This weekend I attended the Machine Consciousness Conference, “MC0001”.

C-Zombies definition. Some people were arguing that uploaded minds (or any digital minds) wouldn’t be conscious. That instead, they would be “C-Zombies”—that is a mind that acts exactly as if it was conscious (/as its biological conscious counterpart) without actually being conscious (ie. they compute the sensory input in the same way, and therefore produce the same behavior given the same input). I personally believe uploads are (quite likely) conscious, but let’s assume they are C-Zombies.

Addendum: Here’s the refutation for P-Zombies: https://www.lesswrong.com/s/FqgKAHZAiZn9JAjDo. Probably a better use of your time to read why P-Zombies don’t make sense rather than this post arguing about the implications if they did 😄

C-Zombies downloading themselves. In the future, if you realized that uploads were not conscious, you might want to change their substrate in order to make them conscious again. Let’s assume you were cryopreserved, and then were uploaded as your revival method. Your p-zombie would act the same way as you would, by definition, and so would also be wanting to download p-zombies / make them conscious again. Therefore your p-zombie would presumably decide to download itself back into a substrate that supports consciousness. Problem solved.

(Unless you think most of the value was already destroyed by having a temporary p-zombie between the 2 conscious states.)

Addendum

Clarification on C-Zombies observing their brain: C-Zombies act exactly the same as their biological counterpart given the same environment. However, there’s one part of their environment that has to be different, which is their own brain. So if they “open their brain” to look inside of it, then they will observe something different. However, the biological brain was in a vat, connected to the same virtual reality as the C-Zombie, and in the virtual reality you showed to both that they were biological brains, or showed to both that they were digital brains (even though that’s a deception for one of them), then in that scenario both would be acting in the same way. So it’s not quite their brain that changes how they behave, but rather the observation of their brain.

On believing you’re not conscious: (As far as I understand) According to C-Zombie believers (which I’m not), what causes them to believe they are conscious is not the introspection that they’re conscious, but rather the observation of how their brain is embeded in physics. Consequently,

• Their probability that they’re conscious should be the same as the probability that they’re not in a simulation (or otherwise digital).

• If they realized that they were actually an uploaded mind all along (by our civilization rather than a simulation), they should believe that they aren’t conscious. They should claim that observing that they’re conscious wouldn’t change their stated belief that they’re not conscious if they’re digital.

• Their probability that they’re in a simulation shouldn’t be updated from their introspection that they’re conscious.

• More generally, none of their beliefs should change from introspecting on their consciousness. They should never say “because (I observe introspectively that) I’m conscious”. C-zombie would process the information in exactly the same way, and a belief is only as good as its capacity to differentiate true worlds from false worlds. They must come to the conclusion that they’re conscious by a process that never requires first knowing that they’re conscious (from introspection). If their (introspection of their) consciousness causes them knowing they’re conscious equally well as it would cause a non-conscious being to “know” that, then the belief has zero correlation with the fact, and so it’s not a rational belief and should be discarded.

Corrected error 6/2: I originally used the concept of P-Zombies instead of C-Zombies as I should have. See this comment for an explanation of the difference.

General
Effective Altruism & Life Extension – Facebook group

Cryonics
Cryonics discussions – X Community
The Cryosphere – Discord
Cryonics discussions – Facebook group
Cryonics leaders – Facebook group
Cryonics Memes for Frozen Teens – Facebook group
Cryonics – Reddit
Sparks Brain Preservation Forum – Forum
Cryonics discussions – Don’t Die app
Other: Online groups

Infostasis
Lifelogging as life extension – Facebook group
Lifelogging memes for life extension teens – Facebook group

Modal immortality
Modal immortality – Facebook group

Survey presentation

Link to survey: Cryonics Career Survey

Background. During the annual Teens and Twenties Cryonics Gathering (a fully funded yearly gathering for young cryonics members), there is usually a survey that is distributed to all participants to gauge their interests around getting involved in various roles in cryonics, professionally or as a volunteer. This has been useful, and I think it would be even more valuable if it were accessible for anyone to fill out–so I made my own version.

Goals. The goals of this survey are to gather people that are either:

• (potentially) interested in utilizing their skills/knowledge/experience to support cryonics endeavors – there are many work opportunities you probably don’t know about;

• (potentially) interested in learning and seeking guidance/mentorships/information about having a career in cryonics – we’re already in touch with cryonics researchers willing to mentor.

