Ask HN: What scientific phenomenon do you wish someone would explain better?

Quantum Computers. Not like I'm five, but like I'm a software engineer who has a pretty decent understanding of how a classical turing machine works. I can't tell you how many times I've heard someone say "qubits are like bits except they don't have to be just 1 or 0" without providing any coherent explanation of how that's useful. I've also heard that they can try every possible solution to a problem. What I don't understand is how a programmer is supposed to determine the correct solution when their computer is out in some crazy multiverse. I guess what I want is some pseudo code for quantum software.

Macroeconomics. Central banks are &quot;creating&quot; a trillion here, a trillion there, like nobody&#x27;s business. But what are the consequences? What is the thought process that central bankers have gone through to make these decisions?<p>Also why, exactly, are they buying the exact assets that they are buying (govt. debt, high-yield bonds, etc..) and why not others (e.g. stocks or put money into startups)? And then, what happens if a debtor pays back its debt? Is that money consequently getting &quot;erased&quot; again (just like it&#x27;s been created)? What happens if a debtor defaults on its debt? Does that money then just stay in the economy, impossible to drain out? What is the general expectation of the central banks? What percentage of the debt is expected to default and how much is expected to be paid back?<p>And specifically in the case of central banks buying govt. debt: Are central banks considered &quot;easier&quot; creditors than the public? What would happen if a country defaults on a loan given by a central bank? Would the central bank then go ahead and seize and liquidate assets of the country under a bankruptcy procedure to pay off the debt (like it would be standard procedure for individuals and companies)?

I would like to understand how cellular biology processes actually work. Like, how do all the right modules and proteins line up in the right orientation every time? Every time I watch animations, it seems like the proteins and such just magically appear when needed and disappear when not needed [0]. Sometimes it&#x27;s an ultra-complex looking protein and it just magically flys over to the DNA, attaches to the correct spot, does it&#x27;s thing, detaches, and flies away. Yeah right! As if the protein is being flown by a pilot. How does it really work?<p>[0] <a href="https:&#x2F;&#x2F;youtu.be&#x2F;5VefaI0LrgE" rel="nofollow">https:&#x2F;&#x2F;youtu.be&#x2F;5VefaI0LrgE</a>

I find most explanations of the Equivalence Principle that lies at the foundation of General Relativity to be very lax.<p>To wit, the idea is that you cannot distinguish whether you are in an accelerated frame or in a gravitational field; alternatively stated, if you’re floating around in an elevator you don’t know whether you’re freefalling to your doom or in deep sideral space far from any gravitational source (though of course, since you’re in an elevator car and apparently freefalling... I think we’d all agree on what’s most likely, but I digress).<p>Anyway, what irks me that this is <i>most definitely not true</i> at the “thought experiment” level of theoretical thinking: if you had two baseballs with you in that freefalling lift, you could suspend them in front of you. If you were in deep space, they’d stay equidistant; if you were freefalling down a shaft, you’d see them move closer because of tidal effects dictated by the fact that they’re each falling towards the earth’s centre of gravity, and therefore at (very slightly) different angles.<p>Of course, they’d be moving slightly toward each other in both cases (because they attract gravitationally) but the tidal effect presents is additional and present in only one scenario, allowing one to (theoretically) distinguish, apparently violating the bedrock Equivalence Principle.<p>I never see this point raised anywhere and I find it quite distressing, because I’m sure there’s a very simple explanation and that General Relativity is sound under such trivial constructions, but I haven’t been able to find a decent explanation.

Sort of meta, but I always shudder when someone says that science has &quot;proven&quot; something.<p>What sets science apart from most other methods of seeking answers is its focus on <i>disproof</i>. Your goal as a scientist is to devise experiments that can <i>disprove</i> a claim about the natural world.<p>This misconception rears its head most prominently in discussions at the intersection between science and public policy. Climate change. How to handle a pandemic. Evolution. Abortion. But I&#x27;ve even talked to scientists themselves who from time to time get confused about what science can and can&#x27;t do.<p>The problem with believing that science proves things is that it blinds its adherents to new evidence paving the way to better explanations. It also leads to the absurd conclusion that a scientific question can ever really be &quot;settled.&quot;

I don&#x27;t know if this would be my &quot;one question&quot; if I could ask the most brilliant minds in science, but something that always bothered me:<p>When I took physics they basically said &quot;at first scientists were disturbed by the fact that magnets imply that two objects are interacting without any physical contact, but then Faraday came along and said &#x27;the magnets are actually connected by invisible magnetic field lines&#x27; and that resolved everything.&quot;<p>How does saying &quot;but what if there&#x27;s invisible lines connecting them&quot; resolve anything? To be clear, I&#x27;m not objecting to any of the actual electromagnetic laws or using field lines to visualize magnetic fields. It&#x27;s just that I don&#x27;t get how invoking invisible lines actually explains anything about how objects are able to react without physical contact.<p>(Also, it is not lost on me I that this question boils down to &quot;fraking magnets, how do they work?&quot;)

Crypto and practical security. I get tired of the circular “don’t roll your own crypto unless you’re qualified”. How does one become qualified? I don’t feel like I know how to evaluate many of the arguments people make for or against technologies people argue about on HN, such as Signal or different password managers. I feel like “security through obscurity” is a bad thing, and “layers of security” are a good thing, but isn’t all security obscuring something, and how does one evaluate whether a layer is adequate? “Just use bcrypt” - okay, help me understand!

