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Cryonics is NOT fringe pseudoscience

LEVITY podcast episode #27 - with Ariel Zeleznikow-Johnston

In this week’s newsletter

✅ Introduction to episode 27 with neuroscientist Ariel Zeleznikow-Johnston. ✅ Show notes. ✅ Prolon sweepstakes. ✅ Humanity’s apathy toward aging is a form of learned helplessness. ✅ Pro-mortality rhetoric is “palliative philosophy”. The connectome may remain readable for minutes to hours.

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🧹 Housekeeping

🎁 Prolon sweepstakes

Off to a flying start! There’s still time to enter - doors close 13 July 2025. Grand prize: three next-gen Prolon kits (657 € total value - plus, of course, the health boost they might give you). Want more info before you jump in? Check this post.

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🎙️ Latest LEVITY episode

Our guest this time is Ariel Zeleznikow-Johnston. It’s one of my favorite conversations yet. As many of you know, I’m captivated by the topic of cryonics - and I’ve even enrolled with Tomorrow Biostasis for future preservation.

📝 Show notes experiment

I usually write a full guest intro, but since I reviewed Ariel’s book a few weeks ago and I’m trying a new format, I’m jumping straight into the show notes this time.

🔮 Next episode teaser

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You can watch the episode with Ariel Zeleznikow-Johnston below or listen to it on Spotify, Apple Podcasts or other places, like PocketCasts. Please follow, like and subscribe! 🙏🏼 This will boost our chances of reaching a bigger audience.

A detailed overview of the episode

  • Ariel Zeleznikow-Johnston, a Monash neuroscientist and author of The Future Loves You, claims death is a technical rather than metaphysical problem.

  • He opens with Jonathan - a 192-year-old giant tortoise - to show that long, enjoyable lifespans already exist in nature.

  • Pleasure, purpose and companionship, not an arbitrary “expiry date”, drive the case for radical longevity.

  • Humanity’s apathy toward aging is a form of “learned helplessness” that stifles research momentum.

  • We lavish resources on late-stage disease care while under-funding root-cause aging science.

  • Ariel dismisses the phrase “healthy aging,” calling it slow-motion pathology.

  • Fears of over-population, power hoarding and existential boredom are real but solvable trade-offs.

  • He labels pro-mortality rhetoric “palliative philosophy,” comparing it to pre-anesthetic justifications for surgical pain.

  • As a fallback, terminal patients should have access to whole-brain biostasis that halts decay until cures exist.

  • Cryonics has evolved from crude freezing to vitrification and now “vitrifixation” that marries antifreeze with chemical fixation.

  • Chemical fixation best preserves the connectome - the synaptic wiring that encodes identity.

  • Psychological continuity, not flesh, defines the self; the connectome is the substrate-neutral blueprint.

  • In teleportation thought experiments, Ariel argues each duplicate legitimately continues the original person.

  • He reframes death as “information-theoretic” loss of the connectome, noting current brain-death laws lag behind science.

  • The connectome may remain readable for minutes to hours post-circulatory arrest, pressing the need for rapid protocols.

  • At projected costs near $10 k, biostasis beats many end-of-life interventions on quality-adjusted life-year metrics. [Note: this is what Ariel claims could be achievable - today’s preservation is an order of magnitude more expensive than that.]

  • A 2024 survey of neuroscientists put the odds of fixation preserving identity at ~45 %.

  • Ariel forecasts human-grade emulation within decades if AI and compute trends hold, but warns existential risks could void the bet.

  • He plans to use Oregon Brain Preservation if stricken young, yet calls for more providers and bench-top validation.

  • The guiding ethic: act so “the future loves you,” allowing descendants to repay ancestral struggles with renewed life.

Ariel Zeleznikow-Johnston, a Monash neuroscientist and author of The Future Loves You, claims death is a technical rather than metaphysical problem

Zeleznikow-Johnston frames mortality as an engineering puzzle: preserve the physical information that constitutes the mind, then restore function when tools mature. By divorcing “death” from spiritual finality, he aligns longevity research with routine disease work. His Monash Neuroscience of Consciousness post and 2024 book give him a laboratory and public-policy perch.

“Death as the loss of personal identity is a solvable problem,” he tells us.

