Looking for opinions of people like Nick Bostrom or Anders Sandberg on current cryo techniques

Paul Crowley here.

I am signed up for cryonics and I'd encourage others to do likewise. My comments on Twitter were meant as a caution against a naïve version of the expert opinion principal. As you can see, I've worked very hard to find out whether expert dismissal of cryonics is on expert grounds, or on ill thought out "silliness" grounds combined with a lingering supernatural idea of death. The evidence I currently have points overwhelming at the latter. To me this poses a problem not for cryonics but for how to make the best use of expert opinion.

Assuming a good future, I'd put the chances of revival through scanning and emulation at over 50%. For the cryonics process to do so much damage that there's no way for us to infer the lost information given full-blown neural archaeology, Nature would have to surprise us.

Eliezer's hard drive analogy convinced me the chances of revival (at least conditionalizing on no existential catastrophe) are good

Why did you find the analogy convincing? It doesn't look like a good analogy:

• It's cherry picked: erasing information from hard drives is hard, because they are very stable information storage devices. A powered down hard drive can retain its content for at least decades, probably centuries if the environmental conditions are good. Consider a modern DRAM chip instead: power it down and its content will disappear within seconds. Retention time can be increased to days or perhaps weeks by cooling to cryogenic temperatures before power down, and after the data has become unreadable by normal means, specialized probes and microscopy techniques could in some cases still retrieve it for some time, but ultimately the data will fade. It's unlikely than any future technology will be ever able to recover data from a RAM chip that has been powered down for months, even if cryogenically stored. Of course brains are neither RAM chips nor hard drives, but the point is that having high data remanence is specific to certain technologies and not some general property of all practical information storage systems.

• It suggests an Argument from Ignorance: "Pumping someone full of cryoprotectant and gradually lowering their temperature until they can be stored in liquid nitrogen is not a secure way to erase a person." The implicit argument here is that since you can't be sure that cryopreservation destroys a person, you should infer that it doesn't. That's obviously a fallacy.

Furthermore the referenced post introduces spurious motives (signalling) for signing up for cryonics, committing the fallacy of Social Conformance: "Not signing up for cryonics - what does that say? That you've lost hope in the future. That you've lost your will to live. That you've stopped believing that human life, and your own life, is something of value."

Nick Bostrom or Anders Sandberg

Why do you particularly care about their opinion? They are not domain experts, and being futurists/transhumanists there is a non-negligible chance that their opinion on the subject is biased.

It is important to realize that the moment you sign up for cryonics and the advancements made thus far are not the ones that you are likely to be subject to. While current practices may well fail to preserve usable identity-related information (regardless of experts opinions on whether or not this is happening (if it were known now, we could know it)), advancements and research continue to be made. It is not in your best interests to be preserved as soon as possible, but it is in your best interests to sign up as soon as possible, to ensure eventual preservation. Too often I see people basing their now-decisions on the now-technology, rather than the now-measured rate of advancement of the technology. The condition of, "If I'm going to be dieing soon," is simply not likely enough that most of us should be implicitly considering it as a premise.

To answer this question we should talk to lots of neuroscientists. Here's one:

There's a burden of proof issue here: If there is a small group making a scientific claim that the larger scientific community finds ludicrous, skepticism should be the default position. I'm not aware of any peer-reviewed publication explicitly debunking cryonics. Probably the reason is that practicing lab scientists aren't inclined to write up a refutation of an particular idea when all you need to see it's bullshit is an undergraduate-level understanding of biology. So, since I can't point you to a systematic refutation, I'll give you this in the way of citation: http://jcb.rupress.org/content/188/1/145.full

This is a technically impressive study, they get really pretty and informative EM results. Excepting minor advances in the few years since it was published, this is close to state of the art as far a vitrification of brain tissue goes. If what the cryonics huckster companies were offering provided THIS level of preservation in a whole brain, then maybe we could have an interesting conversation. Cryonics would still be hopeless and vapid for other reasons, but at least you could count on fine membrane structure in synapses being preserved.

But in order to GET such good preservation, they had to take a slice of brain 400 micrometers thick and 1mm in diameter and vitrify it at 2000 bar. The high pressure required would damage an entire brain, and this works specifically because you're dealing with a small volume of tissue. Slicing an entire MOUSE brain and reconstructing it at this level is a major goal of connectomics, pretty far off. But I promise you (my lab does this kind of freezing for EM fairly routinely, it's time-consuming and the sectioning is artifact-prone), what the huckster companies are offering to do to your head is NOT going to give the kind of preservation that maintains synaptic structure. Thinking that in the early 21st century you're going to pay a company to freeze your brain in a way that it could be "reanimated" is insane, and shows a stunning naivete of the underlying biological complexity. The service you are paying for is "please destroy my already-dead brain in a way that involves chemicals and coldness". -- David Ruhl on facebook:LessWrong

There was also a discussion with another neuroscientist, kalla724, here a year ago.