Has someone that thought they were taking LSD <i>ever</i> turned into a permanent schizophrenic zombie or in a mental institution, or is it all urban legend. If someone that didn&#x27;t know they were predisposed to mental illness, is it applicable to dismiss their experience in order to maintain how safe LSD is?<p>If any of this is true, are there any sources aside from &quot;my friend&#x27;s friend&#x27;s brother took too much and now he is....&quot;, and what is the scientific explanation and do we know enough about the mind at all?<p>I feel like LSD has a lot of contradictory information out there, and the proponents feel the need to hand waive concerns away because it is &#x27;completely harmless and leaves your system in 10 hours&#x27;. But when nobody knows what they&#x27;re actually getting because it doesn&#x27;t exist in a legal framework, then it muddies the whole experience.<p>People say certain doses can&#x27;t do more effect than lower doses after a certain threshold. It seems like the same people say &quot;omg man 1000ug you are going to fry your brain!&quot;<p>What is the truth? If it &quot;just&quot; had an FDA warning like &quot;people with a family history of schizophrenia should not take it&quot;, that would be wildly better than what we have today.<p>Please no explanation about shrooms. Just LSD the &#x27;research chems&#x27; distributed as LSD.

If I buy a stock, does the price at which I agreed to buy it become the new share price on the stock exchange?<p>Every article on &quot;Where do stock prices come from?&quot; seems to just talk at a high level about supply and demand.<p>But where does the price come from at a nitty-gritty level? Is it an average of all existing offers or something?<p>Do different exchanges and stock-ticker websites have different formula for calculating share price?<p>If a very low-volume stock is listed at $4, and then I offer to buy a share for $100, does the NYSE suddenly start listing its price at $100?

Quantum spin. Electrons aren&#x27;t really spinning, right? But why do we call it spin? I know it has something to do with angular momentum. What are the possible values? Is it a magnitude or a vector? Is there a reason we call it &quot;spin&quot; instead of &quot;taste&quot; or some other arbitrary name? How do you change it? What happens to it when particles interact?

Law. How much of it rests on technicalities, and how much do judges care about the essence of the facts of a case? You only hear about the weird outcomes on the news. For example, I was once working with an attorney because my landlord didn’t supply heat in the apartment. I started keeping a temperature log, but how would a judge know that the log was accurate? Do I need to prove that my thermometer is accurate... etc. In practice, no, but how can I better reason about what is “likely” vs not?

I consider that there are 4 levels of scientific writing.<p>1) news articles&#x2F;lay press - basically terrible and typically get things wrong<p>2) scientific lay press (scientific american, discover, science news) - get things right, but generally no data&#x2F;citations or nuance<p>3) journal summaries - get things right, citations and data for everything. Good summary of the latest scientific thought on a topic. Tend to push a point of view, which generally will be right, but that educated people can debate. Dont always show the data, but at least refer to it. These help you to get up to speed with the primary experiments that were used to establish current thinking.<p>4) first source articles - typically make claims too broad for the actual results. But has all data. Often times the claims don&#x27;t follow from the data at all. Generally have to work in the field to understand strengths and weaknesses of methods and you cant just take the conclusions at face value.<p>As a PhD student, I used #3 a lot to get centered on a space. To understand 4, I typically had to learn directly from my research advisor or other grad students that specialized in an area.<p>My point here is that you can find these summary articles in journals (microbiology, immunology,virology etc). They are published infrequently so can be hard to find, but they exist and you should look for them.

Subreddit &#x2F;r&#x2F;askscience does a good job at explaining science in plain words. I usually google &quot;site:reddit.com&#x2F;r&#x2F;askscience&#x2F; __QUESTION__&quot;.<p>The StackExchange sites have less coverage and answers tend to be more technical.<p>University websites return reliable answers, but often neither short nor accessible.

Bell&#x27;s theorem. It somehow proves that quantum physics is incompatible with local hidden variables, but I could never see an understandable explanation (for me at least) of just how it works.

Abiogenesis. I understand that this is not considered understood but I&#x27;d be interested in hearing a qualified scientist talk about how we get from &quot;dumb&quot; matter to self-replicating, goal-driven matter. The closest I&#x27;ve ever heard anyone get (in a personal conversation) is that chemistry is about transformation, so &quot;dumb&quot; matter isn&#x27;t really dumb in the sense that it&#x27;s static. Still lots of hand waving to get from baking soda and vinegar volcanoes to me typing this question, however.<p>What&#x27;s the playing field look like for proto-life? How &quot;smart&quot; are the simplest molecular interactions? What does almost-replication look like? Could we use a computational model for this?<p>Not sure how much of this is known, but I&#x27;d love to hear an expert paint a picture of their mental model of the subject.

Fourier Transforms. I&#x27;d wish I had a intuitive understanding of how they work. Until then I&#x27;m stuck with just believing that the magic works out.

