Chapter 1: Understanding Cryonics

These three terms are often used together, but they refer to very different things. All involve extreme cold, yet each focuses on a different question: how to create it, how life reacts to it, and how it can be used to preserve people. Understanding this distinction helps make clear what cryonics actually is.

• Cryogenics is the field of physics and engineering that studies how to reach and control very low temperatures, usually below -150 degrees celsius. It deals with the production of liquid gases, the behavior of materials in cold environments, and the design of equipment that can safely store them. Cryogenics provides the technology that makes modern cryopreservation possible, from cooling systems to the insulated dewars used for long-term storage.
• Cryobiology focuses on how living matter responds to those low temperatures. It studies how freezing affects cells and tissues, and how cryoprotective agents can prevent the formation of damaging ice crystals. Thanks to research in this field, it is now possible to store sperm, eggs, embryos, and even small organs for medical use. Cryobiology is the science behind techniques like vitrification, where biological material becomes a glass-like solid without freezing.
• Cryonics brings these two areas together and applies them to humans. It is the medical practice of preserving a person’s body or brain at cryogenic temperatures after legal death. By combining the physics of cryogenics with the biological insights of cryobiology, cryonics aims to maintain the structure of the body and brain until future medicine can repair and revive them.