Comment by xpe

Cryonics doesn't work currently on the scale of human brains. It works at much smaller scales, though. There was a natural experiment where roundworms were revived after 46,000 years [1] [2].

Assessing how well cryonics might in the future at different scales is a prediction. So, yes, cryonics is speculative; it is making a bet that future technologies will somehow bring a brain back to life, in some form. Digital: a brain scan followed by whole-brain emulation. Biological: physical repair at the molecular level. If/when some kind of revival works, the question of consciousness remains.

The current edition of Wikipedia's entry on cryonics writes: "It is generally viewed as a pseudoscience" which is attributed to Jens Karlsson saying "Cryonics ... is generally viewed as a fringe pseudoscience." [3]

I don't care for this characterization. When I think of pseudoscience (such as a homeopathy and astrology) makes claims that are unfalsifiable, often by design. On the other hand, cryonics is falsifiable. Scientists are trying to figure out scales where it can work: it has far to go, and it may not get there.

I personally can't speak to the degree of lies, hucksterism, or fraud swirling around cryonics. I won't defend any such practices.

Will future history show cryonics to be impossible, not dependent on the currently-available technology, but as a provable claim based on the laws of the universe? Maybe. Maybe cryonics is a long-shot worth trying. I'm not an expert, but I lean towards the latter: allocating a small fraction of resources towards exploring it seems wise.

[1]: https://www.smithsonianmag.com/smart-news/scientists-revive-...

[2]: https://www.scientificamerican.com/article/46-000-year-old-w...

[3]: https://www.chicagotribune.com/2002/09/29/mainstream-science...