• Magnetism. There are plenty of videos out there calling it the result of a relativistic charge imbalance. But I&#x27;ve never been able to use this point-of-view to practical use cases like understanding how permanent magnets work or how increasing the number of windings in inductors boosts the magnetic field strength. There were more situations I tried to put this POV into use but I can&#x27;t remember them off the top of my head.<p>• Qualia. What is this subjective experience that I know as consciousness? I&#x27;ve gone through Wiki, SEP and a fair number of books on philosophy and a few on neuroscience but I still don&#x27;t understand what it is that I experience as the color &quot;red&quot; when in reality it&#x27;s just a bunch of electric fields (photons). Why can&#x27;t I get the same experience — i.e., color — when I look at UV or IR photons? These too are the very same electric fields as the red, blue, green I see all the time.<p>• Photographic composition. I&#x27;m a designer. I know them. I use them. But only empirically. I just do not understand them at a neuroscientific level. Why does rule-of-thirds feel pleasing? Is the golden ration bullshit? My gut says yes but I&#x27;m unable to come up with a watertight rebuttal. Why do anamorphic ultra-widescreen shoots feel so dramatic&#x2F;cinematic? Yet to see an online exposition on the fundamental reasons underlying the experience. Any questions to artists are deflected with the standard &quot;It&#x27;s art, not science&quot; reply.<p>• Wave-Particle duality. &quot;It&#x27;s a probability wave that determines when a particle will pop into existence out of nothingness.&quot; okay, where exactly does this particle come from? If enough energy accumulates in a region of empty space, a particle pops into existence? What is this &quot;energy&quot;? What is it made of? What even is an electron, really? I&#x27;ve followed quite a few rabbit holes and come out none the wiser for it.<p>• Convolution. It&#x27;s disappointing how little I understand it given how wide its applications are. Convolution of two gaussians is a gaussian? Convolution in time domain is multiplication in frequency domain and vice-versa? How do these come out of the definition which is &quot;convolution is sliding a flipped kernel over a signal&quot;?

Lot&#x27;s of quantum related phenomenon here, but what keeps bothering me is that while I get it that light is both a wave and a particle, but I have no clue what that means. I mean, a wave of sound, is made from air particles, a wave of ripples in a pond is made of movement of water molecules. In the double slit experiment, it&#x27;s explained that the single photon has to be &quot;interfering with itself&quot;, so I don&#x27;t get it if by being a &quot;wave&quot; it means that the single photon is basically a bunch of &quot;magic&quot; photon ghosts that behave like a wave, but once it is measured or any other reason to &quot;collapse&quot; these ghosts &quot;disappear&quot;. I just don&#x27;t get what the &quot;wave&quot; of light&#x2F;radio wave is. Is it just an abstract concept of something that behaves like a wave but not the same as sound waves &#x2F; ripples since we simply don&#x27;t know? Or is it just a wave of these &quot;not yet collapsed&quot; probabilities of the photons locations that are interfering with each other right until we ask them to choose a location, then they just collapse magically into a single &quot;real&quot; photon. Another thing I don&#x27;t get is in the double slit experiment, a LOT of the measure before, measure after, etc, are told to be thought experiments, but it&#x27;s also claimed that someone managed to actually replicate them. Why isn&#x27;t there a video showing it? I obviously believe they happened, and understand why more or less (e.g. in the one photon at a time experiment, it&#x27;s spooky that over time you get the same pattern that indicates interference as if you shoot many) but the more spooky result is that thought experiment, that if you measure which slit the photon actually traveled through, you&#x27;ll see 2 slits on the screen vs the famous pattern. e.g. you&#x27;ll cause the wave to collapse back to particles. So any video of reproducing of that thought experiment or explanation why it&#x27;s so hard to reproduce, will be super helpful.

Flight. Apparently &quot;air flows faster on the top side of the wing, lowering the pressure&quot; is an incomplete explanation; I even heard we don&#x27;t completely understand why it works (?!?).

Why does time slow down&#x2F;go faster with movement compared to another object.<p>The well known example that if you travel into space you&#x27;d gain let&#x27;s say 5 years and people on earth 25 in the same time or so.<p>I just don&#x27;t get it and I can&#x27;t find any logic explanation.<p>For instance: Two twins who came to live exactly at the same moment in the year 2000 and both die on their 75th birthday at the same time. One travels into space, the other stays on earth. Earth-brother dies on earthyear 2075,space-brother dies in earthyear 3050 or so...<p>I know its Einstein&#x27;s point but that just doesn&#x27;t instantly make it correct to me.

What happens when you actually fall inside a black hole and what is the singularity.<p>I never really understood what happened really when the guy fell inside it in Interstellar and how come he started seeing all those photos. I just accepted it as Hollywood bs.<p>I know my question is based on a movie but would still like to know what will someone witness (assuming of course they somehow live)

Avogadro constant - I can accept the number, if someone can show me how, over a hundred years ago, without having every really seen a molecule, this number could be derived. Obviously no one ever sat there and counted them but I find it hard to believe, they could have decided this without being able to see it.

Why tardigrades are so hardy, how their biology is so different?<p>How immune system and medications work.<p>Why some plastics are recyclable and others are not.

Non-interactive zero knowledge proofs.<p>ZK proofs have a number of good explainers, mostly using graph colorings. Non-interactive versions, however, require quite a bit more than that explanation allows - and despite asking experts, I still haven&#x27;t found a good, basic explanation.

A non handwavy explanation of how does evolution result in such complicated and carefully orchestrated mechanisms, way beyond our engineering capability. The computer analogy of genetic algorithms certainly doesn&#x27;t explain much, they are not very effective, and if they were, we should be able to generate marvels of engineering with GAs and current computational power.

