Despite common debate over its desirability, immortality has been an object of fascination for humans since the beginnings of recorded history. Why do we die in the first place? Religious and philosophical explanations abound. Evolution also provides important insights, and we are just beginning to understand the detailed molecular underpinnings of aging. With knowledge, of course, comes application. Whether or not you seek immortality, the technology for significant life extension may become available in our lifetimes.1 Eventually, with these new advances, every year we live will add more than a year to our lifespans; this is the point when we become immortal.

Immortality is a more complex concept than many realize. In the dictionary, it is defined simply as “the ability to live forever.”2 What if you lived forever as an extremely old man or woman, physically and mentally weak and handicapped? This is not often the image associated with eternal life. Immortality, then, would be desirable only if it came hand-in-hand with another important concept: eternal youth. Another notion of immortality is embodied by Superman or the mythic Greek hero Achilles: invulnerability. By definition, however, invulnerability is not an essential feature of immortality. The real obstacles to immortality are not freak accidents or acts of violence but aging. Aging causes the loss of both youth and immunity to disease. In fact, no one dies purely from the aging process; death is caused by one of many age-related complications.

Eliminating aging is thus synonymous with achieving immortality. The first step in this direction, of course, is to understand the aging process and how it leads to disease. The best answer to this question has been offered by Cambridge biogerontologist Aubrey de Grey. De Grey argues that aging is the accumulation of damage as a result of the normal, essential biological processes of metabolism.2 This damage accumulates over the course of our lifetimes and, once it passes a critical threshold, leads to pathological symptoms. The field of biogerontology mainly focuses on understanding the processes of metabolism in the hopes of preventing accumulation of damage. Geriatrics is a related specialty that focuses on mitigating the symptoms of age-related disease. De Grey points to the enormous complexity of understanding either process and offers an alternative: identifying and directly dealing with the damage.3

What types of damage does this entail? To begin, it is essential to understand that the body is a collection of billions of cells. The health of these cells directly translates to the wellbeing of our bodies. Aging is caused by deterioration of our cells, which typically destroy and recycle substances to prevent accumulation of damage over time. De Grey believes there are seven categories of damage that lead to aging. Two are mutations of DNA, the molecule that stores our genetic information. Two are accumulations of molecules that our cells have lost the ability to destroy. One is an accumulation of crosslinks between our cells, causing our tissues to become constrained and brittle. Another is the loss of irreplaceable cells, such as those in our heart or brain. The final classification is an accumulation of death-resistant cells that cause damage to our bodies. De Grey has proposed Strategies for Engineered Negligible Senescence (SENS) for repairing each source of damage. Some of these strategies, such as stem cell therapy, are theoretical and unproven; others, like gene therapy, are modeled after pharmaceuticals that have already gone through clinical trials. De Grey’s SENS are innovative and radical by the standards of the medical and scientific community, causing many to question their viability.

The first SENS therapies will not be perfect. They will eliminate enough damage to keep us below the threshold of developing age-related diseases for a few extra decades, but they will leave even more stubborn forms of damage behind. A few decades, however, is a long time for modern science. By the time our bodies start to show signs of aging, more effective therapies will be available. This process would continue indefinitely.

The fundamental weakness of SENS is that it is based on keeping an imperfectly understood biological organism functioning long after it was ever designed to be. The alternative is to switch out of our flesh and blood homes and into new territory: electronics. For our bodies, this seems relatively straightforward; while fully functioning humanoid robots are far from perfect, it is not a great leap to assume that they will be as capable, if not far more powerful than human bodies in the future-certainly by the time SENS would begin to wear out. Transferring our minds to an electronic medium offers far more considerable challenges. Amazingly, progress in this direction is already under way. Many scientists believe that the first step is to create a map of the synaptic circuits that connect the neurons in our brain.4 Uploading this map into a computer, along with a model of how neurons function, would theoretically recreate our consciousness inside a computer. The process of mapping and simulating has already started with programs such as the Blue Brain Project and Obama’s BRAIN initiative. In particular, the former has already succeeded in modeling an important circuit that occurs repeatedly in the mouse brain.5

Transferring our minds to computers would mean that any damage that occurred could be reliably fixed, making us truly immortal. Interestingly, the switch would also fulfill many other ambitions. Our mental processes would be significantly faster. We would be able to upload our minds into an immense information cloud, powerful robots, or interstellar cruise vessels. We would be able to fundamentally alter the architecture of our minds, eliminating archaic evolutionary vestiges (such as our propensity toward violence) and endowing ourselves with perfect memories and vast intelligences. We would be able to store and reload previous versions of ourselves. We would be able to create unlimited copies of ourselves, bringing us as close as possible to invulnerability as we may ever get.6

While you may have never seriously considered the idea that you might be able to live forever, theoretically it possible; technologies for radical life extension are currently in development. Whether such advancements reach the market in our lifetimes is in large part dependent on the level of public support for key research. Although the hope of living forever comes with the risk of disappointment, keep in mind that efforts toward achieving immortality will increase, if not your lifespan, that of your children and future generations.

References

  1. Kurzweil, R. The singularity is near: when humans transcend biology. Penguin Books: New York, 2006.
  2. Oxford Dictionaries. http://www.oxforddictionaries.com/us/definition/american_english/immortality (accessed March 13, 2014).
  3. De Grey, A. D. ; Rae, M. Ending aging: the rejuvenation breakthroughs that could reverse human aging in our lifetime. St. Martin’s Griffin: New York, 2008.
  4. Morgan, J. L.; Lichtman, J. W.  Nature Methods 2013, 10, 494–500.
  5. Requarth, T. http://www.nytimes.com/2013/03/19/science/bringing-a-virtual-brain-to-life.html (accessed March 13, 2014).
  6. Hall, J. S. Nanofuture: What’s Next for Nanotechnology. Prometheus Books: New York, 2005.

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