What is your interesting fact or knowledge that is completely useless that you wish to share?

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Submitted ⁨⁨1⁩ ⁨day⁩ ago⁩ by ⁨WanderWisley@lemmy.world⁩ to ⁨[deleted]⁩

https://lemmy.world/pictrs/image/b0064cb4-1582-46c5-a66d-7c1ac7fc58d7.jpeg

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

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tiny_hedgehog@piefed.social ⁨2⁩ ⁨hours⁩ ago
There are more atoms of hydrogen in a molecule of water than there are stars in the whole solar system.

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- Fjdybank@lemmy.ca ⁨2⁩ ⁨hours⁩ ago
  So, more than the 1 star in our solar system? Did you type that right?
  
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  - tiny_hedgehog@piefed.social ⁨2⁩ ⁨hours⁩ ago
    Correct. I essentially said 2 is bigger than 1.
    
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SirEDCaLot@lemmy.today ⁨2⁩ ⁨hours⁩ 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 :)

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- Professorozone@lemmy.world ⁨1⁩ ⁨hour⁩ 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?
  
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MeatballMam@lemmy.zip ⁨2⁩ ⁨hours⁩ 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.

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iocase@lemmy.zip ⁨2⁩ ⁨hours⁩ 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 sea scorpion ancestor. King crabs evolved from a hermit crab too (still a true crab)

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

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whoxtank28@lemmy.world ⁨4⁩ ⁨hours⁩ 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 lin 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…

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- Doomsider@lemmy.world ⁨4⁩ ⁨hours⁩ ago
  Piss comes from blood!
  
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agent_nycto@lemmy.world ⁨4⁩ ⁨hours⁩ 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.

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Bytemeister@lemmy.world ⁨4⁩ ⁨hours⁩ ago
Useless knowledge.

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

I 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.

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- Professorozone@lemmy.world ⁨1⁩ ⁨hour⁩ ago
  I don’t know. Sounds kind of useful to me.
  
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- Ellvix@lemmy.world ⁨3⁩ ⁨hours⁩ ago
  Probably more difficult if you have pets
  
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  - Bytemeister@lemmy.world ⁨2⁩ ⁨hours⁩ ago
    Nah, my snakes don’t really mess with the foot pedals.
    
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Jankatarch@lemmy.world ⁨3⁩ ⁨hours⁩ ago
The guy who did localization for the Zambak magazine’s Turkish translation of “the alice in wonderland” has the cool birthday January 1st, 1969.

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expletivedeleted@lemmy.zip ⁨6⁩ ⁨hours⁩ ago
Ketchup, or catsup, which is the same word latinized differently, was a fish sauce from China.

The western Europeans and American colonists used the recipe, and expanded it to things like mushrooms and many other ingredients. (for proof, look at the ketchup entry on wikipedia).

Tomato ketchup (which is specified on your bottle still today) wasn’t invented until we realized that tomatoes weren’t poisonous despite their color, and their sweetness and tang totally rocked with the ketchup recipe.

Now we use it to eat frenched fries, which aren’t French! In fact, they are Belgian, and are named because they used a cooking technique invented by the French called “frenching” which has evolved into deep frying.

So, you are dipping your belgian potatoes into a chinese sauce that use a North American fruit as a base.

And with this information, you shall father nations!

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- Professorozone@lemmy.world ⁨1⁩ ⁨hour⁩ ago
  Thank you. This sounds like the kind of useless knowledge I can use.
  
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- pseudo@jlai.lu ⁨2⁩ ⁨hours⁩ ago
  And in the Philipines, ketchup refers to a banana ketchup, not a tomato ketchup.
  
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- Twinklebreeze@lemmy.world ⁨6⁩ ⁨hours⁩ ago
  That picture of mushroom ketchup is vile.
  
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  - DrSoap@lemmy.world ⁨5⁩ ⁨hours⁩ ago
    I bet that would be bomb on roast beef tho
    
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scrodumb@lemmy.ca ⁨1⁩ ⁨day⁩ ago
The Moon is 384,400 km away from Earth. If you took every elephant on Earth and stacked them one atop another most of them would die.