Mach&#x27;s principle. Why is there a &quot;preferred&quot; rotational frame of reference in the universe? Or as stated in this Wikipedia article,<p>&quot;You are standing in a field looking at the stars. Your arms are resting freely at your side, and you see that the distant stars are not moving. Now start spinning. The stars are whirling around you and your arms are pulled away from your body. Why should your arms be pulled away when the stars are whirling? Why should they be dangling freely when the stars don&#x27;t move?&quot;<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mach%27s_principle" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mach%27s_principle</a>

Asynchronous programming<p>With the addition of async to django core, I felt its time to finally learn the concept. I first took interest in async early last year when I re-read a medium post on Japronto; an async python web framework that claims to be faster than Go and Node.<p>Since then, I&#x27;ve been on the lookout for introductory posts about async but all I see is snippets from the docs with little or no modifications and a lame (or maybe I&#x27;m too dumb) attempt at explaining it.<p>I picked up multi threaded programming few weeks ago and I understand (correct me if I&#x27;m wrong) it does have similarities with asynchronous programming, but I just don&#x27;t see where async fits in the puzzle.

[Sorry I have misinterpreted the subject, I thought it could be some phenomenon still not well understood by science.]<p>Placebo. There are biological bases of it (I don&#x27;t believe in soul). Find these bases, study them, make a model of them. Then use proxy variables to measure it instead of trying to eliminate it statistically. Predict it in studies to avoid the need of placebo groups (and possibly of double blind methodology). Also, after it is completely measurable and its mechanisms are understood, if (very hypothetical) it has a really substantial effect, just use it to help treat patients.

What actually happens to the money that gets put into the stock market? I mean, I understand that there are people holding stocks and then people offer to buy&#x2F;sell them at a given price; but, how does the company plan to benefit if the stock just keeps moving back and forth multiple third parties? Doesn&#x27;t a company go public to raise money? If so, how does the company benefit from the daily changes in the stock and when someone buys stock in the company? Does the company have a fixed number of stock that they trade as well on the market?

The one-electron universe is always a personal favorite. Though more a far-fetched theory than a proper &quot;scientific phenomena&quot;, I&#x27;d be eager to learn more about it in layman&#x27;s terms<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;One-electron_universe" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;One-electron_universe</a><p><a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=9dqtW9MslFk" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=9dqtW9MslFk</a>

vertical alignment in CSS

Automatic differentiation. It&#x27;s useful to so much computational work, but most people only get a cursory introduction to the topic (a rough intro to the minimum they need to know), whereas really understanding it seems to open up a lot of research.

I&#x27;m sure there are great explanations out there but I haven&#x27;t had time to read up on them, but a few of the space things that always bother me when I watch pop-sci space tv:<p>- &quot;as soon as iron starts to be produced in the core of a star it instantly collapses&quot; - I get that fusing iron costs energy rather than produces it and this causes a collapse.. but can it really be that quick? There are other fusion reactions that are still producing energy, right?<p>- dark matter &#x2F; energy - I understand we have observations that indicate there is some type of matter we can&#x27;t see but it feels a lot like saying &quot;magic&quot; or &quot;the ether&quot;.<p>- how different size stars form - if there is a critical mass where a star &quot;ignites&quot; and after igniting starts pushing away from itself with the energy being produced, how do we get stars of such varying masses? Like, why didn&#x27;t this 100x solar mass star start fusing and pushing the gases away before they were caught in its gravity? Do the more massive stars ignite on the same schedule but continue to suck in additional matter anyway, gravity overcoming the solar wind?

When I hear explanations like “space is expanding like the surface of a balloon” it’s always confusing. Because a surface is an object, separate from anything on it, but space is the thing we’re all embedded in, so we’re like drawings on the balloon.<p>If space is expanding why aren’t the radii of fundamental particles and their orbits and molecules also expanding? And if that were the case we couldn’t notice space expanding.

Antenna Design&#x2F;RF Theory. I would love a simple text&#x2F;YouTube series to learn this stuff...would definitely be good learning for the summer :)

* Lie algebras and Lie groups - I still don&#x27;t understand this, what they&#x27;re used for or how to use them in any practical sense.<p>* Galois Theory - I have a basic understanding of abstract algebra but for some reason Galois theory confounds me, especially as it relates to the inability of radical solutions to fifth and higher degree polynomials<p>* &quot;State-of-the-art&quot; Quantum Entanglement experiments and their purported success in closing all loopholes<p>* Babai&#x27;s proof on graph isomorphism being (almost&#x2F;effectively) in P - specifically how it might relate to other areas of group actions etc.<p>* Low density parity checks and other algorithms for reaching the Shannon entropy limit for communication over noisy channels<p>* Hash functions and their success as one-way(ish)&#x2F;trapdoor(ish) functions - is SHA-2 believed to be secure because a lot of people threw stuff at the wall to see what stuck or is there a theoretical backpinning that allows people to design these hashes with some degree of certainty that they are irreversible?

Light, a mixture of why a thing is the colour that it is? As well as why reflection would be angle of incidence is angle of exit.<p>My current understanding of colour is that the colour of an object is defined by the ability of the electrons in the compound jump different energy levels. I don&#x27;t know if that in itself is enough to result in all the colour we see.<p>My current understanding of reflection is that because of wavyness of light when lots of light gets absorbed (to my understanding a single photon exciting a single electron to jump some amount) and reemited (the electron falling back down) together the light ends up forming that angle pattern. Under than understanding single photons don&#x27;t bounce in the same way rays of light do?<p>I don&#x27;t know how correct either of those understandings are, but my understanding has been put together from so many places and I&#x27;ve never heard any source explain either like that so I don&#x27;t trust they are correct.

