140Medical Time Travelvitrification will require fundamental new knowledge of mechanisms of cryoprotectant toxicity, and means to inter-vene in those mechanisms.If reversible vitrification of humans is developed in future decades, what would be the application of this ‘suspended animation’? Space travel is sometimes suggested as an applica-tion, but time travel – specifically, medical time travel – seems more likely to be the primary application. People, especially young people dying of diseases expected to be treatable in future years would be most motivated to try new suspended animation technologies. Governments would probably not even allow anyone but dying people to undergo such an extreme process, especially in the early days. Applications like space travel would come much later.Medical time travel, by definition, involves technologi-cal anticipation. Sometimes this anticipation goes beyond just cures for disease. After all, if people are cryopreserved in anticipation of future cures, what about future cures for imperfections of the preservation process itself? As the medi-cal prospect of reversible suspended animation draws nearer, the temptation to cut this corner will become stronger. In fact, some people are already cutting this corner very wide.In 1964, with the science of cryobiology still in its infancy, Robert Ettinger proposed freezing recently deceased per-sons until science could resuscitate them. [24] The proposal assumed that the cause of death, the early stages of clinical death, and crude preservation would all be reversible in the future. Even aging was to be reversed. This proposal was made in absence of any detailed knowledge of the effects of stopped blood flow or freezing on the human body. The proposal later came to be known as ‘cryonics’.Cryonics was clever in that it circumvented legal obstacles to cryopreserving people by operating on the other side of the legal dividing line of death. However 40 years later, as