  • Note: Ramping up to being able to do meaningful cryonics research might be easier than you think, so I invite you to err on the side of signaling your interest to us.

Email use. We will email the list with work opportunities, as well as (if you opt-in) share your information with interested and approved cryonics(-relevant) organizations for the purpose of helping them find people to work for them. We will also email the list with any information relevant to working in cryonics, such as relevant interviews of cryonics researchers or mentorship opportunities. We expect to send emails infrequently—less than once per month. You can unsubscribe at any time of course.

Related opportunities:

• If you’re an MD and/or PhD and support the Scientists’ Open Letter on Cryonics, please also let us know.

• If you’re involved in cryonics and willing to mentor others, please reach out!

Fill out the survey here: Cryonics Career Survey

Currently open roles

After an extensive web search of cryonics organizations we know of, here is a list of some current job postings we were able to find (when the country isn’t specified it means it’s in the USA or remote) – some of those roles might have recently close, but I’m leaving them up to show the diversity of options (most or all should still be open at the time of posting though). Fill out the survey to get information about future such opportunities.

• Advanced Neural Biosciences (Portland, OR)

  • Research Perfusionist (LinkedIn)

• Alcor Life Extension Foundation (Scottsdale)

  • CPA/Corporate Controller/Bookkeeper (LinkedIn)

  • Senior Accountant (LinkedIn)

  • Paramedics/EMTs (Ongoing Contracts) (Alcor’s website)

  • Volunteer (Alcor’s website)

• Biostasis Technologies (New York City, NY)

  • Maker / Fabricator (private communication)

• Brain Preservation Foundation (remote)

  • Volunteer (Brain Preservation Foundation’s website)

• European Biostasis Foundation (Switzerland)

  • Facility Manager for Research Institute (Full-Time) (Join.com)

  • Senior Researcher/Medical Engineer (Full-Time) (Join.com)

• Tomorrow Biostasis (Germany)

  • Full-Time Junior Product Manager – Berlin (Join.com)

  • Internship – Business Development (Join.com)

  • Part-time account manager (Join.com)

  • Full-time Engineering Internship (m/w/x) – Berlin (Join.com)

• Trans Time Inc. (Bay Area)

  • Marketing Specialist (Trans Time)

• Southern Cryonics (Australia)

  • Facility Caretaker (Part-time) (Southern Cryonics)

  • Volunteer (Southern Cryonics)

• 21st Century Medicine (Fontana, California)

  • Professional Research Surgeon (21st Century Medicine’s website)

• Lorentz Bio (Bay Area)

  • Lab Manager (Lever.co)

  • Research Assistant (Tissue/Cell Culture) (Lever.co)

  • Research Assistant II/III (Lever.co)

  • Research Associate (Neuroscience) (LinkedIn)

• Nectome (San Francisco)

  • Senior Scientist (Nectome’s website)

  • Prototype Engineer (Nectome’s website)

• Resurgence Biomedical Sciences (New York City, NY)

  • Paramedic / Nurse (private communication)

• Winfried Denk Lab (Max Planck Institute)

  • Open Application (Rolling Basis) (Max Planck Institute for Biological Intelligence’s website)

Set-up: In a world that’s otherwise the same, an anthropomorphic God comes to you with a gun and a check, and offers you the following deal, should you accept it. (God can perfectly see the future and is honest.)

Dilemma: God will give you a check of X USD if you accept to be immediately and instantly killed iff the current cryonics protocole is sufficient to preserve identity.

Alternative: God kills you iff the following is true: If you were signed up for cryonics and died this year, you would get reanimated at some point in the future.

Question: What’s the minimum X for which you would accept this deal? What probability of dying are you trading this for?

Comparison:

Say 100,000 USD and 5%. This means this deal would give you:

• 100% earning 100k USD

• 5% of dying (right now, instead of ~0%)

If you die and get cryopreserved:

• 100% losing 100k USD (i.e. a typical cost for state of the art cryonics)

• 5% of living (instead of 0%)

If you die and don’t get cyropreserved:

• 100% of saving 100k USD (by not paying for cryonics)

• 5% more chance of dying (100% instead of 95%)

In this sense, taking the deal is similar to not getting cryopreserved (and vice versa).

