In the Live Forever Manual, I introduce readers to some of the terminology used in the discussion of life extension. It’s not meant to be a comprehensive glossary, but it is hopefully a useful guide to some of the terms that won’t appear in a normal dictionary.

I’m reproducing it here on my blog, along with the infographic, to help the club’s website visitors in their understanding of how the different life extension terms relate to each other.

Life Extension Glossary

There are many terms used in the discussion of living longer. Many of these are established scientific terms and therefore have clear definitions; however, some are newer concepts, which are still being developed, so their use may be less consistent, and their meaning may change over time.

Ageing - gradual biological deterioration that increases an organism’s mortality rate (i.e. chance of dying) over time.

Biological Age – the equivalent chronological age of an individual, based on their current risk of death as determined by a variety of biomarkers.

Biological Immortality – human state once ageing has been cured and risk of death from disease or infection is negligible, but still subject to death from accident, natural disaster and human conflict (aka physical immortality).

Chronological Age – number of years that have passed since an individual was born.

Digital Immortality – replicating consciousness in a computer (aka mind uploading). No longer subject to biological weakness, however immortality is still not guaranteed given the risk of a technical failure.

Escape Velocity - when scientific breakthroughs are extending life expectancy by more than twelve months every year, i.e. fast enough that we can escape the pull of biological demise. Note that between 1911-2011 the life expectancy at birth in the UK increased by over three months every year.

Healthspan – the duration of an individual’s life spent in a healthy state. Currently the UK average is around 64 years.
Immortality – a fictional concept where individuals, creatures or races cannot be killed (or only in a very specific way), for example Dorian Gray, vampires and Highlander.

Indefinite Life Extension – see biological immortality

Life Expectancy – the average age, within a given population, that people will live to. Currently this is 70.5 (68.3 males, 72.7 females) globally, 81.2 (79.4, 83.0) in the UK and 79.3 (76.9, 81.6) in the US. Note: this can also be specified for a particular age (e.g. 65) rather than at birth.

Life Extension – research and practice into extending human lifespan by slowing, and eventually halting, biological ageing. Sometimes prefixed with “radical” to emphasise its use of technological solutions (e.g. bionic organs) over purely biological methods.

Lifespan – actual amount of time an individual lived before death.

Living Agelessly (aka negligible senescence) – when an individual no longer ages. Note, however, that if an 80-year-old stopped ageing today, their current level of physical damage would give them a one in twenty chance of dying each year, therefore only a 1 in 500 chance of surviving to be 200 years old.

Longevity – a subset of a population who are predisposed to living longer than average.

Maximum Lifespan – the maximum amount of time an individual member of a population has ever lived. The oldest verified human was Jeanne Calment, a French woman who died in 1997, and who lived to 122 years and 164 days.

Radical Life Extension – see Life Extension

Rejuvenation – reversal of the mental and physical damage caused by ageing; enabling those with a high chronological age to become youthful again.

Senescence – see Ageing.