Immortality

Immortality is the idea of living without death. In scientific discussions, it is often differentiated from the broader notion of extension of life. Biological immortality refers to aging being negligible or absent, so that an organism does not die from senescence, though it can still die from injury, disease, or accident. Absolute immortality would imply immunity to all causes of death.

Some organisms show signs of negligible senescence or have been described as biologically immortal. Hydras, some jellyfish such as Turritopsis dohrnii, and certain simple organisms can sustain life for long periods, but none are truly immune to death in all circumstances. In humans, aging is associated with accumulating damage, and current science has not demonstrated a way to achieve true biological immortality.

Research in biogerontology focuses on extending healthy life and delaying aging. Approaches include caloric restriction, senolytic drugs to clear senescent cells, telomere biology, genetic and epigenetic reprogramming, regenerative medicine, and organ replacement. Some researchers explore cryonics or future technologies as postponement strategies, but these remain speculative.

Ethical, social, and philosophical questions accompany longevity research. Potential implications include resource distribution, inequality in access to life-extending therapies, impacts on population dynamics, identity and meaning, and conflicts with cultural or religious beliefs about death and afterlife.

In culture, immortality appears in myth, religion, philosophy, and science fiction, ranging from eternal life in spiritual terms to hypothetical scientific cures. It remains a contested and evolving topic, with no consensus on feasibility or desirability.