world promotes being thin, when in reality, being extremely slim and being extremely obese are equally dangerous.

Accidents happen and usually, there's nothing we can do about it, and for some of us, that's sadly the way we're going to die. Whether it's a motor vehicle accident, simply falling on the ground to your death, or accidental poisoning, most of the time, there's really nothing we can do to prevent these accidents. Yes, we can try to be safe, but sometimes things simply don't work out the way they're supposed to and we come crashing to the ground. However, sometimes these accidents are not completely accidental. If you drink and drive, that's most likely how you're going to die. Technically, it will be described as an accident, but it would have been a very preventable one.

Every one of us has a one in three chance of being involved in a drink-and-drive accident, whether as drivers or passengers. If you don't want to end up as a statistic, always make sure that you have a designated driver or order an Uber when you go out for a night of drinking. While dying in a drinking-and-driving accident is easily preventable, the thing that's most likely to kill you isn't cancer. Just as there's a one in three chance that you'll be involved in a drunk-driving accident, there's also a one in three chance that you'll be diagnosed with cancer in your lifetime. This isn't very surprising considering the fact that there are just so many different types of cancer, and none of them are completely preventable.

It's true that things like a healthy diet and exercise can reduce your chances, but it doesn't completely eliminate them. And for the most part, this is true for death in general. We can try our best to protect ourselves and be safe, but when death comes knocking, sometimes all we can do is open the door and be ready to be taken. Life isn't fair. If it was, we would all be born with the same genes, predisposed to the same diseases and health risk factors, but we're not.

Diseases can be hereditary, and straight from our mothers' wombs, we're simply born to die. HIV, sickle cell anemia, high blood pressure—sometimes we simply inherit these diseases that make us more likely to die than the next person the moment we're born. High blood pressure is one of the deadliest inherited diseases because it exposes us to the biggest killer in the world—heart disease. One in every four deaths is caused by heart disease. If you smoke or have high cholesterol, this is most likely how you're going to die. Heart disease, for the most part, is preventable, but with things like poverty not giving people the opportunity to have the most nutritious meals they can, it's really difficult.

When you think about it, it actually makes sense. The heart is the center of our lives, so we're most likely going to die when it's not functioning properly, which is why exercise and a healthy diet are always encouraged. For all your heart does for you, it deserves to be treated right. If you're saddened about how likely and unpreventable your death is, don't be. Things have actually been getting much better. Between 2000 and 2019, the global life expectancy increased by more than six years, and it's still going up. Modern-day medicine is getting better, mortality rates are going down, and we're living much better than we used to.

No matter how old you are watching this video right now, in a way, you've already lived a full life. If you lived in the Victorian era, which is just less than 200 years ago, you would have had a one in three chance of dying before you even turned five. So live, enjoy life to its fullest. Life is so fleeting, so take time to pause and reflect. Be thankful for what you have and hopeful for what's to come. Ashes to ashes, dust to dust. From Sand we came to sand we will return. No matter what we do, no matter how hard we try, one day we will live, and the next, we will die.

Thank you. Death can only be interpreted by people who are alive. Yet since no one who is alive can simultaneously experience what it's like to be dead, who then does death actually concern? This logic is oddly reassuring. Even so, if my doctor were to call me up right now and tell me that I would die in 12 hours, I would still likely spend all that time in a state of debilitating fear and anxiety. Just thinking about this possibility makes me realize that whether I like it or not, death terrifies me right now, even as a person who is fortunate enough to be in good health.

It seems irrational and perhaps illogical to fear something that I have so little knowledge about or control over, but no matter what I do, I just can't seem to shake this nagging fear of the unknown. And I'm not alone. According to the 2017 survey of American fears conducted by Chapman University, 20.3% of Americans are either afraid of or very afraid of dying. But why do we have such a strong fear of death? Fear of death largely comes from the uncertainty and lack of control of the situation. But perhaps there is a better way to think about our lives and our eventual passing that might end this fear or at least chip away at its root cause.

To start off, let's talk about the only other life event aside from death, which has happened and will continue to happen to every single person who will ever exist on this planet: birth. Try to imagine the moment you were born. Of course, you can't actually remember this, I know, but just try for a second to bring yourself back to that time. The moment when you were pulled out of the darkness by a mysterious set of hands, only to be flooded by fluorescent lights and the chaotic bustle of a delivery room as your eyes adjusted to the light for the very first time.

You also had it taken in. A room full of total strangers who were all likely staring at you, some of whom you'd never see again and others you could go on to spend the next 80 plus years with on this journey we call life. This journey that you, in that hospital room, however many years ago, had absolutely no tangible knowledge about. We talk about how scary death is, but the truth is, birth was probably equally as scary, if not more so. It's no wonder that we judge the health of the newborn by how sterically they cry in the delivery room.

My point in bringing all of this up is to say that death isn't the first life-changing existential experience you've gone through. Was birth scary? Most likely. But every single day since then, you learned more and more about the experience that is being alive to the point where you thought of going back to the state you were in before birth has now become the idea you fear. Mark Twain once wrote, "I do not fear death. I had been dead for billions and billions of years before I was born and had not suffered the slightest inconvenience from it."

This perfectly expresses another truth that most people fail to consider when it comes to death. We all know and seem to accept easily that there was an infinite amount of time before we were alive on Earth, so why is it so hard for some of us to grapple with the fact that there will also be an infinite amount of time that comes after our existence on Earth? When someone dies at an early age, we feel great sadness for all the earthly events they won't be able to be a part of, but when a baby is born, we don't mourn everything they missed out on before their delivery.

We all seem to know how nonsensical it would be to feel sad about that. A baby's time of birth is what it is—a fixed situation which nobody has had any really control over. But when it comes to death, there seem to be so many what-ifs or if-onlys involved. Maybe it's because of the how—when one of our passing seems to say something about the way that we live. Consider the death of Robert Atkins—the man who dedicated a large majority of his life to refining the Atkins diet and preaching it as the most health-conscious way to live—only to die by slipping on an icy sidewalk.

