Here is where I'll try (sometimes not very hard) to answer your questions. My judgment has often turned out to be terrible, so any advice should be greeted with great skepticism.Tweet questions to @dumbassgenius or email them to email@example.com.
What do you think of cryopreservation? You like it/believe in it?
Dear Steve -
If you want to live forever, cryonic preservation isn't a great method, but it's better than nothing. It's logistically complicated - have to get relatives, doctors, coroner to sign off on it, or your dead self turns to mush while they're arguing. Need a cryo team in place right when your heart stops beating to start filling you full of antifreeze. All the steps, and there are many as your temperature gets lowered by 300 degrees, need to be done precisely, and even then, there's no guarantee that future medical technology will be able to bring you back and that future beings will even want to. Go to Alcor.com, the website of the leading cryonics organization. You can read the case histories of more than 100 of their clients who've been more-or-less preserved. In nine out of ten histories, the preservation did not go well.
You can't just be frozen. As water turns to ice, it forms knife-like crystals and stabs, stabs, stabs all your cells. You're mush. Most of the water has to be flushed out of your cells and replaced with a series of cryoprotectants as your temperature goes lower and lower. And your temperature needs to drop faster than crystals can form - instead of turning to ice, you turn into a kind of non-crystaline glass - they call it vitrification, not freezing. And even if they can get you vitrified, you might fracture on a large scale. It'll take a lot of future nanobots to put you back together.
All the risks you encounter on the way down to the temperature of liquid nitrogen, you run into again when it's time to thaw you out - crystals can form during thawing, too. And once you're back up to room temperature, you're still dead of whatever killed you in the first place.
Research is proceeding, but legit scientists can be reluctant to say that they're working on freezing people for resurrection immortality. Instead, scientists research cryonics to make transplantable organs viable longer or to reduce trauma as wounded soldiers are transported to hospitals.
When it comes to lowering the temperature of bodies and brains, the third dimension is the problem. It's relatively easy to cryopreserve two-dimensional tissue such as skin or corneas - you can reach the entire surface with the preservatives. But getting to the middle of three-dimensional organs and making sure that the outside and interior cool at the same rate is tough. Right now, cryonic tech can't handle organs much larger than a golf ball.
Only one celebrity has announced that he wants to be cryopreserved, and that's Simon Cowell, who doesn't care if people think he's a dick. Once more people publicly embrace the option, perhaps more scientists will do research on it. (It's pretty affordable - you buy a life insurance policy and make the cryo organization the beneficiary. Watch out for greedy relatives with forged wills saying you changed your mind and want them to have the money. By the time the judge throws out the bogus will, you're mush.)
Better to stay healthy and alive for the next 30 years, when advanced medical technology should be able to buy you another 20 or 30 years, by which time anything may be possible. Controlling weight, blood sugar, and inflammation can buy you an extra ten years. Even something as simple as flossing can add a couple years, time in which medical breakthroughs may save you from having to share a cryo tank with Ted Williams' head.