Appended text to the "Scientists' Open Letter on Cryonics"
Cryonics holds promise because controlled freezing can preserve, and controlled unfreezing can restore life. Lobsters that are frozen apparently return to life at times and experiments with small animals have also confirmed similar results. The difficulty lies in the human size. Today’s technology is not adequate for the job. However sectional freezing, and unfreezing may be extended in the future so that in effect a human becomes as large as several small animals, as far as the freezing is concerned, and other technologic advances are likely in the various techniques that now prevent the process from being harmless.
The preservation of an individual in cold has been successfully carried out by nature through its hibernation solution, which works. Also some species of frogs bury themselves in hot sand for several years until rains come again in central Australia.
So a solution for prolonging life span through temperature control is not unnatural, and it is likely that a good way will be found to do it, supplementing nature by conscious intelligent design, as has been done in so many other areas, such as spectacles, and bicycles already for centuries.
Professor Manfred Clynes