Immortality is eternal life or the ability to live forever.[2]Biological forms have inherent limitations that medical interventions or engineering may or may not be able to overcome. Natural selection has developed potential biological immortality in at least one species, the jellyfish Turritopsis dohrnii.[3]

Certain scientists, futurists, and philosophers, have theorized about the immortality of the human body, and advocate that human immortality is achievable in the first few decades of the 21st century, whereas other advocates believe that life extension is a more achievable goal in the short term, with immortality awaiting further research breakthroughs into an indefinite future. Aubrey de Grey, a researcher who has developed a series of biomedical rejuvenation strategies to reverse human aging (called SENS), believes that his proposed plan for ending aging may be implementable in two or three decades.[4] The absence of aging would provide humans with biological immortality, but not invulnerability to death by physical trauma; although, mind uploading could solve that issue.

What form an unending human life would take, or whether an immaterial soul exists and possesses immortality, has been a major point of focus of religion, as well as the subject of speculation, fantasy, and debate. In religious contexts, immortality is often stated to be among the promises by God (or other deities) to human beings who show goodness or else follow divine law.

Life extension technologies promise a path to complete rejuvenation. Cryonics holds out the hope that the dead can be revived in the future, following sufficient medical advancements. While, as shown with creatures such as hydra and planarian worms, it is indeed possible for a creature to be biologically immortal, it is not yet known if it is possible for humans.

Mind uploading is the transference of consciousness from a human brain to an alternative medium providing the same functionality. Assuming the process to be possible and repeatable, this would provide immortality to the consciousness, as predicted by futurists such as Ray Kurzweil.[5]

The belief in an afterlife is a fundamental tenet of most religions, including Hinduism, Buddhism, Sikhism, Christianity, Zoroastrianism, Islam, Judaism, and the Bah' Faith; however, the concept of an immortal soul is not. The "soul" itself has different meanings and is not used in the same way in different religions and different denominations of a religion. For example, various branches of Christianity have disagreeing views on the soul's immortality and its relation to the body.

Physical immortality is a state of life that allows a person to avoid death and maintain conscious thought. It can mean the unending existence of a person from a physical source other than organic life, such as a computer. Active pursuit of physical immortality can either be based on scientific trends, such as cryonics, digital immortality, breakthroughs in rejuvenation or predictions of an impending technological singularity, or because of a spiritual belief, such as those held by Rastafarians or Rebirthers.

There are three main causes of death; aging, disease and physical trauma.[6]

Aubrey de Grey, a leading researcher in the field,[7] defines aging as "a collection of cumulative changes to the molecular and cellular structure of an adult organism, which result in essential metabolic processes, but which also, once they progress far enough, increasingly disrupt metabolism, resulting in pathology and death." The current causes of aging in humans are cell loss (without replacement), DNA damage, oncogenic nuclear mutations and epimutations, cell senescence, mitochondrial mutations, lysosomal aggregates, extracellular aggregates, random extracellular cross-linking, immune system decline, and endocrine changes. Eliminating aging would require finding a solution to each of these causes, a program de Grey calls engineered negligible senescence. There is also a huge body of knowledge indicating that change is characterized by the loss of molecular fidelity.[8]

Disease is theoretically surmountable via technology. In short, it is an abnormal condition affecting the body of an organism, something the body shouldn't typically have to deal with its natural make up.[9] Human understanding of genetics is leading to cures and treatments for myriad previously incurable diseases. The mechanisms by which other diseases do their damage are becoming better understood. Sophisticated methods of detecting diseases early are being developed. Preventative medicine is becoming better understood. Neurodegenerative diseases like Parkinson's and Alzheimer's may soon be curable with the use of stem cells. Breakthroughs in cell biology and telomere research are leading to treatments for cancer. Vaccines are being researched for AIDS and tuberculosis. Genes associated with type 1 diabetes and certain types of cancer have been discovered, allowing for new therapies to be developed. Artificial devices attached directly to the nervous system may restore sight to the blind. Drugs are being developed to treat myriad other diseases and ailments.

See the article here:
Immortality - Wikipedia, the free encyclopedia