People often reference this as a way to say that death is inevitable, no matter how healthily one chooses to live—a message which, ironically enough, is the exact opposite of the one Atkins spent his life trying to convey. Stories like Robert's are another major reason why some of us find death so frightening. The idea that the where, how, and when of our passing puts a climactic punctuation mark at the end of our existence and somehow adds to the definition of what our life meant. You either die a hero or live long enough to see yourself become the villain.

We seem to accept and even participate in creating these punctuations or labels, even when it comes to external things and people that we have no interpersonal connections to. When a breaking news story emerges where an innocent person is murdered, the majority of us collectively label their life as beautiful and their death as tragic. And when that person's killer is found guilty and sentenced to death, we label their life as despicable and their death as deserved. Labeling others is a comforting habit that is strongly hardwired into our psychology.

It's part of how we organize, simplify, and make sense of our world. Yet we all know that even the best one-word label couldn't possibly be used to sum up the entirety of who and what a person is and what the life they lived was. So the idea that our death could assign us with one of these simplistic labels which don't allow any room for the complexity of who we really were is terrifying.

If there's anything certain and non-debatable, it's that death is a termination of our physical bodies. Our hearts stop beating, our neurons cease firing, and we take one last breath. Our physical presence here on Earth is terminated at the time of our deaths. While this is undeniably true, it still leaves us with multiple unanswerable questions— a large one being, are we just a body? A spectacularly designed or random collection of cells, atoms, and molecules that is purely physical? Or is it possible that we're composed of a physical body, a physical mind, and something else, something intangible and non-physical, like—for lack of a better term—a soul?

This debate has been going on between philosophers for a millennium. Epicurus believed quite adamantly that we were merely physical beings whose deaths were a total annihilation of our existence, while some of Plato's most famous dialogues argue for the immortality of the soul. If you believe that there's nothing more to us than the atoms and DNA that compose our physical bodies and minds, then you might be what modern philosophers call a physicalist. If on the other hand your inclination is to believe that we are composed of a physical body, a physical mind, and something intangible that resembles the soul, then you might be what they call a dualist.

There are other variations and subsects of these definitions, but for simplicity's sake, we'll leave it there. Thinking back now to the problem of death with all this in mind, we can clearly see that whether or not someone is a dualist or physicalist makes an enormous difference in the ways they would interpret their beliefs about death and ultimately whether they would fear death or not. If death is a definitive end to the physical body, then as far as physicalists are concerned, death is a pretty straightforward pill to swallow. Death is just the end.

But for dualists, the possibilities are quite endless. For if we possess something like a soul, then the range of options of what could happen to that soul after our physical bodies die is wide open. While some people cling to religious texts and beliefs for answers and comfort, non-religious people are left with a huge uncertainty over what life after death holds. And as humans, we have evolved to be naturally scared of the unknown.

Maybe the best place to turn to for a further investigation of death is to consider the stories of people who have died. The near-death experience Research Foundation presents what many would consider to be the most compelling scientific evidence for life after death. Jeffrey Long, the foundation's creator, has studied and examined the accounts of thousands of people who have reportedly had near-death experiences. While no two people's near-death experiences are exactly the same, there are some characteristic features that have been commonly observed.

Long has conducted and posted 5,100 interviews to date with people who have claimed to have had an NDE and compiled the data he's gotten from them over the years. In this, he identified 12 essential elements that are consistently present in his subjects, some of which are an out-of-body experience, encountering deceased relatives, friends who are mystical beings, and experiencing a sense of alteration in time or space. Technically speaking, having any kind of lucid experience while one is clinically dead, without a heartbeat, should be impossible. Still, 74% of the people interviewed reportedly felt conscious and alert during their time spent dead than they did in their waking lives.

The remaining 20.4% reportedly felt the same amount of consciousness and awareness in death as they do alive, while only 5.2% said they experience less. Even though the belief that death is the end of our consciousness is relatively common, out of the thousands of people who participated in this survey, only 5% reported that to be true for their near-death experience. These statistics are startling for sure, and there are plenty more like this that are equally compelling.

But I think that sometimes it can be too easy to tune out the significance of figures like these, because, well, you can find statistical data to support just about any claim you're trying to make these days. Perhaps a more powerful and effective way to discuss NDEs is to delve into specific stories.

Take this one for example, reported by a woman who died by accidental electrocution at the age of seven. "I was transported out of my body and surrounded by the brightest, warmest light ever. The only way to explain it is our true home. It felt very familiar. It felt like home. I had never felt at home here on Earth before or after this experience. I didn't feel or see my body. I believe it was more like a pure light source that flows just like a river of pure love and joy. I was just so happy to be home."

Another person claimed that "the Earth is like a film that hasn't been developed. Not until we reach the other side is the film developed. Everything will be seen in beautiful colors that don't exist here on Earth." And another said, "In an instant, I knew that the life we live is an illusion. It's not real because it's a creation of our minds. We continually create thoughts and project these thoughts outside of the mind, just as cinematic frames are projected onto a screen." Reports like these are incredibly interesting, but you might be wondering where the proof is.

For all we know, these are just subjective accounts that people could be making up. And you would be right. Sadly, as of right now, there is no definitive proof of the validity of NDEs. Like you, I also started off my research into this a little bit skeptical. But the more of these stories I heard and read over time, the harder it became for me to believe that there wasn't at least some validity to them.

No matter what belief you choose to carry with you about what happens to us after we die, I think it's important to research the literature out there, learn what the people who have first-hand knowledge have to say, and use all the information to form a real thought-out opinion for yourself, because sadly, there is no way to tie a bow on this topic and wrap it up nicely. No matter what any of us say, death will always remain an existential mystery. But if you struggle with the fear of death, here is something that helped me tremendously in hopes that it helps you too: The most comforting thing about death is that it will happen to us all.

New York City, one of the United States's most recognizable cities. In September 2020, one of the many artistic landmarks of the city was repurposed. It was the metronome near Union Square. If you've ever walked by it or have seen it online, you'll probably notice two things. One: a giant piece of artwork by Kristen Jones and Andrew Ginsberg that is supposed to convey instancy and infinity, transience and permanence, all at once.

