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.
Your bones are made of calcium, which is also a metal. You’ve got a metal frame inside your body.
Your bones are not dead rocks! They are living organs that happen to have a lot of sturdy calcium structures in them. They do a lot of other stuff besides hold your body up. They store minerals for all the other stuff your body needs minerals for; that’s why osteoporosis is even a possible failure mode. Your bone marrow produces white blood cells for your immune system, too.
The fact that calcium is a metal is the reason why bones can be detected in X-rays.
(I’m pulling this out of my ass and I’m too lazy to look it up to see if it’s actually true.)
It’s true!
Source: my ass too!
Hate to burst your bubble, but the calcium inside your bones is not in a metallic form but as calciumphosphate. So no metal frame but one made of a salt I guess.
The thing that started this conversation is hemoglobin, which is also not metallic but a protein. I don’t think anyone was confused and thought that there’s actually shiney silvery elemental metallic calcium in our body.
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Now I know why many people act so salty. Feelings are chemistry.
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.
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!
Wow, a reply that goes above and beyond, have some Lemmy Silver 🥈
Ty it’s probably deeply and fundamentally wrong but my high school physics teacher isn’t here so…
Gravity likes water even more than it likes boats.
There was this one huge boat, one might even call it’s size Titanic compared to boats, that gravity really loved more than water
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.
Gravity is pretty weak, all things considered. A tiny magnet can easily overcome the entire Earth’s gravity on a small metal object.
The mitochondria in all but your blood cells are a different species than us with their own separate DNA.
They have their own separate genetic code, yes, but that doesn’t make them a separate species, because they aren’t a distinct organism at all. They don’t exist in the absence of our cells.
Maybe it is semantics as you are correct but others do consider them a separate species that just happen to live in our cells. https://qbi.uq.edu.au/brain/brain-anatomy/mitochondria-what-are-they-and-why-do-we-have-them#:~:text=Two separate species became one,in every other human alive.
You mean the power house of the cell?
Wait what?
A book that I love that covers this in an accessible manner is “Power, Sex, Suicide: Mitochrondria and the Meaning of Life” by Nick Lane
Basically, it looks like a single cell, predatory amoeba of some sort engulfed a parasitic bacterium that was the ancestor to mitochondria, and instead of being digested, it ended up living inside the amoeba, helping to produce energy.
This is a big deal because the way that cells harness energy is by doing some cool biochemistry across a membrane. When a cell has to rely on its main, cell membrane to do this, then the energy production is proportional to the cell’s surface area, which means that it’s proportional to the cell’s radius squared (E ∝ r^2 ) . However, the energy requirements of the cell are determined by its volume, which means that energy requirements are proportional to cell radius cubed ( E ∝ r^3 ). For small numbers the difference between r^3 and r^2 isn’t much, but as radius increases, the cell volume far outstrips its surface area, which means that there was an upper ceiling on how big a cell could get while still fulfilling its energy requirements.
Mitochrondria allow cells to break this size limit by decoupling energy production from cell size, because scaling up energy production is as simple as having more Mitochrondria. Mitochrondria have their own independent genome - in the years since the endosymbiotic event, the mitochrondrial genome has shrunk a lot, because it’s sort of like moving in with a friend who already has a house full of furniture - no sense in having duplicates.
That’s so rad. Thanks!
It still weirds me out how ancient organisms could pick up biochemical mechanisms like Kiryu learns fighting styles. “That’s rad!” and now we have mitochondria.
Yeah mitochondrial RNA is separately inherited and only from the mother, because the egg cell has mitochondria whereas the sperm does not.
i love my powerful little friends
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.
The body knows iron is hard to uptake
I had to take iron supplements in the past because my periods were so bad that I would lose my vision and pass out from loss of blood.
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.
There are also iron “fish”, or fish shaped blocks of iron, that can be used while cooking which do the same thing!
That is super interesting information and kind of makes sense with the seasoning involved.
