• UltraGiGaGigantic@lemmy.ml
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    1 hour ago

    What follows is a guide on how to hurt your hand. No not do it. Do not “do it just a little bit”. I actually strained my hand when I first discoverd this and honestly dont want anyone hurt because of my comment:

    dont do this

    If you wrap your fingers around your thumb (like a closed fist with your thumb on the inside and pull the thumb down you can hurt your hand.

  • Akasazh@lemmy.world
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    7 hours ago

    The origin of the name ‘Amerigo’ Vespucci is ‘Emmerich’ in German. So the namesake of a contintent is a very demure provincial city close to the German/Dutch border.

  • Salamander@mander.xyz
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    14 hours ago

    If you catch a frog in between your hands and quickly flip it around, you can get the frog into a kind of paralyzed state called ‘tonic immobility’.

    Here is a photo from Wikipedia:

    Frog stuck in tonic immobility

    OK, well, many years ago I was very interested in this phenomenon and decided to look into the literature.

    I found a paper from 1928 titled “On The Mechanism of Tonic Immobility in Vertebrates” written by Hudson Hoagland (PDF link).

    In this paper, the author describes contraptions he used to analyze the small movement (or lack of movement) in animals while in this state. They look kind of like torture devices:

    OK, but, that’s still not it… The obscure fact is found in the first footnote of that paper, on page #2:

    Tonic immobility or a state akin to it has been described in children by Pieron
(1913). I have recently been able to produce the condition in adult human beings.
The technique was brought to my attention by a student in physiology, Mr. W. I.
Gregg, who after hearing a lecture on tonic immobility suggested that a state
produced by the following form of manhandling which he had seen exhibited as a
sort of trick might be essentially the same thing. If one bends forward from the
waist through an angle of 90°, places the hands on the abdomen, and after taking a
deep breath is violently thrown backwards through 180° by a man on either side,
the skeletal muscles contract vigorously and a state of pronounced immobility
lasting for some seconds may result. The condition is striking and of especial
interest since this type of manipulation (sudden turning into a dorsal position) is
the most common one used for producing tonic immobility in vertebrates.

    Apparently this or a similar effect can be observed in humans too?! In this paper, the author himself claims to have done this and that it works! I tried to locate more recent resources describing this phenomenon in humans but I could not find them… Is this actually possible? If so, why is this not better documented? Or, maybe it is better documented but understood as a different type of reflex today? Not sure.

    • zipsglacier@lemmy.world
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      22 hours ago

      Excellent fact, and bonus points because the fact is only recorded in a footnote of a writeup about an already moderately obscure fact.

    • tpyo@lemmy.world
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      1 day ago

      That reminds me of a “game” kids would (try) to play when I was young at school. The kids would say to do just that “bend over, take a deep breath” and the other one would try to lift them up really quickly. I never saw it work. I guess you were supposed to pass out. Idk

      • Salamander@mander.xyz
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        13 hours ago

        Some of these ‘games’ do trigger real physiological mechanisms. A well-documented example is the Valsalva maneuver, where forcefully exhaling against a closed mouth and nose affects heart rate and blood pressure.

        In some games, this maneuver (or similar) is combined with a second action that normally increases blood flow demand to the brain. The mismatch between reduced blood pressure and sudden demand can cause dizziness or brief loss of consciousness due to insufficient oxygen reaching the brain.

        Actually, there is a similar effect sometimes seen during heavy deadlifts, suddenly releasing can sometimes make people pass out. There are many “deadlift passing out” videos online.

        So, those ‘games’ can work. I have known of kids breaking their teeth after face-planting against the floor while playing those games. Not a very smart thing to do.

  • Lokoschade@feddit.org
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    22 hours ago

    Not that obscure, but most orange cats are male since the orange gene is tied to the x-chromosom, so male cats only need one copy to appear orange. Female cats have to have the orange gene on both x-chromosom to be fully orange.

    And usually only female cats can be calico/tortoise since the orange gene is co-dominant, so if they only have one copy of the orange gene both the orange and black will be visible.

    A seemingly male calico/tortoise cat is usually intersex and sterile.

  • HiddenLayer555@lemmy.ml
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    1 day ago

    Ancient Egypt was ancient before it ended. The time when Cleopatra ruled is about as close to today as it was to the first pyramids.