Disanalogies:

There are significant disanologies of course:

• The type of life you would live

• How long you life would be if you didn’t die

• The social cost of signing up for cryonics

I still think this might be a useful thought experiment to bring this dilemma to a more near mode way of thinking. It also reverses the default option.

By short-termism, I basically mean a method of analysis where one assumes the world stays the same. With longtermism, indirect effects and uncertain futures are taken into account. The longtermist approach focuses on increasing the probability of different stable outcomes, whereas the short-termist approach focuses on the short-term direct impact.

When it comes to personal life extension, short-termist strategies include things like:

• Increasing the number of dreams, and notably lucid dreams experienced and remembered

• Reducing the amount of time sleeping

• Avoiding drugs that erases memory

• Having habits that are conductive to faster thinking

At a first approximation, these interventions might all look great. They can all increase subjective life expectancy more than they decrease objective life expectancy, and maybe even robustly so.

However, when the stakes are astronomical, this approach is completely backward. The long termist approach for personal life extension focuses on dying later, not (directly) on living more. Using the following as a toy example, that could mean things like sleeping 10% more only to live 1% more, which doesn’t seem to make sense given this would reduce one’s total subjective lifespan at a first approximation, except that this 1% increase in objective lifespan could actually transform into astronomically more because it could allow one to live long enough to live maximally long; i.e. reach a point where cryonics, anti-aging, or other anti-death technologies reach longevity escape velocity. Some longtermist interventions will come at a negligible or zero short-term subjective life expectancy cost, such as lifelogging as life extension, while others will greatly diminish your short-term subjective life expectancy, such as pre-emptive biostasis.

The longtermist approach still has overlapping recommendations with the short-termist one, but when it does, they will sometimes arise for different reasons, and to a different degree. For example, sleeping less might be good to earn more money and therefore be able to afford better biostasis instead of being good because it increases the length of your short-term subjective experience. On the other hand, other interventions are good from both the short-termist and longtermist perspectives because they increase both subjective and objective lifespan. Such interventions include a healthy diet, a healthy amount of safe exercise, breathing clean air, etc. This category tends to be the one people naturally think about when thinking about longevity.

Some interventions are not obvious to categorize; they will depend on the context and the specific reasoning behind them. For example, avoiding a new experience because it cannot be lifelogged would help avoid a micro-death at the cost of the experience. On the other hand, this experience might help preserve your self as a whole (ex.: attending a cryonics conference that is not lifelogging-friendly), and so might be worth sacrificing.

For an agent with no diminishing returns on additional subjective experiences, it’s still not literally impossible for the short-termist approach to be superior (ex.: maximum lifespan could be small or unlikely), but in practice, it seems to me like the longtermist approach is basically always correct.

There will still be various interventions within the longtermist approach that will trade-off against each other. For example, there will be longtermist arguments to get cryopreserved earlier (ex.: avoid further identity degradation) and there will also be longtermist arguments to get cryopreserved later (ex.: to wait until cryonics technologies get better).

For more in this vein, see the Facebook group on death-focused ethics

Edit: This was posted on April’s fool

While the core ideas are not entirely unfounded, they were presented as stronger than they really are.

• While it’s true that we can cool down mammals to near 0 °C without apparent damages, damages would very likely start becoming apparent after multiple surgeries; plus, the risk of surgical complications would presumably become significant.

• There’s not really a “big dilemma” in the cryonics community about whether healthy people should get cryopreserved now or later.

• While I haven’t researched hemispherectomy much, I suspect they are much more dangerous, complicated, and damaging than how I presented it here.

Perpetual cooldown

Acknowledgement: Hunter Glenn came up with the general idea in a discussion with Mati ; written by Mati Roy

We already have the technological capability to cool down mammals to near 0 °C temperature for multiple hours and bring them back without any damages (reference: https://timelines.issarice.com/wiki/Timeline_of_brain_preservation).

While this was originally developed to improve critical care medicine as well as initial cryonics cooldown, there’s another way in which we could use that technology.

