Indefinite Lifespan

Indefinite lifespan or, indefinite life extension, is a term used in the life extension  movement to refer to the longevity of humans, and other life-forms, under conditions in which aging  can be effectively and completely prevented and treated. Such individuals would still be susceptible to accidental or intentional death  by trauma, starvation, or infectious diseases, but not death from aging. Their lifespans would be "indefinite"  because protection from the effects of aging on health does not guarantee survival. Some life extensionists  consider the term "indefinite lifespan" technically more correct than "immortality"  which, especially in religious contexts, implies an inability to die.

Longevity Escape Velocity
Life expectancy increases slightly every year as treatment strategies and technologies improve. At present, more than one year of research is required for each additional year of expected life. Longevity escape velocity occurs when this ratio reverses, so that life expectancy increases faster than one year per one year of research, as long as that rate of advance is sustainable.

The concept was first publicly proposed by David Gobel, founder of the Methuselah Foundation. The idea has been championed by biogerontologist Aubrey de Grey and futurist Ray Kurzweil. These two claim that by putting further pressure on science and medicine to focus research on increasing limits of aging, rather than continuing along at its current pace, more lives will be saved in the future, even if the benefit is not immediately apparent.