The biggest drama of the past century was arguably caused by the two world conflicts and the subsequent transition to nuclear warfare: humanity had to learn to coexist with the impending threat of global annihilation by thermonuclear war. But today, in addition to that dreadful scenario there are now others we have to cope with.
We observe an accelerating pace in many troubling phenomena; to a large extent we are responsible for their existence or emergence. In the course of the past thirty years we have witnessed a boom of population increase, wealth inequalities, an increasingly globalized economy, and global warming. Like thermonuclear warfare these are game changers, all potentially very dangerous issues that are extremely hard to cope with. In particular, the speed at which they are progressing makes is difficult to react and adapt to them.
At the same time at which these changes have started to taking place, the increase of our technology has been fast. This brings in more challenges as well as opportunities. It is no longer science fiction to discuss the interfacing of the human brain with artificial storage or computing devices, nor the creation of "chimera embryos" -animal embryos injected with human zygotes (see here for a recent advancement). Interstellar space travel (not just interplanetary travel, which we have experienced since the seventies) is possible, and its realization seems just a few technical details away. Artificial intelligence is around us. These intelligent devices are not yet self-aware, but many foresee that they will soon start to be, as their level of complexity is soon reaching the relevant threshold.
So our own technology advances bring in additional, dreadful challenges. Will artificial intelligence make humans second-class citizens? Will it eventually destroy us, given -in the mind of a superior intelligence- our imperfect, expensive, expendable nature? And even if we manage to create a world where we can coexist with artificial minds, will we be able to handle the sociological impact of machines that can do our jobs better than us and more cheaply?
All the above are nagging questions to which nobody has clear answers, depending as they do on too many unknown factors. All we can do for now is to try and get equipped to deal with those questions as they arise. With this in mind, I cannot but be happy to see that this seems to be a stable item in the agenda of very wealthy individuals.
Over the past few decades we have been witnessing an increasing inequality of wealth, with the creation on a new category of super-billionaires. The idea that allowing bigger profits to enterpreneurs by reducing their tax load would eventually generate benefits to all, through a "trickle-down" mechanism, has been shown to be a big lie - it does not work that way: the rich keep their wealth to themselves; they largely do not reinvest it for the good of society.
On the other hand, at the very high-end of the wealth spectrum the liberalized global economy has created a small class of people with previously unthinkable economic means. Now, for the largest part these are individuals with a thinking brain, and as they sit on their piles of cash they unavoidably come to the conclusion that they ought to invest some of it for something good for humankind as a whole. And with their means they can tackle problems and challenges that individual countries cannot take on, because those problems and challenges appear too far fetched, or ethically questionable, or simply beyond the mission of public administrations.
The one good thing
Can this be the one good thing that this immoral inequality has brought to humankind? Is it possible to believe that among the Milners, the Zuckerbergs, the Musks hides someone who will give us the means to defeat the next wave of threats to our very existence? As much as it smells of marketing, the input we receive about e.g. the new "Neuralink" project of Elon Musk seems to indicate that the seeds of such a process are being planted.
We are only at the start of the XXI century. By the end of it, we might already have succumbed to one of the above mentioned threats. But I think we will manage to survive. Surviving, however, will require us to change, and adapt. One clear example of this is the need to change our whole food production model, which is not sustainable for long. Another is the change from fossil fuel to more renewable energy sources. But we will also have to cope with rising temperatures and sea levels. We will probably need to grant a universal income to cope with an increasingly machine-dominated workforce.
Looking Still Farther Forward
More extreme forms of adaptation might require us to change in more dramatic ways. This is bound to happen on a longer time scale. When I was a student, fascinated by the universe and by science fiction, I was taught that habitable planets were an absolute rarity in the cosmos. I never believed this concept, but it seemed corroborated by hard, unassailable logic. Now we know just how false that logic was: habitable planets exist around a very significant fraction of our nearby stars (see a few planetary systems from a wikipedia sketch above). I think the destiny of the human race - a way to answer the reducing resources on Earth, as well as the possibility of global catastrophes - is to eventually leave our planet, spread throughout our corner of the milky way, and eventually colonize the more welcoming of those close worlds laying around us.
But how can we accomplish that?
I can see a multi-pronged attack of the problem already in progress before us. Colonizing Mars is a step in the right direction, although it is probably not much more than a warm-up exercise. Our knowledge of that planet is good enough to make it utterly unattractive to us: it is desert, ugly, and unhospitable; it can barely pass the standards to be a penal colony for recurring felons. The allure of farther, wholly unknown planets may better motivate humans to undertake a 100-year-long journey.
Unfortunately, cosmic rays would kill us.
Cosmic radiation -mostly composed of protons and light nuclei, as well as energetic X- and Gamma rays- can be screened in some measure. Their electrically charged component can in principle be deflected by strong magnetic fields, and yet I see no way to reduce the radiation exposure of human beings over long journeys to an affordable level. We know what happens when our body is exposed to ionizing radiation for long time: we are subjected to a number of nasty consequences including brain damage and cancer. Unless we develop a technology that repairs individual dna strands, or at least reverses all carcinogenic processes, there is no way we can survive long period in the cosmos. But how can we pull that off ?
I am as ignorant on the matter as a regular Joe, so I will not venture to discuss what looks to me as a really unsolvable problem by ordinary means. But I think we can sidestep it. Once we develop a way to move our cognitive abilities and our sense of self into a non-biological support, we are done. That is what the above-mentioned start-up "Neurolinks" of Elon Musk is aiming at: as biological human beings we will never be able to colonize the cosmos, but if we move to a non-biological support, things become quite easy!
As robot-humans we can imagine boarding a space ship for a journey to a nearby star system, lay down, and go into a suspended state, setting the alarm clock 100 years in the future to save energy. We would then wake up as we approach our destination, fresh as a digital rose. Science fiction? Maybe, but this looks like the way to go.
I also believe that the conversion into robot-humans entails a paradigm shift in the purpose of our life. And there lays another challenge, of entirely different nature. As biological beings our mission is to survive, by creating siblings who carry our genetic code. When we change the support, from a biological to a non-biological one, we lose our ability to transmit our genetic code (we could of course still keep that, but that is beyond the point). On the other hand, we gain the ability to create copies of ourselves by just core-dumping the whole contents of our brain into another support. And with such a process, we really gain immortality - and more.
So, what can be the mission of a sentient, immortal robot-human? I have no answer to this question other than a most trivial one: to acquire more knowledge, and to explore the cosmos, art, and beauty. Is it enough to justify eternal life? I do not know, but I believe knowledge and art are unlimited, so I do think that the human race may retain a purpose even in a distant future. This gives me hope.