क्या Technology इंसान को अमर बना सकती है ? Can We Cheat Death ? full Documentary
MORGAN FREEMAN: Are we born to die? For millennia, we've tried to outsmart our own mortality... ..only to find that death is the greatest certainty. But for the first time in history, that may be about to change. Science is unravelling the mysteries of ageing. Discovering an animal... ..that comes back from the dead, and turning our quest for eternal life on its head.
Are we about to enter the age of immortality? Or is death necessary for the survival of our species? Can we cheat death? Space, time, life itself. The secrets of the cosmos lie through the wormhole. When will I die? It's a question I've asked myself.
I'm sure you've thought about it too. From the day we are born, the clock of our lives marks our inevitable decline, ticking inexorably toward our final hour. Medical science has made incredible advances in prolonging life.
For most of human history, people were lucky to survive into their 40s. Now, people often break 100. The oldest person we know of lived to celebrate her 122nd birthday.
And as we probe deeper into the fundamental biology of life, we are now questioning whether death really has to come at all. Whether we can... ..stop the clock. David Sinclair likes to live in the fast lane. (STARTS ENGINE) But he knows our bodies, like cars, can't push the needle forever. Well, I've been interested in studying ageing since I can remember.
I think it was around the age of four when I realised that my parents would one day die and I would too, and that seemed extremely tragic. And I also thought that if we could figure out why we age and what we could do about it, that would have a really big, beneficial impact on the world. David spends a lot of time thinking about old age.
But he's interested in more than the wrinkles on our skin. As a professor of genetics at Harvard, he asks what role our genes play in ageing. An ageing body is a lot like a rusty old car. Rust, or oxidation, is what causes everything, including our DNA, to break down.
David believes we may soon be able to repair our failing bodies as easily as a mechanic can spruce up a rusty body panel. David's research focuses on our body's own set of repair mechanics - a group of genes called sirtuins. As our bodies age, they accumulate old, or senescent, cells.
And longevity genes prevent those cells from accumulating. This would be similar in an old car to the mechanics removing rusty old parts and replacing them with new ones. But these repair genes begin to fall silent as we pass our 30s and 40s. So if we could find a way of getting those longevity genes working harder, this would be a way to keep our bodies healthier and working for longer. If our cells have the tools to restore and rebuild themselves, why can't they do that forever? In other words, stop ageing? Sinclair has dedicated his career to finding ways to help our repair mechanisms keep going well past middle age.
It's driven him deep into the inner mechanics of the cell. In order for a human cell to function, it requires close collaboration between two distinct parts - the nucleus, the cell's control centre, and its tiny power engines, called mitochondria. Every task a cell performs relies on precise communication between these two.
Imagine this kitchen is a young cell. Inside it are the nucleus and mitochondria, two chefs working in concert. Our genes are just like a recipe book. In a young cell, the nucleus and the mitochondria, they're reading the recipe perfectly and they're really working well together. A delicious meal is taking shape.
But over time, the communication and coordination between the chefs gets worse. In an old cell, the nucleus and the mitochondria, they're throwing in things that don't belong, they're leaving things out, they don't communicate well. One chef might be trying to pass a spoon to the other and the other one's not paying attention. It's as if the chefs are spilling on the recipe book and losing that ability to read it.
DNA is the recipe of life, but over time, wear and tear makes the recipe hard to read and our cells lose the ability to prepare the meal. Whether it's damage or changes in the environment, the cell eventually loses the memory of which gene should be on and which gene should be off, and that, we think, causes ageing. David has been combing through ageing cells, trying to see if he can identify which vital ingredient they lack. And now he thinks he's found the molecule that will get our cellular kitchen back on track. It's called NAD. It's a molecule that's essential for life.
Without it, you'd be dead in about 20 seconds. And as we age, the levels of this molecule go down steadily to the point where you have about half the levels of what you once had. David wondered if there was a way to restore NAD to more youthful levels. He injected mice with a special compound that boosts production of NAD. The effects were dramatic.
This mouse is very youthful and energetic, and you can see the ears are still nice and young-looking and the fur isn't turning grey. So you can see here this mouse is going grey. She's losing hair, her ears are getting wrinkled, her spine is starting to bend. Well, what's amazing about these mice is that they were born on the same day. What we saw was a rapid ageing reversal in their muscles from a mouse that's equivalent to a 60-year-old human back to a 20-year-old.
