Human Cryopreservation

Human Cryopreservation: An Ambulance to the Future

Cryonics — also called human biostasis — is the practice of preserving a human body or brain at ultra-low temperatures (typically –196 °C in liquid nitrogen) immediately after legal death, with the hope of revival once medical technology becomes capable of repairing the underlying cause of death, the damage of ageing, and any injury caused by the preservation process itself. It is not, as it is sometimes caricatured, a promise of immortality. It is an option: a chance, not a certainty, of seeing a future medicine that may consider today’s “terminal” conditions routinely treatable.

The scientific foundation of cryonics rests on several established facts. Low temperatures slow chemical reactions; at –196 °C they are effectively stopped, allowing structures to be preserved for centuries. Modern vitrification techniques replace blood and bodily fluids with cryoprotective solutions that prevent the formation of ice crystals, preserving the structure of tissues. And legal death is not biological death: the loss of personhood requires the destruction of the brain’s information content, what cryobiologists call information-theoretic death. Where the brain’s structural information is preserved, the underlying person — in principle — has not been lost.

Critics dismiss cryonics as pseudoscience because no preserved human has yet been revived, and because the technology required to do so does not yet exist. We take a different view: cryonics is an act of considered hope under uncertainty. It assumes that the technologies needed for revival — advanced nanotechnology, regenerative medicine, perhaps whole-brain emulation — are not forbidden by the laws of physics, even if their development may take decades or centuries. For those who would otherwise face certain dissolution, this is a non-zero probability worth taking.

The transhumanist movement has been deeply involved in cryonics from its origins. Robert Ettinger, “the father of cryonics,” published The Prospect of Immortality in 1962, founding what would become the modern movement. Today, cryonics is offered by a small number of organisations in the United States, Europe, and Russia, with growing scientific scrutiny from groups such as the Brain Preservation Foundation and academic researchers in connectomics and cryobiology. The reading list below covers the foundational works, the active organisations, and the contemporary debate.