While the pulsing nature of the artwork is supposed to embody the city's energy, elements such as the massive piece of bedrock symbolize millennia of geological history. And the rippling centerpiece all come together to help the viewer visualize one thing: time. Another thing you might notice is the nearly 60-feet-long display of digits. This digital facet of the artwork is what allows it to be reprogrammed to fit such an occasion. Previously, it was used to display the time of the day and the number of hours, minutes, and seconds that remain in it.

It is all fittingly titled, "The Passage." But this September, this artwork embarked on a new mission. The numbers changed to not display only the regular time but the time that Earth has left in our carbon budget before given the current rate of emissions. We crossed the 1.5 degrees Celsius threshold outlined by the IPCC in 2018. Now it all sounds like things people have heard before. Scientists come up with numbers, they urge how important it is, and then people move on with their days. This is different. A complete depletion would result in a total destruction of our planet, and it will have been at the fault of our own hands.

If the Earth's temperature is increased by just 1.5 degrees Celsius, we will feel its consequences: extreme heat waves, fire across the world, droughts in places there shouldn't be, and less and less of the one resource on Earth we all need: water. The concern for climate change is certainly nothing new. In fact, it's been with us not for just the past few decades but for centuries. British archaeologist Ian Morris spoke at the World Economic Forum to talk about how civilizations in the past had collapsed.

He incorporated modern-day scientific methods, excavation practices, and billions of artifacts to dissect the collapse of previous civilizations. He concludes by saying that all major collapses tend to have five common factors time and time again. Firstly, they tend to have massive uncontrolled population movements that overwhelm societal infrastructures—pretty much overpopulation. Secondly, they have major pandemics and diseases which, because of the population movements, spread and merge faster. Then there's state failure and increased warfare.

This, in turn, leads to an economic collapse. And then there's one final piece of the puzzle: climate change. Civilizations rarely collapse because of one thing, and so these five factors can often co-occur, and it's their combined effect that leads to the collapse of civilization. It's easy to see how these factors connect with each other because all of these things are taking place right now around the world. Climate change is displacing millions of people. A pandemic is ravaging the world as we speak, and bad governance about these issues is making it all worse.

And while the population growth is certainly not out of control, it is, in fact, declining steadily. All in all, we're well on our way to collapsing. Ian Morris says there is some hope, however. In fact, in his study of past civilizations, he notes that quite a few actually survived the five Horsemen of the Apocalypse and rebuilt themselves afterward. He credits their survival to economic growth. Now, I'm really not about to debate capitalism versus other economic models in the world because, well, I don't want to start a war.

In his book about the future of human civilization, Tomadeus historian Yuval Noah Harari notes that although we experience occasional economic crises and international wars, in the long run, capitalism has not only managed to prevail but also to overcome famine, plague, and war. In fact, in modern times, we've experienced so much economic growth that today more people die of eating too much than eating not enough. It turns out we have a little too much stuff sometimes, and that too much stuff isn't produced out of nothing. Beyond the dollar value we pay for things, there's a far greater cost to abundance: an ecological cost—the overuse of unsustainable natural resources, water pollution, soil pollution, and loss of biodiversity.

In recent times, we've meant that we are closer to ecological collapse than we have ever been. Even though in the past, there wasn't a global governing body like the United Nations to oversee and recommend actions to reduce our environmental footprint, the footprint itself was always very localized. People hardly traveled as far as we do today, and business was not nearly as robust. Sure, a few centuries ago there were no solar panels or recycled plastic, but there also weren't any fuel-hungry airliners either. We also weren't siphoning oil and fossil fuels out of the ground either.

The scale of the industrial world seems to be truly unique to our time and civilization. There are of course other aspects to our civilization that make it more unique, and extension more complicated. Total nuclear obliteration is still a non-zero possibility, and as low as that number might be, the simple possibility of something like that happening is terrifying. Both natural pandemics and bioweapons are also a threat; in fact, both are quite common throughout the history of collapsed civilizations. Until very recently, more soldiers died from disease than from actual combat itself.

It's just that modern advances, while allowing us to cure far more diseases than before, have also opened up a Pandora's box of future threats. There's obviously the threat of runaway super intelligence as well. Such a technological singularity can encompass the threat of nanotechnology and their rising incorporation into everything from manufacturing to medicine. All of these factors understandably complicate the modern infrastructure, and Joseph Tainter, a historian, suggests that this rising complexity is what could ultimately be our society's downfall.

He suggests that societies emerge as problem-solving collectives—that's what they're there for—but eventually they reach a point where the complexity and intricate structures required to solve problems actually reach a point of diminishing returns, and civilizations collapse under their own weight. Tied to this idea is that of energy return on investment, or EROI for short. Simply put, it's how much energy is needed to produce or extract a set amount of energy. Fossil fuels have historically had good EROIs, but as we're burning through tons and tons of non-renewable fossil fuels, this EROI is steadily declining.

The EROI for petroleum, for example, has fallen by around 10 times in the past century. Because well, we're stealing all of it. Besides, despite being more in line with our goals of a greener future, as it stands, renewable energy sources are quite hard to develop, manufacture, and implement, which doesn't help their EROI either. These are all factors that are truly unique to our time, and they sound pretty complex.

However, there is one factor that civilizations in the past have certainly never had before: social media. It's unique in the sense that there's never been a platform that allows us to connect with so many people so easily. It's a society within our society—one we certainly didn't evolve to live in. It was just a byproduct of other advances. Of course, social media has led to some wonderful things, but like every other element I just talked about, it’s allowed lost families to reconnect, allowed fundraisers to reach significantly larger audiences, and it's even a platform to the ordinary person.

But the problem with social media, well, it's much more nuanced. Much like the cost of biological advancements, there's the threat of virality in social media too; only it's much, much worse. If falsehood spreads six times faster than truth on Twitter, then there's only ever going to be one winner in the battle of ideas. The virality of ideas—or bad ideas, I should say—is a newfound threat to civilization. It means the ripple effect of a bad idea is now much more likely to escape the geographic confines in which it took place and affect the rest of the world.

