Cryonics is the idea of freezing someone for a long period of time until the cause of death is curable (including general old age). This is not really the vision of immortality most people want and there was evidence presented on sci.longevity that freezing and thawing produces so much cellular damage that all you end up with is a person shaped pile of meat product. It's also a tempting target for fraud, since your customers pay in advance and don't complain.

There is a species of frog I read about that, because of a higher sugar content in its cells, formed ice crystals with more sides that humans. Because there were more sides the points were less pronounced and the crystals for the most part did not damage the frogs cells. The frog could be completely frozen for an period and be thawed and still live.

I am not sure how long the frog could freeze for though. I'm sure if it was frozen for too long when it thawed it would not resume living.

There are two main strategies for protection from low temperatures; one is cryoprotectants, the other is ice binding proteins. The frog mentioned by no comply uses a sugar (glucose) as its cryoprotectant, as do many insects. The 'arctic willow gall insect' (which uses glycerol, not glucose) can withstand temperatures down to -66 degrees centigrade. Chilly.

However, the frog's story is a little more complicated. You may be thinking "if the frog has cryoprotectants, why does it freeze" (you may be thinking something else entirely - if so, piss off!)). The strategy this creature has adopted is to actually promote freezing in the extracellular space (outside the cells) but supress ice formation inside the cell. So it produces proteins that make crystals in the blood while raising glucose levels to 200 times normal. The small ice-crystals that form are less damaging than larger ones (as no comply mentioned they are also 'rounded' crystals) and the cells are protected from the inside by syrup.

The question of whether a) this could be extended to humans and b) this could work indefinitely is tricky. Certainly metabolism in such frogs (and other freeze-tolerant organisms) slows but does it stop? Is there some slow decay in this state - and can all cell types survive equally?

Solution? Participate in your own manipulation!

All information in this node was messily ripped from the heart of : H₂O A Biography Of Water by Philip Ball (ISBN 0 75381 092 1) published by Pheonix. Which I highly recommend (read it - if you know what's good for you...).

Ethel, Mabel and the Cryonic-Man Shop

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Warning:This is non-PC and contains tongue-in-cheek stereotypes. Do not read on if you are of a nervous disposition.

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It was late at night. It had been a busy day and two elderly women needed to let off steam. Mabel picked up the 'phone and called her friend, Ethel. In no time at all they were 'chewing the cud', as women do, chatting half seriously, half jokingly about their lives in general and the male species in particular. They rapidly came to the conclusion, as they always did, that women are superior but this time maybe they should do something about it.

Ethel: Perhaps we would all be better off if we just wiped out men altogether?

Mabel: Well, yes, but men do have their uses don't they? We would still want them around sometimes!

Ethel: True, true! But wouldn't it be great if you could just...errr...well think about it! What's it called - cryogenics is it? Just think how good it would be if we could just freeze them and thaw them out when we wanted a man around. That way you could still have your hubby for instance, but if you got fed up with him, needed a change or a set of skills that he didn't have, you could just pop him in the freezer, go to a shop and get another one. "Ooh, young man!" - we sound like those old dears on Harry Enfield's programme.

Mabel: Hmmm, nice idea! We could open a supermarket, Ethel, call it "Iceman" or something. You'd go through the door and there would be row upon row of frozen men to choose from - far more exciting than shopping for food. You could walk in and pick up the one you fancied having for dinner, take him home, thaw him, and Bob's your Uncle (or lover, so to speak).

Ethel: I think we'd have to invent something to make sure they can be re-frozen. We don't want any of those "Do not refreeze once thawed" labels cluttering up the place.

Mabel: You know what though, all the good looking ones would be out of stock. Y'know how annoying it is when you go to the supermarket and they don't have the one thing you went in for? Wouldn't it be typical if you wanted a handsome decorator and they only had fat mechanics with their butts hanging out over their jeans!

Ethel: In that case we'd have to make it like a video shop so you could pre-order the popular ones, borrow them and return them after a few days. Hehe, we could even call it "Freeze Frame". And then, to make sure that the ugly ones didn't get left on the shelf you could do 'two for the price of one' special offers. I can see it now, buy a chocolate gateau, get a gingernut free! Mmm, the mind boggles.

Mabel: Oooh, stop! You are awful, I'm gonna wet myself laughing in a minute!

Ethel: Well, in that case, borrow a man to mop it up for you.