After being fed NAD for a week, the metabolism of the old mice improved. On the outside and the inside, they appeared years younger. In the history of ageing research, we've come such a long way. We started extending the life span of little, microscopic yeast cells, and we've gone through nematode worms and flies and mice and even monkeys now.
So we've come 99% of the way. It's that last little 1% to get to humans, and that's where we are now. If we can apply this to humans, imagine what a city street might look like 50 years from now. Almost everyone would appear youthful, free of the illness and frailties of age. (STARTS ENGINE) David's research may one day slow down and even reverse ageing in people.
We're not talking here about being older for longer. It's quite the opposite. It's about being younger for longer. But David's work only treats the symptoms of ageing. It doesn't attack the root of the problem - the gradual decay of our DNA. Japanese scientist Shin Kubota thinks we can turn that tide.
My dream is to live with my families of different generations, so that we can enjoy our great-great-grandchildren. The sea is where all life began, and with every empty shell it leaves behind, it seems to prove that all lives must end. But Shin knows otherwise.
Shin studies a tiny marine animal called Turritopsis dohrnii, or the immortal jellyfish. This creature has figured out how to cheat death. At Shin's lab in the town of Shirahama is the world's only captive population of immortal animals.
First discovered in the Mediterranean in 1988, this jellyfish is no bigger than your fingernail. Immortal jellyfish is very cute, small jellyfish. Diameter is about several millimetres.
But after showing these creatures such tender, loving care, Shin does the unthinkable. He chops them into pieces. Try to kill this jellyfish, you will be surprised. A remarkable thing happens. The jellyfish does not die beneath Shin's hand.
Instead, it seems to be reborn. The bell re-absorbs the tentacles and become a gelatinous blob. I call this stage the meatball. The meatball becomes a polyp and soon it matures into an adult jellyfish.
The jellyfish shows very remarkable transformation. The jellyfish's secret is a process called cellular transdifferentiation. The cells and any fragment of the animal can figure out what body parts are missing, then retrofit themselves to grow back the entire body. If we could determine how do the jellyfish rejuvenate, we could borrow its techniques.
MORGAN FREEMAN: Are we born to die? Imagine Shin were attacked by a mutant sea monster. It's Japan, after all, so it's not such a crazy idea. If the only thing left of Shin were the tip of one little finger, transdifferentiation could turn those finger cells into brain cells, heart cells, muscle cells. Shin would come back from the dead. It seems like science fiction, but jellyfish and humans have surprising similar genes. If a jellyfish can learn this trick, perhaps we can as well.
From the ruins of a single animal, hundreds of identical jellyfish have sprouted. It's a feat unequalled in nature, but perhaps not for long. If we could unlock the genetic secrets of this jellyfish, we could regenerate ageing organs, perhaps even entire bodies. I believe one day, the humans can become immortal, using the same process as a jellyfish. Shin's discovery has driven him to write and perform songs about the immortal jellyfish. He hopes they'll inspire his ageing friends to think about the promise of immortality...
(SINGS IN JAPANESE) ..and encourage them to hold on long enough to benefit from the genetic secrets of his remarkable jellyfish. The promise of immortality always seemed a fantasy, but the infinite regeneration of the jellyfish is biological reality, so can we get there with our biology? Some people believe we will, and sooner than you think. Death has always been a fact of life. Why? Because our bodies wear down. Our hearts won't beat forever.
Our muscles gradually weaken. Our brains lose their edge. But it doesn't have to be that way. Our bodies have built-in technology to repair themselves. Stem cells. These cells have the potential to replenish any organ in the body if we can coax them into doing it.
Cell biologist Larry Goldstein thinks that if we want to extend our life spans, we'll have to leap past a major obstacle - the slow decline of our minds. I had the unfortunate experience of helping to care for my mother when she developed Alzheimer's disease in her late 60s. It was a terrible experience and I hate the idea of anybody else having to go through that with their family members and their loved ones. 50% of us will develop Alzheimer's disease by the time we're 85 years old. It does no good to age to 85 and be physically healthy if your brain doesn't function. At the Sanford Consortium of Regenerative Medicine, Larry keeps an hourglass on his desk.
It reminds him of the all the people who are running out of time. But Larry thinks he's found the key to fighting debilitating diseases of ageing like Alzheimer's. Stem cells. The problem is that we don't really understand what goes wrong in brain cells that have the disease, and we're using stem cells to try to tackle that problem in a unique way. Stem cells are the body's original building blocks.
