Liquid Nitrogen is one of the cheapest fluids on the planet. Dewars are refilled every week. If the supply of LN was cut, the LN on each dewar would take months to evaporate -- And the patients are stored upside-down, so the head is the last thing to reach thermal equilibrium.

There is no electricity involved.

A friend of mine who works for Alcor once converted somebody from full body to head only. They used a chain saw.

IIRC, that was in 1983, when three TransTime patients were transferred to Alcor thanks to donations. There's a very interesting article written about it: http://www.alcor.org/Library/html/postmortemexamination.html

They are poised to have tens of thousands of people on ice. The first few generations are recouping the R&D and opportunity costs, future customers can recoup the ongoing power demands of the facility and any expansion necessary to accommodate newer clients.

I think you pay for those upfront. Similar to how todays Nobel prize money is still payed from money grown from Nobel's assets at the time of his death.

This requires a growing economy.

> By the time we have the technology to revive cryopatients, that question will likely be "why not?".

It's a big leap of faith to think we'll ever be able to revive frozen dead people. Early applications of cryonics didn't take the tissue destruction of freezing into account. What other problems are being completely missed in the process?

And that's to say nothing of the problems related to reviving a dead person and fixing the causes of their death in a timely manner. Even granting a relatively uninterrupted progress of technology, it's a big assumption that such things are possible.

>Early applications of cryonics didn't take the tissue destruction of freezing into account. What other problems are being completely missed in the process?

Literally everyone knows about ice formation. Robert Ettinger wrote about it in his cryonics book before it ever happened. Cryoprotectants have been used since the first real (ie non-cosmetic) cryopreservations.

>reviving a dead person and fixing the causes of their death

Cancer (for example) is nothing compared to reviving a vitrified human. Absolutely nothing. By the time you have the biological machinery to repair the kind of damage that thermal stress fractures, residual ice and cryoprotectant toxicity causes, cancer will be a curiosity in the bookshelves of history.

If the person died due to some kind of brain aneurysm, then sure, you probably can't fix that, but then again you're talking about a situation where there's really no structure to preserve in the first place.

> Literally everyone knows about ice formation. Robert > Ettinger wrote about it in his cryonics book before it ever happened. Cryoprotectants have been used since the first real (ie non-cosmetic) cryopreservations.

Note that the vitrification process didn't exist before the 90s, and so it's a bit of a stretch to think that it's been handled adequately. And even then, there's the fracturing problem, which despite Alcor's handwaving, is a serious problem.

> By the time you have the biological machinery to repair the kind of damage that thermal stress fractures, residual ice and cryoprotectant toxicity causes, cancer will be a curiosity in the bookshelves of history.

It's a very big assumption that we'll ever have the machinery to repair the damage caused by the freezing process. But apart from that, there's real and rapid decay of tissue in the brain when a person dies. Loss of even a small percentage of brain tissue has seriously traumatic effects on otherwise healthy people who haven't been frozen.

It's probably not gonna work.

I'm an Alcor member. For me, it's a no-brainer. It might have a low probability of success. (Depends on your assumptions.) Regardless, it's a higher chance than if I were buried or cremated. Since epsilon > zero, I signed up.