But I recently learned you can get different enamel types that you don’t have to season.
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, for some reason it gets to me that there is something left on the pan on purpose. My brain just wants me to scrub it all off.
You’ll just develop a new ocd about how sexy you can make your cast iron look. They’re the only dishes related thing I enjoy cleaning up.
lmao that’s definitely not how OCD works.
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.
Please tell us more or other things!
A day on Venus is longer than a year on Venus. One day takes 243 Earth days, while a year takes 225.
Maybe it’s not “well known”, but still interesting in my opinion.
Wouldn’t spinning in the opposite direction indicate that it’s axial tilt is flipped or something?
The leading theory is a moon sized object hit it with enough force to spin it backwards.
The energy used to reverse the existing motion might explain why it’s so slow
I’ve seen this fact somewhere before, but I still am unable to grasp it in my mind
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.
Now, to confuse people further, read about the difference between a solar day and a sidereal day.
How does this affect its gravity?
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)
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.
Interesting.
It doesn’t. Gravity is related to its mass, not it’s orbit or rotational velocity.
Ok hold up so the way I’m understanding this is that its tilt (day) is slower than it’s rotation around the sun (year). Is that right or am I way off?
Yep, and as a result, the ‘movement’ of the sun across the Venusian sky during a day seems to change direction (I think?)
Yeah the Venus makes a lap around the sun in less time than it does a rotation around itself relative to said sun’s position in its sky.
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.
Not exactly bizarre, but it’s fun to learn that the delicious fragrance of shrimps and crabs when cooked comes from chitin, and chitin is also why sautéed mushrooms smell/taste like shrimps.
And since fungi are mostly chitin, plants have evolved defenses against fungi by producing enzymes that destroy chitin, which is how some plants eventually evolved the ability to digest insects.
EDIT: a previous version of this post mistakenly confused chitin with keratin (which our fingernails are made of). Thanks to sndrtj for the correction!
Wow I didn’t know this and I’ve never felt a similarity between seafood and mushrooms either in flavour or smell. But, still a cool fact.
It’s one of those things that feels really obvious if you cook a lot of east/south Asian dishes - shrimp sauce and mushroom soy sauce have a pretty similar aftersmell to them because they’re so concentrated
I’ll be honest, I’m not much into cooking Asian. I’m also not a frequent crustacean eater, but I eat mushrooms regularlish. I’ll pay more attention from now on, but I would have never otherwise thought of making a link between the two
Chitin is not produced by mammals.
Fingernails are composed primarily out of keratin (same as hair and skin).
Huh. Oddly I am allergic to shrimp and lobster, but love mushrooms. To me they don’t smell the same though. Though this fact probably explains why veg oyster sauce is mushrooms.
Queuing theory can have some fun surprises.
Suppose a small bank has only one teller. Customers take an average of 10 minutes to serve and they arrive at the rate of 5.8 per hour. With only one teller, customers will have to wait nearly five hours on average before they are served. If you add a second teller the average wait becomes 3 minutes.
Can you elaborate on the math here? (I believe you, I just want to understand the simulation parameters better).
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Aren’t they arriving slightly slower than can be served, according to these numbers:
If one customer takes 10 minutes to serve, you can serve 6 customers in an hour
and you get 5.8 customers every hour, which is less than 6
So you serve 6 customers, meaning you have a leftover capacity of 0.2 per hour or 1 extra customer every 5 hours
Maybe the numbers are switched over or I am misunderstanding something
Edit: nevermind, read the link in the thread and realised I treated the average as the actual serving time and I’m guessing that’s what makes it non intuitive. I’m still not entirely clear on how it works.
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They’re arriving slower than they can be processed. So the line shrinks slowly it there’s a line.
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Also, in this simulation are the customers arriving in equally spaced intervals or is random arrival time within the bounds assumed?
In the linked article they are arriving randomly. It takes 10 minutes per customer and they arrive every 10.3 minutes.
Not OP, but this website should explain everything.