The claim repositions aging from an inevitable endpoint to a reversible condition - inviting budgets, patents and ethics boards to treat senescence like any tractable disorder.

He opens with Jonathan — a 190-year-old giant tortoise — to show that long, enjoyable lifespans already exist in nature

Jonathan of St Helena outlived Napoleon and still grazes, courting two female tortoises. The anecdote isn’t mere whimsy; it sets a biological precedent for centuries-long vitality. Ariel argues that if a reptile can thrive for almost two centuries, human biology should be stretch-able too, provided we master repair and maintenance.

Patrick connects the image to Aristotle’s envy of long-lived animals, highlighting a millennia-old longing. “If we could all live on beach islands in good health, sort of indefinitely, I certainly would.” The tortoise becomes a living counter-argument to claims that “natural lifespan” caps meaning or joy.

Pleasure, purpose and companionship, not an arbitrary “expiry date”, drive the case for radical longevity

The hosts and guest list simple reasons to stay alive - ice cream, novels, bending inequality, artistic grand projects. Under favorable conditions, Ariel sees no point where people are “finished” with living. The quality-of-life frame recasts longevity as enabling ordinary flourishing rather than elite technocracy. Critics often ask why add decades; Ariel flips the burden: why not, if those decades are rich? He concedes that suffering bodies warrant cessation, but insists suffering is curable, not sacred.

Humanity’s apathy toward aging is a form of “learned helplessness” that stifles research momentum

Drawing from Seligman’s shock-box experiments, Ariel says societies internalize death-inevitability the way lab animals stop escaping opened cages. The result: modest investment in geroscience compared with oncology or cardiology, even though aging underlies them. Cultural scripts - religious or stoic - normalize senescence, muting demand for cures. He cites anesthesia’s 19th-century delay as a cautionary historical parallel.

We lavish resources on late-stage disease care while under-funding root-cause aging science

Globally, end-of-life oncology consumes billions for marginal survival gains, while basic aging biology scraps for grants. Ariel notes the ethical inconsistency: society spares no expense for a dying patient’s extra month but balks at funding interventions that could prevent the terminal cascade years earlier. Peter calls current spending “maligned allocation.” The conversation suggests health-economic models should weigh prevention and biostasis on the same ledger.

Ariel dismisses the phrase “healthy aging,” Patrick’s calling it slow-motion pathology

He brands the term oxymoronic because chronological aging multiplies disease incidence exponentially. Patrick jokingly proposes “the slowest possible age-related disease progression” as a more honest label. Ariel’s critique reframes gerontology: if aging itself is disease, treatments must target the underlying hallmarks, not merely delay frailty.

Fears of over-population, power hoarding and existential boredom are real but solvable trade-offs

Ariel acknowledges demographic, political and psychological objections yet rates them manageable. Over-population can be mitigated via technological carrying-capacity gains; wealth and power can be regulated; meaning can be cultivated through projects that span centuries. “They’re probably not as bad as dying,” he quips.

He labels pro-mortality rhetoric “palliative philosophy,” comparing it to pre-anesthetic justifications for surgical pain

Just as 19th-century surgeons rationalized agony as therapeutic before ether, modern thinkers romanticize death to ease existential dread. Ariel critiques The Lancet commission’s claim that “it is healthy to die” as intellectual anesthetic. Patrick links this to ancient “wise view” arguments; both hosts note how philosophical comfort becomes dangerous when technology renders old limits obsolete.

Note: For more on the wise view argument, check out our very first LEVITY episode, where Patrick was my guest.

As a fallback, terminal patients should have access to whole-brain biostasis that halts decay until cures exist

Ariel proposes medically supervised induction of stasis before irreversible damage. The aim is to preserve the neural substrate until future medicine or mind-uploading can restore function. He frames it as compassionate extension of current ICU practice: we already bridge hearts and lungs with machines; brains deserve parity.

Cryonics has evolved from crude freezing to vitrification and now “vitrifixation” that marries antifreeze with chemical fixation

Early cryonics suffered ice-crystal rupture. Modern vitrification uses cryoprotectants to form glassy solids, yet large organs shrink and dehydrate. Vitrifixation first cross-links tissues, then cools - keeping ultrastructure intact and potentially storable at warmer sub-zero temperatures. Ariel credits labs like Nectome and Tomorrow Biostasis for refining protocols.