Do people know of other places where a neuroscientist who knows about vitrification gives their opinion?

Susskind's Rule of Thumb seems worthwhile here. The actionable question doesn't seem to be so much "Does Bostrom publicly say he thinks cryonics could work?" as "Is Bostrom signed up for cryonics?" (Hanson, for example, is signed up, despite concerns that it most likely won't work.)

I don't believe any of the various purely computational definitions of personhood and survival, so just preserving the shapes of neurons, etc., doesn't mean much to me. My best bet is that the self is a single physical thing, a specific physical phenomenon, which forms at a definite moment in the life of the organism, persists through time even during unconsciousness, and ceases to exist when its biological matrix becomes inhospitable. For example, it might be an intricate topological vortex that forms in a (completely hypothetical) condensate of phonons and/or biophotons, somewhere in the cortex.

That is just a wild speculation, made for the sake of concreteness. But what is really unlikely is that I am just a virtual machine, in the sense of computer science - a state machine whose states are coarse-grainings of the actual microphysical states, and which can survive to run on another, physically distinct computer, so long as it reproduces the rough causal structure of the original.

Physically, what is a computer? Nuclei and electrons. And physically, what is a computer program? It is an extreme abstraction of what some of those nuclei and electrons are doing. Computers are designed so that these abstractions remain valid - so that the dynamics of the virtual machine will match the dynamics of the physical object, unless something physically disruptive occurs.

The physical object is the reality, the virtual machine is just a concept. But the information-centric theory of what minds are and what persons are, is that they are virtual machines - a reification of a conceptual construct. This is false to the robust reality of consciousness, especially, which is why I insist on a theory of the self that is physical and not just computational.

I don't want to belabor this point, but just want to make clear again why I dissent from the hundred protean ideas out there, about mind uploading, copies, conscious simulations, platonic programs, personal resurrection from digital brain-maps, and so on, in favor of speculations about a physical self within the brain. Such a self would surely have unconscious coprocessors, other brain regions that would be more like virtual machines, functional adjuncts to the conscious part, such as the immediate suppliers of the boundary conditions which show up in experience as sensory perceptions. But you can't regard the whole of the mind as nothing but virtual machines. Some part of it has to be objectively real.

What would be the implications of this "physical" theory of identity, for cryonics? I will answer as if the topological vortex theory is the correct one, and not just a placeholder speculation.

The idea is that you begin to exist when the vortex begins to exist, and you end when it ends. By this criterion, the odds look bad for the proposition that survival through cryonics is possible. I could invent a further line of speculation as to how the web of quantum entanglement underlying the vortex is not destroyed by the freezing process, but rather gets locked into the ground state of the frozen brain; and such a thing is certainly thinkable, but that's all, and it is equally thinkable that the condensate hosting the vortex depends for its existence on a steady expenditure of energy provided by cellular metabolism, and must therefore disintegrate when the cells freeze. From this perspective cryonics looks like an unlikely gamble, a stab in the dark. So an advocate would have to revert to the old argument that even if the probability of survival through cryonics is close to zero, the probability of survival through non-cryonics is even closer to zero.

What about the idea of surviving by preserving your information? The vortex version of this concept is, OK, during this life you are a quantum vortex in your brain, and that vortex must cease to exist in a cryonically preserved brain; but in the future we can create a new vortex in a new brain, or in some other appropriate physical medium, and then we can seed it with information from the old brain. And thereby, you can live again - or perhaps just approximate-you, if only some of the information got through.

To say anything concrete here requires even more speculation. One might say that the nature of such resurrection schemes would depend a great deal on the extent to which the details of a person depend on information in the vortex, or on information in the virtual coprocessors of the vortex. Is the chief locus of memory, a virtual machine outside of and separate from the conscious part of the brain, coupled to consciousness so that memories just appear there as needed; or are there aspects of memory which are embedded in the vortex-self itself? To reproduce the latter would require, not just the recreation of memory banks adjoining the vortex-self, but the shaping and seeding of the inner dynamics of the vortex.

Either way, personally I find no appeal in the idea of "survival" via such construction of a future copy. I'm a particular "vortex" already; when that definitively sputters out, that's it for me. But I know many others feel differently, and such divergent attitudes might still exist, even if a vortex revolution in philosophy of mind replaced the program paradigm.

I somewhat regret the extremely speculative character of these remarks. They read as if I'm a vortex true believer. The point is to suggest what a future alternative to digital crypto-dualism might look like.