We could spend 6 hours at that temperature each day. Of course, that would mean days would be 6 hours longer as metabolism is stopped at that temperature, and the normal sleep functions are not operating. That means for each 4 subjective days, 5 objective days would pass. Waking hours would cycle like this:

• Day 1: 6:00 to 22:00

• Day 2: 12:00 to 4:00

• Day 3: 18:00 to 10:00

• Day 4: 00:00 to 16:00

This would delay the moment of your death by up to 25% given metabolism is slower at lower temperature, which means you would likely reach a time when anti-aging and cryonics technology has been improved, hence increasing your chance of living radically longer.

The cost includes:

• monetary cost for the surgeries

• how you feel after surgeries

• losing opportunities for work that require a regular schedule

• generally makes it harder to coordinate with people, especially other people into perpetual cooldown

• makes it harder to work 40 hours per week

Split brain preservation

Acknowledgement: Matthew Barnett came up with the general idea ; written by Mati Roy

A big dilemma in the biostasis community is whether one should get cryopreserved now or later. On one hand, getting preserved now has the advantage of stopping any further identity degradation (ex.: memory distortion, value change, etc.). On the other hand, cryonics technology will be more advanced in the future, and so it might be worth waiting for that before getting cryopreserved.

The other big dilemma in the biostasis community is whether one should get their brain plastified or cryopreserved. One one hand, plastification provides a more fidel preservation of the brain ultrastructure. On the other hand, cryopreservation maintains a higher biological viability of the cells.

Well, with hemispherectomy, those problems are no more. Hemispherectomy is a procedure where half of the brain is removed. It has been performed multiple times without any apparent complications (example).

With hemispherectomy, you can now choose to be preserved both now and in the future. We suggest considering the year leading to puberty for your first preservation as puberty is a good candidate for an identity altering event, responsible for a high number of microdeaths. If you’re already passed puberty, then we suggest considering getting half your brain preserved immediately.

Although there’s still the dilemma of deciding whether to preserve half now and half later OR preserve both halves using different technologies. We unfortunately haven’t yet found a way to split the brain in 4.

x-post: Buying micro-biostasis – LessWrong

Help / Quality: I’m publishing this post slightly unfinished because a friend of a friend might need this information today (or in the next few days) to (micro-)cryopreserved their grandmother. If you have knowledge on how to use online gambling platforms in the ways described in this post (see section “How to” and “Replacing credences with frequencies”, your input would be appreciated.

Warning: This article talks about gambling. I think gambling is almost always a bad idea, and gamblers are often irrational and/or addicted. This article discusses an exception where I think gambling is rational.

Summary: If you need to buy cryonics very soon, and don’t have enough money, you can gamble the money you have for a chance of being able to afford getting cryopreserved.

Important note: Other options for people in an ermgency situation with a low budget not discussed in this post include low-cost preservations and fundraising. Lifelogging can also be considered as a complementary option.

Related: Meme

Table of content:

• General idea

• How to

• Replacing credences with frequencies

• Trading among different forms of preservation

• Note on terminology

General idea

If the cheapeast biostasis option available to you is more expensive than the amount of money you have, you can gamble your money to buy a probability of getting cryopreserved, which itself is a probability of living longer.

Cryonics is already a gamble: you bet money that it might allow you to live longer. Gambling money that might allow you to get enough money to get cryopreserved is not qualitatively different.

Even if what you’re buying is just hope, buying a probability of having the hope for a fraction of the money should generally still be worth it.

It seems to me like this is true for any expense that is:

• larger than your total disposable assets: otherwise you can just pay directly for it

  • note: it could be that you keep separate budget for separate values, in which case you might want to gamble your budget to save a loved one, and keep the rest of your assets separately

• time sensitive: otherwise you can accumulate more resources to pay for it

• more valuable than what you could otherwise do with money: otherwise you should but those other things

• where borrowing money isn’t an option: otherwise you should borrow money to make sure you can buy it

The only example I can think that fits those criterias is for an emergency life saving technology. Given current medicine is generally pretty ineffective, the main example is cryonics.

Note that this is a desparate measure. If you want to get cryopreserved, I recommend having a solid plan on how to pay for it. Probably by either buying a whole life insurance, or by buying a term life insurance while you put enough money aside, or by buying it out-of-pocket. Gambling your money to save a loved one with cryonics will also mean you won’t be able to use that money to save other loved ones with cryonics.

That being said, you could find yourself in a situation where this is the correct move. In which case I think it will require a very rational person to be able to go through with this.