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- mrmacduggan@lemmy.ml ⁨1⁩ ⁨day⁩ ago
  If you took a horse’s large intestine and stretched it out end-to-end, the horse would not survive.
  
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  - CelloMike@lemmy.world ⁨1⁩ ⁨day⁩ ago
    If you laid every road on earth end-to-end a lot of people would be annoyed with you
    
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- zout@fedia.io ⁨1⁩ ⁨day⁩ ago
  I have one related, the diameter of the moon is smaller than Australia.
  
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- Z745812939054@lemmy.zip ⁨1⁩ ⁨day⁩ ago
  jokes aside, the vastness of space is incomprehensible www.joshworth.com/…/pixelspace_solarsystem.html
  
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  - NaibofTabr@infosec.pub ⁨1⁩ ⁨day⁩ ago
    I love this demo.
    
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  - thomasloven@lemmy.world ⁨1⁩ ⁨day⁩ ago
    Hey, is that fairy cake?
    
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- MIDItheKID@lemmy.world ⁨14⁩ ⁨hours⁩ ago
  Did you know that if you took a blue whale, the largest mammal on earth, and laid it end to end, tail to mouth, on a basketball court, the game would be cancelled?
  
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  - NotAnOtter@lemmus.org ⁨13⁩ ⁨hours⁩ ago
    The moon causes tides, but mooning does not involve tiddies
    
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- Noodle07@lemmy.world ⁨1⁩ ⁨day⁩ ago
  If every human held hand in a straight line around the earth a lot of them would drown
  
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  - kossa@feddit.org ⁨11⁩ ⁨hours⁩ ago
    The last people on land just have to be a wee bit stronger to keep the tension, then it works out fine.
    
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- LostCarcosan@lemmy.today ⁨18⁩ ⁨hours⁩ ago
  There are more hydrogen atoms in a single molecule of water than there are stars in the entire solar system
  
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  - mika_mika@lemmy.world ⁨9⁩ ⁨hours⁩ ago
    You would guess this is useless info, but I can use this fun fact to remember how many suns the earth has also.
    
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  - Glifted@lemmy.world ⁨16⁩ ⁨hours⁩ ago
    🤦‍♂️
    
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- aeronmelon@lemmy.world ⁨21⁩ ⁨hours⁩ ago
  I’m going to go out on a limb and say all of them would die for one reason or another.
  
  Also, my first experience with the internet back in 1994 was a page of elephant jokes, I feel I’ve come full circle now.
  
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  - kossa@feddit.org ⁨11⁩ ⁨hours⁩ ago
    Why full circle, though. Is this your last experience with the internet? RIP aeronmelon’s internet experience, 1994-2026
    
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- jambudz@lemmy.zip ⁨14⁩ ⁨hours⁩ ago
  Every sixty seconds in Africa, a minute passes
  
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- NotAnOtter@lemmus.org ⁨13⁩ ⁨hours⁩ ago
  It’s hard to imagine any of them would live. I guess one near the top might survive by using the flood of elephant pieces to slow their fall. But an elephant can’t survive a ~10 foot fall. That’s about 2 elephants tall, and the bottom two or the ones I am most confident are dying in this.
  
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- tuxiqae@lemmy.dbzer0.com ⁨9⁩ ⁨hours⁩ ago
  Aould you say that all of them will? Some from lack of air and some from the weight of a gazillion other elephants on top of them
  
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SaveTheTuaHawk@lemmy.ca ⁨4⁩ ⁨hours⁩ ago
Albert Einstein was rejected from Swiss army duty for having sweaty feet.

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- MonkderVierte@lemmy.zip ⁨2⁩ ⁨hours⁩ ago
  They don’t like people who question things in military anyway. Probably a reason too, why Autism and ADHD are reason for exemption (in Switzerland at least).
  
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menas@lemmy.wtf ⁨5⁩ ⁨hours⁩ ago
Ear piercing was a sign of wealth in ancient rome. Having access to hygien to prevent infection was a social distinction

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Quilotoa@lemmy.ca ⁨6⁩ ⁨hours⁩ ago
The theme song for the game Civilization IV is The Lord’s Prayer is Swahili.

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Krudler@lemmy.world ⁨14⁩ ⁨hours⁩ ago
With vanishingly rare exception, addicts choose the mood altering substance that is closest to what the medically accepted treatment for their underlying disorder(s) would be.

