The brevity of the human lifespan limits our ability to completely witness or influence the arc of history. This leaves us at the whim of cosmic happenstance. Each generation of humanity interacts with a different face of the same enduring coordination problem, never to fully know it, never to fully solve it: how do we connect the knowledge and wisdom of our distant past, the actions of the present, and our hopeful visions for the far future?

Governance decisions made by leaders of a younger generation do not always carry with them the wisdom of the elders, who have seen and done much in their lives. Decision-makers of older generations, in turn, have an incentive to prioritize short-term interests with little regard for actions that ripple into a future they will never live through. There is no one who has both the experience of a full turn of the wheel of history and remained sufficiently youthful to have enough stake in the future.

The first manned Moon landing was watched live by an estimated 650 million people in 1969. Putting a man on the Moon was the dominant cultural event of the time, and yet today in 2025, our direct connection to that shared experience, along with the Apollo era’s ambitions, has all but vanished. The youngest of those that remember the awe of witnessing the Moon landing in real time are now over sixty years old, and the numbers of those still alive—along with the cultural memory of the Moon landing—are waning.

The cultural memory of a society is valuable because it partially addresses the challenge of preserving humanity’s collective knowledge and experiences and serves as a vital bridge across generations. Our civilization has further intentionally recorded history through written records, a great effort that only buys society a little more time to learn the lessons of past events before even those records crumble or become lost. Writing, and more recently audio and video recording, have their limits. It is one thing to learn about the Moon landing from a documentary and quite another to participate in and be inspired by a culture that aimed not just for the Moon but Mars. These primary sources of cultural memory shape how we perceive and act upon the lessons of history, breaking through the noise to inspire reflection and action. Inevitably, however, these witnesses to critical events are lost to time and both organizations and entire cultures that contain this historical knowledge can forget it.

We as a civilization need the most robust mechanisms possible to carry information, lessons, values, and sentiments forward in time. Perhaps the best possible mechanism is extending the reach of living memory. Might there be a way to preserve not just the records of history, but the agency and immediacy of those who lived it?

A Man For All Seasons

Human hibernation offers a surprising and—on its scientific fundamentals—plausible solution. Rather than relying solely on imperfect archives or the dwindling memories of older generations, imagine if individuals, particularly those with significant knowledge or leadership capabilities, could be preserved in stasis and reanimated in the future. This innovation in medical technology would unlock for humanity vast new reaches in both time and space, allowing us to endure the eons of interstellar travel and the eons of multigenerational projects with the same innovation.

Nature has already proved the feasibility of this approach for us. Facultative hibernators like American black bears use specific environmental stressors to trigger hibernation and can enter hibernation for up to 7.5 months at a metabolic rate that drops as low as one-quarter that of their euthermic (non-hibernating) baseline. During hibernation, they do not eat, drink, urinate, or defecate, and their body temperatures drop by about 7-10 degrees Fahrenheit. Protein and urine are recycled, allowing bears to stave off muscular atrophy. The case for how this might be useful in long-duration spaceflight where air, water, and food recycling systems would be strained practically makes itself.

There is nothing fundamental about human biology that is necessarily incompatible with such a process. Hibernation is a longer and typically seasonal form of what is termed “stasis.” This umbrella term in biology refers to evolved physiological strategies that organisms employ to slow or pause the chemical reactions of life. Torpor, one form of stasis, involves a drastic reduction in physical and metabolic activity as a means to conserve energy during periods of extreme temperature or resource scarcity. Unlike sleep, however, torpor involves substantial drops in body temperature, and individual bouts of torpor can last for weeks or months.

One cycle of hibernation consists of one or more bouts of torpor that, depending on the species, are punctuated by periods of interbout arousals, during which vital signs briefly return to a euthermic baseline. In addition to these changes, mammals also experience marked decreases in heart and respiratory rates, switch to a lipid-based metabolism that consumes stored body fats for energy, suppress hunger and thirst, and activate molecular mechanisms that mitigate damage to genetic material by oxidative stress.

One recently published evolutionary study from German researchers has provided evidence that torpor occurs on a continuum throughout the animal kingdom and has evolved independently multiple times within the Mammalia class, including at least once within the Primate order to which Homo sapiens belongs. The adaptation of torpor has emerged often in recent evolutionary history, is dispersed throughout mammalian species, and is used by our close relative, the fat-tailed dwarf lemur. If such studies hold true, they support the notion that whatever it takes to induce hibernation in a human, it likely does not require a complex genomic change.

