Tell your (grand)parents about cryonics

Author: Mati Roy | Creation: 2020-03-19 | Updated: 2020-06-09 | Version: English clean version | Other versions: original version, French clean version

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.

How many humans will have their brain preserved? Forecasts and trends

Created: 2020-02-02 | Updated: 2020-05-07

Premise: If It’s Worth Doing, It’s Worth Doing With Made-up Statistic



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


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: (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.


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.


  • [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


  • [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.

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

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.

Cryonics 2019 Annual Update


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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