"Death is a slow, analogue process, rather than a digital on/off switch. A dimmer-switch (an analogue device) theory of death and aging is more appealing than the digital switch theory of death – a switch that has only two positions: on or off corresponding to fully alive or fully dead."

Dr. Guy BrownDept. of Biochemistry, Univ. of Cambridge

Said : Dr. Guy Brown of Department of Biochemistry, University of Cambridge, in his "The Living End :The Future of Death, Aging & Immortality," a popular science book. 

Following excerpts are from the Introduction of the book by the author.

Today, the average lifespan in the developed world is about 78 years.  And this lifespan is increasing by 2 years every decade.  That is every decade you live, your expected age of death recedes by at least 2 years, or 5 hours per day, or 12 seconds per minute. If this trend persists (as it has done for at least 100 years) someone born today would be expected to live to the age of 100 years.  

Our concepts of ‘old’ and ‘old-age’ are out-of-date.   It is no longer useful to categorise everyone over the age of 65 as just ‘old’ – there are the ‘old’ (65-85 years), the ‘very old’ (85-100 years) and the ‘extremely old’ (over 100 years).  Just because we are old, or know people who are old, does not mean we know what it is like to be very old or extremely old.

There are different types of death occurring in the same person at different rates and to different extents in different people.  There is death at different levels: molecular death, cell death, and organ death; death of the individual, death of the culture and death of the species.  There are multiple deaths of different parts of our body and mind: death of our physical abilities and appearance, death of our various mental capacities.  There is Reproductive death, Social death, and Psychological death.  There is death of desire, there is the death of memory, there is death of the will to live.  All these things fade away at different ages, at different rates, and to different extents.  

Throughout history people have sought to escape Death and claim immortality in three different ways: spiritual, genetic and cultural.  We may survive as spirits in some afterlife.  We may survive through our genes passed on to our children and children’s children.  We may survive though our works, deeds and memories - ‘memes’ - left to our family, friends and society in general.  The desire to survive spiritually, genetically or culturally has been, and continues to be, one of the most important motivators in life.  Indeed society as we know it (religion, family, culture) would be impossible without such motivators.  

In the 20th century Death replaced Sex as the taboo subject we could not talk about, yet we all end up “doing it”.  The suppressed dread of death has allowed our society to sleep walk into a situation where people face real horrors at the end of life, simply because we can not face dealing with the issue of how people should exit life.  Death has been banished to hospitals, the worst possible place to end life.  Medicine has become devoted to keeping people alive at any costs, rather than helping people die.  Huge resources are devoted to preventing infectious diseases and heart attacks, possibly the ideal way to die, which inevitable condemns people to die by more protracted means.  

Only by recognising that death is part of life and that many people experience a living death at the end of life, can we make sensible decisions about whether people should be allowed to choose a dignified exit from life.  We all recognise that we need to make provision for a pension, but how many of us are making provision for dementia?  If society really cared about the last ten years of life to the same degree as the first ten years of life, then we would have a real chance of preventing aging and dementia before it was too late.  If not, we have the real prospect of creating Hell on Earth, and locating it at the end of Life.

However, looking on the bright side, many researchers are now seriously suggesting that aging may be completely solved during the 21st century.  The promise of stem cells, cloning, RNAi, gene therapy, the sequencing of the human genome and the deep understanding of our biochemistry, suggests it is just a matter of time before we can make humans for all practical purposes immortal.  However, not everyone is happy at the prospect of universal immortality.  Bioethicists and politicians are reaching out to restrain these sciences, for example banning cloning, stem cell research and genetic engineering.  But aging and dementia are not natural, and we should not accept them as our inevitable fate – allowing millions to suffer in silence.

The relatively new science of aging has discovered an inexorable process of decline at the heart of our molecular machinery, but also claims to have found potential ways to interfere with that decline. Leading aging researchers are now urgently calling for society to prepare for an era of dramatically extended life span.  Scientists, doctors, economists, social planners, philosophers, theologians and even politicians are waking up to the massive impact that aging and increased life span will have on our society. For ourselves and our children we now need to urgently consider the future of death, dying and dementia.