When the great pyramids were being built there was still woolly mammoths walking the earth.

  • tiny_hedgehog@piefed.social
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    7 days ago

    There are more atoms of hydrogen in a molecule of water than there are stars in the whole solar system.

  • NotAnOtter@lemmus.org
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    6 days ago

    You can double an hourly rate to approximate the annual wage. $30/hr ~= $60k / year.

    Because 50 paid weeks * 40 paid hours = 2000 hours -> 2k

    $30 * 2k = $60k

  • whoxtank28@lemmy.world
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    7 days ago

    There is no thru line from mouth to urethra. You drink water, it gets absorbed into your blood, your urinary system filters excess water and waste, you pee it out. Your pee is filtered blood, the only thru line for water to take from your mouth is your ass. I understood that when it was taught, but I didn’t really think about it…

  • SirEDCaLot@lemmy.today
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    7 days ago

    Everyone knows you jump in the pool in summer, smell the chlorine, and know the water is clean, right?

    Fun fact- chlorine dissolved in pool water at the usual sanitation levels has almost no perceptible smell or taste.
    HOWEVER, when chlorine binds with certain organic substances, especially ammonia (from the urea in sweat and urine), the result is chloramine which has a significant chlorine-y smell. Chloramine has essentially no disinfecting properties.

    So when you go to the public pool and get a whiff of chlorine and think ‘man they’re using a lot of chlorine today’, no, it probably means someone peed in the pool.

    You’re welcome :)

    • Professorozone@lemmy.world
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      7 days ago

      Ok, but why then when you open a bottle of bleach or container of chlorine pellets, does it smell like chlorine. Do they add the piss ahead of time?

      • adarza@lemmy.ca
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        7 days ago

        take all but 1.5mL out of that gallon jug of household bleach, then fill it back up with water. that’s roughly the concentration of chlorine in a swimming pool.

      • SirEDCaLot@lemmy.today
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        7 days ago

        That’s pure chlorine, much higher concentration. At the concentrations of pool chlorination there’s essentially no smell.

        • Professorozone@lemmy.world
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          6 days ago

          But couldn’t they just be over-coordinating. That’s what it feels like.

          Either way, I’m glad they came up with salt water systems. Much nicer.

          • SirEDCaLot@lemmy.today
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            6 days ago

            Fun fact, salt water systems require a gadget called a salt cell which converts some of the salt in the water into chlorine. The salt isn’t actually sanitizing the water, it’s not there in nearly enough concentration to do that. Rather, the salt cell is splitting the sodium chloride into sodium and chlorine, the chlorine is then sanitizing the pool.

          • sem@piefed.blahaj.zone
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            6 days ago

            Overchlorination doesn’t lead to the smell, but it can dry out your skin.

            Where I live, free chlorine concentrations up to 10.0 ppm are legal, but pools are normally set closer to 2.5 or 3 ppm. Even at 10, you can’t smell a chlorine smell, but my skin won’t feel great after.

            However, chloramine concentrations as low as 0.2 ppm can give a chlorine smell.

            One of the ways to get rid of chloramines is adding a lot more free chlorine, enough to break down the chloramines.

  • IamMoonPie@lemmy.world
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    7 days ago

    Humans can’t feel wet, what we’re actually feeling is cold. It’s why when you have a cold patch on a blanket or carpet you can’t quite figure out if it’s wet or not.

    • wolframhydroxide@sh.itjust.works
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      7 days ago

      It’s actually an even greater level of abstraction: we feel the rate of heat flow through our skin. This is (kind-of) why plastic feels warmer than metal. Colder things don’t feel colder because they are colder. Colder things feel colder because they more efficiently sap heat from our skin. Wet things feel colder because water and other highly conductive fluids which have wet the skin (and are thus in direct contact with it) are much more efficient in removing heat, thus feeling colder. This is the twofold reason why oil doesn’t feel as cold as water: it has significantly worse heat conductivity, and it doesn’t readily evaporate (as evaporation is a highly endothermic process, sapping heat even more efficiently than a conductive liquid on its own.)

