What do experts say?
Cryobiologists are scientists that specialize in cold tolerance in nature and demonstrably reversible cold preservation of cells and tissues. Cryobiologists correctly point out that cryopreservation of whole humans is not demonstrably reversible. Some cryobiologists say that this means that cryonics is not founded on science. This would be correct if cryonics were claimed to be reversible today, which it is not. The claim of cryonics is that it is possible to preserve sufficient biological information today to permit reversal in the future with foreseeable technology. Evaluation of this proposition requires knowledge of cryopreservation methods used in cryonics, knowledge of neuroscience, and knowledge of future technologies proposed to reverse the process. Very few scientists possess knowledge of all these areas.