It will require:

• Fully accepting that cryonics is a good thing, and you might have failed to acquire enough resources to saved a loved one

• Having the agency to learn how to use the required technology for the first time, in what might be a pretty stressful situation

• Potentially not be properly acknowledged for your heroic effort

• Do something even weirder than normal-cryonics

• Gamble money, which is usually seen as low-status

I imagine someone sitting alone, not just physically, but emotionally, in silence, in front of their computer. Without any loved ones knowing or understanding what they are about to do.  With all their assets transformed in a crypto-currency. Looking at a low-quality HTML page. Rechecking yet again that all the numbers were entered correctly. The second they click that button, they will know their faith. A few pixels representing a death, or a possibility at a second life. A hearth crushed, or a heart filled with hope.

If you find the courage to do this, I’d be delighted to meet you.

See next section for how to do this.

How to

Warning: I have not tested Just Dice. Please make your due diligence, and test it with a small amount of money. 

Fortunately, the blockchain community has brought us provably fair gambling platforms at low fees. They seem like an excellent tool for this purpose.

I’ll use Just Dice as an example. I might review others at a later point. If you want to review them, please leave a comment or let me know if you want to make a post.

Just Dice (https://just-dice.com/) takes a 1% fee.

Let’s say the cheapeast preservation available to you cost 50,000 USD, and that you have only 5,000 USD.

First, you need to buy the crypto-currency used by the website, in this case Clams. See: How to Buy Clams. To simplify this example, let’s say the exchange rate is 1 Clam = 1 USD.

Then for your bet size you would put the money you have, so 5000 Clams. And for the profit you would put the cost of cryonics minus the money you have, so 50,000 Clams minus 5,000 Clams. If the website didn’t take a fee, that would give you a 10% to win: 90% * -5000 + 10% * +45,000 = 0. However, the website takes a 1% cut, so your chance to win becomes 99%*10% = 9.9% instead of 10%. This represents an expected cost of 1%.

Two ways of calculating it:

• 90.1% * -5000 Clams + 9.9% * + 45,000 Clams = -50 Clams

• 1% * -5000 Clams = -50 Clams

In summary:

• bet size: your total budget

• profit: the total amount of money you need minus your total budget

Once you’ve entered those values, you can click on “deposit” to deposit money. Then once you’ve done the bet, you can click on “withdraw” to withdraw the money.

Replacing credences with frequencies

The website Random Numbers (http://www.randomnumbers.info/) claims to have a quantum origin.

I’m not positive on whether that means when you generate a number from, say, 1 to 10, there will be versions of you seeing each number. And I’m even less confident that each number gets roughly a similar fraction of the quantum measure.

Assuming:

1. something like the many-world interpretation of quantum mechanics is true, 

2. gambling doesn’t naturally have this property

3. we value being in a fraction of worlds more than a probability of being in all worlds (ex.: because of quantum immortality)

Then it seems like replacing credences (“epistemic probabiliities”) with frequencies (“physical probabilities”) would be valuable.

I expect most people to agree with (1), some people agreeing with (2), and most people disagreeing with (3). I personally think this doesn’t seem entirely unlikely. And it seems more unlikely that it would be worse. So assuming it’s either neutral or positive, then it seems worth doing even if the probability of being positive is low.

Although I haven’t investigated how to use the Random Number generator along with one of the betting websites exactly, but I think it should be doable. If anyone knows how, please let me know.

Trading among different forms of preservation

Let’s consider various preservation options:

• DNA storage (218 USD with the Cryonics Insitute)

• Neuropreservation (100,000 USD with Alcor)

• Whole-body preservation (220,000 USD with Alcor)

Note: Cheaper options exist, this is meant as an illustrative example.

Note: Alcor charges surcharges for last-minute sign up and thrid-party sign up (see: Required cost and cryopreservation fund minimums).

Let’s say we have 218 USD, and are about to die.

This would mean we’d have the following options.

• 100% of preserving our DNA

• (218*99%)/100,000 = ~1/463 chance of a neuropreservation

• (218*99%)/220,000 = ~1/1019 chance of a whole-body preservation

I think the case for the DNA is hard. In many ways, this is the equivalent of learning you had an unknown biological twin which was living in another country. Not that much of a consolation as far as I’m concerned. But maybe if you combine DNA with extensive lifelogging, then that brings a lot of value. But otherwise, I think I’d prefer a shot at a neuropreservation. If you have more money, then the trade-off becomes even more favorable — with 1000 USD, it becomes: 100% DNA preservation vs 1% neuropreservation.