Chemical fixation best preserves the connectome—the synaptic wiring that encodes identity

Electron-microscope slices of fixed brains retain clear synapses, unlike the compressed images from pure vitrification. Fixatives halt enzymatic decay rapidly, buying unlimited calendar time for revival science. Critics worry reversal looks harder, but Ariel counters that severe osmotic shrinkage is also hard to reverse; fixation just makes integrity verifiable today.

Psychological continuity, not flesh, defines the self; the connectome is the substrate-neutral blueprint

Neurons turn over their molecular components; only connection patterns persist. Ariel aligns with mainstream “psychological accounts” of identity: memories, preferences and personality matter more than carbon atoms. He distinguishes connectome (physical map) from personality (behavioral profile) but sees them as linked layers of the same phenomenon.

In teleportation thought experiments, Ariel argues each duplicate legitimately continues the original person

If a transporter copies a traveler to Mars while leaving an Earth twin, both branches carry the full psychological history and thus qualify as survival. The Earth branch’s fear of death is subjectively real, yet in third-person view the person persists in at least one world-line. “Either counts for the survival of the individual who stepped into the teleporter.” Critics like Patrick balk, revealing deep intuition gaps.

He reframes death as “information-theoretic” loss of the connectome, noting current brain-death laws lag behind science

Legal criteria hinge on “irreversible” loss of brain function, yet “irreversible” depends on technology level. Hypothalamic activity often persists in ventilated “brain-dead” patients, contradicting statute language. Ariel suggests defining death by when all identity-coding information becomes unrecoverable, not by heartbeats or EEG silence.

The connectome may remain readable for minutes to hours post-circulatory arrest, pressing the need for rapid protocols

Animal studies imply synapses stay morphologically traceable for up to ~36 h, but uncertainty is high. Ariel criticizes cryonics outfits for skipping rigorous ultrastructure audits; viability might demand intervention within 10–15 min of legal death. Faster response teams and pre-planned consent could close the gap.

“This is my criticism of traditional practice, which is I think they have not put enough emphasis into really trying to test whether the connectome of individuals preserved with their practices is still intact and those synapses, those brain connections are still there under the protocols that they have devised.”

At projected costs near $10 k, biostasis beats many end-of-life interventions on quality-adjusted life-year metrics

Chemical fixation omits decades of liquid-nitrogen storage and complex surgery, slashing marginal costs. Using public-health thresholds (~$50–60 k per QALY), even a single extra decade of life makes preservation a bargain. Ariel urges policymakers to apply standard cost-effectiveness calculus instead of moral reflexes.

A 2024 survey of neuroscientists put the odds of fixation preserving identity at ~45 %

Zeleznikow-Johnston polled hundreds of peers; responses spanned “0 %” to “near certain,” but the mean hovered just below coin-flip. Importantly, the modal answer was ≥70 %, hinting optimism among those most familiar with synaptic biology. While far from consensus, the data undermine claims that preservation is fringe pseudoscience.

Ariel forecasts human-grade emulation within decades if AI and compute trends hold, but warns existential risks could void the bet

Fly-brain simulations appeared in 2024; experts peg mouse uploads for the 2040s and human uploads circa 2100. Accelerating hardware or algorithmic leaps could pull timelines forward. Yet nuclear war, runaway AI or societal collapse could erase preserved brains before revival - making existential safety integral to biostasis ethics.

He plans to use Oregon Brain Preservation if stricken young, yet calls for more providers and bench-top validation

Living in Melbourne leaves him vulnerable to logistics delays; he’d fly to the U.S. for a rapid fixation if diagnosed terminally. He applauds Tomorrow Biostasis and Nectome but demands electron-microscope audits and transparent protocols.

The guiding ethic: act so “the future loves you,” allowing descendants to repay ancestral struggles with renewed life

Ariel’s grandparents survived the Holocaust; many others died before enjoying the modern peace their toil enabled. Reanimating preserved ancestors would let posterity share those fruits. The motto “the future loves you” serves as moral heuristic: build societies rich, safe and compassionate enough to welcome the past back home.