What are some commonly known facts that are too bizarre for you to believe to be true?
For me it is the fact that our blood contains iron. I earlier used to believe the word stood for some ‘organic element’ since I couldn’t accept we had metal flowing through our supposed carbon-based bodies, till I realized that is where the taste and smell of blood comes from.
Planets and stars and galaxies are there. You can see them because they’re right over there. Like, the moon is a big fucking rock flying around the earth. Jupiter is even bigger. I see it through a telescope and think “wow that’s pretty,” but every once in a while I let it hit me that I’m looking at an unimaginably large ball of gas, and it’s, like, over there. Same as the building across the street, just a bit farther.
The stars, too. Bit farther than Jupiter, even, but they’re right there. I can point at one and say “look at that pretty star” and right now, a long distance away, it’s just a giant ball of plasma and our sun is just another point of light in its sky. And then I think about if there’s life around those stars, and if our star captivates Albireoans the same way their star captivates me.
And then I think about those distant galaxies, the ones we send multi-billion dollar telescopes up to space to take pictures of. It’s over there too, just a bit farther than any of the balls of plasma visible to our eyes. Do the people living in those galaxies point their telescopes at us and marvel at how distant we are? Do they point their telescopes in the opposite direction and see galaxies another universe away from us? Are there infinite distant galaxies?
Anyway I should get back to work so I can make rent this month
If I point my finger at one of those galaxies, there’s more gas and shit between us within a hundred miles of me than there is in the rest of the space between us combined
You should try Space Engine. It’s a program to explore the universe, based on real telescope data. It also has the ability to procedurally generate galaxies, planets, and stars in unobserved parts of the universe.
What’s even more fascinating is that most of the stars we see in the sky are afterimages of primitive stars that died out long ago yet they shine as bright as the stars alive today
That doesn’t seem right. The galaxy is only 100,000 light years across (give or take) and the life span of stars is measured in billions of years.
Most of the stars we see are in our galaxy, so at most, we are seeing them as they were 100,000 years ago, which means that the vast majority of them will still be around, and looking much the same as they did 100,000 years ago.
Thinking about it further, if we’re talking about stars that we can see with telescopes, Hubble, James Webb etc, then you’re on the money. Stars in remote galaxies far outnumber the ones in our galaxy and show us glimpses of the early stages of the universe. And many of those stars are long gone
Not too sure where you got that number from. From what I can find, the radius of the observable universe is estimated to be about 46.5 billion light-years.
Edit: I see now that you are talking Galaxy. That’s different.
I can really relate to this. I remember a weird night in my teens where I must’ve spent at least an hour staring out of my bedroom window at the moon, because really for the first time I’d had the exact same thought. It’s right there. It’s so easy to get desensitised to that and to just think of it all as an image projected on the sky. The thought has never really left me and even now I still linger on the moon every time I see it and try to acknowledge that it is a 3 dimensional object lol.
First, it is massive compared to Earth. The mass of the Moon is so large that it messed with definitions of planets and plutinos.
Second, the Moon’s size and distance from Earth is a near match for the Sun’s, which is really rare.
And for a strange fact, the Moon is about as reflective as worn asphalt. The Moon looks white in photos of just itself, but it is a dark grey when in photos with Earth.
In the same vein, I like to remind myself that every field in physics is literally happening all around me, right now, and it always has been, in fact, I’ve never seen anything without these invisible fields in it and for some reason, that really makes me super aware of our place in the order of magnitudes.
It’s wild we can see so much further down than up.
I suppose it is for the best, but nonetheless I find it uncomfortable how our bodies have the ability to manipulate our brains’ memories and our consciousness residing in the same place cannot do anything about it
I always thought it interesting that every time we talk about when our kids were born, I remember all these details and my wife’s like huh, weird, can’t remember a thing.
Every time that comes up, I think to myself “Something I’ve gone through must be more painful, right? I’ve gone through some pretty hellish things, and you’re trying to tell me something MORE painful exists? Not just a little more, but dramatically more? For my own sanity, I’m gonna have to live in denial of that.”
Huh. I’m guessing the pain of kidney stones comes in varying levels, because the one time I had them I wouldn’t have called it the most painful thing in the world.
Then again, I could also have inherited my mom’s pain tolerance, who gave birth multiple times without any kind of pain relief and without flinching.
I’ve read that passing a kidney stone through the urethra has a brief level of pain matching childbirth… but it’s usually much briefer than childbirth.