The connection between elementary particles and group representations. I get the math, I just don&#x27;t see in what way it corresponds to reality (i.e. in addition to being a bijection).

Wormhole time machines.<p>The idea is, you can transform a normal [0] wormhole that isn’t a time machine into one which is by:<p>1) accelerating one end to high speed relative to the other<p>2) keeping on end in a lower gravitational potential than the other<p>Why are either of these considered meaningful statements, never mind <i>correct</i>?<p>In the case of 2 in particular, isn’t GR supposed to require smooth values? So any time dilation effect would be almost identical on a pair of points +δ and -δ from the throat? Making it similar to the case of a gravitational potential without a wormhole?<p>And in the case of 1, the more I think about it, the less I understand the concept. What is being moved? An imaginary clock that would’ve been in the part of the wormhole at the far end? The apparent speed as measured going through the throat will be zero regardless of the apparent speed of the same as measured when going the long way around.<p>[0] yes, I know

How can metric expansion of space redshift light? Doesn&#x27;t that violate conservation of momentum, since the redder light has lower momentum?<p>And adding on to that: Will light inside a box redshift? If I weigh the box (i.e. weigh the light inside the box), then wait a bit for the light to redshift, then weigh the box again?

Flight. How can a plane fly when it&#x27;s thrust to weight ratio is less than one? It&#x27;s like, if you can produce 10 pounds of thrust, who would look at that and say &quot;ah ha, we can use this to keep a 100 pound machine miles in the air indefinitely&quot;?<p>I understand flight from a mathematical point of view. I&#x27;ve actually read a few books on the subject, and I could explain how flight works to someone. However, I&#x27;m still fishing for an explanation that &quot;feels&quot; more satisfying though. Per the question, I still want it explained better.<p>EDIT: There&#x27;s already a thread about flight. I asked the same question there, but phrased a bit differently: <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=22993460" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=22993460</a>

I wish I could get a clear explanation of why faster than light travel breaks causality. I have seen the math but intuitively I am having trouble grasping it especially when you have only two reference frames (most explanations will use three reference frames to show the violation)

Absorption spectra baffle me and I&#x27;ve never seen an explanation that helps me understand.<p>It seems conceptually simple, except the requirement that the energy of an photon <i>exactly match</i> some required energy in order to be absorbed seems really unlikely, since photon energy not a discrete quantity, and varies according to doppler effects and other things.<p>It seems like the vast majority of photons would just fly through the universe without interacting with anything, unless there are other ways for photons to interact with matter besides being absorbed. (If there are other ways, they are seemingly never mentioned as a potential alternative fate for the photon).

Another frustrating one - what is heredity? If it&#x27;s possible to inherit something due to a shift in behavior (i.e. it&#x27;s a cultural change that leads to a biochemical change), how does that connect neatly to mendalian inheritance?

Quantum Mechanics, and why we need interpretations of it.

Wave function collapse. As far as I can tell there is no discernable difference between a particle whose wave function collapsed (perhaps via measurement with another entangled one) and one that hasn&#x27;t.

Sort of trying to piggy-back on this thread in hopes someone with knowledge will be able to share it.<p>I&#x27;ve been having conversations about viruses recently and in those conversations &#x2F; thought experiments I keep coming back to a point someone made to me.<p>Someone this person knows, with extensive medical expertise, explained that the &quot;membrane&quot; of the cell contains a ridiculously large number of unique types of proteins.<p>Understanding, in vague terms, how viruses penetrate cells the question I pose is &quot;is this true because each of those proteins has a unique and distinct function in the cell membrane? Or is it more a matter of scale and utility?&quot; In other words, does the observation simply indicate that our bodies are not as perfect as we&#x27;d like to think they are and the body&#x27;s process for creating &#x2F; repairing cells is more a utilitarian function where the &quot;rules&quot; of cell construction are extremely flexible such that these molecules are constructed in various ways where our cells are using materials available to them at the time?<p>If this is the case it starts to make a lot of sense to me at a molecular level why certain people tend to be more susceptible to contracting certain diseases. Could a lot of it really just come down to diet, along with probably a hint (or more) of DNA&#x27;s interaction with those proteins we&#x27;re providing to our bodies? And to what extent does each of those play a role? DNA and the proteins.

Time dilation with regards to the &quot;no absolute rest frame&quot; in physics.<p>The famous twin thought experiment where one gets in a spaceship, accelerates away from the planet, turns around, and comes back.<p>The twin that stayed on earth is old and the traveling twin is young still.<p>On one hand, I know that time will &quot;pass differently&quot; for each twin....but why is it the twin in the spaceship that ages less? Why isn&#x27;t it true that the entire universe accelerated away from the spaceship and then returned, leaving the entire earth young?

The rising cost and decreasing productivity of scientific research.

When two particles get closer, their mutual gravitational attraction increases. As the distance approaches zero, the force approaches infinity. In the limit of d -&gt; 0, the <i>energy released</i> -&gt; infinity. Obviously at some scale the notion of a point mass breaks down, but even quantum theory would be problematic if we think of a wave function as describing a <i>probability</i> distribution, wouldn&#x27;t it? What&#x27;s the &quot;official&quot; story on this?

