Time to Stop Aging
Obviously, we need to stop aging. (There's a compelling article/story by Nick Bostrom about this: https://nickbostrom.com/fable/dragon.html.) Somehow, I guess this isn't obvious to everyone, though, because (a) our society doesn't seem to be making any serious effort to do it, and (b) sometimes I hear people give arguments about how aging is good. I find this totally bizarre.
Maybe it just doesn't occur to most people that curing aging is something we could do. I'd like to make it occur to more people. If you're a smart person considering a career in science, and you need a good research area, you should work on curing aging.
Why We Age
Why do we age, anyway? I'm talking about senescence, the deterioration of the body with age. (So don't say, "Oh, it's analytic that you age as time passes." That's not the answer.)
For almost all of human history, people had no idea. Today we have a good idea. Each cell in your body has only a limited number of times it can divide. As a cell divides, bits of material are lost from the ends of the chromosomes, the telomeres. When the telomeres get short enough, the cells lose the ability to divide. This is probably why all bodily functions deteriorate with age, until you inevitably die.
There is an enzyme, telomerase, that lengthens telomeres. It is active in germ cells, stem cells, and cancer cells, but not in most somatic cells.
(Note: That's a simplification. There is a lot of weird stuff going on that is not understood.)
Another thing I wondered for a long time: Why doesn't evolution select for longer and longer lifespans, since living longer gives you more opportunities to reproduce? It's not impossible to live much longer, since some animals in fact live much longer than humans. Greenland sharks are said to live 300-500 years.
I learned the answer in a book several years ago, but I can't remember which one. The reason is basically that in our evolutionary past, few people died of old age, because other things (like other people) were killing them first. If few people are going to live to be old anyway, then there is little evolutionary pressure to increase innate lifespan. If, say, there is some gene mutation that makes you stronger when you're 20, but also makes you more susceptible to heart attacks when you're 70, that gene is going to be selected for. Optimizing for success when you're young is generally not going to optimize for overall lifespan.
Can We Cure Aging?
Maybe we're not trying to stop aging because we assume that it's impossible. For centuries, and maybe throughout the life of the species, people have dreamed of finding a "fountain of youth", etc. All these dreams were delusory.
Today, however, is different. Of course people couldn't cure aging before -- they had no idea why it was happening. Today, we have lots of scientific knowledge about why aging happens, which no one before ever had, and we have reasonable lines of research into how it might be reversed. E.g., maybe increasing telomerase expression could stop or reverse aging.
So it is perfectly plausible that we could, in fact, cure aging through scientific research. One day, we will cure it. It probably won't be for a long time, though (not until after you and I are dead), because for some reason, we're really not trying very hard. We're expending far more resources on cancer research, other specific diseases, and many much less important things.
Should We Cure Aging?
Why would we want to cure aging? Should I even be speaking of a "cure"? After all, aging is a natural process.
Well, of course it is natural; so is cancer, so are viruses and parasites, so are hurricanes and earthquakes.
Let's assume that cancer is bad. Alzheimer's disease is bad. Heart attacks are bad. Strokes are bad. I hope nobody needs an explanation for that.
Well, age is the #1 risk factor for cancer. And heart disease. And Alzheimer's disease. And strokes. And many other extremely bad things. Very few people get those conditions when young. So aging is basically the cause of all those shitty things. If you don't want those shitty things, then you don't want senescence.
Not only does aging kill you; it also greatly reduces your quality of life for decades, before it kills you. Your body gets weaker, your mind slower, you forget things, you can't do the activities you used to enjoy, you become less attractive and more tired. You're forced to stop working; later, you may become a financial burden to your family or society.
It seems obvious that we don't want this.
Do We Really Want to Live Forever?
I don't know if we want to live forever, but we don't have to answer that, because there is no possibility of living forever. Curing aging does not make you invincible. If you crash your car into a tree, you'll still die. Or if you shoot yourself. Or if you catch certain infectious diseases. Etc. Eventually, some non-aging cause will kill all of us, if age doesn't do it.
You could, however, greatly extend your life expectancy. If your life is overall good, that's good. And if your life isn't good, or if it's going to cease being good at some point, you have the option of committing suicide; a cure for aging won't stop that.
Won't the World Become Overpopulated?
I don't think it will, because fertility is declining in the developed world and is now below replacement rate in many countries. We will actually need to do something to stop the population from dwindling. If we keep aging, while at the same time having smaller families, we're going to wind up with an ever smaller working-age population having to support ever larger numbers of old people unable to work.
Priorities
If you buy all that, then it seems clear that stopping aging has to be one of our top priorities. (I don't know if it is the top priority -- maybe stopping animal cruelty, or reducing existential risks, would be higher. But this one is very high.)
Aging is by far the leading cause of death for humans worldwide, accounting for tens of millions of deaths every year. Many more than the number of people who die from poverty, or war, or infectious diseases. Curing aging also would have a much greater impact on a person's overall life expectancy than curing any (other) disease that a person might have. E.g., instead of extending their life by, say, 10 years, you might increase their life expectancy by thousands of years. We're spending billions of dollars researching many other diseases, when we could be spending those resources finding a cure for aging, which would drastically reduce many different diseases all at once.
To stop tens of millions of deaths due to old age every year, we would need a large up-front investment for discovering the needed scientific knowledge -- but after that, it will continue to pay off year after year, for the indefinite future. You don't have to keep making the big investment (there would be a smaller cost for administering the cure to people, once it was discovered). This makes aging research highly cost-effective.
Why aren't we doing this? Granted, there are some people who are working on this. See, e.g., the SENS Foundation, https://www.sens.org (which you can donate to!). But we as a society are treating it as a marginal project, a much lower priority than lots of other medical and other causes. We're trying harder to cure baldness, or to ensure erections for old men, than we are to cure aging.
What are we waiting for?