Immortality

====Technological immortality, biological machines, and  "swallowing the doctor"====
{{Main|Molecular machine}}

Technological immortality is the prospect for much longer life spans made possible by scientific advances in a variety of fields: nanotechnology, emergency room procedures, genetics, [[biological engineering]], [[regenerative medicine]], [[microbiology]], and others. Contemporary life spans in the advanced industrial societies are already markedly longer than those of the past because of better nutrition, availability of health care, standard of living and bio-medical scientific advances.{{citation needed|date=October 2021}} Technological immortality predicts further progress for the same reasons over the near term. An important aspect of current scientific thinking about immortality is that some combination of [[human cloning]], cryonics or nanotechnology will play an essential role in extreme life extension. [[Robert Freitas]], a nanorobotics theorist, suggests tiny medical [[nanorobot]]s could be created to go through human bloodstreams, find dangerous things like cancer cells and bacteria, and destroy them.<ref>Robert A. Freitas Jr., ''Microbivores: Artificial Mechanical Phagocytes using Digest and Discharge Protocol'', self-published, 2001 [http://www.rfreitas.com/Nano/Microbivores.htm]</ref> Freitas anticipates that gene-therapies and nanotechnology will eventually make the human body effectively self-sustainable and capable of living indefinitely in empty space, short of severe brain trauma. This supports the theory that we will be able to continually create biological or synthetic replacement parts to replace damaged or dying ones. Future advances in [[nanomedicine]] could give rise to [[life extension#Nanotechnology|life extension]] through the repair of many processes thought to be responsible for aging. [[K. Eric Drexler]], one of the founders of [[nanotechnology]], postulated cell repair devices, including ones operating within cells and using as yet hypothetical [[biological machine]]s, in his 1986 book [[Engines of Creation]]. [[Raymond Kurzweil]], a [[futurist]] and [[transhumanist]], stated in his book ''[[The Singularity Is Near]]'' that he believes that advanced medical [[nanorobotics]] could completely remedy the effects of aging by 2030.<ref>{{Cite book |first=Ray |last=Kurzweil |author-link=Raymond Kurzweil |year=2005 |title=The Singularity Is Near |publisher=[[Viking Press]] |location=New York City |isbn=978-0-670-03384-3 |oclc=57201348|title-link=The Singularity Is Near }}{{Page needed|date=September 2010}}</ref> According to [[Richard Feynman]], it was his former graduate student and collaborator [[Albert Hibbs]] who originally suggested to him (circa 1959) the idea of a ''medical'' use for Feynman's theoretical micromachines (see [[biological machine]]). Hibbs suggested that certain repair machines might one day be reduced in size to the point that it would, in theory, be possible to (as Feynman put it) "swallow the doctor". The idea was incorporated into Feynman's 1959 essay ''[[There's Plenty of Room at the Bottom]].''<ref>{{cite web
 |url=http://www.its.caltech.edu/~feynman/plenty.html
 |title=There's Plenty of Room at the Bottom
 |author=Richard P. Feynman
 |date=December 1959
 |access-date=1 March 2010
|url-status=dead
 |archive-url=https://web.archive.org/web/20100211190050/http://www.its.caltech.edu/~feynman/plenty.html
 |archive-date=11 February 2010
}}</ref>