Thanks! This article really clears up a lot of the details that help the simulation make sense.
Assume the bank opens up to a long line and it makes sense.
Concepts coming from quantium mechanics take you into a rabbit hole. 2022 Nobel winning experiment that proved universe is not locally real.
Can you elaborate on what that means? “Universe is not locally real”? How do we know what is real? What precisely does ‘local’ mean? Real relative to what?
Marcus Chown’s book is a good primer on quantum theory, but it will make your head spin.
(you’ll understand the dad joke after you’ve read the book)
In quantum mechanics, the concept of “locality” and “realism” are often discussed in the context of the EPR paradox and Bell’s theorem. In a “locally real” theory, the properties of particles are well-defined independently of measurement (realism), and no influences can propagate faster than the speed of light (locality).
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Realism: In a “realistic” theory, the properties of a system exist independently of observation. For example, if you have an electron, the idea is that it has a definite spin direction whether or not you measure it.
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Locality: The principle of “locality” holds that physical processes occurring at one place do not depend on the properties of objects at another place that is spacelike separated, which would require information or influence to travel faster than the speed of light.
However, quantum mechanics challenges these intuitive notions. Experiments with entangled particles suggest that the properties of one particle can instantaneously affect the properties of another distant particle, seemingly violating locality. Meanwhile, the superposition principle suggests that particles don’t have definite properties until measured, challenging realism.
In my opinion, the breakdown of “local realism” is one of the most unsettling and fascinating aspects of quantum mechanics. It forces us to reconsider our intuitive understanding of reality and has implications for fields like quantum computing and quantum cryptography.
— ChatGPT4
As physicists, I can confirm, this is not bad explanation.
Reality is like society: a strong consensus is good enough and as good as you can get.
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Ok. I’m gonna give an example that will be slightly wrong if we nitpick, but it will give you an idea.
Lets take the old philosophical idea “if a tree falls in a forrest and theres nobody to hear it, does it make a sound?” and modify it for this example.
“If you are not there to observe will the tree in the forest fall?”
If you are not there to observe the tree will be in all possible states. Two notable states being “it has fallen” and “it is still standing” that exist simultaneously.
If you go in to the forest and observe, one of the states will randomly become your reality according to certain probability amplitude.
You don’t necessarily have to go in to the forest to observe the tree. You can send your buddy who will then tell you the state.
As your friend is returning back from his observation, there’s actually two friends walking back to you. He is “entangled” with the tree. When he opens his mouth, one of them is randomly selected as your reality.
Entity checking the state of the tree does not have to be a living consciousness. It can be a particle, that interacts with a particle, that interacts with a particle, that interacts with you. You are not conscious of the trees state, but the information is delivered to you and for you there is now only one state for the tree.
So quantium level information is constantly delivered to you and your reality is weaving itself around you through this “decoherence”
now you see how my first two examples were false. Quantium decoherence is so much faster than you or your buddy, that you can only catch this mechanism at work on quantium level.
…and “local” basicly just means that the experiments result is true, as long as nothing can transfer information faster than light. So far nothing has.
Heard about it. I initially thought the universe should exist regardless whether someone is there to observe it or not…
…but then I also studied quantum mechanics, so I am not really in a position to say anything…
There is about 8.1 billion people in the world. Assuming romantic cliches to be true and that we all have exactly one soulmate out there, we would have a very hard time sifting them out. If you were to use exactly one second at meeting a person it would take you 257 years to meet everyone alive on earth at this moment, which due to human life span being significantly shorter and the influx of new people makes the task essentially impossible without a spoonful of luck. Moral of the story: If you believe you have found your soul mate, be extra kind to them today.
I mean, you should be extra kind to most people most of the time. Comunism begins at home.
Soul mates are made, not found. You get with someone compatible to you, and through the sharing of experiences and affection, if nothing goes excessively wrong, they become unique for you.
Well said!
