The fact that planes are kept in the air by the shape of their wings, which forces air to go over at a pace when it can't push down on the wing as hard as it can push up from underneath. It's like discovering an exploitable glitch in a videogame and every time I fly I worry that the universe will get patched while I'm at 10,000 feet.
I remember reading a couple years ago that's not actually how plane wings work. The actual way is much more complicated and hard to explain and hard to teach, so they just teach it this way because its an intuitive mental model that is "close enough" and "seems right", and it really doesn't matter unless you're a plane wing designer.
The basic way an airplane works actually is simple and intuitive: it meets the air at an angle and deflects it downward. The equal and opposite reaction to accelerating that mass of air is an upward force on the wing.
There is, of course a whole lot of finesse on top of that with differences in wing design having huge impacts on the performance and handling of aircraft due to various aerodynamic phenomena which are anything but simple or intuitive. A thin, flat wing will fly though, and balsa wood toy airplanes usually use exactly that.
The false thing they teach is that air has to go over the longer side faster. Actually, it's under no obligation to meet back with the same air on the other side, and doesn't in practice. The real magic bit is the corner on the back, which is not aerodynamic and "forces" air to move parallel to it (eventually, as the starting vortex dissipates).
The pressure difference from different volumetric flow speeds is real, it's just not that straightforward to produce, because air mostly does whatever it wants. A lot of aerodynamics is still more art than science, and it's even possible the Navier-Stokes equations it's based on fail under certain conditions.
Dude! I told you in confidence not to share that info.
I guess I have no choice but to share that @spittingimage@lemmy.world has the world's biggest human anus. It's been a scientific mystery about how it got to be so big.
Retinal photosynthesis, also known as the Purple Earth Theory. Colours are weird. Earth plants absorb red and blue light, they look green to us because that’s the wavelength of light that cannot be used by the chloroplasts.
It’s hypothesized that this was advantageous on Earth because blue light goes further into water than the other wavelengths, facilitating the development of photosynthetic algae
Retinal photosynthesis is another viable chemical chain reaction that could be used to create ATP (usable biological energy) from light.
It’s another molecule similar to chlorophyll, but it absorbs green light instead of red/blue - alien planets might be purple!
There’s a viable parallel evolutionary pathway that leads to plants with magenta leaves
So humans vision is much more sensitive to green than other colors. it's why camera sensors are 50% green 25% red 25% blue. Which makes sense as being able to detect small differences in plant cover is useful in both detecting predators and prey.
Actually, there's some contradicting evidence that came up recently-sh. If you factor in the challenge of not being fried by the very incoming light you need, every photosynthesiser is about the right colour for it's environment.
By that, alien planets would be coloured depending on their star type, and the ancient cyanobacteria of Earth were probably green too.
Our Sun is humongous. UY Scuti's radius is 1700 times larger - 185300 times larger than the Earth's. And then there's TON 618, which has a mass 66 billion times larger than our Sun's.
And even those are barely grains of sand when compared to solar and galactic structures... It is humbling, to say the least.
Edit 2: I deleted the previous edit, because my first observation is correct (scale is maintained when going from comparing radii to comparing diameters...), which is why I have an Arts degree.
Just in general how spread apart everything is in space is wild. As big as planets and stars are, there’s still unfathomably more nothing in between them all. And that’s in a solar system where it’s comparatively “dense” compared to interstellar space let alone intergalactic. It makes the vastness of the ocean look tiny.
My old school had a scale model of the solar system. It used the same scale for the planets size and distance. The sun was a 12" ball on one end of campus. Around campus were poles with little glass domes on top inside were tiny pins with little planet models on them.
the implication of einsteins mass-energy equivalence formula is mind-blowing to me. one gram of mass, if perfectly converted to energy, makes 25 GWh. that means half the powerplants in my country could be replaced with this theoretical "mass converter" going through a gram of fuel an hour. that's under 10 kilograms of fuel a year.
a fun fact: for the most efficient mass energy conversion, you need a huge spin black hole (preferably naked). Then you can get about 42% conversion. (there was a minute physics video about it i think)
Because this is a science thread I'll be a bit pedantic. Mostly because I think it's an interesting topic. It's a mass-energy equivalence (≡) and not just an equality (=) they are the same thing.