They have the potential to become any type of cell. In the primordial furnace of the womb, our bodies use these raw materials much like a master glassblower, sculpting beautifully intricate finished organs from shapeless, raw ingredients. You can think about stem cells as being like biological raw material just like these glass pellets are the raw material that you can throw into a really hot oven and use to make anything at all that you'd like to make. So let's see how this works.
In you go. Ooh, that's hot! As we grow from an embryo, our bodies prepare and shape stem cells for the adult roles they will need to fill. Each stem cell decides what adult cell type to become based on cues from the cells around it.
Stem cells respond to biochemical signals from other cells. And so a heart cell started out as a stem cell and it got instructions to become a heart cell. You can imagine putting a heart together with different vessel cells or different muscle cells. A great glassblower can put all these different shapes together to make something beautiful at the end.
Cool enough to touch. Amazing. It's incredible, really, when you think about it. Millions and millions of stem cells get together, respond to the right sorts of biochemical signals, and make this heart. The power of stem cells to create organs from scratch has drawn the interest of scientists for decades. The goal is to harness this resource to rebuild and replace failing tissue. But there's a problem.
By the time we're fully grown, we've exhausted our supply of embryonic stem cells, and the few stem cells we have left are not nearly as flexible. There are so-called adult stem cells which are partially formed. They're committed to make one of the types of adult tissues. Skin stem cells make skin, brain stem cells make brain tissues. But the important point is that it's partially committed - it has part of a shape that commits it to do some things and not others.
Only embryonic stem cells have the flexibility to become any cell in the body. But harvesting them from embryonic tissue has proved politically controversial. Then, in 2006, scientists made a stunning discovery. Adult stem cells can be recycled back to embryonic form by modifying just four of their genes. They become what are called induced pluripotent stem cells, or IPS cells. So the discovery of IPS cell was like the shot heard round the world.
It was a true revolution in our understanding of what cells could do and how simply it could be done. By throwing glass back into the furnace, we can now restore cells to their embryonic state and create raw materials we could use to stay eternally young. You could make this into brain cells or heart cells or skin cells or what have you. We've used genetic trickery to take, for example, a skin cell from my arm, trick it, using genetic elements, into becoming a cell like an embryonic stem cell in its abilities. Larry is now using these rebooted cells to uncover what goes wrong in Alzheimer's. He starts with skin cells of people with the disease and changes them into brain cells.
Then he can study exactly what's going wrong in those cells, and develop new drugs to treat them. Right now, we have zero drugs that alter the course of Alzheimer's disease. I do know that if we wanna make it past 85 or 90 on a regular basis, we're gonna have to solve the problem. Larry hopes his work on Alzheimer's is the beginning of something bigger.
He thinks if we stored our stem cells while we're young and healthy, we could use them later to replace our ageing organs. It's incredible, really, when you think about it. The ability to someday build an organ from stem cells like this will be a huge breakthrough. If our organs have the power to regenerate, why do they allow us to age and die? Plants, bugs, animals. Happens to us all.
Perhaps it's because death is programed into us by evolution. Old animals must die to free up space for the young. So if we cheat death, if we regenerate the sweetness of youth... ..will evolution end? So what the computer model does is simulate the competition between mortals and immortals. When you see blue, it means that that region of space, there is a mortal living there. And if it's red, there is an immortal living there.
They fill out every space and then they start competing for the limited resources there. To picture Andre's simulation, imagine a head-to-head contest between two very different soccer teams. The immortal players, in red, do not wear out with time, but the mortals, in blue, will eventually become too tired to play. By pitting the two against each other in a game lasting many generations, Andre thought he could find out just how much advantage immortality conveys.
Every time I run the simulation, the same thing happens. The advantage of not dying makes a huge difference and the immortals start winning. Like soccer, life is a competitive struggle. If you compete more effectively, you control the game. But Andre's simulation contains another lifelike factor - environmental change.
Just like in the real world, Andre's virtual players face constantly shifting conditions. Like new diseases... ..predators... ..and climate change. While immortals can struggle through them, not all mortals make it. However, when they die, they are replaced with younger, stronger players.
In any evolutionary process, if you are mutating and adapting, the new generations will be slightly better than the older ones because they are the ones that survive. Since the mortals can evolve, this gives them an advantage that allows them to get back in the field. In evolution, each new generation has some tricks the last one didn't, and the faster you get them on the field, the faster the species improves. The impact after many generations... ..is huge. First, there is no advantage for any side, and then, slowly, the blue mortals starts winning, and after a while, they can actually drive the red team, the immortals, to extinction.