Across species, hibernation occurs with significant phenotypic variation. Arctic ground squirrels are obligate hibernators—animals that undergo hibernation seasonally without regard for environmental cues—that hibernate up to nine months of the year, have metabolic rates that drop to just 2% of their euthermic baseline, and have body temperatures that can drop below freezing. This likely cannot be endured by humans without further biotechnological progress or perhaps genetic engineering.

Unlike humans, these squirrels have evolved adaptations to prevent their bodily fluids from freezing and expanding into damaging ice crystals. Unlike the American black bear, Arctic ground squirrels experience interbout arousals during stasis. In spite of how varied their stasis parameters are, American black bears and Arctic ground squirrels both lose approximately 30% of their body mass over their respective stasis periods. The calorie expenditure of waiting for better times is not zero and metabolism continues, albeit at a slowed pace.

Animals such as the deer mouse use daily torpor as a short-term energy conservation strategy during periods of cold temperatures or food scarcity. During daily torpor, which lasts anywhere from 4-12 hours, their body temperature drops by 45-75%, metabolic rate decreases by 30-50%, and heart rate slows by over 80%.

In hibernating animals, the biological processes of transcription and translation of genetic material into proteins are significantly suppressed but not entirely paused as part of an energy-conservation strategy during dormancy. Reduced metabolic activity and lower body temperatures slow enzyme activity, which in turn downregulates the vast majority of gene expression and protein synthesis. While most processes are minimized, essential genes related to stress responses, metabolic adaptations, and cellular protection continue to be transcribed and translated. This selective activity ensures cellular maintenance, energy conservation, and proper preparation of tissues for survival and recovery during arousal periods.

Mammalian hibernators further tend to have significantly longer lifespans than their non-hibernating counterparts. The vesper bat known as Brandt’s bat, for example, can live up to 41 years—nearly ten times its expected lifespan based on its body weight. Other small hibernating mammals, such as gray mouse lemurs and thirteen-lined ground squirrels, also exhibit extended lifespans compared to similarly-sized non-hibernating species like house mice. While reduced predation risk during hibernation may partly explain this gain in longevity, the molecular mechanisms have better explanatory power. These mechanisms, which protect against stressors such as oxidative damage, telomere shortening, and genomic instability, appear to have coevolved with processes that promote longevity and mitigate cellular aging. For human beings, such added longevity would grant individuals waking, active, and healthy years in a distant future beyond the reach of even the most long-lived humans today.

The State of the Art in Humans

With respect to the research, where are we now? Closer than you might think. Prominent hibernation scholars and cryobiologists like Kenneth and Janet Storey, Brian Barnes, and Thomas Ruf have already laid the groundwork for subsequent scholars to begin betting on the translation of hibernation into humans. And the first important step in this process of developing the technology is already underway: to make use of the latest genetic, imaging, and computational tools to understand and activate the mechanisms of torpor and hibernation, including induction, maintenance, and arousal.

In 2020, a research paper out of Michael Greenberg’s laboratory at Harvard pointed to a specific population of neurons that regulate mouse torpor by using a combination of whole-brain imaging and machine learning-enabled mapping, as well as highly specific chemogenetic activation in transgenic mice. One of the study leads, Siniša Hrvatin, now runs his own laboratory at MIT, where his team is unraveling the mechanisms of torpor and hibernation. His research focuses on how the brains of animals that undergo torpor and hibernation regulate these states of stasis, how cells and genomes of different organisms adapt to this physiological stressor, and how such technology can slow down tissue damage, disease progress, and aging with a goal to explore potential applications of inducing similar states of suspended animation in humans. Recently, Hrvatin’s team used a multi-species CRISPR screen to identify conserved suppressors of cold-induced cell death, an integral piece of the hibernation puzzle.

Three years later, a team led by Hong Chen at Washington University in St. Louis developed a non-invasive method to safely induce a torpor-like state in rodents. Using focused ultrasound on the preoptic area of the hypothalamus, they were able to trigger this state and maintain it for over 24 hours using automated feedback to control body temperature. This process works by activating a certain population of neurons to reduce heat production in the body. While the use of ultrasound as a non-invasive inducer of a torpor-like state was already a breakthrough for the field, the researchers also demonstrated this technology works in rats, a non-torpid animal. Perhaps with certain mammals, the ability to induce hibernation may not even be substrate-dependent.