    • riccardo@lemmy.ml
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      5 hours ago

      One of my favorite facts is that while the first pyramids were being built, there were still Mammoth roaming some northern European regions (never checked whether this is true or not but I’ve heard it so many times that I want to believe it is true)

    • rmuk@feddit.uk
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      1 day ago

      It’s actually even wilder than that.

      The earliest know pyramids date back to around 2600BCE, and Cleopatra reigned around 50-30BCE, so her reign is closer to the modern day than to the first pyramids by about 600 years. One of the earliest surviving pyramids, Djoser, was built by Imhotep (with help, I assume) during a period called the Third Egyptian Dynasty meaning, as it’s name suggests, the unified Kingdom of Egypt was already well-established by the time it was built. The First Dynasty started about 3100BCE so even ignoring the proto-Dynasty period of Egypt, that’s pretty humbling: if you drew a timeline with the founding of Ancient Egypt on the left and the founding of OnlyFans to the right, Cleopatra would be three-fifths of the way along it.

    • PearOfJudes@lemmy.ml
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      22 hours ago

      Cleopatra had a kid with Julius Caesar lmao. When you think of it like that it makes more sense.

  • rodbiren@midwest.social
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    1 day ago

    A large amount of visual inspections on the inside of nuclear reactors is done literally with a camera duct taped to either a really really long pole assembled in sections or a rope. Operators “swim” the cameras to various locations and camera handling is basically an occupation in that field. You also need camera shots for any work being done on the inside of the flooded reactor with, again, really really long poles that end up acting more like pool noodles at such a length. It is silly and difficult work. Also you basically are wearing a trash bag sitting above a hot tub while doing this work. So it is a wild experience.

  • Unusable3151@lemmy.ml
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    1 day ago

    There is a dust layer in the ice at the South Pole about 2km under the surface that interferes with about 5000 photomultiplier tubes spread out over a cubic kilometer in the ice that are watching for light created from high energy muons moving faster than the speed of light in the ice that were in turn the result of the very rare chance of a high energy neutrino interacting with the nucleus of a single atom in the ice.

    • setInner234@lemmy.ml
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      10 hours ago

      Just want to make sure I am understanding this correctly: Faster than the speed of light, within the medium, right? So the neutrinos are a bit like Cherenkov radiation. But not actually faster than the speed of light, since if that was happening, my world view was just revised rather abruptly :)

      • Unusable3151@lemmy.ml
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        6 hours ago

        You’re correct! It is Cherenkov Radiation; specifically from the muon (or electron or tau) that is a result of the neutrino interacting with the nucleus of an atom because Cherenkov Radiation happens with charged particles.

  • Ceruleum@lemmy.wtf
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    1 day ago

    The Latin meaning of the color ultramarine is “over the sea” Also, they once made a pigment called mummy, which was literally made out of finely grinded mummy.

  • Hugin@lemmy.world
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    1 day ago

    Most military simulation databases have a classified and unclassified version. In the unclassified database a spefic russian apc is usually set to be indestructable.

    It’s used for a quick test when setting up a federated sim. Drop one in the sim and trigger a detonation at the location. It should either be destroyed or not in all the instances.

      • Hugin@lemmy.world
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        18 hours ago

        So military simulation for actual militaries is used for training. There are programs like OneSAF a training and stimulation RTS or VBS2 a first person shooter.

        They can all be networked together using a federated system. Similar to Lemmy there is no master instance. Each program is trusted and manages it’s entities like tanks and soldiers.

        They each have their own database that can be classified or not. The classified database has very accurate stats and the nonclassified has general simple stats. Think people leaking classified documents on War Thunder to get their tank better stats in the game.

        Because each system is using it’s own database you don’t want some system using classified data and some not. So in the unclassified databases a spefic unit type is set to invulnerable.

        So if it’s supposed to be an unclassified stimulation you fire up the sims and create one of the special units. You then trigger a detonation like an airstrike at the location of the unit.

        The unit should be fine as it’s invulnerable. You then go and check each stimulation and if it’s been destroyed that one is using a classified database and you need to change it out before letting people use the system.

  • lorty@lemmygrad.ml
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    21 hours ago

    There have been 3 observed interstellar objects that passed through our solar system: Oumuamua, Borisov and ATLAS.