As for whole-body preservation vs neuropreservation, I would take a 100% chance of a neuropreservation over a 45% chance of a whole-body preservation. I might actually take a 100% chance of a neuropreservation over a 100% chance of a whole-body preservation because the field cryoprotection protocole Alcor uses is more advanced for neuropreservations given they are less complex.

Another trade-off I might consider is lowering the probability in exchange for being able to afford moving near the cryonics service provider.

Note on terminology

I coined the term micro-biostasis in a similar vein of ideas to the term micromort which means “a unit of risk defined as one-in-a-million chance of death” — a micro-biostasis meaning “a unit of risk defined as one-in-a-million chance of being put in stasis”.

If you know older people, now might be a good time to talk to them about cryonics.

I will present the main objections I hear from my friends to justify not talking about it to their (grand)-parents (and/or elderly friends) as well as my answers. My answers are not generalized to everyone, but I do think they are applicable to many. I know it’s difficult to broach this subject: it can be embarrassing and harm your image. But, generally, I think these are trivialities in the face of the issue. Please allow me to challenge your view

Objection 1) Surely they will not want to register

My answer: This excuse bothers me. It is often the same people who say that elderly people do not adapt quickly enough. It doesn’t help if we stop sharing this kind of information with them. I find it condescending to make such an important decision on their behalf. And even if they don’t register, at least they will have been in control of their destiny.

Objection 2) I want to work less / buy more things with their inheritance

My answer: They love you enough to bequeath their wealth to you, so it seems to me like the least you could do in return is to give them this chance for a “second” life.

Objection 3) It will harm my relationship with them

My answer: You can bring it up indirectly; like, “Hey, I read that some people froze their bodies when they died hoping to be reanimated in the future.” Stay cooperative and support their choice. Aim to inform, not persuade. Consider starting with those who are most open to new ideas.

Objection 4) It is too improbable that cryonics will work

My answer: They potentially have not many years left. Let them decide if they prefer to be “buried with their money” or take this chance.

Objection 5) I don’t think it’s good for humanity

My answer: The more people register for cryonics, the more affordable cryonics will become for everyone because of economies of scale (see: Cryonics as Charity). There are more effective ways of being selfless than letting your (grand)-parents die.

Also more generally, as I often say: Good friends tell each other about cryonics.

The safest would be to move near a cryonics facility to reduce response delay, and to use assisted suicide before a neurodegenerative disease destroys their brain; but that’s a much more delicate topic.

• Metaculus — How many humans will have their brain preserved on January 1st, 2030?

• Metaculus — How many patients will be in cryonic suspension at the Cryonics Institute in 2030?

Summary

Doubling time for the number of people that got cryopreserved has been pretty consistently 9 years since the beginning.

Operationalization

If a body is disposed of because it was proven to not have been properly preserved, it still counts in the total number. If a body is disposed / destroyed for another reason, it doesn’t count in the total. A preserved brain counts as 1 even if only part of the brain / identity is preserved.

Brains accidentally preserved such as those for scientific studies unrelated to cryonics don’t count.

People preserved digitally, but without having their brain preserved doesn’t count for the purpose of this text.

If a patient has been revived / uploaded, they still count in the total patient count.

Non-human animals don’t count for the purpose of this text.

On January 1st, 2030

Simple extrapolation would give us 1009 patients.

The raw data for the above graph comes from the list of cryonics patients.

Average absolute deviation from trend has been 4.18, but this seems very low, so I’ll just go with 50 from intuition.

To improve this prediction, I also made predictions of patient count for various organizations (see graph below). I think the trend for the “Other” category actually significantly undershoot what will actually happen as new organizations tend to bring more growth, and there will be two new organizations very soon (ie. the European Biostasis Foundation and Southern Cryonics). I also think the projection for Yinfeng Biological Group is much more uncertain (given they are new), and probably more modest (given they are still private; ie. not everyone can become a member).