Also at the forefront of mechanistic hibernation research is a husband-wife team of Yale researchers Slav Bagriantsev and Elena Gracheva. Last year, a collaboration between their laboratories led by Madeleine Junkins recently yielded a paper describing the mechanisms of fluid homeostasis in hibernators. In it, they observed a notable capacity of evolutionarily conserved brain regions to enable long-term survival without water. That the neural circuitry of fluid control is not so different between mammals is especially promising for translational research in promoting human survival without a typical circulation of fluids.

The shift in the field’s research methods from wildlife observation and basic laboratory studies to neuronal population-level intervention and cybernetic control of homeostasis in the last five years shows that research in hibernation has matured into a serious and rigorous undertaking worthy of more investment.

Beyond university laboratories, industrial and non-academic organizations have also been playing a critical role in realizing human hibernation by mobilizing capital, prototyping prerequisite technologies, and encouraging cultural buy-in. Long before hibernation research began to mature, the long-term cryopreservation of humans was championed by the cryonics movement, which backed the controversial practice of freezing human remains in the hope of later revival.

Despite allegations of pseudoscience, the movement gained enough support and formed various organizations, including the Alcor Society for Solid State Hypothermia. Founded in the 1970s, the non-profit, which now goes by the name Alcor Life Extension Foundation, has experimented in cryopreservation, refining techniques like vitrification to preserve human tissues at ultra-low temperatures. Alcor, valued at over $10 million last year, has cryopreserved nearly 250 patients following legal death and has a waiting list of over 1400 people who have completed legal and financial arrangements to be cryopreserved. While many cryobiologists have expressed doubts about their methods, Alcor is an early example of the broader ambition to extend biological viability over long periods of time, offering insights into preserving human physiology that can be used to inform hibernation technologies.

Human Hibernation in Deepest Space

SpaceWorks Enterprises, a company founded in 2000, has been exploring the viability of hibernation for long-duration space missions. In 2016, the team released a white paper outlining the design of hibernation pods for spaceflight, utilizing therapeutic hypothermia to place astronauts in a torpor-like state. This approach not only aims to reduce metabolic demands and life support requirements, but also lowers mission costs by decreasing the need for consumables—not to mention the alleviation of the mental and psychological tolls of long periods of isolated space travel for astronauts.

To better illustrate this benefit, let us do some back-of-the-envelope calculations for a Martian flyby. Spaceflight constraints limit each astronaut to 3.8 pounds of food, translating to 983 pounds of food per person for the 259-day trip to Mars—nearly 2 tons of food per crew member for a round trip. While NASA’s 98% water recovery milestone reduces some strain on the water requirement, the sheer weight and volume of food, water, and related life support systems makes transporting these resources expensive and logistically demanding. However, if astronauts entered a torpor-like state with just a 10°F drop in body temperature, this would, in humans, translate to a 50-70% reduction in metabolic rate. Food and water needs could drop to as little as 30-50% of normal levels with the help of hibernation.

In June 2024, another company called Cradle, founded by Laura Deming and Hunter Davis, emerged from stealth having raised $48 million to build reversible cryotechnology. The series A funding round demonstrates a willingness by investors to explore this space for opportunities. In this announcement, the company also broadcasted achieving a major objective in the field: measuring robust electrical activity from cryopreserved and rewarmed rodent neural tissue. The company claims whole-body human cryopreservation is a solvable problem with clear next steps. Indeed, Deming has written: “Think the hibernation pods you see in space movies for long-term travel – we want to build that.”

Those hibernation pods might well prove necessary. While it is still possible to make a round trip to and from Mars without human hibernation, the technology could save hundreds of pounds of consumables per astronaut, significantly reducing payload mass, launch costs, and system complexity. Program directors could allocate any freed-up weight and volume for scientific equipment or colony infrastructure.

Deep space exploration beyond the Martian orbit, however, may just make the maturation of human hibernation technology an absolute necessity. Resource considerations aside, decades of astronaut data have shown that spaceflight exacts a heavy toll on the human body. Some of the most significant physiological challenges—cellular damage from increased radiation exposure, muscle and bone atrophy from decreased activity, and the psychological strain of living in a confined space for prolonged periods—could potentially be alleviated through hibernation.

