NewStats: 3,264,365 , 8,183,481 topics. Date: Tuesday, 10 June 2025 at 06:43 PM 6m583i

Geologist who accidentally discovered humans have an 'internal clock' by spending 63 days underground

Michel Siffre from the Sorbonne spent 63 days in a dark and icy cave, cut off from clocks, sunlight, and conversation. When he emerged in a disoriented fog, he realized that his perception of time had unraveled way more than he had expected.

The curious results from his subterranean stay turned into a whole new chapter in the study of chronobiology, which examines how living creatures keep time within their bodies.

Michel found himself at the center of a movement that would later connect to everything from jet lag to space travel.

A surprising pursuit
In 1963, Siffre planned to stay underground for 15 days to study a glacier.

He soon realized that this time would not be enough, so he decided to push past normal limits and live beneath the surface for more than two months, relying on basic supplies and no timekeeping devices.

“You have to understand, I was a geologist by training,” said Siffre. He stripped away external markers of day and night, and was content to note his daily activities while losing track of how the outside world ticked along.

Unlocking an internal clock
His most astonishing takeaway was that people have a personal timer that keeps ticking.

Separated from sunrise, standard schedules, and everyday routines, he uncovered an internal clock that slowly drifted beyond the standard 24-hour day.

“Without knowing it, I […] created the field of human chronobiology,” explained Siffre. Free from external prompts, his circadian rhythm slid into a longer pattern, suggesting that our bodies don’t always stick to the planet’s day-night spin.

The body’s clock works differently in isolation
Other people who followed Siffre’s method – and sometimes worked alongside him – saw similar results. Their sleep-wake cycles bent and stretched, sometimes reaching absurd lengths, including instances of 33 hours of sleep and 72 hours of wakefulness.

One subject even wore a microphone, prompting panic when he didn’t stir for more than a day. Researchers initially feared he had died.

These unpredictable shifts proved that the body’s timing system operates independently and erratically when left to its own devices.

Unexpected interest in internal clock findings
The Cold War era was in full swing, and NASA wanted to understand how astronauts might cope with time shifts away from Earth’s regular day.

Military programs also became curious about best practices for submariners, who spent lengthy intervals away from natural light.

Research teams observed that these extended hours of wakefulness and rest could pose unique challenges, and arrived swiftly to probe deeper into what happens when people are removed from typical time cues. NASA’s backing highlighted the immediate value of Siffre’s discoveries.

Relevance in modern science
Today, scientists continue exploring how disrupted sleep patterns can throw off hormone levels, mood, and even immune function.

Shift workers benefit from an understanding of these natural cycles, and knowledge gleaned from cave experiments helps guide strategies to minimize fatigue.

Some experts also link out-of-sync body clocks with heightened health risks.

The 2017 Nobel Prize recognized further breakthroughs on the genetics behind internal clocks, also known as circadian cycles. This gave a nod to the foundations laid by bold adventurers like Siffre.

Criticism and caution
From day one, his work stirred a lot of chatter. Some observers argued that his approach seemed reckless or theatrical, while others worried that placing people in such extreme isolation might bring undue stress.

Questions were also raised about the potential effect of human presence on delicate underground life.

Still, the push to clarify how biology maintains time overshadowed those doubts, and Siffre’s name became associated with gritty persistence and unexpected scientific impact.

Siffre’s legacy of timing
His method won ers who saw its practical side. There was particular excitement over data on how the body adapts when divorced from external time prompts.

This offered a window into biological machinery that touches nearly every corner of health and performance.

He showed that patterns of rest and activity can stray far from the familiar 24-hour day.

More importantly, he demonstrated how resilient people can be when conventional signals are stripped away, sparking conversations among physiologists, psychologists, and government agencies alike.

Reflections on exploration
Siffre’s work revealed that stepping away from clocks goes beyond missing a few appointments. It underscored how powerfully our inner timer enforces its own schedule, even when we don’t realize what’s happening.

These revelations opened the door to studies on how rhythms shift during space missions or across hectic flight schedules.

They offered practical solutions to reduce the strain of unusual work shifts, prevent mental fog, and potentially lower disease risks.

He never expected a geological side-trip to ignite a deeper understanding of how the human system handles time.

But the power of curiosity – and a willingness to live alone in absolute darkness – proved that we can learn much by trading daylight for the faint glow of a single lamp.

https://www.earth.com/news/geologist-who-accidentally-discovered-humans-have-an-internal-clock-by-spending-63-days-underground/

33 hours of sleep? Person go get up go pee at least? Ordinary staying up for 13 hours, everywhere don begin dey do me like person wey dey intoxicated. The thought of staying awake for 72 hours straight is a nightmarish thought for me.