People who are addicted to alcohol, without exception, have an underlying anxiety disorder.

People with ADHD and similar brain functioning tend to choose amphetamines.

The list goes on and it gets very complicated, because most mood altering substances have multiple effects, and most people have a blend of underlying issues. But the point is, there is a very noteworthy observation there, I feel.

I feel qualified to say this as myself I am 11 years sober and have worked in the field of addiction for 8 years and I’m formally educated.

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- bitjunkie@lemmy.world ⁨5⁩ ⁨hours⁩ ago
  
  People who are addicted to alcohol, without exception, have an underlying anxiety disorder.
  
  People with ADHD and similar brain functioning tend to choose amphetamines.
  
  I feel attacked…
  
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- Schlemmy@lemmy.ml ⁨9⁩ ⁨hours⁩ ago
  I have ADHD and I trend to get into a comfortabele alcohol Buzz every evening because it shows down the train of emotions. Amphetamines don’t really feel good, nor do other drugs. I hate speed and weed.
  
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- Agent641@lemmy.world ⁨9⁩ ⁨hours⁩ ago
  But I liked all of the drugs.
  
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- bstix@feddit.dk ⁨10⁩ ⁨hours⁩ ago
  Is this related to the cravings for certain food?
  
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applebusch@lemmy.blahaj.zone ⁨17⁩ ⁨hours⁩ ago
human brains use bang-bang control to control our body movement. all muscles are either on or off, with many individually actuateable groups of fibers per major muscle group. if youve ever lifted weights and started to shake on a hard lift, thats your body switching rapidly between different muscle fibers trying to complete the lift. body feedback takes more than 100 ms, which is way too long to do active feedback control on a lot of the really fast actions we do with our bodies, so for those our brain just does it open loop. it generates a sequence based on your intent and past training and just lets it rip, but we for sure can modify the sequence midway.

this is part of why humanoid robots look so uncanny when they move, they do continuous control which is fundamentally different from how we move our bodies. our brains have special pathways that process others body movements and what those robots do doesnt line up with how we know our bodies move so it looks wrong.

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- melsaskca@lemmy.ca ⁨7⁩ ⁨hours⁩ ago
  Muscles can be either voluntary (choosing to lift a chair) or involuntary (a beating heart) as well.
  
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- howler@lemmy.zip ⁨10⁩ ⁨hours⁩ ago
  I’ve really enjoyed this fact, thank you!!
  
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- isleepinahammock@lemmy.blahaj.zone ⁨15⁩ ⁨hours⁩ ago
  We should pass a funny law that requires all humanoid robots to grunt as they move.
  
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  - ouRKaoS@lemmy.today ⁨12⁩ ⁨hours⁩ ago
    You’ve never been close to one of those clankers, huh? The constant whining of every servo motor is like a bunch of small, high pitched groans in tandem.
    
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chunes@lemmy.world ⁨11⁩ ⁨hours⁩ ago
monads are monoids in the category of endofunctors.

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- bitjunkie@lemmy.world ⁨5⁩ ⁨hours⁩ ago
  Found James Iry
  
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cinoreus@lemmy.world ⁨14⁩ ⁨hours⁩ ago
If you own a rig to run local LLMs, your computer can also pretty much run weather prediction softwares

GraphCast: AI model for faster and more accurate global weather forecasting — Google DeepMind share.google/R24aEDxkDuFfnitzo

This is the most recent one I learnt.

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HodorPlease@lemmy.world ⁨5⁩ ⁨hours⁩ ago
You can’t lick your elbows.

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yesman@lemmy.world ⁨1⁩ ⁨day⁩ ago
I learned today that transplanted hearts will grow biologically younger or older to match the new body.

www.biorxiv.org/content/…/2026.09.15.751836v1

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- isleepinahammock@lemmy.blahaj.zone ⁨15⁩ ⁨hours⁩ ago
  What if I replace most of my organs with younger ones? If a billionaire gets a whole body transplant, does that also de-age his brain?
  
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  - Lumisal@lemmy.world ⁨11⁩ ⁨hours⁩ ago
    It’s the blood that seems to matter more than the organs, and not all organs follow this rule. Kidneys for example don’t really change much.
    
