If you’re human, you’re going to die. This is not the most comforting thought, but death is the inevitable price we must pay for being alive. Humans are, however, getting better at pushing-back our expiration date, as our medicines & technologies advance.
If human life span continues to stretch, could we one day become immortal? The answer depends on, what you think that it means to be an immortal human.
“I do not think when people are even asking about immortality, they really mean true immortality, unless they believe something like a soul,” Susan Schneider, a philosopher & founding director of the Center for the Future Mind at the Florida Atlantic University. “If someone was, say, to upgrade their brain & body to live a really long time, they might still not be able to live beyond the end of the universe.”
Scientists expect universe will end, which puts an instantaneous dampener on a mystery about the potential for human immortality. Some scientists speculated about surviving the death of the universe, as science journalist John Horgan reported for Scientific American, but it’s unlikely that any humans alive today will experience universe’s demise anyway.
Many humans grow older & die. To live indefinitely, we might need to stop the body from aging. A group of animals, which may have already solved this problem, so it is not as far-fetched as it sounds.
Hydra are small, jellyfish-like invertebrates with a remarkable approach to the aging. They’re largely made from stem cells that constantly divide to make new cells, as their older cells are discarded. The constant influx of new cells allows hydra to rejuvenate themselves & stay forever young.
“They do not seem to age, so, potentially they’re immortal,” Daniel Martínez, a biology professor at Pomona College in Claremont, California, who discovered hydra’s lack of aging. Hydra show that animals don’t have to grow older, but that does not mean humans could replicate their rejuvenating habits. At 0.4 inches (10 millimeters) long, hydras are small and do not have organs. “It’s impossible for us because our bodies are super complex,” Martínez said.
Humans have stem cells which will repair and even re-grow parts of the body, like in the liver, but human body isn’t made almost entirely of those cells, like hydra are. That’s because humans need cells to do things aside from just divide & make new cells. For instance, our red blood cells transport oxygen around the body. “We make cells commit to a function and in doing that, they need to lose the power to divide,” Martínez said. As the cells age, so do we.
We cannot simply discard our old cells like hydra do, because we need them. For instance, neurons in the brain transmit information. “We do not want those to get replaced,” Martínez said. “Because otherwise, we cannot remember anything.” Hydra could inspire research that permits humans to live healthier lives, for instance, by finding ways for our cells to function better as they age, consistent with Martínez. However, his gut feeling is that humans will never achieve such biological immortality.
Though Martínez personally does not want to live forever, he thinks humans are already capable of a kind of immortality. “I always say, ‘I think we are immortal,'” he said. “Poets to me are immortal because they are still with us after so many years and that they still influence us. And, so I think that people survive through their legacy.”
The oldest living human on record is Jeanne Calment from France, who died at the age of 122 in 1997, consistent with Guinness World Records. In a 2021 study published in the journal Nature Communications, researchers reported that humans might be able to live up to a maximum of between 120 & 150 years, after which, researchers anticipate an entire loss of resilience (the body’s ability to get over things like illness or injury). To live beyond this limit, humans need to stop cells from aging & prevent disease.
Humans might also be able to live beyond their biological limits with future-technological advancements involving nanotechnology. This is manipulation of materials on a nanoscale, less than 100 nanometers (one-billionth of a meter or 400-billionths of an inch). Machines this small could travel in the blood, and possibly prevent aging by repairing damage cells experience over time. Nanotech could also cure certain diseases, including some kinds of cancer, by removing cancerous cells from the body, consistent with University of Melbourne in Australia.
Preventing human body from aging still is not enough to achieve immortality; just ask the hydra. Even though, hydra do not show signs of aging, creatures still die. They’re eaten by predators, like fish and perish if their environment changes too much, like if their ponds freeze in winter, Martínez said.
Humans do not have many predators to contend with, but we are prone to fatal accidents and vulnerable to extreme environmental events, like those intensified by global climate change. We will need a sturdier vessel than our current bodies to ensure our survival long into the future. Technology may provide the answer for this, too.
Long live technology
As technology advances, futurists anticipate 2 defining milestones. The first is the singularity, in which we’ll design AI (Artificial Intelligence) smart enough to re-design itself, and it’ll get progressively smarter until it’s vastly superior to our own intelligence. The second milestone is virtual immortality, where we’ll be able to scan our brains and transfer ourselves to a non-biological medium, such as a computer.
Researchers already mapped the neural connections of a roundworm (Caenorhabditis elegans). As a part of the so-called OpenWorm project, they then simulated roundworm’s brain in software replicating the neural connections & programmed that software to direct a Lego robot, consistent with Smithsonian Magazine. The robot then seemed to start behaving like of a roundworm. Scientists are not close to mapping the connections between 86 billion neurons of the human brain (roundworms have only 302 neurons), but advances in AI may help us get there.
Once human mind is in a computer and can be uploaded to the internet, we cannot need to worry about the human body perishing. Moving human mind out of the body would be a significant step on the road to immortality but, consistent with Schneider, there is a catch. “I do not think that will achieve immortality for you and that is because I think you would be creating a digital double,” she said.
Schneider, who is also the author of “Artificial You: AI and the Future of Your Mind” (the Princeton University Press, 2019), describes a thought experiment in which brain either does or does not survive the upload process. If brain does survive, then the digital copy cannot be you as you are still alive; conversely, digital copy also cannot be you if your brain does not survive the upload process, because it wouldn’t be if you did, copy can only be your digital double.
According to Schneider, a better-route to extreme longevity, while also preserving the person, would be through biological enhancements compatible with the survival of human brain. Another, more controversial route would be through brain chips.
“There has been lot of talk about gradually replacing parts of the brain with chips. So, eventually, one becomes like an AI,” Schneider said. In other words, slowly transitioning into a cyborg, and thinking in chips instead of neurons. But if the human brain is intimately connected-to-you, then replacing it could mean suicide, she added.
The human body appears to have an expiration date, no matter how it’s upgraded or uploaded. Whether, humans are still human without their bodies is an open question.
“To me, it isn’t even really an issue about whether you are technically a human being or not,” Schneider said. “The real issue is whether or not you are the same self of a person. So, what really matters here is, what’s it to be a conscious being? And when is it that changes in the brain change which conscious being you are?” In other words, at what point does changing, what we can do with our brains change who we are?
Schneider is excited by potential brain & body enhancements of the future and likes the thought of ridding ourselves of death by old age, despite some of her reservations. “I would love that, absolutely, she said. “And I would love to see science & technology cure ailments, make us smarter. I would love to see people have option of upgrading their brains with chips. I just want them to know what is at stake.”