Archive for August, 2011

Martinenaite and Tavenier on cryonics

Luke Parrish points me to what is clearly by far the most serious critique of cryonics ever written: a 57-page treatment by Evelina Martinenaite and Juliette Tavenier, presented as a 3rd semester project at Roskilde University in Denmark supervised by Ole Andersen. I want to congratulate them both on raising the bar for cryonics criticism by a factor of about ten thousand. In 1994 Ralph Merkle wrote:

Interestingly (and somewhat to the author’s surprise) there are no published technical articles on cryonics that claim it won’t work.

After 44 years of cryonics, that has finally changed.


December 22nd, 2010

Evelina Martinenaite, Juliette Tavenier

Abstract: The preservation of cells, tissues and organs by cryopreservation is a promising technology nowadays. However, the primary purpose of this science has been diverted to a doubtful technology, cryonics. Cryopreservation techniques are now being adapted with the aim of preserving people’s bodies after death in hope that in the future, medicine will be able to revive them. In this report we analyze both scientific and social issues involved with this technology. We first studied the events taking place in the cells during regular freezing. Various research experiments show that freezing causes damage to the cells. Therefore, vitrification presented by cryonics companies as an alternative, seems to be reasonable. We also looked at all the difficulties of this procedure and at the injuries that such a treatment could cause to the human body. Studies show that the vitrification procedure suppresses the injuries related to freezing but the use of cryoprotectants, although necessary, is toxic to the cells. Organs, such as kidneys, are the largest entities ever vitrified and thawed with success. By analyzing all present scientific data, we conclude that there is a limit to the size of living matter that can be cryonised effectively; therefore we conclude that it is not possible to cryonize an entire human body with the current technology without causing severe damage to it.

Full paper

A brief response: Yes, cryonic preservation causes all sorts of severe damage far beyond our current ability to overcome; all the damage discussed in this paper is well understood and widely discussed by cryonics practitioners. This paper doesn’t seem to quite engage with the central contention of cryonics: that so long as the information that makes up memory and personality is preserved, future technology may find a way to repair the damage caused by cryopreservation. Two distinct paths to this end are widely talked about: molecular nanotechnology, and scanning/WBE. As far as I can tell, no argument is made in the paper that human cryopreservation causes information-theoretic death, and neither of these repair options are discussed at all. In fact it doesn’t seem to observe much more than the well-understood fact that reanimation is not feasible with current technology. As a result, this paper, while it is vastly vastly ahead of the arguments made by other critics of cryonics, is some way behind the arguments already considered and answered by cryonics advocates.

Professor David Pegg’s remarks to “Last Word”, BBC Radio 4, 2011-07-29

Radio 4’s weekly obituary program devoted five minutes to the death of cryonics founder Robert Ettinger, and spoke to longstanding cryonics foe Professor David Pegg of the University of York. Here’s a transcript of his broadcast remarks:

Pegg: There are three areas of damage (if you like) which have to be undone for this process to work: one is to bring the dead back to life, another is to cure the thing which caused them to be dead, and the third thing is that the process of preservation should not inflict any damage. It is possible to achieve effective cryopreservation of single-celled systems. What is not possible is to adapt that to multi-cellular systems. So although it might be advantageous to be able to cryopreserve kidneys for example, for transplantation, that is not possible. And the reason that it’s not possible is that the ice, which is innocuous to the cells in themselves, destroys the structure and the kidney will no longer function.
Interviewer: Well now, Robert Ettinger’s supporters would say you’re just being very very shortsighted, you’ve just got your head in the sand, because of course there are problems at the moment, but in the future, science will overcome all of these problems
Pegg: Yes, well that’s an item of faith. it’s not a question of — a scientific question. The fact is of course that we can’t predict the future, and we don’t pretend to do so. But nor can they.
Pegg (later in the programme): We are making progress, but we haven’t got the problem licked just yet. If that problem could be solved, then it would perhaps be reasonable to ask the question whether this should lead to the cryonics endeavour in practice. But at the moment, it’s frankly just premature.

Two technical points, both from Alcor’s cryonics myths page:

  • Cryonics providers have used vitrification to eliminate ice crystal formation for a decade now, and even before that other cryoprotectant techniques greatly reduced freezing damage.
  • While cryopreservation of kidneys is not yet advanced enough to be used for human transplants, it was demonstrated in rabbits in 2005. One of the rabbits tested survived for 48 days with the cryopreserved kidney as its sole kidney, before being euthanized for histological follow-up.

Perhaps Pegg was taking shortcuts because of the time pressure of radio; however sadly he has not taken the time to present a technically accurate argument in any forum. I once again urge him to do so.

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