The sharing of misinformation on social media has led to levels of polarization that have never been seen before. A lack of tolerance seems to be at an all-time high. You see, one of the psychological side effects of prolonged social media is a broken concentration. You could argue that that's less of a side effect and more of an objective. Regardless, people are constantly glancing at their phones no matter what they're doing, and it's turning them into short-sighted individuals who are preoccupied with the next burst of dopamine.

That is exactly the problem we're facing with climate change and ecological collapse. We now have a world that is unwilling to look beyond the next presidency or the next election or the next generation or two. Social media in this case might just be a good analogy. But the fact of the matter is, we're slowly but surely walking towards the collapse of civilization as we know it. Now, while an asteroid strike or an alien invasion is a more spectacular possibility, they're not nearly as likely as, say, a slow ecological collapse.

A popular saying goes, "Civilization may not end with a bang but with a whimper." The moral imperative to do something really presents itself when you think about the number of lives that will eventually be affected by climate change, ecological collapse, or another factor that might cause societal collapse. The number of people presently alive pales in comparison to the number of people that can be alive in the future on this very planet, at least as long as the sun isn't too close. That number skyrockets once you factor in the possibility that given enough time, civilization could become multi-planetary. But that's the thing—enough time.

We barely have enough time to think about the policies of today, let alone tomorrow. Think about this: A man named Danny Hillis invented the idea of a ten thousand year clock in 1984 with one singular purpose: to encourage long-term thinking. As the name suggests, this clock will continue ticking without human intervention for 10,000 years when construction is complete. Much like the metronome near Union Square, this clock reminds us of time, albeit in a different way.

This clock is not necessarily counting down from something, but by its very presence, its sheer scale, it serves to remind us that the world will go on long after we've passed, and as such, we can still have an impact. Who knows, maybe under thousands of layers of sediment and fossilized remains are the lives buried of another civilization—another civilization exactly like ours—at this exact stage of their journey. Their time had come.

Seven years, 36 days—the passage takes away second by second to remind us. As of lately, it seems that everybody is trying to tell you when and how the world will end. Some scenarios are far more familiar and likely than others. Those that are widely discussed in the media range from infectious diseases to nuclear war, all the way into collisions with massive asteroids. While they are all vastly different from one another, they all share one thing in common: they're all able to effectively end the human species once and for all.

But all of these scenarios fall short when compared to one thing: black holes. We're all familiar with them, but what exactly is a black hole? Black holes are regions of space where the gravity is so high that the fabric of space and time has curved back on itself, taking the exit doors with it. But what does that even mean, and why are black holes black? Well, any large object, such as a black hole, star, or planet, has a certain escape velocity that is needed to escape the gravitational pull of that object. For example, Earth's escape velocity is about 11 kilometers per second.

Move that fast, and you can escape Earth's pull and fly off to the edge of the universe, but chances are you’ll probably be pulled in by something's gravity eventually. But that's not the point. The stronger the gravity an object has, the higher the escape velocity is. Now black holes have some of the highest gravitational pulls in the entire universe. In fact, black holes are theorized to have singularities where gravity pulls you with infinite force.

But we'll get to that later. Let's say, somehow, we made a black hole with the same exact mass as Earth, about 6 times 10 to the 24 kilograms. Alright, this looks good. Except this isn't to scale. It would look something more like this. In order to turn Earth into a black hole, you'd have to crush it down to about the width of your pinky finger—about nine millimeters. So these two massive objects have the same exact mass, except one is the size of your finger, and the other is the size of a planet. So how does this happen?

When black holes are created, they are typically formed by the death of massive stars—those with about 20 to 30 times the mass of our sun. While living stars undergo nuclear fusion in their cores, fusing together lighter elements such as hydrogen and helium, this fusion of elements creates energy and pressure that pushes out away from the sun, while gravity keeps the star held together. But as time goes on, over billions of years, stars begin to run out of these lighter elements and move on to heavier ones. They begin to fuse together denser elements such as carbon and oxygen, all the way up to silicon and iron. However, here lies the problem: iron can't fuse with anything. There isn't any more energy being produced.

So the power of the star's gravity takes over, collapsing the star under its own weight until it explodes in what we call a supernova. Parts of the star fly hundreds of thousands of miles into space, while the core continues to collapse under its own weight and becomes densely compressed. Remember how Earth has an escape velocity of about 11 kilometers per second? Well, if after all that, the core of what was the star is still massive enough, about 2.5 times the mass of our sun and dense enough, the escape velocity of the core becomes much greater than the speed of light—over 300,000 kilometers per second.

This forms what we know as a black hole, an area of space created where nothing, not even the fastest thing in the universe—light—can escape. But let's have some fun with it and dive into one. Imagine just for a moment that you are aboard a spaceship—but not any normal spaceship. One that can defy physics, one that could accelerate you to any extremely high velocity, even higher than the speed of light. This is completely impossible, but it's okay because you know your spaceship can reach any speed imaginable. You have no fear of black holes and decide to fall into one in the quest of science. You choose the supermassive black hole at the center of the Milky Way galaxy: Sagittarius A*.

This behemoth of a black hole is over 88 million kilometers wide—nearly 100 times as wide as our own sun. A black hole of this size will give you enough time to observe it as you fall into it. At first, things might actually be peaceful, and here's why. Because of the black hole's size, at this point, the gravity isn't exactly going to be painful for you, but it will have a noticeable effect on the light coming from behind you. As you fall towards the black hole, you notice some unusual things.

First, the stars behind you as you fall into the black hole begin to grow much brighter. The light from those stars is being pulled so strongly by the black hole's gravity that they begin to blue shift. As you fall further and further towards the event horizon—that is the point where our universe and the inside of the black hole meet—it begins to take up more and more of your field of view. It's almost as if the entire sky in front of you is filled with darkness. As you're about to cross the event horizon, you see the rest of the observable universe condensed into one single minuscule point directly behind you. If you were able to zoom in with your telescope onto this point, you would see the light from all the stars in the galaxies in the universe.