Which brand of clock? Balderdash!

The person above me na wicked person

Really?

Morbeta11:

https://www.earth.com/news/geologist-who-accidentally-discovered-humans-have-an-internal-clock-by-spending-63-days-underground/

Kobojunkie:
33 hours of sleep? Person go wey up go pee at least?

So amazing.

Let me peach here first 😁

Hmmmm

I see Nigerians selling their clock so they can have something to survive on in this economy.

I see China opening a human clock factory across Africa to buy clocks in people. I see yahoo boys taking advantage of the business to scam innocent people by collecting their clocks and not paying them.

I see kidnappers kidnapping people for the sole purpose of selling their clocks to the Chinese. I see Nigeria becoming more dangerous.

This I have seen.

Does it demystify body count and unexplained complicated DNA tests of children from hookupers after marriage?

Self imprisonment...

Really?

Wow !

Lol

The circadian rhythm is vital for the human body.

If the sleep-wake cycle is out of sync, it can damage the body.
It means the central clock in the suprachiasmatic nucleus, controlled in the brain's hypothalamus, is messed up.

For example, people whose sleep pattern is disrupted over years by shift work are at risk.

Body weight increase, HBP, diabetes, insomnia and a whole lot.

Even though sunlight is a vital cue, the body does retain the clock for a long time, even in total darkness.

Awesome

Lamba

I read this piece and all I can say is that God is awesome.

Bro, sis, no need to argue about end time.

Time ticks.....

Tick. Tock.......and then death comes....

What happens next?

Eternity !!!!!

Then decision making will be too late.

Make sure you are convinced beyond sentiments and hearsay....

Find the truth...your eternity depends on it.

I am certain of eternal rest.

You?

Lanifo:

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I've forwarded this your details with screenshot to the official EFCC correspondence. May y'all thieves (scammers) be jailed and rot in the deepest part of Nigerian prison.

FalseProphet1:
I see Nigerians selling their clock so they can have something to survive on in this economy.

I see China opening a human clock factory across Africa to buy clocks in people. I see yahoo boys taking advantage of the business to scam innocent people by collecting their clocks and not paying them.

I see kidnappers kidnapping people for the sole purpose of selling their clocks to the Chinese. I see Nigeria becoming more dangerous.

This I have seen.

I see you being sold in exchange for clock 🕰️

Our circadian rhythms are affected by environment as well.

thesicilian:
Which brand of clock? Balderdash!

You read all of that and this is all your brain could contribute?

Dancebreaker:
The circadian rhythm is vital for the human body.

If the sleep-wake cycle is out of sync, it can damage the body.
It means the central clock in the suprachiasmatic nucleus, controlled in the brain is messed up.

For example, people whose sleep pattern is disrupted over years by shift work are at risk.

Body weight increase, HBP, diabetes, insomnia and a whole lot.

Even though sunlight is a vital cue, the body does retain the clock for a long time, even in total darkness.

The existence or invention of circadian rhythm in the actual sense reduces life span as you are structuring your system to react to a particular pattern (Unnatural/anti-science)
Any normal human being should sleep at anytime or work at anytime.

Our forefathers would farm or hunt(at their convenience) for few hours, trek back or use the bicycle to their huts, sleep for several hours, wake, and have mind blowing sex with wife/wives.

In igbo land, there were very familiar responses whenever you did visit a particular household like; "nna anyi na ehi ura" meaning "our father is sleeping".

Most people think, sleeping too much is sedentary.. or risk factor for HBP or body weight increase. Sedentary life style is more of psychological (not engaging your brain with a group) eg. If a man sits in front of his house every morning and discusses the news on the dailies with neighbors, it isn't sedentary.

But what the agendist will never tell you is ; the tiniest of stressors will kill you faster in a long run

Ok

I'm surprised this wasn't already known before hand

Morbeta11:

https://www.earth.com/news/geologist-who-accidentally-discovered-humans-have-an-internal-clock-by-spending-63-days-underground/

I no believe. How Dem take know the time 15min then 2 months den staying wake 4 72hrs den Dem talk say Dem no use human time. Story no add up abeg

The circadian rhythm is real, that's why we hear the word jet lag.
Your body has an internal clock.

I read half of the story and yet I don't still grab the news.

I just tire.

nwirinedu:
The circadian rhythm is real, that's why we hear the word jet lag.
Your body has an internal clock.

You have jet lag because you structured your system to the Unnatural concept of circadian rhythm.


If you sleep and work at anytime in your small village, wetin concern you with jet lag ?

ReacherSaidNoth:
You read all of that and this is all your brain could contribute?

If you actually read through and understood like I did you'd know there's no substance to it.