Can silence drive us mad? This question arises from a unique room in Minneapolis, where visitors report eerie sensations and disorientation due to its profound silence. They often hear faint ringing in their ears, and so far, no one has lasted more than 45 minutes.

Holding the Guinness World Record for the quietest place on Earth, the anechoic test chamber at Orfield Laboratories has a background noise level of -24.9 decibels. The human audible range is from zero to 120 decibels, so a sound of negative decibels is inaudible by humans.

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An anechoic chamber, meaning “no echo,” achieves profound silence through its design. Fiberglass wedges coat the walls, floors, and ceilings, absorbing any internal sounds, while thick layers of brick and steel reinforce the soundproofing. This meticulous design guarantees complete isolation from external noise.

The maximum someone has stayed inside this chamber is 45 minutes. The room is so quiet that a person inside it will hear their heartbeats, even the sounds of their organs, Steven Orfield, the lab’s founder, told Hearing Aid Know. “We challenge people to sit in the chamber in the dark – one person stayed in there for 45 minutes. When it’s quiet, ears will adapt. The quieter the room, the more things you hear,” he said, adding, “In the anechoic chamber, you become the sound.”

But the room isn’t designed for the sake of distressing or tormenting people. NASA regularly sends astronauts here to help them practice adaptability to the silence of space. Many people also visit the room to meditate, Orfield told CBS.

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Yet, for most people, the room offers an eerie and unsettling experience, as it can disrupt one’s sense of balance and orientation. “How you orient yourself is through sounds you hear when you walk. In the anechoic chamber, you don’t have any cues,” Orfield said. “You take away the perceptual cues that allow you to balance and maneuver. If you’re in there for half an hour, you have to be in a chair.”

Like Orfield Laboratories, the Microsoft headquarters in Redmond, Washington is also an anechoic place. It is the previous Guinness World Record holder for being the “quietest place on earth.” The room is designed in an onion-like structure that isolates it from the rest of the building and the outside world. Here too, people cannot stand the silence for too long, not more than 55 minutes to be precise.

Explaining to CNN, Hundraj Gopal at Microsoft said that in the real world, our ears are constantly subject to some level of sound, so there is always some air pressure present on the ear drums. But when someone enters the anechoic room, this air pressure zips away due to the total absence of sound reflections. In a room like this, there is no interference of noise.

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Ideally, silence is intended to pacify and soothe; however, its unsettling effect in these rooms is both uncanny and intriguing. For centuries, philosophers and poets have written that “silence is not empty,” and these anechoic rooms seem to provide evidence of this.

This article originally appeared last year.

  • Spanish zoo study suggests that giraffes can do basic math
    Photo credit: CanvaA study is showing giraffes could be using math.
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    Spanish zoo study suggests that giraffes can do basic math

    These hoofed mammals can understand addition.

    The results of an experiment done in a Barcelona zoo suggest that giraffes are capable of doing basic mathematics.

    A group of researchers from the University of Leipzig, the Max Planck Institute for Evolutionary Anthropology, and the University of Barcelona published their study observing four giraffes at the Barcelona Zoo. The experiment involved the giraffes observing containers that had different amounts of carrot pieces inside.

    How did this experiment work?

    The researchers showed each giraffe the two yellow containers and the amount of carrots within each one. After a few seconds, they closed the containers, keeping the carrots out of sight. They then showed each giraffe a green container which had extra carrots inside. Researchers took the carrot pieces from the green container and placed them into one of the closed yellow containers. They then let each giraffe independently choose which of the two closed yellow containers they preferred, without them seeing the total number of carrot pieces within each box.

    The results found the giraffes would choose the container that had the most carrot pieces around 68% of the time. This suggests to the scientists that the giraffes were mentally adding the carrots up in each container before making their choice. After all, there have been past studies suggesting that other hoofed mammals, such as horses, had similar capability of basic quantity tracking.

    The researchers did the experiment again. Only this time they subtracted the amount of carrots in each container. The giraffes were mostly unsuccessful at finding the container with the most pieces. So while giraffes showed signs of knowing addition, they don’t quite process all forms of arithmetic.

    Math = Survival

    Scientists believe that this understanding of addition helped giraffes survive in the wild. They cite that acacia trees, a dietary staple for wild giraffes, can be spread far apart in Africa. Being able to figure out which area has the most trees and the most leaves can help them decide where to graze next.

    Giraffes also live in flexible groups that often change in size. One grouping can mix in with another group and then branch off or away. This means that the giraffes often have to keep track of those currently within their group and surroundings to survive.

    Can other animals do math?

    Giraffes are just the latest animal species known to have some form of mathematical skill. Chimpanzees displayed similar abilities to count as giraffes in a similar experiment that involved them picking the bowl with the most chocolate pieces rather than carrots. Chickens and black bears also showed aptitude in quantity tracking, too. 

    Scientists theorize that most of the animals that can do this basic math through evolutionary survival. After all, the animal that can deduce where more food is tends to live longer.

    One species that displays remarkable mathematical ability are Tunisian desert ants. An observation of their navigational skills of finding their way to food and back to their nest suggests they use the sun as a compass in combination with mentally keeping track of the number of steps they take in a three-dimensional space. In short, these desert ants possess basic geometric and trigonometry skills.

    While you wouldn’t want wild animals to calculate your taxes, it’s interesting to see how rudimentary math is a language that goes beyond species.

  • A bonobo’s make-believe tea party has scientists rethinking whether imagination belongs only to humans
    Photo credit: CanvaAn adorable baby bonobo.

    Childhood activities like playing house, superheroes and villains, the floor is lava, and the classic tea party all involve imagination. We create stories and worlds with rules and roles to play.