Interesting. I suppose they’re both objects with pointy bits much larger than the holes they’re trying to pass through. On that note, I’ve been through very severe anal stenosis and THAT I would say was closing in on the most horrific pain I’ve ever been through. Before I could go to the doctor about it my wife basically had to spend all day and sometimes night keeping me occupied so I had something to do other than cry.
Wait, what? Are you saying you actively don't like music? I mean i can (kind of) understand if a person doesn't really get a pleasure response from listening to music, but you're saying listening to music actually gives you a displeasure response?? ALL music? It's ok if that's the case, you didn't choose to have that response, but i just want to be clear that this is what you're saying?
A lot of music generates unpleasant sensations for me too, though I can tolerate it a bit. Unlike the other commenter though, I can enjoy a lot of other music. What’s unusual in my opinion is that it’s all music, not the negative response. Lucky you if the worst that music can get from you is indifference!
I thought my significant other was one of these to a certain extent. It does weird things to me as a DJ. Turns out that she just likes the limited music that she likes and cannot stand most everything else.
For me it’s not like I don’t like music, but there are large stretches of time, where I do not care so much for it. I would guess that I haven’t actively choosen to hear music for weaks, possibly months, now. Obviously excluding the music you can’t avoid, like background music in movies and video games etc.
I used to be like this, but with movies. When I first met my wife, she was utterly baffled at the concept of somebody not enjoying movies, and she made it her mission to make me enjoy them.
Come to think of it, she actually doesn’t like music much. I’ve failed to change her opinion on that though because my taste in music is shit (and I’m proud of it.)
It just doesn’t appeal to me. I’ve seen a handful of movies/shows that I’d call “not boring as shit” ever, and even then, its not something I’d choose to do myself, but is fine if I’m, like, chillin and chatting with people or whatever.
Might be my neurodivergence, might also just be how much of a reader I am. Movies are just so slow compared to reading.
That’s basically how I was. Honestly, the reason I enjoy movies nowadays isn’t really because it’s my thing, but because my wife is always so excited to show me the movies she likes, and I can’t help but enjoy myself when it’s making her happy.
I rarely watch movies on my own, or with other people besides her, but when I do, it’s usually because I think it’d be fun to tell her all about it, and maybe watch it with her too.
I’m also bigger on reading, but I have really severe, unmedicated ADHD, so I can’t sit down with an actual book for longer than a few minutes. Gotta have pretty pictures, like a manga or graphic novel or something (and even then it’s hard.)
I’m the opposite. I can’t ever ‘zone out’ while listening/watching/reading/playing stuff; I can’t even listen to music while playing games, and usually turn background music on low or off.
I mentioned this one to my friends the other day and it took so much convincing before they actually believed me! Definitely an interesting one. Venus also spins the opposite direction to all the other planets in the solar system, meaning the sun rises in the west and sets in the east.
It doesn’t. Gravity is caused by mass not spin. The planet’s rotation about it’s own axis will create a centrifugal effect that offsets gravity, but the effect is negligible for anything rotating as slow as planets.
The others already said the core aspect, but to get specific: the difference between your weight on the pole and your weight on the equator differs only by like .5% or something like that. This is the difference between spinning and not spinning (centrifugal force and no centrifugal force). (And also the difference in radius, since the Earth’s rotation makes it a tiny bit flatter than a perfect sphere would be)
Short: It completes a full 360° of the sun before the planet itself does a full 360° spin.
A few sentences longer:
In planet Earth human terms, we have defined one day as “how long it takes the planet to do a full 360 degree rotation”. Example: You spin a basketball on your finger and it does one full rotation.
A year to us is “how long it takes the planet to go around the sun”. Example: You hold a basketball out in front of you and you do one full rotation.
You’re close. Not the tilt of its axis, but its rotation around its axis (day) is slower than its rotation around the sun (year).
Earth’s axis is tilted at about 23 degrees, which causes the seasons. Venus, by contrast, is tilted only about 2.6 degrees, and thus basically doesn’t have seasons in a comparable way.
Earth’s axis does very slowly wobble around (precession). Over long enough time scales, this affects the seasons, and it means the North Star has not always been aligned with Earth’s North - once, North pointed at a patch of black sky and the North Star was just another star appearing to rotate around that arbitrary point.
I’d imagine Venus’s axis might also wobble at least somewhat, but I haven’t actually looked into this at all.
Thinking about this sent me down a rabbit hole because the day and year lengths are so extremely close to each other, and Venus rotates around its axis clockwise (unlike the other planets) while spinning around the sun clockwise, and its tilt is so slight… so as it spins around the sun, it rotates just enough to keep one side facing the sun almost all the time. I ended up googling whether it was tidally locked, like the moon is to Earth (such that we only ever see one side and it never changes) - and apparently it would be, but its atmosphere is so wild that it prevents tidal locking. But it almost is. It kinda has a dark side, and a light side, like the moon, but there’s just enough mismatch between the yearly rotation the axial rotation that the side facing the sun changes slowly. This is the first article I found.