But you would also see a very dim red glow. You remember this—this is the cosmic microwave background, or CMB. It's essentially a map of the electromagnetic radiation left over from the Big Bang—the very instant that the universe came into being. The dim red glow you would see is actually this radiation being boosted into the visible spectrum, and then finally, it goes dark. You have crossed the event horizon, and it's only darkness from here on out. You realize that it's time to get to work before you get ripped apart by the black hole's gravity, so you begin to observe.

Except you don't see anything. There is no light. The view out of your cockpit window is completely and literally black. There is nothing to see. There's nothing to observe. You begin this journey to dive deeper than any human could into a black hole to discover what truly lies there, but there is nothing. You know the singularity of the system that we use in our universe doesn't work. Time does not flow similar to the way we experience it here in the normal universe; time flows downwards.

Meet Arthur. Arthur is really good at math, and he always has been. In fact, he planned on going to college to study math, but recently life didn't pan out the way he expected it to. And so he's not quite where he thought he would be by now. Sounds like most of us. What is more probable? One: that Arthur is a lifeguard at the local beach, or two: that Arthur is a math tutor at a local school and a lifeguard in his free time? The correct answer here is one—that Arthur is a lifeguard at the local beach and only that.

Now, don't worry if you got it wrong. The majority of people do, even people with years of experience in statistics. If you chose two, the error you made is known as a conjunction fallacy. You see, even without knowing anything else about Arthur beyond what the problem tells us, we can be certain that two is less probable than one. Why? Because it's more specific, meaning it involves the probability of Arthur being a lifeguard and the probability of Arthur being a math tutor in conjunction. You may find it easier to visualize using a Venn diagram like this one. Questions like this one were developed in the 1980s to test cognitive biases, among other things.

Why is this important for this video though? Because it offers a general statistical insight that is relevant everywhere else as well. Even as you will see in the deepest trenches of reality, the insight is simply that more specificity is less likely. The scenario of Arthur being a lifeguard and a math tutor may seem more likely, given how I've intentionally described Arthur to be mathematically inclined. But no matter how mathy he might sound, option two is the more specific scenario of the set, meaning more things have to go a certain way for it to occur, and is therefore less likely.

For a more drastic example, which is more likely—getting struck by lightning or getting struck by lightning and getting hit by a car in the same day? Now, on to the deepest trenches of reality. Have you ever wondered why most of the processes that go on in our lives are so seemingly irreversible? Why do they tend to go one way and not the other? Why is it that sugar can be stirred into a cup, but when you move your spoon the other way, it never unstirs itself?

Why is it so that the sock drawer always needs to be organized by someone and never does so on its own accord? Why is it that a cup of cold water doesn't suddenly start boiling? These questions might seem unwarranted and even dumb. We have so much intuition for these things that it almost seems unnecessary to ask these questions to begin with. But the reason why they need to be asked is because there's actually nothing in physics, no law or theory, that is against these processes reversing themselves. Laws that are obeyed when a cup of warm water cools down are obeyed just as well as when it heats up.

So there must be something—something else that's tipping the balance. Almost something that almost wants gases to disperse through a room; something that wants that cup to go cold. That thing is known as entropy, and it may have more to do with probability than with physics or chemistry. But first, let's try to understand what entropy means. You can understand a lot about a concept just by thinking about how it was named. The term entropy was coined in 1865 by Rudolph Clausius, who used it to define the second law of thermodynamics.

However, it's much better if we try to understand the term using classical languages. The Greek word for entropy doesn't necessarily refer to disorder like you might expect; rather, it talks about isotropic turning, meaning the same no matter how you turn it. It's talking about the number of ways you can change something or transform something and still have it look the same. If you want to think of it in simpler ways, think of a disorganized desk. There are some ways in which you could organize the desk and you can directly specify them since an organized desk refers to a particular arrangement of things in a particular way.

When it comes to a disorganized desk, there's really no rule that needs to be followed. A desk can be disorganized in so many more ways. Of course, a stash of papers on the left might look different than a stash of papers on the right, but in the grand scheme of things, it's simply disordered, especially when that's the only distinction you're drawing—one between order and disorder.

Now, these things might seem simple enough, but there are certain missing links we need to address before we jump from an analogy like that to reality. First, let me remind you of what we just talked about at the start of the video: that more specificity is less likely. If we use that in the desk analogy, it means that since an organized desk is a comparatively more specific arrangement, it is less likely than a disorganized desk to occur just by random chance.

I'm sure you have some intuition for this. If you organize your desk at the start of the week, unless you do something to maintain that order, it's probably not going to stay very ordered as the week goes on. Another missing link is the fact that in reality, things aren't super distinguishable. Particles at the atomic level are much harder to tell apart than the things on your desk. Even if certain disorganized versions of your desk might look different to you, you can rest assured that that won't be the case when you're looking at a million particles that all look the same.

But arguably the biggest link that makes entropy a hard concept to digest is the scale of things. You and I really have no clue— and I mean it when I say it—no clue as to the real size and number of things. Of course, you've heard things about there being more stars than grains of sand and whatnot, but you really don't know how big it is. The term unfathomable gets thrown around quite a lot, but rarely is its use as fitting as it is now. Reality is unfathomably complicated.

Even if you measure complexity just by the number of particles, you and I will fail to internalize the sheer size of things no matter how much we try. But I'm gonna go ahead and try anyways. Let's look at a box with two compartments and a few balls in them. Let's start nice and easy. So we have two identical balls. We allow the balls to move freely in between the two compartments. At any given point in time, where could the balls be? Well, they could all be in the left compartment—that's scenario number one—or one ball could be in the left and the other could be in the right. That accounts for two scenarios, actually, since there's two identical balls. If we were able to swap them in this arrangement, we wouldn't be able to tell them apart.

Or they could all be in the right compartment. The fourth and final scenario—all of these situations are equally likely. Now, what is the probability of finding both balls in the left compartment? Only one out of the four possible scenarios meets our requirement, so it's going to be one out of four, or twenty-five percent. Now, let's bump it up a bit. Instead of having just two identical balls, let's have four. Now, since there's more balls to move around, the number of ways that can be arranged also goes up. This can be represented by two to the power of the number of balls—in this case, 2 to the power of 4 is 16.