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sakphul@discuss.tchncs.de ⁨9⁩ ⁨hours⁩ ago
During the medieval period there was no currency used throughout the whole of Germany. Most used the Silver Penny (Pfennig) but there were different types with a different value (amount of silver in them) that also changed over time (some were more stable, some changed every year). People from one location moving to another had to exchange coins (or silver bars) to the one used locally. The exchange rates were quite different.

It was a complete mess. But somehow it worked.

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- MonkderVierte@lemmy.zip ⁨2⁩ ⁨hours⁩ ago
  I think Spice and Wolf paintd a pretty good depiction of the market (and world) of the early middle age’ europe.
  
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rockerface@lemmy.cafe ⁨15⁩ ⁨hours⁩ ago
Sharks evolved before Saturn’s rings and the North Star existed.

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- Bytemeister@lemmy.world ⁨5⁩ ⁨hours⁩ ago
  Sharks are older than trees.
  
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- ivanafterall@lemmy.world ⁨15⁩ ⁨hours⁩ ago
  The Appalachian Mountains are 2-3x older than sharks.
  
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  - DrSoap@lemmy.world ⁨5⁩ ⁨hours⁩ ago
    This is why they never visit. They’re bitter.
    
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Z745812939054@lemmy.zip ⁨1⁩ ⁨day⁩ ago
more time passed between the building of the great pyramid and cleopatra, than between cleopatra and today

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translucent_tube@lemmy.world ⁨1⁩ ⁨day⁩ ago
Our ability to feel social judgment and shame reuses the same neural circuits as physical disgust or nausea. This effectively makes it so that you can take anti-nausea medication to temporarily make you less judgy of other people’s life choices.

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nullify3112@lemmy.world ⁨13⁩ ⁨hours⁩ ago
The aging sun will make the continental drift stop via increased solar activity which will accelerate rock weathering. This will break the carbon cycle long before the earth is absorbed by the sun going in its red giant phase.

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gastroglizzy@piefed.social ⁨1⁩ ⁨day⁩ ago
The specifications for all varieties of “9mm” cartridges (9x17, 9x18, and 9x19) actually call for a projectile with a diameter of 0.355 inches, which is actually 9.017 millimeters.

Similarly, the specification for .38 Special calls for a projectile with a diameter of 0.357 inches.

If you measure the barrel of any firearm chambered in any variety of 9mm, .38 Special, or .357 Magnum, you’ll find that they’re all ostensibly .35 caliber (0.350 inches).

Why? Well, the simplest answer is, things aren’t always what they’re called. In the world of cartridge designations, there are many, many such idiosyncrasies; these are only scratching the surface. I find this interesting because many people perceive cartridge designations as being very uniform, logical, and standardized, but the actual truth is far from that.

In some cases, the number is even made bigger just to make it sound more powerful, such is the case with .460 S&W Magnum, which is a more powerful version of .454 Casull, which itself is a more powerful version of .45 Colt, all of which actually fire a projectile with a diameter measuring 0.452 inches.

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jambudz@lemmy.zip ⁨14⁩ ⁨hours⁩ ago
Popes and priests before the renaissance (I can’t remember the specific cut off) were told not to fuck, but all did as it was seen that no one was that godly to deny sex. Early bishops were a hereditary position passed from “celibate” father to son. Oh and the Avignon popes basically built the first European sin city because one of them really loved fucking and gambling.

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medem@lemmy.wtf ⁨21⁩ ⁨hours⁩ ago
Pumpkins are the largest species of…berries. Yes, seriously.

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meat@lemmy.blahaj.zone ⁨1⁩ ⁨day⁩ ago
A quarter of known animal species are beetles.

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E_coli42@lemmy.world ⁨23⁩ ⁨hours⁩ ago
Sharks are older than fire! It took billions of years for Earth to get the oxygen levels and fuel (land plants) needed for fire. Earth is the only place in the universe where we have seen fire.

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Thebeardedsinglemalt@lemmy.world ⁨15⁩ ⁨hours⁩ ago
Blue eyes in humans were the result of a mutation. Due to less pigment than average eyes are more sensitive to glare and bright light

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