11 Science Facts We're Having A Hard Time Wrapping Our Heads Around

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Vote up the science facts that bend your brain.

Biology, chemistry, physics, and other natural sciences are part of our educations from a young age. Whether we remember much of what we learn in classrooms can be hit or miss, but generally, there are always some science facts we know. Alongside the details that seem obvious, we're pretty science-savvy.

Or so we thought.

It turns out there are scientific facts that upend what we thought we knew, as well as some truly unexpected things we weren't ready to hear. Simply put, a lot of science has our minds all twisted into knots. We're having a hard time wrapping our heads around these scientific facts - how about you?


  • Humans Have More Than 42 Billion Miles Of DNA In Their Bodies
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    Humans Have More Than 42 Billion Miles Of DNA In Their Bodies

    The human body contains, according to estimates, 37.2 trillion cells. The uncoiled DNA from each cell would span about 6 1/2 feet (or two meters), which amounts to a little more than 223 trillion feet of DNA.

    With 5,280 feet in a mile, this calculates to 42,234,848,485 miles. That means there's enough DNA in the body to extend to Pluto from Earth and back about six times (if you average the closest and farthest distances between the two entities, given their elliptical orbits around the sun.

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    Fingers And Toes Don't Get Wrinkly From Absorbing Water; It's A Nerve Reflex

    If you step out of the bathtub or swimming pool, you may notice your fingers and toes look like they've shriveled up thanks to water absorption. In fact, wrinkled skin when you're fresh from the water results from the nervous system constricting blood vessels - something that happens involuntarily.

    Researchers believe the body does this to facilitate holding onto things when it's wet. Evolutionary biologist Tom Smulders explained:

    We have shown that wrinkled fingers give a better grip in wet conditions - it could be working like treads on your car tires, which allow more of the tire to be in contact with the road and gives you a better grip.

    Individuals with nerve damage don't have the same wrinkled fingers, and evolutionary neurobiologist Mark Changizi notes, "At this point, we just don't know who has them, besides [humans] and macaques."

  • Anesthesia Doesn't Necessarily Numb Pain; It May Just Make You Forget It
    Photo: Loughlin (Sgt), No 2 Army Film & Photographic Unit / Wikimedia Commons / Public domain
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    Anesthesia Doesn't Necessarily Numb Pain; It May Just Make You Forget It

    There are different types of anesthesia, notably local, regional, conscious sedation, and general. Local anesthesia numbs a small area of the body, while regional anesthesia takes the feeling out of larger areas like limbs. Conscious sedation, administered intravenously, is a milder way to bring on a sleep-like state, while general anesthesia causes a complete loss of consciousness.

    A common belief about conscious sedation and general anesthesia is that a person (or other animal) doesn't feel pain, but this has proved to be less than clear. When anesthesiologist Ian Russell administered sleep-inducing drugs to patients in 1993, he also monitored any signs that they were aware of what was happening to them. Instructions delivered via headphones telling unconscious patients to squeeze the doctor's hand if they felt pain resulted in 20 of his 32 individuals doing just that.

    When Russell asked the patients about it immediately after they regained consciousness, they had no memory of pain. Some of them developed vague recall after a few days, prompting Russell to conclude:

    If the aim of general anesthesia is to ensure that a patient has no recognizable conscious recall of surgery, and views the perioperative period [during the surgery] as a “positive” experience, then... [this regimen] may fulfill that requirement. However, the definition of general anesthesia would normally include unconsciousness and freedom from pain during surgery - factors not guaranteed by this technique. 

    Changes to the drugs used in anesthesia, as well as how they are administered, have been implemented to try to combat the experience of pain. According to Dr. Howard Nash from the National Institutes of Health, "general anesthesia looks more like a coma - a reversible coma" during which individuals lose the ability to feel pain. Despite this, however, scientists can't say for certain that patients experience no pain while under anesthesia. 

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    Venus And Uranus Are The Only Planets In The Solar System That Rotate Clockwise

    All planets in the solar system rotate around the sun in the same direction, and with the exception of Venus and Uranus, rotate on their axes in the same direction, too. Venus stands alone in how it spins on its axis, going clockwise - east to west - in contrast to other planets. Uranus tips so far on its axis that it spins on its side, but is also considered a clockwise spinner.

    Scientists have no explanation as to why Venus and Uranus are distinct, but it's widely believed both planets spun counterclockwise at some point. Theories about Uranus include a massive impact that toppled it, so to speak; mini-collisions over a long period of time; or a problematic ring system that made the planet wobble.

    Venus may have slowed to such a degree at one point that it essentially stopped, and then started spinning clockwise. The slow speed of its rotations makes for days that are longer than years on the planet. It's also possible Venus flipped 180 degrees on its axis and never changed directions at all.

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    Polar Bears Can Be Practically Undetectable By Infrared Cameras

    Because they live in such cold climates, polar bears have layers of blubber and fur to keep in body heat. This protects them and allows them to survive even the harshest of conditions, but there's an unexpected consequence: they're nearly invisible - or at least incredibly difficult to detect - using infrared cameras.

    While the extent of their undetectability is debated, there are concerns about ineffective infrared cameras. The use of these cameras to find polar bears in their dens without disturbing them is one way for researchers to survey and keep track of polar bear populations. Considering they are white as well, which makes detecting them in snowy settings challenging, the bears are doubly equipped to stay relatively hidden in plain sight, given the right circumstances. 

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    There Are More Trees On Earth Than Stars In The Milky Way Galaxy

    Because, as Ithaca College professor David Kornreich put it, "you can't just sit around and count stars, generally, in a galaxy," astronomers estimate the Milky Way is home to between 100 and 400 billion stars. 

    In 2015, estimates put the number of trees on Earth at more than 3 trillion, although the number continues to decline. Previously, scientists believed there were only about 400 billion trees here. It should be noted that each year, the planet loses about 15 billion trees to various circumstances.

    As a follow-up to number counts on trees, in 2022 researchers announced that more than 73,000 estimated species of trees live on the planet, 14% more than previously believed. More than 9,000 of them have yet to be discovered, however.