Subsequently, our luck needs to be that much better to have all the balls spontaneously place themselves in the left compartment. And sure enough, the probability of having all four balls in the left compartment is now down to 1 in 16. Let's keep going. What happens when we have five balls? The probability goes down to 1 in 32. What happens with 16 balls? The probability goes down to one in sixty-five thousand five hundred and thirty-six.

Notice how quickly the numbers jump up. Let's jump ahead a bit. What happens with 128 balls—which is still a pretty good number we can still kind of visualize? The probability is now down to a staggering one in whatever this number is. Now let's take a step back to put things in perspective. We rarely have these well-defined compartments. In reality, things move around wherever they want to, and so the number of ways in which they can arrange themselves, even with two balls, is—and I'll say it again—unfathomably large!

But that's still with just two balls. Remember earlier in the video I said it would be hard for you to distinguish between particles when you're looking at a million of them at once? Even a million particles is such a gross underestimation of reality, it's not even a contest. Something as little as 20 milliliters of water—basically the last sip of water in a bottle—has not a million particles, not 10 million, not even a quadrillion particles. It has over 10 sextillion or 10 to the 23 particles.

I'll spare you the math on this one, but let this be the takeaway: Things get really complicated, really fast. To connect the dots with our other takeaway, in reality, an ordered arrangement of particles, such as gas that is not dispersed or sugar that has not been mixed, is also significantly more specific when compared to other disorderly arrangements like the desk example. That specificity makes it so much less likely.

There's that many more particles to arrange. There's that much more luck needed for an orderly arrangement to exist. When you put all of that together, it starts making sense why things tend towards disorder. It's not so much that the laws of physics are biased towards one arrangement or another; rather, disordered arrangements are so overwhelmingly more likely than ordered arrangements that if you let nature do its thing, things will always become more and more disordered.

It's remarkable that at the core of it all, it's not a law of physics or chemistry, but rather one of probability. Interestingly though, this can lead to the curious insight that it is indeed possible for a cup of water to spontaneously go from cold to hot. If the trend towards disorder is indeed independent of the laws of physics, there should be no problem with that happening. And in reality, there really isn't.

Why don't we see it then? Well, the scale of things comes into play again. Going back to the ball compartment example, even if, say, we reduce the number of balls back to a thousand and say that the balls change to a different arrangement a million times a second, we would still have to wait 300 quarter non-agintillion years to see them all in the left compartment. That's many more orders of magnitude than the age of the universe—all for something as simple as a thousand balls being put into a box.

It's fair to say that it wouldn't be very wise to wait for that to happen. But what if you did? What if you saw out all of the arrangements of everything in the universe? Well, that brings us to the power of entropy. When giving us an insight into the end of existence, we see energy that we can use often needs to be in a particular form—in an ordered form.

You can think of it in terms of food. All food is just molecules, and everything has molecules, but you just can't eat everything. You can only eat things in which those molecules are arranged in very particular ways, and any other disordered arrangement of energy simply isn't very useful. Across the universe, energy is constantly transitioning from an ordered to a disordered form, causing a loss of useful energy. This sort of a progression also implies that at the start of the universe, energy was probably very ordered.

But what must have got it there? Was it just a fortuitous ordering of particles? And what happens if this process keeps going on? Well, the most likely outcome is what is known as the heat death of the universe. As the airwolf time pushes us forward each day, the universe inches closer to maximum entropy—a state of no thermodynamic free energy. It doesn't necessarily mean that the universe will be hot or that it will be cold; it just means that once everything has equalized to disorder, there will be no temperature difference to motivate a thermodynamic process to occur. Nothing changes; nothing happens. Time ceases to have any meaning.

This gradual process is inevitable, but it is nonetheless hard to see. The universe is hardly distinguishable from one day to the next, so to imagine that it might all one day simply cease to exist is a bit hard to wrap your head around. But that's not to say that we're so oblivious to the regularity of decay—it's all around us. Fading memories, aging, death, and the ultimate impermanence of our existence repeatedly remind us of decay.

But if it's all so inevitable, what's really the point of it all? Why even bother? In his book "Enlightenment Now," Stephen Pinker says the second law of thermodynamics defines the ultimate purpose of life: mind and human striving to deploy energy and information to fight back the tide of entropy and carve out refuges of beneficial order. An underappreciation of the inherent tendency towards disorder and a failure to appreciate the precious niches of order we carve out are a major source of human folly. Maybe it really is just that small moments of apparent order against an inescapable reality of decay.

But eventually, the lights have to go out one last time. The heat death of the universe is still a theory—it's a theory in a sense that we would have to cycle through all the different ways in which things can arrange themselves. And while the sheer numbers and time scales involved are too large for a human lifetime, that's not the case for the universe. The universe has time, and in a sense, is time. What is to say that in doing so and going through all the different combinations, we won't stumble upon an orderly arrangement again?

Sure, it might take many quarter non-agintillion years for something like that to happen, but it can happen. The possibility is vanishingly small, but it remains non-zero, and when that does happen, the lights just might turn back on. For all we know, we might just end up back at square one. The universe was really small and dense at one point, and then all of a sudden, it wasn't.

Wait a minute. Let's rewind and figure out what happened right here. This is because of two things: entropy and dark energy. Put simply, entropy is the measure of order in the universe. It's a measure of uncertainty or randomness. The higher the entropy, the more disorderly the universe is. It's like your bedroom. A messy room is a high entropy state because it's much harder for you to be certain of where any specific object could be—for example, that sock you lost last week.

But once you clean everything up and make it neat and orderly, it's much easier to be certain about where an object will be. This is entropy in a simple nutshell. But why is it important? Simply put, it could be what causes the end of our universe. Right now, the Milky Way galaxy and the Andromeda galaxy, the closest galaxy to our own, are racing towards each other at a speed of about 110 kilometers per second. But in 4 billion years, the night sky will look the most beautiful that it has ever been.

