The state of the art technology in 2023 is closer to long term theoretical limitations in some areas than others. Some technologies, like aircraft and nuclear power, have only modest room for improvement beyond their theoretical limits.
But, there is particularly great room for improvements with profound societal implications during my lifetime and the lifetime of my children in the area of medical science and technology.
Consider, in particular, the quest for a cure for cancer. We have a decent biochemical understanding of cancer. We have some treatments for cancer in our arsenal that work for some kinds of cancer in some circumstances. It is an area for which there is lots of funding for research.
We know that curing or dramatically reducing the lethality of cancer is possible in principle because we've identified animals, and even some select human subpopulations that have dramatically lower cancer rates than those of the average humans.
We know that certain kinds of cancer are caused by viruses and have a good idea about how to develop vaccines against those viruses, one of which, vaccines for the main viruses that cause cervical cancer, is already in wide use.
We are also making good progress on drugs to treat cancer once you develop it. Some of these drugs can be targeted on an individualized basis to the cancer in a particular person. Some of these drugs have far fewer side effects than earlier chemotherapies because they have effects that better distinguish between cancer cells and normal cells. Some of these drugs have broader application to multiple kinds of cancer.
And, we are making progress in more accurately diagnosing cancer's onset early when it is easier to treat and has done less harm.
It isn't unreasonable to think that in twenty to forty years that advances in cancer diagnosis and treatment could reduce cancer death rates by 80%-90%, on top of incremental but steady reductions in cancer death rates that have already been made by possible through medical research and its wide dissemination.
Now, cancer is one of the two leading causes of all deaths, and makes up an even larger share of deaths of "natural causes" in old age (the other one is cardiovascular diseases like heart attacks and strokes). But advances in cancer diagnosis and treatment could lead cancer to join the ranks of leprosy, the bubonic plague, and HIV as a disease that is still devastating if not treated, but whose lethality can be dramatically reduced as a matter of course with effective treatments.
Dramatically reducing the lethality of cancer would profoundly extend the life expectancy of people around the world and would in short order have a transformative effect on society.
Now, the benefits of dramatically reducing the lethality of cancer also shouldn't be overstated. Old age involves a wide array of declines in body functionality. It just so happens that cancer and breakdowns of the cardiovascular system are most often the first to manifest in a way that can be deadly. But if cancer becomes much less deadly, people who otherwise would have died of cancer will often instead often die of some other geriatric condition, not all that many years later in many cases.
They will die of geriatric falls. They will die because they drive to drive despite declining vision and reaction times. They will die from breakdowns of their cardiovascular systems, or kidney failure, or liver failure, or complications of old age associated dementia. They will die from medical mistakes. They will die from the flu or COVID.
Old age makes your body break down and this can make death by some means or another associated with these break downs almost inevitable. And, the vast majority of animals have a lifespan that is quiet similar measured in units of heartbeats per lifetime, so it is medically more challenging to come up with treatments that stop, slow down, or reverse the global cellular aging process itself.
But there are a handful of animal models of animals that appear to surpass the barrier of the biochemical cellular aging progress itself.
We don't understand the process and the mechanisms for modifying cellular aging quite as well as we understand cancer, but we do have a fairly good big picture understanding of how the aging process works, and we have had a few small successes in trying to modify it (at least in animal models). There is no fundamental theoretical scientific reason that we shouldn't be able to stop, slow, or reverse the aging process. Ultimately, learning how to do this is just one more biochemical engineering problem that is solvable in principle, even though it is difficult and complicated.
Slowing down the aging process is a holy grail of medical research because it has such potentially broad applicability. If you can develop a treatment that causes someone to have a body that biochemically looks like it is 50 years old at age 75, a one-third reduction in the rate at which the aging process proceeds without actually even stopping or reversing the process, the number of people who could live long past age 100 would soar.
Slowing down the aging process would dramatically reduce the death rates from basically all geriatric causes of death simultaneously at any given age, and would also increase the health of older people receiving the treatments at every age thus improving their quality of life.
Taken together a dramatic reduction in the lethality of cancer, followed perhaps two or three decades later by treatments that significantly slow down the aging process, would profoundly change human society forever going forward.
And, along the way, there are other major killers which are likewise basically just bioengineering problems to solve, for which there is no good reason to think that they can't be overcome with enough time, money, and brainpower devoted to the maladies.
We now know that M.S. is predominantly caused by a virus and can probably develop a vaccine to immunize people against that virus in a decade or so. We are making good progress in developing vaccines and treatments that greatly reduce the toll of malaria. We are making good progress in being able to cure HIV. There is promising research on a "vaccine" that would dramatically reduce the vulnerability of people treated with it to tooth decay and gum disease in the next decade or two. Wide spectrum, long lasting vaccines for many variations of the flu and of the common cold look viable in the next decade or two. There is no good reason that an effective vaccine for syphilis couldn't be developed.
Gene therapy may soon be able to cure a wide array of single mutation Mendelian genetic disorders and conditions. We are finding more and more ways to replace organs and other body parts that have failed, either with transplants, or custom grown replacements, or with mechanical substitutes whose quality is greatly increasing.
We aren't anywhere close to reaching immortality and curing all diseases and maladies. But a huge swath of medical conditions seem likely to go the way of measles, mumps, rubella, polio, small pox, cholera, leprosy, the bubonic plague, tuberculosis, gangrene, bacteria infections, scurvy, rickets, lead poisoning, mercury poisoning, maternal mortality, infant death, and folate deficiency, all of which had an immense public health impact a century or two ago, and are now important primarily for their historic impact.