So it's meaningless to say convert mass into energy. It's like saying I want to convert this stick from being 12 inches long to being 1 foot long.
You can convert matter (the solid form of energy) into other types of energy that are not solid. But the mass stays the same.
It's like when people say a photon is massless. It has energy and therefor mass. It just has no rest mass. So from the photons frame of reference no mass but from every other fame of reference there is mass.
Yep. The Higgs field interacts with matter, both holding the waves it's made up of "in place" (so it can seem macroscopically like it's not a wave), and carrying a bunch of energy.
There's also mass-energy just in the very fast and powerful internal movements and fields of the nuclei and the individual protons and neutrons (which are made of gluons and quarks). Not sure about the breakdown off the top of my head, though.
If you blew up an atomic bomb in a magically indestructible sealed container, it would stay the same weight, just with a noticeable contribution from pure electromagnetism now.
The size of the universe and the distance between everything in it. It takes about 8 minutes for light from our own sun to reach us. And the observable universe is about 5,859,000,000,000,000,000 times larger than that! That is quite a trip. I would need about 293,283,000,000,000,000,000,000,000 charging stops with my electric car to get to the end. I think I’ll pass.
(Someone smarter than me will probably find out that my math is wrong)
What I find mind blowing about the scale of the universe, is that on a logarithmic scale from the smallest possible thing to the largest possible thing, humans live at almost the exact centre.
It’s so absurdly big. Our galaxy (the Milky Way) is estimated to have between 100 and 400 billion stars in it. For a long time we thought our galaxy was all there was, it wasn’t until 1925 when Edwin Hubble was able to prove that M31 was not a nebula or cluster of stars in our galaxy, but in fact an entirely different galaxy altogether that we realized there are more galaxies out there.
Look at the Hubble Ultra Deep Field picture
This was a taken by pointing the Hubble Space Telescope at a basically empty bit of space 2.4 by 2.4 arcminutes in size (for comparison, the moon has an apparent size of about 30 arcminutes, or half a degree). So an absolutely tiny part of the sky. It contains about 10.000 galaxies.
The observable universe is estimated to have between 200 billion and 2 trillion galaxies in it, with on average about 100 billion stars per galaxy. It’s absolutely mind blowing.
I dunno whether it counts: but that science has effectively cured AIDS.
In 2004, 2.1m people died from it. Twenty years later that figure was a little over a quarter at 630k. The goal for 2025 is 250k. I think that's absolutely remarkable.
As a child in the 80s I was terrified of AIDS. It made me low-key scared of gay men because the news made it sound like I could I could get it from any one of them. And here we now are, able to provide a medication that can almost completely ensure that you will never be infected by HIV.
You can observe the chirality of some molecules from the crystals they form, sometimes they twist clockwise, other times they twist counter clockwise. Which way they twist is dependent on their molecular structure.
Gravitational time dilation is an effect of Einstein's General Theory of Relativity. Places with stronger gravity would then have time pass more slowly compared to earth. The opposite is also true.
If math is actually uncovering fundamental laws of the universe, rather than just describing it at various scales, then there's a chance we can rewrite reality with our own set of rules that would render the current ones incompatible (by Gödel's-IT).
Tegmark's MUH is the hypothesis that our external physical reality is a mathematical structure.[3] That is, the physical universe is not merely described by mathematics, but is mathematics — specifically, a mathematical structure.
Look, I only heard about this concept, so maybe there's more to it, but branches of mathematics are just a set of rules that we create.
Sometimes these rules can be applied to real systems, in our reality, and that helps to describe and understand the universe.
But it's totally possible to come up with infinite nonsensical, useless mathematical systems that have nothing to do with the universe. The existence of these doesn't mean that we have or could rewrite reality.
If our universe is bound by the laws of mathematics (big IF), then any theorem discovered within it has to be consistent or incomplete w.r.t it.
If a theorem is discovered that upends math as we know it, then the repercussions could be cosmic.
Again, big if about the universe being bound by the laws of maths
That our species took millions of years of evolution and the chance for it to be exactly this way was so infinitesimal... And yet here we are, chasing arbitrary numbers on paper-slices and in some bank-account while also being sexists, racists, whatever-ists and destroying the very rock we exist on.
Yet things like star trek are called utopia not actual-ia.