The collision of galaxies sounds like a really big threat, but actually, our solar system will most likely remain intact due to the huge, huge sizes of our galaxies. This most likely won't affect anything inside our immediate neighborhood. Andromeda is 260,000 light years across, while the Milky Way is only about 100,000 light years. And I say only 100,000 light years like it's nothing, but at our highest estimate, our solar system is only about four light years in diameter at most.

When our galaxy collides with Andromeda, the night sky will be filled with gas clouds nebulae, forming new stars. Assuming there's still life on Earth or in our solar system at this point because galaxies are mostly empty space, we only need to be worried about avoiding any object within light years. Oh, it may be our own sun. In about 5 billion years, the hydrogen in the sun's core will be completely exhausted and will leave what is called the main sequence, the place where dwarf stars, who aren't quite giant, slip.

And this is when the sun will begin to expand, which isn't exactly good for any life on earth. The Earth, moon, and according to many scientists, maybe even Mars will be swallowed whole by what is now the red giant sun. But there's an upside—this destruction may cause Titan, one of Saturn's moons, to have conditions extremely similar to what Earth's are today, meaning that we could possibly have living conditions on Titan.

But even then, things aren't too safe because in the year 22 billion, the first universe-ending scenario comes into play—the Big Rip. Low entropy states require work to achieve, so naturally, everything—even on the scale of the universe—seems to tend towards disorder. You can tie this in with the Big Bang. The universe wasn't an extremely low entropy state in the beginning—all the matter and energy in the entire universe today was compacted down into one minuscule point.

Since then, the universe has been expanding, cooling down into a higher entropy state—a more disorderly state. You would think that over the billions of years since the universe's beginning, the universe's expansion would slow down, but actually, it's doing quite the opposite—speeding up. This is due to dark energy. We have known that the universe's expansion has been speeding up for decades, but the reason why remained unknown. So we call it dark energy.

Right now, the idea is that dark energy will continue expanding the space between galaxies and that large structures in the universe, like galaxies, stars, planets, and even molecular bonds, will be strong enough to stay held together. This is due to forces such as gravity and the weak and strong nuclear forces. If this is true, then dark energy will never be able to become strong enough to pull these objects apart. However, there is a possibility that it might not work like that, and this is a problem.

There is a bit of experimental evidence that suggests dark energy may get even stronger over time. If this is true, then eventually, in billions of years, the distances between objects won't matter. Anything and everything will be torn apart. First, the galaxies themselves will be ripped apart, since the space between objects in the galaxy is so massive—like we talked about with Andromeda. Then the star systems will be torn apart, our solar system, then the stars themselves, and then the planets that even inhabited these solar systems.

And if dark energy is strong enough, if it keeps getting stronger and stronger over time, then even objects that are held together by stronger forces—molecular bonds that are held together by the strong and weak nuclear forces—will be shredded apart by the now overpowering dark energy. Nuclei themselves will be ripped apart from their atoms, and this will result in the universe with nothing left—everything has been ripped apart down to the very last atom. That is the Big Rip—when dark energy causes space itself to expand faster than the elementary particles that make it up.

The universe would just be a sea of empty particles that would never be able to interact with anything ever again. But keep in mind, this is theoretical and based off of only a few scientific experiments. So let's say that doesn't happen. What will happen next? Even if the universe isn't violently ripped apart by dark energy, it still exists—or at least we think it does—and it is still causing the universe to expand. So by the year 100 billion, dark energy will cause the entire universe to expand so far apart—even at the speed of light—we won't be able to see or interact with any galaxies that aren't a part of our local group.

Out of an entire universe made of hundreds of billions of galaxies and 100 billion years, we will only be able to interact with the measly 54 of them. And when you do the math, it's kind of sad how little of our universe we will be able to interact with. In one trillion years, these galaxies that we call the local group will collide with one another back to back to back until eventually the local group is one mega galaxy.

And as cool as that sounds, it's kind of lonely in a way for any life living in the galaxy. That's it; that's all you'll ever know. And around this time, all the gas clouds that are necessary to form new stars and solar systems will begin to exhaust themselves, until eventually there are no new stars being born. All the stars that are alive then will be the last of their kind until the very last star in the universe fades away into nothingness.

And eventually, the universe will go dark, which leads us into our second doomsday event for the universe: the Big Freeze. In 25 trillion years, the last shining star in the universe will either fade out or be swallowed into the supermassive black hole at the center of its galaxy. In 10 to the 30 years, black holes will begin to eat the remaining neutron stars and dwarf stars while the black holes themselves decay away over trillions of years due to Hawking radiation.

In a Google years—that’s 10 with 100 zeros after it—a black hole with a size of 20 trillion solar masses—that is a black hole with a mass of over 20 trillion suns—will finally decay completely due to Hawking radiation. And then there's nothing in the immense universe. Over this unreal time scale, there is practically no activity whatsoever. The only activity is random subatomic particles popping into existence for a brief second before they disappear forever, like the rest of the universe.

That's all there is. The universe has seemed to freeze to a stop. Entropy is at its highest state; the universe is dead. Except maybe it isn't. In 10 to the 10 to the 10 to the 56 years—which, by the way, is a number so big that when I sat down and wrote the script for this video, and even now, I couldn't even figure out how to physically write that number down—I tried to figure out a way to put this into scale, but I can't. It's 10 with this many zeros after it, which honestly just makes me more confused.

If you were to try and fully write out that number with all the zeros and everything on one line on a really, really long piece of paper, that piece of paper would be so large that it wouldn't even be able to fit within our observable universe due to the sheer length of that number. In that many years, due to those subatomic particles we mentioned combined with quantum tunneling—a phenomenon where particles seemingly instantly teleport between locations even faster than the speed of light—there is a chance there could somehow be an extreme random entropy decrease at an extremely specific point in the vastness of the universe, for all subatomic particles in the universe quantum tunnel to the same exact location at the same time.

This would result in a new Big Bang—a new universe, or maybe new universes.