From that article, it seems like the daylight hours you’d experience standing on the surface of Venus would be 117 Earth days of light, before it got dark again. So the sun would rise, and then you’d have about half a Venus year (aka about half a Venus day, too) of daylight before you’d see night again. And then it’d be night for the rest of the year. But still scorching hot because atmosphere.
Anyway this is blowing my mind a bit. I feel like I should have known this - I used to be obsessed with astronomy when I was little. Maybe I knew it once and forgot. I don’t know. But dayum. Planets are cool.
There’s iron particles in your cereal. Shit’s been living rent free in my head since I saw a video on it many years ago where some dude extracted filings from corn flakes.
It’s one of those home experiments that is super easy to do and impress the kids. You just pour a bunch of cereal into a ziplock bag and move a magnet around on the outside until you start to see the little black dust appearing on the magnet.
Here’s one: Iron doesn’t have a smell. It acts as a catalyst in the reaction of bodily fluids or skin oils, which is why you can’t smell coins after washing them
A solid that isn’t undergoing any sort of chemical reaction isn’t going to smell because there isn’t anything to smell. You need a molecule to enter your nose to smell. That’s my basic understanding, someone smarter than I can explain it better.
Also I’m not sure any country still uses iron for coins.
Iron would be a terrible metal for coinage, since it would shed rust all over everything after being handled. Some coins might be cast from iron (if it’s cheaper than alternatives, idk) but plated in other metals to prevent that.
The combustion engine. I know technically it’s not but ultimately we as humans found a way to harness the power of explosions and make them do our bidding. honestly, one of humanity’s finer achievements. yes, it’s not without its barbs like emissions, but that’s a small price to pay for the workload any vehicle can provide.
That stuff about metal is really counterintuitive, because normally when we talk about iron, gold, copper, nickel, zinc, magnesium, aluminium etc it’s usually about the element in its metallic form. However, when you study chemistry a bit more, you’ll come to realize metals can be dissolved in water and they can be a part of a completely different compound too.
Calcium, sodium and potassium are basically the exact opposite in this regard. Normally when people talk about these metals, they are referring to various compounds that obviously aren’t metallic at all. This leads to people thinking of these elements as non-metallic, but it is possible to purify them to such an extent that you are left with nothing but the metal.
In the case of Ca, Na and K, the resulting metal is highly reactive in our aggressive atmosphere, so that’s why we rarely see these elements in a metallic form. Our atmosphere contains water and oxygen, which makes it an incredibly hostile environment for metals like this. Imagine, we’re breathing this stuff that attacks so many elements mercilessly.
Our atmosphere contains water and oxygen, which is an incredibly hostile environment for metals like this. Imagine, we’re breathing this stuff that attacks so many elements mercilessly.
Hydrogen and oxygen and very reactive, which is exactly why they are so necessary for survival. Our bodies function off of chemical reactions, it makes sense to power that off of the most reactive elements it can easily find.
Using engine brakes can cause your car to not use fuel in some cases.
I’ve read and heard this from different sources (even driving instructors) and I don’t get how it’s possible. Your engine is still running, doesn’t it use at least as much as it does while it’s idling?
Edit: thank you all for your answers. I knew how the engine brake effect worked, my confusion was about exactly why the engine didn’t consume fuel in the process. I now understand so thanks all.
the inertia from the cars current speed is used to spin the engine rather than the engine spinning the wheels, the resistances of the engine is what causes the slowing effect
modern cars with fuel injection can complete disable injecting fuel when not needed and can also adjust the timing of the injections for maximum efficiency
If you take an engine out of a car and try to spin it by turning the crank shaft, it will be hard to turn because the cylinders need to compress air (it’s required before adding fuel and spark to explode that compressed air so it expands).
When that engine is in the car, and you don’t add fuel and spark, then the cars wheels have to turn the engine and compress that air, thousands of times per minute. That force that the wheels have to send to the engine to spin that engine slows you down.
I’m thinking you think the engine itself has a brake on it… No.
I’m thinking you think the engine itself has a brake on it… No.
Of course not. I know it’s not an actual brake but it comes from the engine’s resistance to spin on higher rpms, so when you shift to a lower grear the rpm goes up, which “activates” this resistance.
What I’m confused about is the relation between idling and engine brakes.
