 Uh-huh. What's that? Frank wants to know where to drop off the cellular degeneration treatment? Well, tell him here's good. A quick note. This thunk episode is going to deal a lot with death. If you or someone that you care about struggles with suicidal ideation or depression, please check out some of the links in the description for professional help. Now, on with the show. It might sound a little bit like hyperbole, but mortality has been an important part of our conception of what it means to be human since well before the dawn of civilization. We've discovered funerary remains from as early as a hundred thousand years ago, evidence of ritual burial. Even in the Paleolithic era, it seems that humans were well aware that they'd eventually kick the bucket. That's a serious bummer, and it's kind of the oldest bummer that we still have to deal with today. While you and I don't have to worry about hungry predators or sleeping outside during a blizzard these days, we have to confront the inevitability of our eventual deaths. And that sucks. I like being alive. I do all my favorite stuff while I'm alive. And dead people don't look like they're having much fun. That tension between wanting to escape death and not really being able to has clearly driven a whole bunch of wacky shenanigans throughout human history. The elixir of life, the philosopher stone, the holy grail, the fountain of youth, all sorts of people have spent decades pursuing fabled substances rumored to grant eternal life. But it's possible that those stories are representative of a much greater phenomenon. Terror management theory is an idea in social psychology that the existential dread of our own mortality is the unconscious root of a lot of human behavior, that the primary reason we engage in culture, all culture, from art and music to business and nationalism, is to mitigate how uncomfortable we are with the thought of being dead someday. In the case of religion, it's a very direct and literal thing. If you follow a certain code of behavior, you'll get resurrected after you die, or some part of you will get to live forever in an afterlife. For symbol-focused activities like writing or painting or erecting monuments, it's the hope of surviving through a legacy. For stuff like joining organizations or forming groups or national identities, it's about being part of something greater than yourself that will live on. According to TMT, a lot of the stuff that we think of as giving life meaning and purpose is derived from some connection to its capacity to let us cheat death. When we're participating in culture-type stuff, we feel like we're doing alright, but when we stop, the dread starts to creep in. Like all theories in social psychology, TMT has its critics and should be taken with a grain of salt, but it certainly seems feasible to argue that a large part of why humans do what they do is to cope with the certainty of death, which we understand in detail in a way that no other species we know of does. Of course, there's another option for dealing with our stress about dying, convincing ourselves that it's better than the alternative. A huge number of fictional works paint immortality as a burden that weighs heavily on those cursed with it, bringing not but sadness, apathy, and a longing for the sweet embrace of death. Tuck everlasting, Doctor Who, Angel, Highlander, all sorts of seriously angsty fictional characters have lamented their everlasting lives. If these stories are to be believed, although Eternal Youth sounds like a pretty good gig at first, it inevitably becomes torment for all sorts of reasons. Maybe once you've lived for 200 years, you've seen so much that life gets boring and uninteresting. Maybe watching everything you love grow old and die is torturous. In some stories evocative of TMT, death is the only thing that gives life meaning, and living without it hanging over your head feels frivolous. Other narratives try to sell death as an attractive goal in and of itself, a state that's restful and serene, like chilling out at a resort or something. Frequently appearing in these narratives is our old friend, the appeal to nature fallacy, where the word natural is played both to mean of nature and wholesome, or good. You know, natural, like Ebola. It's kind of hard for me to take these ideas about the supposed drawbacks of living forever, or the supposed upsides of being dead seriously. For starters, they only ever seem to come from people who aren't dead. If there were a convincing argument about embracing one's mortality, you aren't likely to hear it from someone who's decided to keep living for some reason. Also, the reasons that people cite for wanting to keep living tend to be very concrete. If someone says, I really love cheesecake, I want to live so I can eat more cheesecake, that's pretty hard to argue with. In contrast, arguments about the supposed undesirability of immortality tend to appeal to highly abstract, hand-wavy concepts, or hypotheticals. Like, but what if you eventually got bored with cheesecake? Which doesn't really seem like it's on the same footing as, but what if I didn't and I got to eat cheesecake forever? As humans, we worry about death. And despite some protestations that sound a little like sour grapes, living forever sounds like it would probably be pretty cool. What do we have for that, besides participating in the cultural immersion that TMT recommends? Well, ostensibly, the whole point of the field of medicine is to keep people from dying, or having their lives compromised by disease. It's granted many of us additional years of life already, despite the fact that evidence-based medicine in its current form has only been around for about 50 years and uses a standard of treatment for less than that. Depending on your sex and how old you are right now, you're likely to live anywhere between five to 25 years longer than you would have if you were born a century ago. A reasonable extrapolation of that trend is that we'll continue finding new treatments for disease, expanding average human lifespans further and further so future people might have a much longer average life expectancy. But I'm not worried about those future people. I'm worried about me. What does all this do for me? Hold on, we'll get there. But first, let's do a little math. The rate at which life expectancies have increased over the past 100 years is close to linear, like every year it gets around three months longer from 1917 until today. That's a little surprising because we discovered some things in the past 100 years that you'd expect to have some pretty drastic effects on average life expectancy. Stuff like, I don't know, antibiotics. The thing is, even with those incredible discoveries, we haven't actually solved the problems that are most likely to kill you as your body ages. Heart disease was the leading cause of death in 1917 and it still is today. Cancer, stroke, they're all still on the list. We've gotten much better at treating them, which accounts for the general increase in life expectancy, but heart attacks are still pervasive and really bad news, especially as you get older. A breakthrough in heart disease would be huge, much better than the linear improvement we've seen so far. If medical researchers discovered a safe, affordable drug that significantly reduced the risk of atherosclerosis and just pumped it into our water supplies like we do with fluoride, we might well expect average life expectancy to jump by 20 or 30 years overnight. The same goes for almost everything else on this list, discovering an exceptionally effective treatment for cancer, using self-driving cars to drastically reduce the rate of fatal accidents, cloning new pancreases to reverse diabetes. There's no reason that most of these risks couldn't be fixed or at least largely mitigated in a very short timeframe with the discovery of certain totally realistic technologies. And there's a bonus here. If you live long enough to see medical researchers cure the next thing that was going to kill you, you get to live even longer, maybe long enough to see the next thing get cured. Some transhumanists envision an inflection point at which medical discoveries outpace the onset of these diseases, a longevity escape velocity, at which point cheesecake forever? Now, before you get your hopes up too high, it's possible that there's something about human bodies that simply can't be fixed. Some inevitable part of how they work, which more or less requires them to expire in a certain timeframe. Evolutionary biologists have noted that the driving force behind biological specialization, the thing that ultimately gives birds feathers and lizards claws is reproduction, not longevity. So long as you live long enough to pass on your awesome genes, evolution doesn't really care if you live for a long time after that. There are some aspects of human biology like the production of free radicals that are great for short-term survival but ultimately cause the body to deteriorate. Some scientists have argued that regardless of future medical discoveries, the data suggests that we're built in a way that more or less caps out at 130 years. But we don't really know for sure. We found some species which under the right circumstances are biologically immortal. It's entirely possible that with the proper resources, healthy human lifespans could eventually be extended indefinitely. In fact, there are some organizations explicitly dedicated to figuring out how to combat aging as a medical syndrome, finding ways to halt or reverse the biological processes that cause our bodies to decay over time and stop healing themselves as efficiently. What would it mean to be human if they succeeded? What if the only cause of death that remained on that list in the future was accidents? How would you feel about getting to eat cheesecake for a few hundred more years? Please leave a comment below and let me know what you think. Thank you very much for watching. 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