I like that for a full decade, people discussed measurements at reputable labs indicating that certain radioactive species decayed at rates that varied &gt;0.1% depending on the season, and explored possible neutrino flux influences.<p>The measurements were finally shown to be effects of the immediate environment on the measurement apparatus.<p>That detectors used in labs may vary with time by &gt;0.1%, unknown to their users, seems pretty important. How did everybody involved not know?

Why does my bread last for a while and then go bad? Or is it constantly going bad and I just haven&#x27;t hit critical mass of mold for me to notice?

Why bicycles stay upright.<p>For every authoritative-sounding, in-depth explanation, there is an equally plausible, yet conflicting and contradictory alternative.

Entropy. Sometimes you read that it&#x27;s a measure of randomness; sometimes, information. Aren&#x27;t randomness and information opposites?

Why are clouds flat on the bottom?

Gravity wells. I only realised in my 20s that the only reason satellites can orbit the Earth without crashing into the ground is by going sideways really, really fast. So as they inch closer to the ground, they also travel parallel to the ground fast enough so that they stay approximately the same height from the ground.

Human Biology, particularly the &quot;bigger scale&quot; things like joints &amp; ligaments.<p>I have arthrtic knees, and I&#x27;d like a better understanding of how joints work, and where the various clicks, pops and swellings come from.<p>It&#x27;s easy to find really simple things, but harder to understand &quot;how things go wrong&quot;.

I&#x27;ve always had trouble following Searle&#x27;s Chinese Room argument as it applies to the nature and identification of intelligent action. I&#x27;ve never understood how the Chinese Room shows what its adherents say it shows, so that would be one topic I&#x27;d like to see more perspectives on.

I have wondered if heat and photons impart a partial charge on atoms and molecules which causes several phenomena. Faster Brownian motion due to the increased repelling action of stronger charges which cause pressure&#x2F;volume changes in gasses.<p>Also are these charges responsible for some weather effects such as the jet stream. In a tornado is the negative charges on the dry side of the dry line interacting with the moist air on the wet side really just a local intense acceleration of the dry air trying to &quot;get to&quot; the oppositely charged moist air?<p>Are the rotation of low and high pressure systems basically due to the same condition? Is lightning also just basically a flood situation of the charges?

Spin aka intrinsic angular momentum

What&#x27;s the point of defining summation methods for divergent series? Do they have any connections to any other area of mathematics or physics? Is analytic continuation of complex analysis relevant to these things? How about p-adics?

Consciousness.<p>How is it possible that the thread is up 5 hours and ctrl-f consciousness returns nothing?

Evolution.<p>How does large scale randomness result in such complicated and intelligent systems, while after decades of research and all the computing power we have today, we still struggle to model and reproduce the intelligence of an insect.

Low, medium, and high-frequency radio waves (below 30MHz, wavelengths longer than 10 meters) are a form of EM radiation. Which means that an antenna is &#x27;transmitting&#x27; low-energy, long-wavelength photons. (Which gets us into the whole wavicle question.) But the signal from a radio station appears to be continuous.<p>So: how to picture this? Is the signal made of discrete &#x27;photons&#x27; overlapping, or combined somehow? Or is it that the &#x27;wave-like&#x27; aspect of these photons is so predominant at these frequencies? (I&#x27;ve grappled with this one for a long time.)

I had a very mathy explanation of Spinodal Decomposition in my graduate work. I wonder if there&#x27;s a more intuitive explanation than just &quot;that&#x27;s how the energy landscape works&quot;.

Quantum entanglement. How do they know it&#x27;s happening?

The periodic table.<p>Can the properties of the elements be computed from the first principles of particle physics, or do you need to observe the atoms in real life to figure them out? For example, some isotopes are stable and others have a finite half-life. Can you know beforehand or you have to observe the decay? Can you compute exactly the mass of each atom without measuring it? Can you know compute its electronegativity? Etc.

Basic probability. How come when I flip a coin it is just as likely to come up heads or tails even if it has just been heads 5 times in a row?<p>I understand the physical properties of the coin make it so it is an independent event but if I were to run the experiment multiple times the number of times it would be heads after 5 heads would not be an even probability, it would be unlikely since 6 heads in a row is a rare event.

The mathematics of training a neural network. I understand how they work once trained, but that you can train them almost seems too good to be true.

Lagrangian and Hamiltonian mechanics. That is usually presented in a very mysterious manner. Also I think most engineers do not get taught these.

I didn&#x27;t see good explanation of Einstein&#x27;s twin paradox. Have you seen one? I have seen only clear explanation based on fact that observer will feel acceleration when he will come back and this is what breaks symmetry, but it appears that explanation based on acceleration are wrong, because it seems that acceleration is not necessary to explain this paradox.

Double slit experiment. There&#x27;s a lot out there detailing what happens but relatively few explanations go into <i>why</i> observing the state of a photon results in it &quot;choosing&quot; one slit over the other. I suspect many come away with the impression that it&#x27;s magic despite there being a reasonably simple explanation for what&#x27;s going on.

Electricity. What is it? Is it related to electrons? I thought it was? If the plug in my house is AC then why is one wire &quot;hot&quot; and one &quot;neutral?&quot; (on plugs in North America at least) if there is a ground wire then why are plugs polarized? Why do some things come with a three prong plug and others don&#x27;t?

Plasma ball, and how to create one. I’ve seen two of those with my own eyes: One in nature after a lightening strike to a lone maple tree in a pasture and one accidentally man-made via 50,000 VDC. And none of the literature shows how how such a plasma ball can travel in a fairly straight line at steady level from the ground.