Even without giving it additional gas the engine is still idling, so on a level road you could travel with a certain speed without pressing the gas pedal.
So what happens when you’re going downhill, you don’t press the gas pedal and the engine brake effect kicks in? Does idling not consume fuel anymore?
I think I’m missing some information that would put everything in its place for me.
When you’re engine braking—like when you downshift and let off the gas—the ECU often cuts off fuel to the cylinders. The throttle valve is also closed. In this scenario, your RPMs are maintained by the car’s forward motion, which is connected through the drivetrain back to the engine.
So yeah, you’re not using any fuel in that case, but you’re still turning the engine over. The wheels are essentially driving the engine instead of the other way around. That’s how you can have RPMs but no fuel flow during engine braking. The energy to keep the engine turning is coming from the car’s inertia.
A common example would be going downhill. You downshift to a lower gear, take your foot off the gas, and let the engine do the work to help slow you down. You’ll see the tachometer showing RPMs, but fuel flow is minimal or even cut off, thanks to our friend the ECU.
So basically because you have more than enough rpms to maintain idling the engine knows to turn off fuel injection until it needs to exert force again?
I’m thinking of a scenario when you start on a level road, reach a slope going downhill, then reach a level road again. Then the engine first consumes fuel, then it shuts it off, then eventually on again, without me pressing the gas pedal at any point?
yeah, exactly. I don’t know enough about the implementation details to know if it is actually consuming 0 fuel though but there’s not much work the engine is actually doing.
I’m not exactly sure how it worked in practice, but if it’s anything like simple aircraft engines with carbs, there’s a mixture control that you’d use in addition to the throttle to control air intake.
Look it depends on the age of the car, but let’s take an old manual car for example.
On those cars, there’s a fuel map to rpm. There’s actually a few maps including throttle and ignition timing. But think of a spreadsheet of rpm and fuel at a certain throttle load.
At 0 throttle: The map says to stop the engine from stealing at under say 800 rpm it needs to have fuel added at rpms lower than that to speed up the engine to avoid stalling. At 800rpm it needs a consistent amount kind of a known amount that keeps it in equilibrium. At over 800rpm it needs less fuel the more rpm it has over the idle 800rpm until it’s zero fuel.
And you’ll feel that, you’ll feel that moment the car starts adding fuel because if you’re only engine braking to a stop your car will get near that idle rpm and your engine will start adding power to avoid a stall, and your braking will diminish.
For the car to be “running” in those cases, the engine just needs to be turning to keep the alternator and potentially the power steering pump going. When engine braking, the rotation of the tires is locked to the rotation of the engine, so the inertia of the car keeps the engine turning without needing to use fuel.
Depends on the ignition system and everything of course, but it can be true.
The fuel injectors are off when engine braking. It is the momentum of the car that keeps the engine running/rotating. That is why you are slowing down more rapidly because you’re losing momentum into the engine.
The most difficult part lf stanrting a car is gettinf the pistons to move, if your engine still has inertia (if you are going downhill for example) you can completely cut the fuel injection and it can starts again because the pistons that are still moving will compress the gas (and for diesel engine that’s enough to ignite given enough temperature in the block, for gasoline the spark plugs will work as usual).
Of course if the engine has low inertia (it’s spinning too slowly) the car will stall, but probably the electronic injection will compensate.
If you drive manual you can go down a hill without burning a single drop of fuel, not sure if automatic are smart enough to do it.
In my car with automatic CVT transmission, I have to downshift using the paddle shifter in order to force it to do engine braking. It doesn’t do any engine braking if I simply let the gas pedal go.
It is probably still “engine braking” in that the engine is putting resistance on the wheels, but it’s probably opening the throttle and halting fuel injection in order to maximize your coasting/minimize rolling resistance.
CVTs usually use a clutch rather than a torque converter, so they like to stay “locked up” to minimize wear.
In my car (it has a cvt transmission with a torque converter instead of a clutch), it doesn’t seem to do any engine braking though. In a steep downward incline, if I let go of the gas pedal, the car would just keep getting faster and faster without any resistance at all. Force a downshift and acceleration will stop, and the fuel efficiency indicator shot up which indicate it doesn’t use fuel at all (thus doing an engine braking).
The fact that things are able to float, despite of gravity pulling all objects towards the big mass of Earth. You would think that the push of gravity should be more than enough to overcome the slight fluid displacement that allows balloons and boats to push away from the Earth’s surface.
