You may have heard stories about how Walt Disney’s head is kept in ice. That particular tale is just an urban legend, but there really are both corpsicles and frozen heads of other individuals kept preserved in the hopes of someday bringing them back to life. That probably sounds crazy – and honestly, it kind of is. Scientific consensus at the moment is that the braindead simply can not be brought back to life, no matter how well preserved. And yet the idea of crypreservation seems to have a lasting appeal, and is still quite popular with certain futurist communities today. Let’s lay out all the facts, and you can come to your own conclusions.
Firstly, it is important to not that the cryopreserved today are not simply forzen in the traditional sense. Human bodies consist mostly of water, which expands and crystalizes when it freezes, effectively destroying the frozen cells. Instead, the body of the person undergoing preservation is pumped full of special chemicals called cryoprotectants, which work sort of like antifreeze, and then the body is cooled to an extreme degree in a process known as vitrification. This process has been used successfully on thousands upon thousands of embryos used in in vitro fertilization, with no known ill effects.
So far, so good, right? Unfortunately, this is where the problems start to creep in. Firstly, vitrification and particularly the thawing process are much, much harder to do properly on larger amounts of tissue. Organs are likely to crack severely. Proponents of cryonics say they’re willing to bet that the technology will improve to the point where they could be reheated without damage, if vitrified properly, or perhaps even repaired if they’ve already sustained damage. This doesn’t seem terribly unlikely – cryonics technology has improved over time – but it’s still most certainly a gamble.
The more serious problem is that cryonics today only preserves the physical structure of the brain and body. We currently have no way to preserve the electrical potentials in a brain, or to precisely or reliably preserve the soup of neurotransmitters that permeate it. Is the pattern of your neurons enough to preserve your memories, your thoughts, your self? No one actually knows right now. The science of the connectome (a fancy name for the way a brain’s neurons are arranged) is still in it’s infancy. Some scientists think your connectome is all that you are, and some passionately disagree. We do no know that people have survived the complete cessation of electrical activity in their brains, and that in theory properly done vitrification should preserve at least roughly the state of neurotransmitters in the brain – but right now no one knows what it is in the brain that makes you who you are. Even if you’re preserved utterly perfectly by today’s standards, the most crucial data may still be lost.
Those who believe in cryopreservation for themselves and others know about these problems, and won’t try to deny them. They argue that they’re willing to spend however much money it takes to be preserved knowing full well that they only have a small chance of ever waking up. It’s a gamble, they’ll say, but what’s there to lose, compared to the chance of coming back to life?
One way or another, some day we’ll know if they chose correctly. Regarding the vitrification process, in 2016 researchers from 21st Century Medicine made a breakthrough and nearly perfectly preserved the brain of a rabbit, to the point where it’s entire connectome was kept in prisitne condition. In 2015, the OpenWorm project plan set it up so the connectome of a simple worm had control of a robot, and without any programming or prodding that robot was able to avoid obstacles. Does that mean cryonics proponents are right? No, this is hardly conclusive proof – but it does suggest that further study and development of the technology could at least be a worthwhile scientific pursuit.