In the end, the mortal population wins because the immortals can't adapt. They're doomed. This suggests that ageing has a biological goal. Andre believes to keep pace with a changing world, we need new generations with new adaptations, and we must make room for them, which makes mortality necessary.
The mortal can drive the immortals to extinction. It was much easier than what I was expecting. From an evolutionary point of view, for the species, it is a good thing to die. Yeah! From a personal point of view, it's not a good thing at all. (LAUGHS) If we ever learn how to become immortal, we'd eventually be usurped by mortals whom evolution would have taught new skills.
But Andre thinks if we could edit our own genes, we could create our own adaptations. When we are talking about changing the way we are and making the decision ourselves, we don't need evolution anymore to do that job. Since we don't need evolution to do that job, the advantage of ageing disappears. We owe our very existence to the wonders of evolution even though it had designed us to get out of the way. But what if we could sidestep natural evolution, manipulate the genes that make us die? Could we evolve ourselves to live forever? At the core of every living cell is a single, fabulously complex molecule.
DNA. Its genetic code is the source of life. But DNA is also the reason we die. As we age, our DNA code gets slowly jumbled until it can no longer keep us alive.
If we can undo those mistakes, we can stop death's shadow from creeping up on us. Professor Jennifer Doudna thinks we're on the brink of being able to fix all the errors in our DNA and make ourselves immune to disease and decay. It's been an amazing decade or more in science when it's been possible to sequence not only the entire human genome, but now many human genomes. And what's really on the horizon is the opportunity to rewrite that information. Over the past few years, Jennifer has developed a revolutionary DNA editing technique which has turned the dream of modifying our genes into practical reality.
What's exciting right now is that we have a chance to make changes to the DNA at the level of a single letter in the more than 3 billion letters in the human cell. So this is a wonderful moment when a technology has become available for that kind of precision genome engineering. In the past, DNA editing has been a crude, hit-and-miss affair. Imagine trying to fix a pair of eyeglasses without being able to see them and with tools that are far too big for the job.
We didn't dare to edit human genes that way. But Jennifer and her collaborator, Emmanuelle Charpentier, have developed a new, far more precise tool that makes DNA surgery not only possible, but easy. It's called CRISPR, and it places almost God-like powers in the hands of humanity. Like many scientific wonders, CRISPR was pioneered by nature herself - inside bacteria. We began our project with the goal of understanding how bacteria fight viral infection.
But we recognised that molecules involved in those processes in bacteria could be harnessed as a technology for rewriting the DNA in cells. You could think about the DNA of a bacterium as a house and the invading viral DNA as a burglar. Jennifer and Emmanuelle discovered that bacteria have a built-in surveillance system. They can't prevent the first attack, but a system called CRISPR takes a precise snapshot of the viral DNA the same way a security camera captures the picture of a burglar. In a real bacterial cell, the CRISPR sequence is the way that the cell records images in the form of DNA that represent foreign invaders and keep it for future reference to protect the cell from those same invaders. When the intruder shows up a second time, the bacterial cell recognises the invader from stored surveillance images and calls the cops.
In the bacterial cell, those cops are the enzyme Cas9. So when the house pulls out a picture from the surveillance camera and identifies a potential invader, that's the CRISPR system using the enzyme Cas9 to find and destroy foreign DNA. The Cas9 molecule acts like a pair of scissors precisely guided by CRISPR to a matching site on the virus's DNA. It then cuts the DNA in that spot, destroying the virus's ability to reproduce. The threat to the bacterium is eliminated.
But Jennifer realised she could adapt this natural mechanism into a pinpoint method for gene editing accurate down to a single letter of DNA, turning a complicated system into something as simple as a keyboard shortcut. CRISPR technology is like the cut-and-paste function in a word processing program. Let's say you're writing a biography of Albert Einstein and you quote him as saying "Imagination is more important than virtue."
But you realise you made a mistake. Einstein actually said, "Imagination is more important than knowledge." With the CRISPR technology, I could change the word 'virtue' to 'knowledge', and then we have the correct sentence. This genome editing technology provides the opportunity both to identify genetic mutations that cause disease, but also to actually correct those mutations. The ability to precisely fix errors in our DNA brings the promise of extending our lives, lifting the shadow that death casts over us.