Definitely agree and beautifully put :)
Soul mates are made, not found. You get with someone compatible to you
That catch is, you need to find that someone in the first place, and that takes a bit of looking around. So in effect, soul mates are found.
It gets much easier once you factor in that you, yourself, aren’t static and constant. The task isn’t to find someone capable of becoming perfect for you, it’s finding someone whose compatibility and willingness when taken into account with your own offers a fair chance to grow into a symbiotic relationship.
You find a partner, who then MAY become a soul mate
it would take you 257 years to meet everyone alive on earth at this moment
Sounds like a terrible sorting algorithm /jk
If you were to use exactly one second at meeting a person it would take you 257 years to meet everyone alive on earth at this moment
Well I don’t need to meet everybody. There’s no need to meet anyone who doesn’t match my sexual preferences, so that’s half right there. Then we can also cut everyone who’s sexual preferences I don’t meet, as well as anyone outside of a given age range (most of the people on earth are much younger than me and would be inappropriate for me to date). We can probably get that down to about 50-60 years. (At one second per person).
The thought experiment was just an attempt to show how hard it is to wrap our minds around big numbers. Even a tangible number such as the amount of people in the world.
There’s a giant ball of extremely hot plasma in the sky and we aren’t supposed to look at it. What is it hiding? Surely if someone managed to look at it long enough, they would see the truth!
I often used to look at it as a child, however the adults wouldn’t let me. I knew there was some ulterior motive behind it.
Scientists look at it. That’s where they get all their sciencing from. The forbidden knowledges comes from the sun.
“You look unhealthy! You should go stand in that really large room and absorb the radiation from that gigantic space-based fusion reactor more!”
You’re right, that sounds like a great idea.
I’ve seen some of its secrets during the eclipse. It’s an angry, writhing tentacled thing. Be thankful it’s so far away.
Humans can smell rain better than a shark can smell blood.
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.
The speed of advancement from the industrial revolution to present.
The relatively short time humanity has been around
The universe is finite but expanding
The Monty Hall problem
The absolute scale of devastation created by humanity
The speed of advancement from the industrial revolution to present.
This one makes Fermi’s Paradox far more confusing and terrifying to me. The time it took to go from agriculture to the steam engine is nothing compared to the age of the universe, absolutely nothing, and from the steam engine to modern technology is fuck ton nothing.
An intelligent species could go from stone age technology to nuclear weapons in the blink of an eye.
And that’s just life as we understand it. We have no idea if we’re the equivalent of Flatland in a higher spatial dimension or something. There could be stars with entire civilizations of plasma-based intelligent life churning inside of them. There could be intelligent civilizations lurking in each and every single subatomic particle.
It’s possible no matter how far out or far in we look, we just keep finding more universe, more space for something to inhabit, forever…
As they said on
, if we look everywhere and we’re the only intelligent species anywhere in this universe … well that would be weirder than if life is hiding all over the universe.We humans are roughly as big compared to atoms and subatomic particles as we are small compared to the largest structures of the observable universe
The funny thing is that sounds exactly like what he would say.
I may be wrong but I thought it was generally believed that the Universe is infinite (or at least that that was the most common belief among those that are qualified in the field)
Edit: I mean infinite in Space, of course it hasn’t existed forever
Edit2: I quickly read this article https://www.swinburne.edu.au/news/2021/08/Is-space-infinite-we-asked-5-experts/ where the 3 astronomers answered maybe, yes, and yes. Whereas the two non-astronomers answered no. Since this seems to agree with me I will believe that this is correct and not investigate further
The speed of advancement from the industrial revolution to present.
The telescoping nature of progress
There’s about 25 blimps in the world, and only 40-50 pilots.
doesn’t really fit the thread, but i was surprised when i learned that the empire state building has a blimp docking station
They really thought blimps were gonna be a thing.
They should have been
this is super cool.
That looks like sea creatures mating
Women have orgasms
It would be less funny if there were no downvotes
reported for misinfo