I have a larger uncertainty for the patient count of specific organizations than for the total count given my uncertainty over the number of cryonics members that will switch to another organization. I combined this prediction with the probability of a disaster to update the initial simple extrapolation. Disasters can include: misreporting of number of patients, insolvency, natural catastrophe, voluntary attack, change of law, or error. I also made predictions for take-off caused by the Yinfeng Biological Group and the European Biostasis Foundation which are two new promising organizations. You can see the model here: https://www.getguesstimate.com/models/15142 (or in the image below).

Details from where the numbers come from:

• Alcor: 3.31-0.994*x+0.0709*x^2-5.44*10^-4*x^3+1.21*10^-5*x^4 where x=63.76 = 287 (WolframAlpha)

• Cryonics Institute: 10.7-4.17*x+0.261*x^2-4.99*10^-3*x^3+4.94*10^-5*x^4 where x=63.76 = 329 (WolframAlpha)

• KrioRus: 6.01*x-261 where x=63.76 = 122 (WolframAlpha)

• Yinfeng Biological Group take-off: sum of 1.25^x for x from 1 to 10 = 42 (WolframAlpha)

• Other: -1.47+0.567*x-0.0327*x^2+5.72*10^-4*x^3 where x=63.76 = 50 (WolframAlpha)

• Everything else comes mostly from my intuition

Sanity check: checking whether the sum of the predicted number of patients for each organization is the samed as the number of patients predicted from the overall trend.

290+330+51+81+120+25+15+6.6+12+12+67=1009

The sum of the organization’s patient count forecast is exactly the same as the total patient count forecast. When I initially made it, it summed to something like 995, but I then adjusted the “Other” part both to make it match and also because I thought it made sense.

My final probability distribution for the number of patients on January 1st 2030 is in the “Forecasted number of patients” box on the Guesstimate model.

In the next centuries

The doubling time is 8 years if we don’t count thawed patients (WolframAlpha), and 9 years if we do count them (WolframAlpha). The latter trend has been followed more precisely since the beginning of cryonics.

A naive extrapolation of the current trend would put the following milestones (patient: year if 8-year doubling time – year if 9-year doubling time) (WolframAlpha):

• 1: 1967 – 1966

• 10: 1987 – 1969

• 100: 2001 – 1998

• 1k: 2029 – 2030

• 10k: 2056 – 2061

• 100k: 2083 – 2091

• 1M : 2110 – 2122

• 10M: 2136 – 2152

• 100M: 2163 – 2183

• 1B: 2190 – 2213

• 10B: 2216 – 2243

• 100B: 2243 – 2274

• 1T: 2270 – 2304

Following are some reasons I can imagine the future count would deviate from the current trend, although a lot of those could also just be part of the trend — I think the sections ‘extinction’, ‘change in rate of change’, and ‘underlying population’ are the most likely to make the trend deviate, although I would only put medium probability mass on the trend continuing long term in the first place. The list below is not exhaustive.

Extinction

• [time: next few decades to centuries; probability: medium; severity: high]
  If human went extinct, this could obviously affect the number of cryonics patients; it’s not impossible that we would preserve them indefinitely, until another intelligent species arose on Earth or an alien civilization discovered us, but that’s really hard and a long shot in any case

Probability of working

• [time: next few decades; probability: low; severity: high]
  An “early” failure from a major cryonics provider could reduce the trust in the whole field, and push back the growth of cryonics for a while

Accessibility

• [time: next few decades; probability: low; severity: medium]
  The Cryonics Institute could offer a neuro option, which would increase the accessibility, and thus membership

  • although CI has been arguing than this would tarnish the image of cryonics

  • also, remote patients without a cryonics SST team are probably generally poorly preserved, and the relative price difference wouldn’t be as important for those with a SST contract: stabilization and transport cost 30,000 USD, and standby at least 7,500 USD, so even if the cryopreservation went from 28,000 USD to 13,000 USD (similar ratio to Alcor), then the total cost would only go from at least 65,500 USD to at least 50,500 USD. but maybe a significant portion of people would be ready to relocate near CI if a 13k$ neuro option was available. More on this here: Should there be more affordable cryonics options?

• [time: next few decades; probability: medium; severity: low-medium]
  An SST team could offer services internationally for the Cryonics Institute, hence making cheaper cryonics accessible internationally (currently, only Alcor offers worldwise SST services

• [time: decades to centuries; probability: low; severity: high]
  A change of law in a country where cryonics is popular could make it harder to perform

• [time: decades to centuries; probability: low-medium; severity: high]
  The Chinese government could support / approve or block / disapprove of cryonics.