Among others, Dr. Yuri Griko, a NASA scientist, has been advocating for human hibernation as a biomedical countermeasure to mitigate the deleterious effects of spaceflight for over a decade through a number of white papers, presentations, and technical studies. In one such study, Griko was part of a team that showed that hypothermia, a core feature of hibernation, can significantly reduce radiation-induced DNA damage and oxidative stress in irradiated rats’ organs.

A Prudent Way to Govern the Future

Hibernation presents us with the option of extended but discontinuous lifespans. Turning this clever natural adaptation into a technology at humanity’s disposal would be a triumph against myopic folly, disease, and the unforgiving emptiness of space that lies between here and our cosmic endowment.Progress in translational hibernation research will unfold at a comparatively slower pace than will, for example, the development of artificial intelligence or computer hardware innovation, simply due to the slower iteration cycles of fundamental biology and biomedical engineering. But steady progress has been made for many years, and the technology is maturing. It is also important to remember that innovation in rocketry seemed stalled for decades until it found a new institutional footing in SpaceX. Perhaps agentic live players in academia, industry, and government can, under a focused vision, turn human hibernation into a reality.

Challenges to developing human hibernation as an earnest scientific and engineering endeavor will be formidable—regulatory hurdles, such as those posed by the U.S. Food and Drug Administration (FDA), and the inherent risks of early trials, including potential fatalities, will test the resilience of the field. For space exploration applications, the roadmap is clear: continue experiments in torpid and non-torpid animals, translate the research to the macaque, and, when we are prepared and confident, initiate the first human trials.

This future technology ironically connects us with our past in a completely new way. It will enable the preservation of cultural memory of any given era going forward and embody cultural memory in youthful awakened individuals who retain both the biological vitality and the “skin in the game” to engage future challenges under the right incentives. By transcending generational divides, human hibernation could infuse cultural memory with dynamism, ensuring the continuity of knowledge, values, and leadership for long-term human endeavors. The use of hibernation would ward off institutional senescence, improve coordination, and facilitate knowledge transfer down generations.

If realized, human hibernation would undoubtedly disrupt the equilibrium of society more dramatically than any prior technological innovation. Our existing notions of agency, rights, health care, social relations, and intergenerational responsibility will have to change. What rights would a hibernating individual retain? Under what conditions should they be awakened? What happens to family ties and community relations? Is it ethical to preserve someone with a terminal illness indefinitely until a cure is found? Given the technology, an institution with a particularly timeless mission and keen foresight might elect to place a volunteer representative into hibernation and awaken them at regular intervals in the future to realign the institution with the original founders’ vision. Such representatives should be understood as diplomats from the past—each would be asked to sacrifice familiarity and social ties in exchange for serving a deeply meaningful cause and the chance to experience what is hopefully a brighter future with each subsequent awakening. Or perhaps they are a family’s advisor seeing and meeting their distant descendants. The practice of consulting ancestors, a practice seen in cultures as different as classical Rome, Medieval China, or Victorian Britain, might, for the first time, become eminently practical and feasible.

Like today’s ambassadors, institutions should vet them for trustworthiness, loyalty, independence, and competence. Institutions would also need to establish protocols to ensure that these diplomats would be respected, listened to with sincerity, and properly assimilated into a new environment. To coordinate across decades and get diplomats up to speed, secure archives and messages from former colleagues would be made available. The duty of each diplomat, then, would hold immense gravitas—to infuse forgotten yet foundational cultural memory into the future as both a living, breathing tradition of knowledge and a reminder to our descendants that we had their best interests at heart.

This is not to say that such social innovations will automatically work as well as we might hope. Used as punishment, hibernation could be a cruel and unusual exile to the future; as an act of memetic preservation, it might lock in anachronistic ideology, stifling progress. They challenge us to find ways for progress to become dynamic and generationally inclusive. Human hibernation could risk embedding outdated paradigms at the expense of future innovation, but it also promises a way to infuse perspectives unbiased by the prevailing currents of a particular era and to unite in dialogue the greatest minds of history at crucial moments. No one today has answers to all the questions raised by technology. We will answer them one way or another with time, since we can only avoid reaching the once-distant future for so long.