In science, there aren't really facts... per se. What we scientists do is make an observation, develop a test of the observation, and either reject or accept our original idea of that observation. Well, that's the simplified version. But in the world of reality we call these supported observatiosn that have tons and tons of data to back it up a fact.
George Washington being our first president is a fact. Birds being dinosaurs is a fact. Not knowing why we yawn is a fact. Wait, what?
NO ONE KNOWS WHY WE YAWN
No one is quite certain why we yawn. There are lots of ideas - lack of oxygen, a holdback from our ancestors, letting a bad date know how crappy they are - but no one really has a clue the exact reason for stretching our mouth and making a weird noise.
Joseph Ducreux of the Archaic Rap meme painted a self-portrait of a yawn years ago. He wasn't the first to notice that the yawn was a thing.
Source: Joseph Ducreux, his meme painting, but not the yawn portrait.
There is the contagious yawn. That's found in tons of animals, from dogs to people, when someone yawns and everyone else joins in. If yawning was merely a lack of oxygen then why would we start yawning when someone else was?
Who knows? And if yawning had to do with a lack of oxygen then why don't we yawn more when we exercise or are at high elevation? Even exposing folks to excess CO2, the thing we want to get rid of, doesn't inrease our need to yawn in an attept to gasp oxygen.
It seems that yawning is a social thing. Yawning causings the parts of our brains associated with sociality and empathy to fire. Except... Yup. Solitary animals yawn. Also, primitive animals yawn and if it were truly a social phenomenon, then wouldn't it be found in only later, more social animals? Well, it's not. Fish yawn. Frogs yawn.
Oh, but sadly, Wilkonson et. al. (2011) showed that yawning does not cause your pet tortoise to yawn. So, maybe your tortoise doesn't love you, or isn't tired, or isn't... Eh, screw it. Yawning is just something man was not meeant to understand. Sorry, everyone. The science fact here is that if you ask any scientist why we yawn, you get a shrug.
PARASITES AND DISEASES MAY BE CONTROLLING YOUR MIND
Source: CDC, cat ladies.
If we make a decision, we all kind of assume that decision is our own somehow. Now, I think everyone agrees that not all decisions are necessarily our conscious and coherent body making an informed choice, but we all believe the "you" in "yourself" is mostly our own doing...
Wrong! You are fake news!
Disease and parasites might be making a bigger impact on your decisions, feelings, and personality than any of us want to admit. Do you own a cat? Lovely! It might be causing you to have mental illness, including schizophrenia. Are you overweight, constantly craving food? Maybe don't get that next cold. Are you engaging in increasingly risky behavior? You probably just have worms, weirdo.
Or, well, maybe or maybe not. We know that animals can have vastly altered personalities or activities because a parasite or disease causes a change in brain chemistry. Pillbugs, those little round buggers in your garden, like to be moist and hide, eating leaves and such. If they get the wrong infection, though, they will suddenly decide to journey out on a sunny day and chill out, waiting to be eaten by a bird. That bird is needed for their parasite to complete its life cycle, hoping to infest another pillbug. And this weirdness isn't just found in crustaceans...
Similar things occur in ants, mice, and... people? Some evidence seems to link a common infection you can catch from cats, Toxoplasmosis, with depression, schizophrenia, and other mental illnesses. Could you cat's sickness be killing you?
Yes. Cats are evil.
Maybe. More research is needed but you can be certain of one thing: the next time you get sick, it might change your brain and turn you into another person altogether...
AMOUNT OF DNA ISN'T RELATED TO COMPLEXITY
This fact isn't really startling but it is extremely interesting. The amount of DNA in your body - the information storage molecule - has no relation to how complex an organism is. You and I have 46 chromosomes in 23 pairs, baring an genetic disorders. A carp has 104 chromosomes. Some plants have as many as 200 or so chromosomes.
But the weirdness doesn't stop there.
Krypto the Superdog has 78 chromosomes and can't even drive a car.
Well, what if we just have really big chromosomes and other animals have smaller ones, so the total data contained on them is the same?