        • wolframhydroxide@sh.itjust.works
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          7 days ago

          Oh yeah? Well menthol tricks your nerves into thinking they’re losing more heat than they are, so if you dissolve a tiny crystal of menthol in everclear, you can make a tincture to rub on a part of your body that’s sweating, and it will feel naturally cool for about ten minutes, reducing discomfort from both heat and sweat! How’s that for “actually useful”?

    • SCmSTR@lemmy.blahaj.zone
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      7 days ago

      I feel like that’s like “you can’t see or touch the world or experience time, your eyeballs and molecules that never touch anything are just affected by magnetic and gravitational waves and translate that to feeling and experiencing those things”

      Like I guess it’s technically true in that perspective, but effectively false

  • MeatballMam@lemmy.zip
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    7 days ago

    If sound could travel through space, from the distance we are to it, the sun would be as loud as a jackhammer everywhere on the planet, all the time.

    • sem@lemmy.blahaj.zone
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      7 days ago

      Are we assuming sound is traveling through space as if it were air?

      If it were like sound through water it would be even louder.

  • Bytemeister@lemmy.world
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    7 days ago

    Useless knowledge.

    When playing Mechwarrior 2 on a Windows 2000 system, make sure to change your video mode to 32bit color.

    I’ll throw in a useful tip too!

    You can buy USB foot switches for your computer and assign keystrokes and other functions to them.

    Almost feels like cheating when you are playing a tactical shooter and can lean left or right and strafe on demand without crossing any controls. Having microphone activation, map, inventory, or any number of misc actions boud to a foot pedal makes a huge difference in your ability to play a game.

    • Captain Aggravated@sh.itjust.works
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      7 days ago

      Further knowledge about Mechwarrior 2: 31st century combat:

      At various stages in the campaigns, you’ll face off against Elementals, escort a Tarantula, and fight a Battlemaster. Through cheat codes, you can add these to the mech lab and play in them in the “Trial of Grievance” free play mode. The Elemental works fine, it functions as a tiny mech, the Tarantula works mostly correctly, but it isn’t 4-legged. It looks like it is but the front two legs are legally arms, they can be blown off and it works fine. Trying to select the Battlemaster in the mech lab will immediately crash the game.

      Cheat codes for Mechwarrior 2 were the very, very first thing I searched the internet for.

  • agent_nycto@lemmy.world
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    7 days ago

    The people who got anime to take off in the US are the same people who started the furry fandom.

    The Superman symbol was based off of the symbol for a sci fi fan club.

    Conventions, and sci fi as we know it, are because of one electronics magazine.

  • RoleplayFaye@lemmy.world
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    6 days ago

    Pigs can’t look directly upwards. Neither can we, when standing on all fours. This is because ours and pigs necks are constructed in the same way.

    • CalypsoGirl@lemmy.today
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      4 days ago

      And according to some weirdos on the internet who apparently know some concerning things from experience, human meat tastes the same as pig meat. Tastes like Pork. But now I’m curious why pork & ham & bacon are three distinctly different tastes & textures if they all come from pig.

  • sem@lemmy.blahaj.zone
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    7 days ago

    Tolkein came up with the broad strokes of the simarillion and other parts of his legendarium decades before thinking about hobbits.

    He also had an incredible saga involving Santa, a talking polar bear, and the North Pole that he made for his children in letters.

  • Goldmage263@sh.itjust.works
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    7 days ago

    The gorgeous Lunar Moth exits the chrysilys fully formed, without a mouth or other structure for the intake of nutrients. It only exists to fly and breed at that point and expires around a week later.

  • iocase@lemmy.zip
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    7 days ago

    Multiple species have evolved into crab body plans, and only a subset of “crabs” are actually true crabs. For example coconut crabs evolved from a hermit crab ancestor. King crabs too.

    The tendency to adopt the crab meta for your species is called carcinization.

      • iocase@lemmy.zip
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        6 days ago

        And then some day there will be recarcinization where a species regrets being a shrimp and will become crab, destroyer of detritus, once again.