A thread sprung up here about self-funding your cryonics arrangements. This has important enough practical implications for cryonicists that I am responding to it at the top level.

In addition to my original arguments that most individuals should not self-fund...

• No one is contractually obligated to pay for your suspension if your own "low risk" investments tank.

• Unless you have a proven track record investing, you are likely overconfident in your ability to invest compared to professionals.

• Creditors and heirs will find it easier to raid your investments than they will an insurance policy of which they are not beneficiaries.

...all of which are by themselves substantive reasons, I could slap myself for not having thought of the obvious fourth reason:

• If you truly are making low-risk investments, it may take a while for them to add up to a sufficient sum of money to cover cryosuspension. Whatever your age, there is some risk that you will die before your investments reach that point.

The best practice is not to self-fund unless you have close to enough money to pay for it up-front and the skills to isolate that money in a long-term trust that will be well-insulated from third-party meddling. And if both of those things are true, it's surprising to me that $80 US or so per month would be more than pocket change to you in the first place.

For more information, I recommend the article in this issue of Cryonics magazine, starting on page 7.

Full disclosure: my family and I set up our policies through this guy.

If I remember right the chance of it rescuing you were estimated to be somewhere between 10-20% by senior LessWrong people in the last census.

The interesting thing was that senior LessWronger were more likely to recommend people to undergo cryonics then less senior people when both believed in the same probability of being revived.

In the end the question is:
p(getting revived) * u(utility of getting revived) <? u(utility cost of acor payments)

This left me with the impression that the chances of the average cryopreserved person today of being later revived aren't great

It may be that people cryopreserved today will not be among the 'first batch' of people revived. The damage caused by ice could be repairable, but it might require more advanced nanotech, and perhaps some 'filling in' of lost information. I wouldn't be surprised if frozen people were revived in batches, starting from the most recently frozen ones, finally ending with those frozen in the 20th century.

One way that patternists could be wrong and I might still be satisfied with a (non destructive) upload or copy as a way to preserve myself is if our memories were prevented from diverging by some sort of sync technology. Maybe it would be a daily thing, or maybe continuous. Sort of a RAID array of brains.

But this still requires actual revival as an initial step, not destructive copying or uploading.

I wish I could give you more up-votes for explicitly making existential catastrophe part of your calculations, too many people focus on the technical considerations to the exclusion of other relevant unknowns.

Here are mine (explanation of edit-- oops, patternists being wrong and right didn't sum to 1, fixed now):

Cryo

(50% not being ended by an intervening existential catastrophe) x
(80% fellow humans come through) x
[(70% patternists are wrong) x (50% cryo sufficient to preserve whatever it is I call my continuity strictly by repairing my original instance) +
(30% patternists are right) x (70% cryo sufficient to preserve whatever it is I call my continuity by any means)]

= 22.4%

Plastination

(70% not being ended by an intervening existential catastrophe) x
(85% fellow humans will through) x
[(70% patternists are wrong) x (0% plastination sufficient to preserve whatever it is I call my continuity by any means) +
(30% patternists are right) x (90% plastination sufficient to preserve whatever it is I call my continuity by any means)]

= 16.065%

Explanations: among existential risks I count human-made problems that would prevent people who would revive me from doing so. So, fellow humans coming through simply means there is someone at any point in the future willing and able to revive me conditioned on no existential catastrophes and it being technically possible to revive me at all.

For patternists to be right, both the following would have to be true...

• A sufficiently accurate representation of you is you (to the point that your amplitude would sum over all such representations that you coexist with).

• It is theoretically possible to achieve such a representation by uploading or reconstruction with molecular precision or some other reconstruction or simulation technique.

... or the following has to be true:

• My sense of continuing inner narrative is an illusion that will be destroyed by a more accurate understanding of reality, and amounts to wanting something that is a empty set, a dangling object, like meeting the real Mickey Mouse or knowing what prime numbers taste like.

It's unlikely that patternists can be right in the first way because there is no evidence that very-very-similar configurations can validly be substituted for identical configurations. Especially if the replica in question did not evolve from the original and even more so if the replica is running on a completely different substrate than the original. Even if they are right in that way, will it ever be possible to test experimentally?

It is far more likely that patternists are right in the second way. My terminal goal is continuity (and I value accurate preservation of the data in my brain only because I think it is instrumental to preserving continuity). The main reason I am signed up for cryonics is because I believe it is more likely to succeed than any currently available alternative. If all alternatives are fundamentally doomed to failure, the entire question becomes largely moot. I'm therefore conditioning my above probabilities on the patternists not being right in the second way.