    Humans want to believe that our creativity and art make us unique. But a bonobo named Kanzi was part of research that has scientists wondering how different we really are. In three evolving experiments, Kanzi correctly identified pretend objects, demonstrating that he could understand and engage in make-believe situations.

    primate research, behavior, bonobo study
    Kanzi associates words and symbols with Sue Savage-Rumbaugh.
    Photo by William H. Calvin, Phd/ Wikimedia Commons (Cropped)

    Kanzi has a make-believe tea party

    Researchers developed a simple setup using cups, a pitcher, and actions that began as real pouring and gradually shifted into pretend play. The first experiment used real liquids. The second had a combination of real and pretend liquids. The final scenario had no real liquids and relied entirely on imagination.

    The scientists used gestures and make-believe to see if Kanzi would react differently depending on what he was being shown. He didn’t react the same way in each setup. His responses showed he was paying attention to more than just the objects, but also to the way the situation was presented.

    bonobo play, animal imagination, Kanzi bonobo, apes
    Kanzi participates in an indoor test.
    Photo by William H. Calvin, Phd/ Wikimedia Commons (Cropped)

    Animals engaging in fantasy

    The experiment revealed that non-human animals can understand and follow along with imaginary situations.

    “[It] shows that animals are capable of understanding pretence in a controlled experimental setting, which hadn’t been done before,” Dr. Amalia Bastos, first author of the research from the University of St Andrews, told The Guardian.

    Scientists involved in the research are careful about how they describe it. They don’t treat it as proof that bonobos imagine things the same way humans do. Instead, they suggest that animals are capable of responding to situations where meaning is implied rather than directly shown.

    Why scientists care about pretend play

    Albert Einstein, one of the greatest scientific minds in history, is often credited with the idea that logic gets you from A to B, but imagination can take you everywhere. This study suggests that the more we learn about animals, the more it seems the difference between us may not be as great as we once thought.

    Developmental research credits early social and cognitive growth in human children to imagining situations that aren’t physically present. A 2024 meta-analysis found that make-believe is not just entertainment but also directly linked to social understanding and real-world interpretation.

    Researchers now describe animal play as more flexible than once believed. A 2025 study of ravens revealed that play included the manipulation of sticks, stones, and other items, suggesting social awareness and responsiveness to context rather than simple instinctive behavior.

    Play and imagination may be versatile behaviors no longer seen as uniquely human traits. A broader cognitive toolkit shared across multiple species suggests the gap between humans and animals may be smaller than it once seemed. Things we’ve long believed to be uniquely human may instead exist along a spectrum of abilities expressed in different ways.

  • Humans nearly vanished 800,000 years ago, revealing a quiet truth: most family lines disappear
    Photo credit: CanvaA group of people hiking in the mountains.

    There was a moment in human history when our entire existence may have desperately clung to a thousand or so people. A DNA-based study found that between 800,000 and 900,000 years ago, our ancestors experienced a severe population crash.

    This wasn’t humans dealing with a giant meteor like the one that wiped out the dinosaurs. It was a much slower stretch during which humanity teetered on the brink of disappearing completely. This bottleneck in the human gene pool, comprising roughly 1,280 breeding individuals, lasted about 117,000 years.

    population, genomes, Ice Age, Early-Middle Pleistocene
    Removing representation of a human population group.
    Photo credit: Canva

    Human population levels plummet

    According to Scientific American, the study analyzed modern human genomes to piece together what the early human population looked like. By constructing a complex family tree of genes from present-day humans, researchers were able to identify important evolutionary events.

    During the Early-Middle Pleistocene, a period within the Ice Age, humans faced severe weather and intense glacial cycles. Most human ancestors may have died out, clearing the path for a new human species to take their place.

    Focusing on Africa, the study showed that 813,000 years ago, human populations began to recover and grow again. With an estimated two-thirds of genetic diversity potentially lost, traits like brain size appear to have been among the important features that survived. “It represents a key period of time during the evolution of humans,” population geneticist and study co-author Ziqian Hao said. “So there are many important questions to be answered.”

    DNA, genomes sequence, human existence, heredity
    DNA genome sequences.
    Photo credit: Canva

    Understanding evolution and ancestry

    What we know about evolution reveals a different story than a simple, continuous line of human improvement. Over time, genetic lines disappear—not dramatically all at once. It’s a slow and steady change, generation after generation.

    Human existence isn’t inevitable. Species strength or technical advancement doesn’t guarantee the future or explain our past. It’s contingent on narrow, accidental circumstances. A 2021 study showed that human evolution is better seen as a continuous flow of incremental fragments over time. Categorizing people into races and groups oversimplifies human history.

    species strength, evolutionary improvement, genetic lines, technical advancement
    A diverse group of wooden figures.
    Photo credit: Canva

    What does the bottleneck study say about us?

    The study reveals humanity didn’t simply decline; it nearly collapsed. With over 98% of our genetic diversity erased, entire branches of the human family tree permanently ceased to exist.

    It’s quite possible that if even a few more of those genetic lines had ended, human history could have vanished with them. Most branches of life don’t continue. What we witness today reflects biological persistence and countless moments that could have gone another way.

    A 2024 study conducted five billion simulations, revealing that as a species’ population shrinks, its risk of extinction rises. Even stable groups can quickly collapse if their numbers suddenly drop low enough.

    A 2025 study found that small populations erode genetic diversity. Isolation increases inbreeding and elevates the risk of extinction. Once a lineage shrinks, recovery becomes vastly more challenging over time. Long-term survival is an exception, not the guiding rule.

    Humanity likes to think of itself as the result of an incredibly unique progression. Perhaps studies like these suggest that we are actually what remains when everything else disappears. The reason any of us live today comes down to a small group of ancient outlasters: persevering individuals whose genetic lines are the building blocks of every human living today.

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