  • The Chinese government has been pushing for more “civilized” burrial methods for decades; see: Burning Up: Rage over China’s Cremation Push is Justified

Cultural fit

• [time: next few decades; probability: low-medium; severity: low-high]
  Cryonics could turn out to be more popular in countries that don’t currently have a cryonics service provider; for example, the exponential growth could be faster in China

• [time: many decades – centuries; probability: medium?; severity: medium?]
  Update in belief that cryonics isn’t necessary because of an increased belief that an atlernative path to longevity is likely, whether credible or not, such as: increased belief in a religious afterlife, in soon solving aging, in digital reconstruction, etc.

Change in rate of change

• [time: many decades – centuries; probability: medium; severity: high]
  Change in the economic growth rate: it could increase (ex.: Economic Growth Given Machine Intelligence) or stagnate or collapse

• [time: many decades – centuries; probability: medium-high; severity: high]
  Important change in human intelligence, espetially intelligence enhancement, but also disgenic pressures

Underlying population

• [time: many decades – centuries; probability: initially low; severity: high]
  The mortality rate could change, which would reduce the fraction of people that could use cryopreservation; also see: number of deaths per year

• [time: centuries; severity: beside the point]
  The world population (also fertility rate) could change, which would affect how many people can ultimately become cryonics patients

Parting remark

In December 1964, after two years of promoting the concept of cryonics, Evan Cooper fumed in exasperation: “Are we shouting in the abyss? How could 110 million go to their deaths without one, at least trying for a life in the future via freezing? Where is the individualism, scientific curiosity, and even eccentricity we hear so much about?”

As of Jan 2019, I estimated that 2.9 billion have died unpreserved since the first effort to cryopreserve people. I predict many more will suffer the same faith. But I work towards reducing that number.

February 2026 update

The doubling rate is still 9 years—from ~466 in 2019 to ~716 now.

Details

Timeline of brain preservation

You can see the changes to the timeline of brain preservation since its creation last year here.

New patients

Total known: 31 new patients
Alcor: 11
Cryonics Institute: 9 (based on November 2019’s data)
KrioRus: 5
Yinfeng Group: 4
OregonCryo: 1
Osiris: 1
Neural Archive Foundation: undisclosed (but at least 1)
TransTime, Cecryon: no reply Private: 0 (?)

2019 was the 2nd year with the most new patients in absolute terms. This represents a 7.9% increase. The average yearly change in the last 20 years was +8.4%.

New members sign up for cryonics

Alcor: 51
Yinfeng Group: 29
Cryonics Institute: undiscolsed (23 with Suspended Animation between Dec. 2018 and Nov. 2019)
Southern Cryonics: 8
Neural Archive Foundation: undisclosed
KrioRus, OregonCryo, Osiris, Cecryon: no reply
TransTime: N/A

2019 was the 4th year with the most new members in absolute terms. This represents a 3.6% increase. The average yearly change in the last 20 years was +4.7%.

Notable events

On April 2019, The Brain Preservation Foundation launched the Aspirational Neuroscience Prize with the commitment to give 4 prizes of 25,000 USD every year for the next 10 years for breakthroughs in the neuroscience of memory, brain preservation, and connectomics.

Wikipedia views spikes

Here’s the pageview graph. On 2019-10-10/11, the Wikipedia article received 25,252* more views than usual; 11 times more. From a Google Search, this seems to be caused by the Chicago Med episode S05E03 “In the Valley of the Shadows” on cryonics released on 2019-10-09; see recap. This TV show is watched by ~10M people (source: Chicago Med – Wikipedia), so maybe about 1 person went to the Wikipedia page for every 400 people that watched the show.

I’m not sure what the peak of 2019-08-10/11 of 4,542/3,304 views was about.

The one on 2019-11-28 of 3,087 views might have been from the article Frozen Dead Guy Days Is the Weirdest Winter Festival in the U.S..

* ( 21191 views on 2019-10-10 + 6559  views on 2019-10-101 ) - ( 2 * 1249 average views per day ) 

Did I miss anything?

Please let me know in the comments.

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