As I turn 25 years old today, I am struck by how young I am. I know most people tend to think about how old they are when their birthdays come around, but my case might be a side-effect of thinking in astrophysical time scales. But I am also aware that someday I will wake up and no longer be young anymore. Still a babe in the grand stream, but frail and worn. When this happens, I assume I am going to be upset, not because of my body, but because it will remind me that I am going to die soon.
Right now, I don’t want to live for a mere 80-100 years. I want to see the future history of the world. Where will science take us? What wonderful new stories will be written? What new philosophical ideas will we come up with? Will we become wise explorers like in Star Trek, or destroy ourselves in World War III? I want to know.
There are many reasons people die—car accidents, disease—but no one can escape old age. And one day, that decrepit figure in the dark hood with the scythe will come knocking on your door. But is death really a fixed thing that we go invariably toward, or could there be a way to stave it off?
If other life forms are anything to go by, the answer is yes. There is a creature called the hydra, which, according to research, does not age. Biological immortality is possible, and it is observed. And if it is possible for something, then we have every reason to consider the possibility that we can engineer it for ourselves.
|The immortal hydra|
Though we often talk about dying of old age, age itself is not a direct cause of death. It merely increases the risks of deadly conditions, like heart disease, cancer, and strokes. It also brings with it a collection of aches and pains that make life ever less pleasant. So in the short term, the better medical technologies we have, the longer we can increase the human lifespan. In the last 300 years, we have more than doubled the life expectancy for a first-world citizen. The conventional method for doing this is to treat the conditions that arise due to aging, so we may be near a limit on this front. However, what if we go for the root causes, the mechanisms that drive the aging process on the microscopic level?
The science of aging is still not very well understood. That is why institutions like the SENS Research Foundation are pursuing the subject. As of now, there are several factors that are suspected to have something to do with the process.
Free radical accumulation:
The name sounds a fringe political group. Free radicals are atoms or molecules with empty spots in their outer electron shells. They are highly reactive, and will take electrons from other atoms and molecules. In cells, this causes damage. Free radicals build up from normal metabolism, but can be increased by unhealthy habits like smoking.
At the end of each DNA strand is a sequence that repeats over and over. This is called a telomere, and it is kind of like the end of a zipper. Each time the cell divides and copies its DNA, it misses a tiny bit at the end. In the next generation of cells, the telomeres are shorter. This imposes a limit on how many times our cells can divide.
Some injuries just don’t heal. Ligaments and tendons can remain damaged for a long time, perhaps indefinitely. Severed digits and limbs don’t grow back. Scars, both external and internal, sometimes don't go away. The brain loses gray matter. However, I would bet that these large-scale problems are the results of small-scale problems, such as the previous two discussed.
I assume there are more; I am no expert in cellular biology. There is a long road ahead of us, strewn with unknowns, but that is why it is called research. Aging is not magical; it can be understood, and once it is, it can be fought with technology and eventually defeated.
The idea of living for centuries, millennia, and even eons might be frightening, conjuring up images of someone bored and sick and tired of life, yet unable to lie down to rest. If given the choice tomorrow to live a normal lifespan or a million years, I imagine the thought of spending day after day, year after year, millennium after millennium waking up, going through the day, and going to sleep, and the fear of the crushing depressive boredom that it could bring with it, might cause many people to choose the normal limitation. But just as aging is not magical, immortality will not be either. We will still be able to die from accident, homicide, disease, or poor lifestyle habits. And if we do get bored, there will always be the option of going off the treatment. Sure, the idea of a million year lifespan may be daunting, but if I were offered the chance to live one more day for a million years, I can see myself taking it every time.
|"He's thousands of years old. Some people say millions, although that's impossible."|
Aging has always been a natural part of life, and it still is. But it does not have to be. Look at how technology advances; fifty years took us from the transistor to the internet, and it seems like every other day some new material, machine, or procedure is invented. So despite how little aging is understood right now, it is not unthinkable that it might be reversed within the next 60 years—my projected lifetime. It may still be too far off, but we can hope. As Isaac Arthur says on his video on the subject, "Live forever or die trying."