144 Medical Time Travel existing technology, more research needs to be published sup- porting this claim. Copious technical information is critical to the evaluation of a highly speculative field that will not have clinical feedback for decades or centuries. Cryonics without feedback is a recipe for mischief. [37] Somewhere between freezing, morphological vitrification, reversible  vitrification  of  the  central  nervous  system,  and reversible vitrification of whole people, there is technology that will lead medicine to take the idea of medical time travel seriously within this century. Whether what is now called cry- onics will eventually become that technology remains to be seen. It will depend on whether cryonicists can manage to outgrow the stigma attached to their field, and develop meth- ods that are validated by more biological feedback and less hand waving. It may also depend on whether critics of cry- onics can manage to engage in more substantive discussion and less name-calling. The ultimate feasibility of medical time travel is a question of science, not rhetoric. References 1) Aebert H & Brawanski A & Philipp A & Behr R & Ullrich OW & Keyl C & Birnbaum DE; “Deep hypother- mia and circulatory arrest for surgery of complex intracranial aneurysms” in: European Journal of Cardiothoracic Surgery (1998, Vol. 13); pg. 223–229 2) Ehrlich M & Grabenwoger M & Simon P & Laufer G & Wolner E & Havel M; “Surgical treatment of type A aortic dissections. Results with profound hypothermia and circula- tory arrest” in: Texas Heart Institute Journal (1995, Vol. 22); pg. 250–253