We could use CRISPR to stamp out hereditary diseases like cystic fibrosis and sickle-cell anaemia or simply make better humans. Ones with extra strong bones, low risk of Alzheimer's, or built-in resistance to cancer. But a dark side looms. Could this technology be used to create genetically engineered embryos for a super race? An elite population of designer babies with enhanced intelligence, beauty or strength? I myself came to this realisation over time, and one of the things that really influenced me was a dream that I had in which I was being asked to explain the CRISPR technology to someone in a dark room, and when that person turned around, it was the profile of Hitler. I still feel chills when I think about that moment in my dream when I really felt strongly that this technology needs to be handled with caution.
In 2007, fishermen caught a bowhead whale off the coast of Alaska. Embedded in its flesh, they found a harpoon tip dating to the 1890s. No mammal on earth lives longer than the bowhead. Some of them live past 200. If we're looking for the genetic tools to cheat death, all that we need is probably already out there in nature's vast pool of DNA.
We just have to find it. Harvard scientist George Church believes we need to probe the vast pool of animal DNA to find the secret of longer life. One of the mysteries of ageing, why it is that some animals, like mice, live for 2.5 years because of their genetic program, while other animals, like bowhead whales, live for 200 years because of a different program. There's a wide range of life spans across all organisms in nature, but there's a consistent trend - large animals tend to live longer. You could think of this in terms of a swimming race...
(BLOWS WHISTLE) ..between long-distance swimmers and sprinters. In this analogy, the bowhead whale, long-lived, they're like the marathon white-cap swimmers, and the mice are like the red-cap sprinters. Big animals move slowly but last for the long haul. Small guys race along and burn out quickly. But George doesn't think size explains the bowhead whale's long life span. He thinks the secret lies in how it takes care of its DNA. Researchers recently found evidence that the bowhead excels at repairing damage to its genes.
In humans, DNA damage is a major cause of ageing. George thinks we could repair that damage using the powerful new CRISPR gene editing technique. We're harnessing vast amounts of information gathered on long-lived animals and converting it into a gene therapy that can test whether we can do ageing reversal in large animals and humans. Most of us die because our organs fail - our hearts, our lungs, livers, our brains.
But George thinks we can build better organs by going back and removing genetic defects from the cells they are made from. To test this idea, George looked at the genomes of pigs. We are using editing methods to engineer cells that are capable of producing pig embryos. Scientists have discovered that over the millennia, pig DNA has been contaminated by 62 different viruses. George decided to use it as a test case to see if gene editing could delete these tiny contaminants.
What we did was unprecedented, which was change 62 pig viral genes simultaneously so that now the pigs are, for the first time, virus-free. With sperm and egg cleansed of ancient contaminants, George made his own pig embryos using in-vitro fertilisation. Once the pig embryos are implanted, we no longer have to keep going back to the embryo stage, and then the pigs breed just like regular pigs would. It's just that they no longer produce viruses. Very soon, we could breed long-lived pigs whose organs could be donated to humans. So pigs have the right size and shape organs for all the organs that are classically part of transplantation - heart, lung, kidney, liver.
We're trying to engineer pig embryos, and eventually, pigs that can be donors of organs to humans in need. But George thinks of this as merely a stepping stone to correcting our own organs. It also gives us the opportunity to make more healthy organs, which are resistant to viruses, cancer and ageing. Ultimately, George wants to apply this technique to humans and to a much broader range of genetic defects, deleting harmful genes and adding in beneficial ones we find in long-lived animals like the bowhead whale. Today, we can test for genetic defects in unborn children, but we lack the means to cure them.
So when you go to a modern obstetrics clinic like this and you're concerned about genetic disease, the mother and the father can get a readout of their genome and make decisions that might involve termination. George believes that in the near future, parents won't have to face these difficult choices. The gene editing techniques he's pioneering in animals will soon be applied to the genes of human parents before they ever conceive a child.
In the near future, you'll be able to edit either the mother or father's body DNA so that the sperm or egg does not contain the very serious disease and it never even makes it into an embryo. Further into the future, we'll even add DNA modification so that children are born not only healthy but with long-lived super organs. Today, living for 200 years is beyond our reach, but with precision editing in the sperm and egg, our genes may soon have the staying power of the genes of the bowhead whale. Just as our ancestors had a life expectancy of 45 years, today, it's more like 90, mothers today can expect their children to live into their hundreds.
Imagine a future where people over 100 years old continue contributing to society as if they were in their 30s again, where their vast experience is valued and ageism is a thing of the past. But this man thinks our quest to cheat death threatens the fabric of civilisation itself. He says it's time for us to embrace death.