It’s actually interesting because when you consider the four fundamental forces of nature (gravity, electromagnetism, strong nuclear, weak nuclear) gravity is by far the weakest one. It’s not intuitive because gravity is the one we interact with most day to day and it has connotations of large objects like planets and stars. But it’s only a significant force when you have such large objects. Two magnets technically are gravitationally attracted to each other (like all things that have mass) but it pales in comparison to the magnetic forces.
Gravity makes up for what it lacks in force with its range and also the exponential nature from things getting attracted to each other forming a point of more potent attraction and so on (it was more relevant in the beginning of the universe, but we’re still feeling its effects)
Think of the fact that pressure increases with depth, so when something is floating there’s a higher net pressure at the bottom than at the top which results in an upward force as the fluid tries to equalize.
The cool thing is that they’re floating because of gravity. Specially, the thing they’re floating in is heavier than they are, so the float medium gets pulled underneath the object.
So when your rowboat is floating, it can displace a certain volume of water and if it displaces more than that volume the water spills over the sides and it sinks. We talk about how many tons of water it’s displacing because that tells us what the total weight of the boat, you, cooler, beers, tackle and oars can be before the boat sinks.
You already knew that though. What might not be clear is what that weight measurement actually is.
Weight is the acceleration due to gravity that an object experiences. So if your rowboat is able to displace a volume of water that experiences more acceleration due to gravity than it and all it’s contents do, it will stay on top of the water in a state we call floating even though it and some of the contents may be more dense than water!
Now your rowboat is different than the balls in that floating glass ball thermometer your aunt bought out of sharper image in one very unique way: it can’t function when submerged! Those little suckers will go up and down all day, but once water starts coming in over your gunwales you gotta get rid of it or the boat sinks and won’t come up.
So there’s a point of no return where your boat can’t stay afloat any more.
When it displaces a volume of water that experiences less acceleration due to gravity than it and all its contents do, it and all its contents are pulled under the surface of the water. At that point, density determines what happens to the boat and it’s cargo. The boat itself may be denser than an equivalent volume of water and sink, but the beers and cooler are less dense than water and they float. You may be more dense than water, but instead of sinking you tread water and push your head up above the surface.
When the swamped boat sinks, it experiences more acceleration due to gravity than the water around it and pushes that water aside on its way to the bottom of the lake. The beers experience less acceleration due to gravity than the water around them so the water is pulled underneath them and they float. The air pocket inside each can also lends some displacement to the cause.
So the volume of fluid displaced isn’t “slight”. It’s exactly what gravity itself requires for objects to sink or float!
Let’s stick with the iron in your hemoglobin for some more weirdness. The body knows iron is hard to uptake, so when you bleed a lot under your skin and get a bruise, the body re-uptakes everything it can. Those color changes as the bruise goes away is part of the synthesis of compounds to get the good stuff back into the body, and send the rest away as waste.
In the other direction, coronaviruses can denature the iron from your hemoglobin. So some covid patients end up with terrible oxygen levels because the virus is dumping iron product in the blood, no longer able to take in oxygen. I am a paramedic and didn’t believe this second one either, but on researching it explained to me why these patients were having so much trouble breathing on low concentration oxygen… the oxygen was there, but the transport system had lost the ability to carry it.
I don’t have iron issues so I haven’t completely fact checked this, but I have read in various places that using cast iron skillets to cook with does add more iron to your foods to help supplement.
I would think an enameled skillet would not provide any extra iron; the glass that the enamel is made of forms a barrier between the iron and everything else. That’s nice because you don’t have to worry about it rusting any more, but it also means no iron in your food.
Yeah, its like a trade off. I’m uneasy about having to season a pan for some reason. I’m pretty sure I have OCD and if I can’t clean a dish the way I clean my other dishes it bugs me to some extent.
Ah gotcha, I can understand how that might be a thing; cat iron is definitely something you treat differently than other dishes. There’s a whole fascinating level of nerdery to proper seasoning, but it’s definitely special cookware that doesn’t fit the usual patterns.
Yeah, I stay away from the nonstick stuff as well, for the same reason. Just thought that thinking of seasoning as a nonstick coating target than as something to be cleaned off might be helpful, though I totally get it if not.
Before using cast iron daily, when I donated blood my iron levels were regularly at the lowest allowable limit or sometimes too low to donate. Once I started cooking with cast iron, I started getting comments about how great my iron levels are every time I donate.
To piggy back on your “bizarre fact”, the same type of iron can be found added to cereal.
I remember several times in school we’d do a science demonstration where we’d smash up Cheerio (or a knock off) brand ceral, mix the powder with water and slowly drag a magnet through the slurry. Every time the magnet would be pulled out of the mix, there’d be more and more tiny iron bits.
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