Mabel: Heh, if you went out to the back of the shop there'd be a shelf full of men who'd *want* to mop it up for you.

Ethel: Oh my God, that reminds me - did you see that gardening programme the other night? There was Charlie Dimmock, as bold as brass, telling everyone about a yellow rose called Golden Showers - and she didnt even smirk! Surely she knew what she was saying...

Mabel: Like that kids' TV programme, you remember, Captain Pugwash!

Ethel: "Come along, Seaman Staines, swab the decks", "Aye Aye, Master Bates!" Ahhh, the days of innocence!! Some people say those weren't their names at all, but I really can't remember. Roger the Cabin Boy still makes me laugh though, whether it was true or not.

Mabel: What's that I can hear in the background? Is your hubby there?

Ethel: Sigh! Yeah, I'd better go. He wants to know where his socks are and whether I've ironed his blue shirt! Still, he'll be out tomorrow night, I'll ring you then.

Mabel: Shame...we were having such a nice chat. OK, talk to you tomorrow then. G'night chuck.

Joke of the day - "Cryonics: Death, on the rocks."

The procedure follows these steps:

1. When a person is pronounced medically dead, but before the structure of the brain starts to degenerate, the body is attached to a heart-lung machine and their heart started again as it is packed in water ice.
2. Blood is flushed out and the body is progressively infused with anti-freeze or a "cryoprotectant" and other cellular stabilisers with the goal of evacuating as much water as possible from the corpse. This is to eliminate icicles which will form inside cells and rupture them upon thawing. The exact composition of this cryoprotectant fluid differs between each unique organisation, but the main ingredient is the same: glycerol, which like automobile anti-freeze has a much lower freezing point than plain water.
3. The body temperature is lowered until it is at liquid nitrogen temperatures. (Different cryonics organisations employ different methods to get patients the rest of the way to -179 degrees Celsius. While some companies prefer to use a thoracic surgeon to crack open the rib cage for access to the heart, the better to use the body's circulatory system to flush the cryoprotectant solution from head to toe, others prefer to use veterinarians or licensed morticians, and make do with the femoral arteries in the groin).
4. At this point all molecular change stops indefinitely and the body is then preserved in liquid nitrogen at -196 degrees C or -320 degrees F.
5. Later, when nanotechnology cell repair devices become available, the fatal disease that caused "death" is reversed, the anti-freeze toxicity is removed, and the body is warmed back up alive and well.

Leaders of the "esteemed" Alcor Life Extension Foundation and other cryonics organisations estimate that frozen patients may be repairable and declared "potentially alive" in sooner than one hundred years.

This procedure without doubt preserves cellular life. Sperm, skin, corneas, and human embryos are routinely frozen in LN2, thawed, and transplanted. More other individual tissues can also be treated this way, resulting in viable cells; but today's resuscitation methods are not yet entirely successful on whole organs or animals. However, since the frozen individuals are not changing further, they can afford to wait until better thawing procedures and cell repair treatments (through nanotechnology) are available in the future.

A major question must be raised however: Do today's cryonics techniques reliably preserve memories and the identity of a frozen individual? Neuroscience cannot yet show us what specific structures in the brain encode memory or identity (or even provide us with a decent working definition of "identity"), so we can't examine brain tissue to look for the presence of those structures. And the basic principles of nanotechnology are still so new that we don't have a firm understanding of its technical and practical limitations. Since many experiments and clinical evidence show that long-term memory has to be something physical (or made of molecules), it seems that a technology capable of moving molecules and repairing cells should be able to repair memory structures, if the information itself has not been lost to brain destruction.

But what of the human after he is awakened? Technology is advancing so rapidly that people born fifty or so years ago are finding it hard to keep up, to cope. What will the world be like in three hundred years? Will we be able to navigate it at all? One would have a frighteningly primitive nature, socially and technologically, if not biologically and intellectually.

Regardless of the inescapable ethics involved, the fact is that many 20th and 21st century citizens are opting for this type of immortality. The cost for this "suspension" procedure alone can range from US$28,000 to US$150,000 depending on which organisation freezes you. For those who cannot spare the big bucks, there is a less expensive route, the route of neuro-suspension. This is just a euphemism for "head only". This is a service which the ALCOR Life Extension Foundation will provide for a slight US$50,000, which lovingly includes cremation and a burial at sea of your non frozen remains.