Nope. That isn't how it works, either. It just so happens that what your cells are doing is dictated by your chromosomes but a person and a fungus don't realy have that much difference on the cellular level. And what we see as complexity isn't necessarily so.
That or some ferns (over 1,000 chromosomes) are secretly the most advanced beings in the universe.
ALLIGATORS CAN USE TOOLS
Wait, what? That's weird but why is this a shocking fact? There's no way alligators are smart enough to anticipate using tools to catch certain prey at certain times of year and in certain locations because...
A recent article from 2013 by Dinets, Brueggen, and Brueggen confirmed what most of us scientists kind of assume: alligators are smarter than we thought. They are using sticks placed on their snouts as lures to catch certain types of nesting birds that are attempting to gather said sticks for said nests. Yup.
This is pretty shocking but that also might mean...
Maybe dinosaurs could use tools. Hell, lots of animals could and can. Dinosaurs are in between alligators and birds on the evolutionary chart, meaning they are all related and, yes, birds are modern dinosaurs. Birds use tools. Alligators use tools. Were dinosaurs using sticks or twigs or rocks or, gasp, power drills?! We can't say for sure, but we can say that now alligators are smarter than most people I know.
Oh, and that doesn't even bring up the fact that at least one kind of octopus can use tools... Which genius animal will be our eventual overlord?
NO ONE REALLY HAS A CLUE WHAT GRAVITY IS
Source: Not even this guy, Sir Fig Newton (Editor's Note: Issac.).
We know how to calculate the forces of gravity, the laws of gravity, and how gravity interacts with other things in the universe. Life isn't a Warner Brothers cartoon, where we can just run off a cliff and never fall because we don't know what gravity is. We have a pretty firm grasp on the forces behind gravity, knowing how it holds bodies in orbit or how we can use it to measure how much weight I've gained since Christmas (gravity's effect on mass).
Gravity pulls us towards earth, pushes earth around the sun, and yet...
What IS gravity? Is it a particle? Is it a wave? Is it a flavor? Probably not any of those. There's the problem.
Gravity, as we all understand it, is an attractive force between two objects. Bigger objects have "more" gravity, whatever that is. But if you are tiny, gravity doesn't mean that much to you. The tiniest objects of matter don't seem to give a crap about gravity, but the biggest things we know of do.
So, yeah, what the hell is gravity? Why does it work? We don't have any clue, but we don know precisely how this universal... thing... works. Maybe it's just a particle in a parallel universe or something like time travel that, hey, wait...
WE CAN TIME TRAVEL
I know what we are all thinking. No, Dr. Who or Back to the Future style time travel doesn't currently exist. Fortunately, time travel is happening all the time and all around us. Kind of.
I'm not talking about those mysterious stories where someone supposedly was caught on video with a cell phone back in the 50's or a story from old timey France where someone supposedly randomly walked into a house from the Middle Ages. No, actual real time travel. Kind of. Sort of.
The faster you go, the slower time moves relatively to people moving at a standard rate on earth. So astronauts go up quickly, travel around space quickly, and come back a few seconds behind those of us on earth. If it's 8:01 PM here, it might ony be 8:00 PM for someone who traveled in space! Wow! Speed!
Ok, that isn't really that groundbreaking.
We've apparently seen particles of light and maybe atoms or other tiny things move back in time. They've disappeared and appeared before they left. Freak, right? Now imagine if we can figure out a way to do that but, like, with a Delorean...
PARTICLES KNOW WHEN YOU ARE WATCHING THEM
How exactly this is true is sort of beyong my graps as a scientists because I am a biologist, but here's a good summary of it. Essentially quantum theory suggested that, hey, just by watching an atom for an experiment we may be altering that experiment because somehow that atom - or other particles of matter - might "know" we are watching them.
I know what you're about to ask, but I don't have a fucking clue either how this works.
A few experiments seem to confirm this. It's an observable action called the Zeno effect. Somehow by studying the very building blocks of reality, we are biasing that reality So, yeah.
Good luck trying to understand anything ever again. What does it all mean? What is the nature of reality if a photon can behave differently when we watch it? Are our socks being lost because we believe they are being lost in the laundry?