A century ago, the average life expectancy of an American was around 52. With genetic engineering, living to 150 will fairly soon be the new norm. Now, that sounds great.
Who doesn't want more time to grow, to love, to create? But what happens if we keep pushing the limit? 300, 500, maybe forever. You'd think a world where death is a rarity would be a utopia. But would it? Stephen Cave is a professional philosopher. He thinks a lot about death.
You might say it's what gets him out of bed in the morning. Most people, most of the time, are running away from death. We're terrified of death, even though it's one of life's great certainties, along with taxes. Most people are in denial of it. But Stephen is a little different.
He's actually running towards death. As he sees it, our civilisation depends on it. I think it's important that we actually face up to mortality, that actually life is richer and better and more valuable when we recognise that it is limited. Stephen has come up with a simple experiment to force people to face the reality of their own demise. Excuse me, can I stop you for a moment and just ask you a couple of questions? It's a little exercise I'd like to get you to do. I'd like you to take this pen.
On the front, could you write the year you were born? That's the easy bit. Now comes the maths. Oh. I'd like you to add 80... 80? 80 to the year you were born.
Now, because you're a woman, can you add two to that number? Now, do either of you smoke? Nope. No? OK.So we'll just keep that number you've got. Now, do you know what that number is? 2077. Yes. That's the year that you are due to die. Oh. (LAUGHS)
Yeah, I suppose it's slightly depressing. (BOTH LAUGH) By doing this simple exercise, Stephen has significantly changed the subjects' state of mind But that awareness of our own mortality causes an intense anxiety. To deal with it, we repress and deny it, and even lie to ourselves. Social psychologists call it terror management theory.
Well, what do we do? How do we cope with that terror? Well, we tell ourselves stories that deny the reality of death, that tell us that somehow, we can keep going forever. In other words, confront someone with the fact that they're going to die and they will believe any story claiming we can live forever. So every civilisation has some story about why we don't need to fear death.
Now, this might be a religion, for example, that promises that if we believe, we can live forever in heaven. Or it might be patriotism or nationalism that promises we can live on as part of this greater whole. Imagine these identically dressed runners represent one subgroup of human society. And now suppose that the group splits in two with each half taking different paths through the city.
The two groups remain indistinguishable from one another until one passes through a graveyard. The group who have been running past the cemetery will unconsciously have been reminded about death, and because of that, they will be in a different state of mind when they finish their run. When the members of the group join back together, they meet a pair of individuals who belong to a new group. The members of the group who saw the tombstones aren't interested in the outsiders. Those who never saw reminders of the dead are more open-minded. Over 400 studies have shown merely thinking about death causes us to pull tighter into our social groups.
This may sound like a bad thing but Stephen argues that, on balance, over the course of history, it has not been. Fear of death is the engine that drives us to create tight-knit societies, and from that, culture and civilisation itself are born. So much of what we've built is about helping us to live longer, and if we can't stay alive physically, you know, if buildings and medicine and science doesn't do it for us, then we've got art and culture and religion that helps to carry us forward even after bodily death. Stephen believes all civilisations exist to defend us against the fear of death. Without the fear of death, humanity as we know it would cease to exist.
If we all woke up tomorrow and found ourselves immortal then there would be profound changes in our society. Religion would lose its unique selling point. We wouldn't need to sign up in order to get eternity in heaven if we already had eternity here on earth.
The inevitability that our lives will one day end has spurred us to leave a legacy - to create literature, art, technology, everything that makes us who we are. Rather than paralysing us with fear, Stephen believes knowledge of our demise can help us live. You can see life as like a book. Just as a book is bounded by its covers, so our lives are bounded by a beginning and end. And even though a book is limited by its cover, still, it can encompass fantastic adventures and distant landscapes and exotic figures.
The characters in a book, they're not afraid of you reaching the last page. And so we shouldn't worry about whether our story is long or short, whether it's a comic story or an epic. We should just focus on making it a good story. We've been so busy striving to cheat death, we forgot to ask ourselves if we really want to live in a world filled with immortals. As science allows life to last longer, it may also grow sweeter - free from disease, physical infirmity and the slow decay of the mind. But nothing needs to last forever.
To the young, death's shadow brings fear, but to a man of my age, it brings vigour - the desire to do what I love while I still have time. Oh, I'm happy to cheat death, but only as long as my passion for life remains.