The Lifespan Horizon
To expand our horizons, we must extend our lifespan.
The Egyptian pharaoh Khufu, with a view to ensuring the immortality of his spirit after he died, built the Akhet Khufu — interpreted as ‘Khufu’s horizon’ — to house his body. Known popularly today as the Great Pyramid of Giza, it remained the tallest man-made structure for thousands of years. It is estimated that it took 20 years for the pyramid to be constructed, a long time for a project even by modern standards.
The most time-consuming projects that humans have embarked upon have lasted at most a few decades. There are cities and places of worship that have taken centuries to get to their final state from the moment the first stone was laid, but those are better characterized as evolution rather than planned construction. One of the earliest walls that eventually merged with others to form the Great Wall — the one built by Qin Shi Huang — took about 14 years to complete. The Taj Mahal — the mausoleum of Mughal emperor Shah Jahan’s wife Mumtaz Mahal — was built in 21 years. In modern times, large projects have been motivated less by military or vanity reasons but for development or scientific research. The construction of the Three Gorges Dam in Hubei took 14 years; the Cassini-Huygens mission to the Saturn system is in its 34th year, counting from conception; Voyager 1 has been traversing the Solar System for more than 38 years, thanks to an extension of its original mission, and is expected to continue functioning, albeit in a limited fashion, for about 9 more years. Perhaps what is bound to be the longest-running project of our era, the International Thermonuclear Experimental Reactor (ITER), that aims to build a nuclear fusion device for energy generation, was conceived in the mid-1980s. The ITER Organization was formed in 2007, and construction began in 2013. If everything goes well, the first fusion experiments are scheduled to start in 2027, more than four decades after conception. An upper limit to these numbers is not hard to guess — the typical active lifetimes of the people involved, which, in turn, is dictated by the human lifespan.
Long-term projects require a lot of funding, but that is not the main issue, which is that people are not motivated to embark on endeavours whose culmination they may never see. The human lifespan inevitably imposes a horizon even on the most perceptive visionary. But as humanity progresses, we will need to start projects that will undoubtedly span timescales longer than a few decades. This is especially, though not exclusively, true for space travel. For example, building a spaceship to go to the Alpha Centauri system would take decades of development, followed by decades of travel. There is simply no motivation for space scientists today to spend their limited amount of time building a part of a spaceship that, long after their deaths, would send back information on another star system. It is impossible to change people’s attitudes, but what we can change, and have been changing, is their useful lifespan. Longevity, and in its limit, immortality, is the key to humans embarking on extremely long-term projects, such as the oft-promised colonisation of the Galaxy.
Thankfully, advances in healthcare shows promise. Life expectancy has been steadily increasing for more than a century. One in three babies born in the UK in 2013 is expected to live to be a hundred years old, even assuming no revolutionary development that would help increase longevity. Companies such as Calico and Human Longevity, Inc., have started up, focussed purely on research on aging. The so-called ‘longevity escape velocity’ is, prima facie, not an unreasonable hypothesis, and if achieved, will lead to people dying only under exceptional circumstances such as disease, accidents, or murder. Given all this, we can expect humans to take on more ambitious longer term projects than we have been tackling hitherto.
It is interesting to note that thousands of years after Khufu, the tables have turned. Khufu’s ambitious project was supposed to be a stepping stone to immortality. The truth, however, is that immortality is the gateway to our most ambitious goals.