Yes, but have you considered [INSERT OUTGROUP] are bad? /s
To play devil's advocate, considering that in evolutionary terms we just left the trees now, we're doing okay, honestly. I just don't know if it will be enough.
When you say "All the atoms and molecules are still in the same places", I can't say I agree. It is the change of chemical composition that renders our body dead. Or should I say, death is defined to be such a chemical composition.
To be fair, a perfectly fine but dead body is impossible to observe since the process of dying is usually the result or accumulation of injuries or disfunctions. For this experiment you either have to kill somebody without altering their body in the slightest or instantly conjure a perfectly intact body without any life in it.
Life is a process of systems within (and outside of) an entity interacting consistently with each other.
Why would a static screenshot of exact chemical composition matter for any process that involves a moving or animated body?
A bricked computer with a corrupt boot loader is chemically the same as one that actually works.
A car is chemically the same before and after you turn the key on its ignition.
A lightbulb is comprised of the same substances whether or not its turned on or off.
... Part of the difference between an alive and a dead body, is that the chemical reactions that constitute animating the thing into being alive ... have stopped.
A dead body is not metabolizing. It has no brain activity. The chemical reactions required to keep its heart beating are no longer happening.
@ThatWeirdGuy1001 That's because it's not only ingredients that are important but order, relation and interaction between them also is. Hypthetically, in terms of *elements*, in a closed system, the engine that has burned through its fuel is no different than a freshly fueled one. But the engine has reordered them in order to extract some energy. So they are not chemically the same, strictly speaking.
95% of our DNA is basically useless gibberish. Since the evolutionary incentive to shorten it is so small in our case, all sorts of processes "hijack" it to propagate themselves without giving anything back.
Recent studies have it at closer to 92% 'junk' DNA, and 8% actively coding.
Also, a lot of non-coding DNA does actually serve other useful functions, it just doesn't actively code.
It could play a role in epigenetics, ie the regulation of what active coding sequences are active and when, it could be telomeres that prevent DNA strands from unravelling at the ends, it could be binding and scaffold sites that assist in the structural stability and integrity of the chromosome.
DNA can be functional, without being active-coding.
Only regions that are both non coding and also totally non functional are truly 'junk', but we keep consistently finding more ways that 'non functional' regions are actually functional.
8% coding DNA? Wow, that's quite a jump from the 2% coding and 5-10% conserved DNA that used to be cited. Full-genome sequencing has truly (metaphorically and literally) filled many gaps in the study of our genome...
For the sake of discussion, let's say on the one hand a magic man intelligently designed life and all that. And on the other hand we have it arise and evolve over the course of billions of years of random atomic interactions and genetic mutations. I honestly find the second one far more amazing, wondrous, amazing, and mind blowing.
Exactly! If it was just magic, things seem underwhelming all of a sudden - like why couldn't you give zebras wings or laser vision? Why not have a grizzly bear with chainsaw arms on wheels? No ant computers or space octopuses? Makes nature seem arbitrarily limited and uncreative (and cruel) in comparison to what unlimited magic could accomplish.
(Just to be clear, this is not an argument against God since you could always just say "god set nature up to allow for natural evolution and has reasons for not going all out with creativity" - it's unfalsifiable but you could believe that)
@bradboimler@lemmy.world
There's no "magic man" and "magic". There are a lot of theories of magic with lots of details. If you'd dive deeper into the topic, it would be as mind blowing for you as a theory of evolution. So you just choose a theory which looks more interesting for you.
Hon I think you maybe misunderstood your chem class.
Carbon is carbon is carbon and doesn't know or care if it's in a living body.
Carbon-14 has a half life of 5700 years. This means that through random decay, the approximate rate of decay is one half of a given amount every 5700 years, this of course breaks down when you reach the single-digit quantities of atoms.
Now, this has nothing to do with the stability of an atom of regular-ass carbon-12, your common garden variety carbon, which is extremely stable and would require outside influence to decay into another isotope.
Ahhh I misremembered. It was this "The average carbon atom in our bodies has been used by twenty other organisms before we get to it and will be used by other organisms after we die."
As you established that is not true, however you can add some of that carbon from some body and add it to the iron from the blood of 400 other human bodies so you can forge one nice sword.