[Music] When you think about the true cost of space exploration, what do you think of? Maybe you think about the challenge or accident, or maybe you think about the Columbia disaster—anything with the space shuttle blowing up really. Perhaps the numerous failed tests of the Apollo missions that tend to go unnoticed in the grand scheme of things. These incidents are spectacular; they are explosive; they're heartbreaking. That's why we remember them.

But what about the more subtle cost of space flight and exploration—the cost of being in an environment we simply did not evolve to live in? In a way, it's a tad surprising. For one, it's not like space has a lot going on. There's quite literally nothing for most of it. And yet space makes its presence felt to your body the moment you leave the nourishing confines of our own planet. So what really happens to our bodies in space?

Well, to answer that question, let's plan out a mission to a planet—any planet. Forget about the return journey; let's just consider the one-way trip for now. Based on the technology we have now, that would take, let's say, around a minimum of 10 months. So let's get to the launch pad; we have a long journey ahead of us.

3, 2, 1, and liftoff! Liftoff is the very first thing you'll feel in your space journey, and it's not to be taken lightly. During a rocket launch, astronauts will only experience around three Gs. I say only because of all three times the force of gravity on your body is certainly not pleasant. Most of us can handle it. Some roller coasters can actually hit g-forces up to double that. But anyway, as the thrill ride slowly calms down, you stop being pushed into your seat. Instead, you are being freed from it.

The effect of weightlessness is perhaps the second visceral indication that you are in space. But now that the weight is literally off your shoulders, you have something else to worry about. You see, as strenuous as it may feel sometimes, our bodies need the force of gravity to remain healthy. Our bone density and muscle mass depend a lot on the daily loads of gravity. The daily wear and tear are reminders to our body that we need to maintain our sturdy frame with all its muscle.

It's essential for our survival. Up in space, where you could basically lift anything without breaking a sweat? Not so much. The closest thing you and I have felt here on Earth is prolonged periods of bed rest. Remember how even standing up and getting out of bed feels like a struggle after sleeping for way too long? In space, at least for now, it's not so much that the astronauts are lying down and doing nothing; it's quite the opposite, actually.

It's different is that their frames are not under any stress most of the time, and as a result, their bodies simply get rid of the excess weight that doesn't need to be carried around. This has meant that astronauts in the ISS have experienced bone density loss of around one to two percent a month, which doesn't really sound like much until you put it in perspective. In comparison, the elderly lose bone density of around one to two percent—not in a month, but in a year. Scientists have been trying to combat this, of course. They're doing this by creating exercise machines that replicate the resistance we feel here on Earth.

And for astronauts in the ISS, exercise is as important as any of their responsibilities as astronauts. It is paramount to the long-term well-being of the crew. But let's continue with our journey. A few hours after weightlessness sets in, you start to realize your head feels all stuffed. This is because the heart evolved to pump blood against the force of gravity, and without that force, the heart is suddenly pumping more blood to your head than necessary.

The effect is somewhat similar to having an allergic reaction, but not just in your nose—in your entire head. Your brain will actually swell up, and the combined swelling in all of your face can lead to structural changes in your eyes, often leading to vision problems. If you've ever seen astronauts in person, notice how most of them have poor vision. If all that work on board does manage to tire you, it's bad news. You see, sleeping in space is not nearly as refreshing as it is on Earth.

We spend an entire day standing up against the force of gravity, so when we lie down, we can finally relax to the withdrawal of the resistance. That's what makes sleeping feel so nice. In space, however, there is no real difference between lying down and standing up because there's no fluid shift inside your body, nor is there any change in the vestibular system that works with the rest of your body to tell you that you're lying down.

Basically, your brain doesn't get the same sense of relief you'd be getting on the surface of the Earth. In addition to that, our circadian rhythm, or sleep cycle, is messed up because there's no regular exposure to sunlight or darkness that would orient our sleep-wake cycles. Astronauts on board the ISS have to deal with the sun coming up every 90 minutes. On longer missions, depending on where you are as part of your mission, it could either be always sunny or always dark.

And we can't really be sure of the effects that will have on humans long term until it happens. Since your heart doesn't have to work as hard as it used to, your cardiovascular health declines. That's why a lot of astronauts are returned from their mission with low blood pressure. Speaking of weak hearts, however, a mission to Mars is a long, long journey, away from people, away from home, away from anything familiar. Beyond 300,000 kilometers a second, even at light speed, communication will be delayed and that delay will only get longer as you go along, driving home the message that you are just one lonely small human in the unending darkness of space.

Right now, psychology is an often underrated aspect, not just in space missions but in reality in general. And in high-stakes missions like the ones astronauts go on, the inclination to leave out mental health to the latter pages of the agenda seems only human. Yet as our journeys become longer and longer, this has become more and more of a concern. To test out this exact concern, a few brave scientists self-isolated on a remote site in Hawaii for almost an entire year in 2016. And according to them, the most challenging aspect was acquiring food or water.

It wasn't their sleeping situation; it was the monotony—being in the same place with the same people, eating the same thing all day, every day. Overlooking the mental implications that something like that causes is pretty much setting yourself up for disaster. From the story. Speaking of disaster, though, after the Columbia disaster in 2003, one of the first things that was done was to let the astronauts aboard the ISS know that their fellow astronauts did not survive the journey.

And those following weeks, all on board were mandated to check in with a psychiatrist. Stressors of being up in space are almost entirely physical, but the mental stress is perhaps just as big of a puzzle piece in the next chapter of human exploration. The path to exploration is a solitary one, but this data has all been derived from experiments conducted on scientists aboard the ISS. And as far as that is, the ISS still enjoys a lot of the protections of Earth, things like the magnetic shielding that protects us from almost all of the sun's harmful radiation.

Beyond a certain portion, we will have none of that protection, and as such, radiation is perhaps one of the things we're least prepared for. While the muscle atrophy can be countered by a rigorous exercise regimen, we have very few answers as yet to the radiation problem and the effects it has on the human body. One of the many effects this has is DNA damage. Perhaps one of the more intriguing effects has been the lengthening of telomeres.

Telomeres are structures at the end of a chromosome that help it divide. As we age, our telomeres