Morphological development of organisms. Mainly, how do cells form the shape of the organism and how do they specialize to different type of tissues? How do cells know where they are? What is the mechanism that puts the constraints on the shape of the body? I can understand mitosis but the rest from there is magic.

The cosmic inflation. Yes, the universe is smooth but how is that enough to justify this unimaginable expansion? There seem to be no proof or possible experiment yet the scientific community apparently accepted this theory with its abrupt start and abrupt end, only secondary to the big bang itself in its scale and energy.

BlackHoles - where does the &#x27;extra&#x27; mass&#x2F;gravity come from?<p>I&#x27;ve been watching a lot of documentaries lately, and I can&#x27;t figure out how a star that _radiates_ light, collapses and suddenly light can&#x27;t escape? Doesn&#x27;t that mean the blackhole has more mass&#x2F;gravity then the star that created it?

How a single hormone can regulate so many different things. Looking at Wikipedia, a single hormone like progesterone which is apparently one molecule regulates a plethora of effects. How is this implemented? As a coder, if I had to use one variable to simultaneously regulate 10 different things I would go crazy.

Fermat&#x27;s theorem: a^n + b^n = c^n For n &gt; 2, why are there no integers a, b, and c that satisfy the equality?

the fundamentals of computer science. Unlike many who comment here regularly, I am not a programmer or developer and though it might seem silly, the way in which a bunch of code written in a programming language of any sort translates to a computer physically or electrically causing things to &quot;happen&quot; because of it has always been a bit fuzzy. I know that electronic systems and machines translate all instructions to binary code but still, from there how does the rest happen? such as an OS on my laptops working the way it does, or more specialized: an unmanned spacecraft autonomously navigating its way through the solar system and doing complex physical tasks. Anyone have a suggestion for a good starting point on learning through these fundamentals and on upwards?

Protein Folding

Genetics. I still have no intuition for how combining my wife’s and my DNA has resulted in children with traits from both of us. My brain always tries to imagine interleaving two binaries and hoping for a resulting program that works a bit like the two sources, which it of course wouldn’t.

Hawking Radiation. I know just enough to know that the story of &quot;anti-particle of virtual pairs happens to always fall in the hole&quot; is a Lie Told To Children, but the explanations seem to go straight from there to rather dense math and I&#x27;ve never wrapped my head around it.

Water pressure (like PSI) and how it relates to water flow (like GPM).<p>It&#x27;s difficult to relate the two together and even after hearing every heuristic and every cutesy analogy, I still can&#x27;t quite wrap my head around what happens to one when I increase the other (and so on).

Interesting that you mentioned exosome, and no one else did. That in itself should give a hint on why people cannot do a better job at explaining stuff. It&#x27;s complicated, , not well understood, extremely messy and does not fit well in a textbook.

I&#x27;d love to see shows like &#x27;Nature&#x27; and &#x27;Planet Earth&#x27; but focused exclusively on single celled organisms; I find that whole world very interesting. Journey to the Microcosmos on youtube is the closest thing I&#x27;ve found.

Relativity.<p>I just can&#x27;t grok it.<p>I can&#x27;t understand how time would flow differently depending of your speed.<p>I don&#x27;t get why C is a constant no matter the referential, for any other object the speed is relative to your referential. I just don&#x27;t see how those 2 are compatible.

Frame dragging. How does space know a body is rotating if the body is &quot;smooth&quot;?

The Coandă effect [1] and how it applies to plane wings and sailboats.<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Coand%C4%83_effect" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Coand%C4%83_effect</a>

Why does quantum mechanics need complex numbers ?<p>Every time I read an introductory QM book &#x2F; article, the complex numbers just come out of nowhere and no one bothers to explain how that makes any kind of physical sense.

The unification of electo-magnetism. I know the classical equation well, but never formally studied physics and have never been able to get my head around Maxwell&#x27;s equations.

The LIGO detector. I&#x27;ve never heard a logical explanation for it. If your explanation is that gravitational waves stretch and squash spacetime so light takes different amount of time to bounce from an emitter back to a measurer, then you don&#x27;t have even a slight understanding of how it works. If your explanation doesn&#x27;t involve higher spatial dimensions (not time) then you don&#x27;t understand it. If you haven&#x27;t even <i>considered</i> higher spatial dimensions when explaining LIGO then you shouldn&#x27;t even try for the incorrect explanation above because you don&#x27;t have any of the pieces of the puzzle.

I&#x27;d really love an explanation of what specific impulse is. I&#x27;ve looked it up a few times but the units seconds^-1 confuses me, what does this represent?

Quantum computers. I still don’t get it. What are they useful for, what are it’s computing bounds and why it’s a big deal. When will the future actually come ?

How to design compact antenna without those math voodoo.

We aren&#x27;t short of interesting problems.<p>To pick a couple fo them randomly, understanding amyotrophic lateral sclerosis or alzheimer would be terrific starts.

Superconductive flux pinning. Specifically, I&#x27;m curious what behavior it&#x27;d exhibit if used as a core for superconducting inductors.

Quantum Physics. Still can’t wrap my mind around multiverse being a simpler explanation then the future holds data we won’t have in the now.

The Oberth Effect. I’ve seen a bunch of awful attempts at the “why” and some “well it’s just in the math, so there” but nothing satisfying.

