| |
How would you like to see the world 200 years from now? Or maybe 500? That’s what some people are hoping for from cryostasis, or freezing the body at death so that one day in the future, scientific advances will allow them to be revived and put in newly-grown bodies, giving them the chance to live forever. No one knows if or when the technology to do this will become available, but in the meantime there are quite a few people paying to be preserved so that they’ll have their chance at immortality. As long as they’re frozen, it doesn’t really matter when the technology comes along, because the Earth is expected to last at least another four billion years, so they’ll have plenty of time to enjoy their new life. And when the sun blows up, they’ll just leave on a spaceship and go to another solar system and live for all eternity, or at least to be several hundred billion years old before the ‘heat death’ of the universe, when everything reaches the same temperature and life is no longer possible anywhere.
One big problem with freezing is that it tends to cause a lot of damage to the body, so much so that even with future advances in medicine, it would probably be impossible to repair. Frozen human tissue tends to form cracks and split, and, even worse, trillions of individual cells are damaged as water is drawn from them during the freezing process, shrinking them and causing unfrozen particles to pierce the cell membranes. To try to prevent this, ‘cryoprotectants’ such as glycerol (antifreeze) have been used, and there is now a process where the body can be ‘vitrified’ so that instead of being frozen, it is turned into a glass-like state, which probably causes far less damage.
But there is an even bigger problem. Considering that irreversible brain damage begins to occur after three minutes without oxygen, that after ten minutes a revived person exhibits almost total brain death (apart from the brainstem), so that the person’s entire memory, personality and mind are wiped out (a la Terri Schiavo), and that complete brain death takes place after about seventeen minutes, it’s hard to believe that there could be any real chance of bringing a cryogenically-preserved person back. Perhaps the body could be revived and kept in a persistent vegetative state, but the whole point of the process is supposed to be bring the mind back. It seems that the only chance of doing this would be if a person’s brain were snap-preserved in less than three minutes after death, but even that seems a long-shot. Nevertheless, some proponents have argued that most of the damage caused to the brain when the heart stops and is subsequently restarted minutes later is not caused by the deprivation of oxygen and nutrients, but by the trauma that occurs to cells when blood flow is suddenly restarted. They believe that if they were preserved quickly enough (in, say, a few hours after death), in the future there would be a way of restarting blood flow without causing any damage, but in the meantime their brains would be preserved. A lot of people do not find this argument very convincing.
At any rate, you only have about half a day after death before it’s considered too late by anyone for preservation even of the body, so it’s best to be near a cryonics lab if you are in the final stages. Of course if you are blown up in a violent accident there’s not much point trying to preserve your body anyway, so cryogenic freezing is only for those who die of natural causes with their bodies relatively intact and close to a laboratory. (Brain tumours obviously aren’t good either. One man sued the State of California to be allowed to be frozen while he was still alive after he developed one, a procedure which, if carried out, would legally have been murder. He lost, but his tumour went into remission.) If you make it, the preservation process involves injecting anticoagulants to reduce blood clotting, as well drugs to prevent various other degenerative processes, which are then circulated by artificially stimulating the heart. The body is cooled to 10 degrees Celsius and the blood is replaced with organ preservation fluid, before the final act of taking the temperature all the way down to -196 degrees Celsius with liquid nitrogen. You are then stored upside down with your feet pointing towards the ceiling, so if the power cuts out your head will be the last thing to thaw.
It is a telling fact that most of the people that own and run cryogenics labs do not elect to be preserved themselves, despite charging between $28,000 and $150,000 (with a ‘head-only’ special at just $50,000) to freeze their ‘clients’ until they can be revived (assuming that they don’t go out of business in the meantime). Nevertheless, if you have the money and want to take a punt on the chance the one day you will be able to be brought back to life by future advances in medicine, you too can have your shot at immortality by signing up to be cryogenically preserved when you die.
|
