Cryonics, Life Extension

Cryonics is the practice of preserving organisms, or at least their brains, at cryogenic temperatures where metabolism and decay almost completely stop, for possible future revival. A person held in such a state (either frozen or vitrified) is said to be in cryonic suspension. Barring social disruptions of their suspension arrangements, a suspended person is expected to remain physically viable for a period of about 10,000 years, after which time cosmic ray damage is thought to be irreparable.

Probably the most famous cryonically frozen patient is Ted Williams. The popular urban legend that Walt Disney was cryonically frozen is false (he was cremated, and interred at Forest Lawn Memorial Park Cemetery). Likewise Robert Heinlein, often said to be cryonically frozen, was cremated and his ashes distibuted over the Pacific ocean.

Cryonics has been largely dismissed by the mainstream cryobiology community, of which it is arguably a part. The reason generally given for this dismissal is that the freezing process creates ice crystals, which do irreparable damage to the cells and cellular structures, making any future repair simply impossible. Cryonicists, on the other hand, claim that cryobiologists routinely exaggerate the extent of this damage. The debate (which has been loud, hostile and sometimes ugly) may have taken a turn in 2000, when a major cryonics organization claimed to have virtually eliminated ice crystal formation, and hence the major source of freezing damage, using a technique called vitrification.

First, let us examine the situation pre-2000, before the announcement concerning vitrification. As a side effect of the traditional cryonic cooling process, cell damage (irreversible by current technology) is caused by ice crystals forming in the regions between cells. Critics often maintain that, in addition, the intra-cellular water (inside the cells) freezes to the extent that the cells actually burst from the inside out. Cryonicists, however, claim this is simply an oft-repeated myth with no basis in fact. Various "anti-freeze" chemicals, typically glycerol, are pumped into the organs before the process starts, in order to minimize the inter-cellular ice formation. Critics maintain that because the organs are already dead, these chemicals do not even reach the majority of the cells. Cryonicists, however, claim that the situation is not nearly that bad, so long as the cryopreservation process begins immediately after legal death is declared, before much damage has a chance to occur. Critics have always admitted that an ideal cooling procedure, producing the "perfect freeze" with no ice crystals (vitrification), is at least possible in principle. However, achieving it has proven nontrivial, with many problems, such as the inevitable temperature differences between portions of the tissues in a large organ, and movement of fluids upsetting the process, making it impossible to properly control. Critics of the cryonics field have often quipped that it is easier to revive a corpse than a cryonically frozen body! But many cryonicists would actually agree with this (presuming the corpse were fresh), but would add that while revival given freezing damage may be a long shot, it is clearly the only shot a just-deceased patient has, and thus is a still a rational gamble to take. Cryonicists would also point out, however, that the definitions of "death" and "corpse" currently in use may change with future medical advances, just as they have changed in the past, and so they generally reject the idea that they are trying to "raise the dead".

The nature of the debate may have changed drastically in 2000, with the announcement by Alcor Life Extension Foundation that they can now vitrify a human brain with virtually no ice crystal formation, using new state-of-the-art cryoprotectants (adapted from conventional cryobiology research), along with a new cooling procedure. While Alcor still admits serious damage is inflicted on brain tissue in other respects, the elimination of ice crystals would make future revival a much more plausible proposition. Critics seem to be taking a wait-and-see approach to this announcement, however, as Alcor has yet to publish their results in the scientific literature.

Cryonics essentially started in 1962 with the publication of The Prospect of Immortality by Robert Ettinger, widely considered the father of cryonics. In the 1970s, the damage caused during cooling was not well known. Two companies went bankrupt and allowed their "patients" to thaw out, bringing the matter to the public eye, at which point the problem with the cellular damage became more well known. During the 1980s the goal changed to brain preservation, on the assumption that bodies could be regrown, perhaps by cloning of the person's DNA. The main goal now seems to be to preserve the information contained in the brain, on which memory and personal identity depends, on the assumption that damage to anything else is in principle repairable. Today, cryonicists point to nanotechnology, claiming that perhaps in the future tiny microscopic computerized probes swarming through the body will be able to repair cellular damage at the molecular level... a kind of futuristic deus ex machina that, while incredible and currently very much a matter of speculation, may perhaps not be that much of a problem, given the rapidity of scientific advances over the past century. It is within this perspective that the habit developed of placing more importance on the information content of the brain than on its organic viability, Alcor (the largest cryonics organization) especially adheres to this viewpoint, which is reflected in most Alcor patients only opting for vitrification of the brain over the alternative of glycerol-based freezing of the whole body. Others question this emphasis on the brain, however, arguing that there is no particular reason to suggest that the mechanical structure of the brain is wholly responsible for personal identity and memories. Partly for this reason, the Cryonics Institute (the second-largest cryonics organization) preserves only whole bodies.