Why is it that the smartest people in various fields constantly need reference materials, but medical doctors never look anything up?

First principle reasoning in real life examples.

I think we should have this thread more often.

- How computers translate bits into electrical signals<p>- What does it mean the universe is expanding<p>- Bayesian statistics<p>- How information is stored in magnetic tapes

Electricity.<p>Electricity is always explained by its effects, but never by its actual nature. I&#x27;d like better explanation :-)

How did Mendeleev and his peers knew something was the final indivisible element and not just another molecule?

The twin paradox. All explanations seem to be just &quot;something something one twin has to accelerate&quot;

Can anyone explain disc loading and solidity in a propeller and if there are any equations governing them?

Wave-particle duality (of e.g. light)

Non-linear optic explanation from quantum standpoint (classical explanation is quite clear).

Kalman filters. The explanations always start easy and then get too confusing.

Einstein&#x27;s (summarized) quote, &quot;Time is a persistent illusion&quot;

- Hegel. I haven&#x27;t found any resource that can explain it clearly.

How depression, autism and gender dysphoria work on a molecular level.

All the credible theories of why there are 3 generations of particles.

How EM radiations propagate through the air and what is an EM field.

Why is there no evidence of black matter annihilation in astronomy?

Eddy currents. Why does a magnet move slowly down a copper tube?

Agile, an empirical survey of whatever the hell it actually is.

Wavelets: Usually given explanations are hard to understand.

Amperes, Voltage, Watts, without using a liquid analogy.

ionization. The resources I can find on it are mostly conspiracy theory types or the same basics explained over and over again.

Axial flux motors

Gauge theory.

Quantum stuff

Why a flat earth is impossible.

How airplane wing really works.

Reactance.

why does blender at times become slower for no fucking apparent reason

Why the earth is a sphere.

Human counsciousness.

1. Carbon dating. Sure, I get that carbon decays over time and this changes the proportion of isotopes. But why does this give you any information? That carbon didn’t come into existence just to be in that bone, it was made in the sun billions of years before that, so why does the age of the carbon tell us anything about organic matter? The key fact, which I think is not emphasized enough, is that the ratio of isotopes in atmospheric carbon is kept at a constant equilibrium by cosmic rays. So you can use carbon dating to tell roughly when the carbon was pulled out of the atmosphere. Without this additional fact, the concept of carbon dating makes absolutely no sense.<p>2. The tides. The explanation I was given is roughly something like “the tides happen because the moon’s gravity pulls the water toward it, so you have high tide facing the moon. There’s also a high tide on the opposite side of the earth, for subtle reasons that are too complicated for you to understand right now and I don’t have time to get into that.”<p>The first problem with this explanation is this: gravitational acceleration affects everything equally right? So it’s not just pulling on the water, it’s also pulling on the earth. So why does the water pull away from the earth? Shouldn’t everything be accelerating at the same rate and staying in the same relative positions?<p>The second problem is that, when viewed correctly, the explanation for why there is a high tide on the opposite side of the earth as the moon is equally simple to why there is a high tide on the same side as the moon.<p>The resolution to both these problem is this: tides aren’t actually caused by the pull of the moon’s gravity per se, but are actually caused by the difference in the strength of the pull of the moon’s gravity between near and far sides of the earth, since the strength of the moon’s gravitational pull decreases with distance from the moon. The pull on the near water is stronger than the average pull on the earth, which again is stronger than the pull on the far water. So everything becomes stretched out along the earth-moon axis.<p>3. This one isn’t so much a problem with the explanation itself, more about how it’s framed. I remember hearing about why the sky is blue, and wondering, “ok, more blue light bounces off it than other colours. But isn’t that essentially the same reason why any other blue thing is blue? Why are we making such a big fuss about the sky in particular? ” A much superior motivating question is “why is the sky blue during midday, but red at sunrise &#x2F; sunset”? I was relieved when I saw this XKCD that I’m not the only one who felt this way:<p><a href="https:&#x2F;&#x2F;xkcd.com&#x2F;1818&#x2F;" rel="nofollow">https:&#x2F;&#x2F;xkcd.com&#x2F;1818&#x2F;</a>

Coroutines in C++.

The Coriolis Force

celullar replication and virus code insertion

Orbital mechanics

Escape velocity

Measure theory.

Conciousness.

Yoneda lemma

Women!

Math!

electromagnetic waves

Haskell&#x27;s Monads

coriolis force

string theory

why does blender become slower at times for no apparent reason

Reminds me of a story:<p>A guy was walking along the beach and found a lamp. Of course he rubs the lamp, and sure enough a genie appears.<p>Genie: master of the lamp I can grant you a wish, you may wish for anything.<p>Guy: Wait, isn&#x27;t it supposed to be 3 wishes?<p>Genie: One or nothing, and do not wish for more wishes.<p>Guy thinks for a while ....<p>You know I have pretty much everything I need. But I have always wanted to travel to Hawaii. But I get sea sick and am afraid to fly.<p>Genie: Very well I will take you there.<p>Guy: No no, if you take me there, I wont be able to come back. And what about next year? Since I only get one wish, I want a bridge built to Hawaii.<p>Genie: That does not make any sense. Please make a different wish. One that does not involve so much construction.<p>Guy: hmmmm you know I know, can you explain women?<p>Genie: So do you want the bridge to be a suspension bridge or truss? and how many lanes ....