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Showing content with the highest reputation since 12/28/20 in Posts

  1. 5 points
    We can all agree that violence on either side is wrong and should be avoided. What we seemingly cannot agree upon is why so many feel the need to engage in whataboutism and mention a protest in favor of following our laws done in Portland with an insurrection on our democracy itself trying to dismantle our laws in Washington DC. Whether intentionally or not, this suggests an equivalence between the events which is false and which only distracts us from dealing with each separately, appropriately, and in accordance with our laws. Person A: Climate change is a major problem. Person B: What about covid?! That’s a problem, too. Me: Both are. They’re not equivalent. They’re not mutually exclusive. We must deal with both at once. Walk and chew bubble gum. Simply replace climate and covid with DC and Portland. This isn’t exactly rocket science.
  2. 4 points
    If you expose frozen chips to air, more moisture will condense on the chips from it. Every ml of water condensed from the air adds 1g to the chips.. The chips, after baking, lose moisture, which concentrates the calories, so if you now weigh 100g of baked chips there are more calories.
  3. 4 points
    While this thread is closed and (I think) being the only person who identifies as female in this thread, I just wanted to provide a little food for thought. Of all the women in my life with whom I am close to, I can't think of a single one who hasn't been sexually assaulted or raped by a man at some point in her life. I cannot say the same about the men I know wrt to false accusations. Anecdotal I know, but something to think about.
  4. 3 points
  5. 3 points
    https://earthlymission.com/dinosaur-mummy-science-discovery-nodosaur-intact-canada/?fbclid=IwAR2wWqKTY7lykqaIexocCP6L16aepPxOVr1dXe-bVywjNbJldL54l3fjgdM Scientists are hailing it as the best-preserved dinosaur specimen ever discovered. That’s why you cannot see its bones – they remain covered by intact skin and armor. This dinosaur was built like a tank. A member of a newly discovered species called nodosaur, it was an enormous four-legged herbivore protected by a spiky, plated armor. It weighed approximately 3,000 pounds. To give you an idea of how intact the mummified nodosaur is: it still weighs 2,500 pounds! more at link................
  6. 3 points
    Hasn't the OP just proved (in a rather long-winded way) that the inner product of four acceleration and four velocity is zero and, hence, that if the four velocity is \( V^t=c \), \( V^x=V^y=V^z=0 \) then the four acceleration has \( A^t=0 \) (and that the four acceleration is spacelike if it isn't zero)? They just appear not to have noticed that in general \( \frac{dA^t}{d\tau} \neq 0 \), so the conclusion that \( \gamma=\mathrm{const} \) does not follow. The fact that a function is instantaneously zero does not mean that either its integral or its derivative need be zero. To me, the argument looks similar to saying that in circular motion in the x,y plane there comes a point where \( (v_x,v_y)=(v,0) \), and at that point \( a_x=0 \), and hence \( v_x \) can never change and circular motion is impossible. Obviously that's nonsense, and realising that \( \frac{da_x}{dt}\neq 0 \) is a part of understanding why it's nonsense.
  7. 3 points
    I'm genuinely relieved that the inauguration proceeded without bloodshed
  8. 3 points
    Thank you so much! May I ask one last question? I would imagine cancer would be at a huge scale right now if phones are harmful. Like, it takes 10-15 years to develop radiation-linked cancer, and right now rates are dropping. Phones became commonplace in the mid 90s, 26 years ago. Most recent data (from 2018) shows a decline in cancer rates, 23 years after phones became popular. Surely if phones did cause cancer we’d see it by now in the rates?
  9. 3 points
    Dim - While your fortune cookie posts and novel views on questions are often fun, this might be a time where it's better to let a person familiar with the literature and process of vaccine-based immunity respond to the actual question asked in the OP Fairly sure a reference to "War of the Worlds" is not going to be helpful here, despite being interesting in its own right
  10. 3 points
    ! Moderator Note I’m moving this to Speculations for now, as that is the correct forum section for personal theories. Why would accelerated expansion be an issue? It’s a natural geometric property of this type of spacetime, and thus fully consistent with the gravitational field equations. Gravity is a geometric property of spacetime; to be more exact, it is geodesic deviation, i.e. the failure of initially parallel geodesics to remain parallel. Using the mathematical tools of cosmology, it is possible to construct a universe that - starting from a Big Bang - first expands, then slows, stops, and re-contracts to end up in a Big Crunch again, only for the cycle to repeat over and over again. The problem is that this is not consistent with what we actually observe in the real world. We already have a very detailed model of (classical) gravity, being General Relativity, which works extremely well - what you seem to propose is not very consistent with what we already know about gravity.
  11. 3 points
    https://www.nytimes.com/2021/01/07/science/jellyfish-swimming-vortex.html contains cool gif at the top of a jellyfish swimming through laser sheet with tracer particles. https://royalsocietypublishing.org/doi/10.1098/rspb.2020.2494
  12. 3 points
    I think the problem is that Trump is very much a Republican. For many in the GOP, he only just now crossed the line with sedition and insurrection (and for others, he hasn’t crossed it yet. Elected officials and the GOP base) The senate could have convicted him after he was impeached, but chose not to. The voters could have voted for someone else, or stayed home, but he got even more votes after 4 years of his actions being front and center. He’s been carrying out the GOP’s policies - restrictive immigration if you aren’t white and Christian, tax cuts for the rich, voter suppression, deregulation, no healthcare, abd fully-aligned with Mitch McConnell’s aim to un-do pretty much everything Obama did. No, the notion that Trump is not a Republican doesn’t hold water. To the extent that it appears to be, it’s because certain political views are reprehensible, and the site is biased towards views that reject them. That would give the appearance of this bias. White supremacy would be one example, or political stances that reject treating groups of people equally. The membership is slanted heavily toward those that are interested in science, and it’s not the site’s fault that some political groups reject science that they don’t like.
  13. 3 points
    In the thread I started, 'Canadian Protests', in Feb 2020, where no actual violence occurred because police chose not to enforce the law, and allowed unlawful behaviour for months, your reply was "Like in Hong Kong, at some point we need to realize the protestors have a poor and that its worth fighting for." Phi for All replied "I don't know about Canadian law, but in the US, the courts don't overturn bad laws on their own, they need people to break them and then argue in court why it was the right thing to do." Dimreepr said "One man's terrorist is another man's freedom fighter; it depends, in general, on which side of the poverty line he resides." Do I need to find you more ? I imagine D Trump thought that the reason for inciting this protest ... "Because that’s the only way enough people will begin paying the required attention to actually change things. If the status quo is too comfortable for you, you’ll act as an obstacle to the change" I assume the protesters, at D Trump's urging, attempted to make Democracy too uncomfortable for Americans. Oh, and I'm not suggesting any equivalence between the above mentioned Canadian protests, and what happened Wednesday in the Capital. But both were unlawful, and only differed by degree.
  14. 3 points
    What, you don’t like rolling 3 month contracts completely contingent on obtaining a portion of the ever-dwindling pools of grant money available? Weird.
  15. 3 points
    ! Moderator Note I have split the increasingly off-topic discussion into a new thread. I apologize for taking matters into my own hands but there are few mods available and most have taken part in this thread.
  16. 3 points
    Most mutations are neutral. The lottery analogy fails due to the fact that evolution is a population level process. A diploid human genome experiences 175 mutations per generation on average. There were 3,745,540 human births in 2019 alone. That's 655,469,500 mutations across the human population in one year. Diploid human genome size is 6.4 Gb - so that population level mutational likelihood space is approximately 10% of the whole human genome in a single year. Next, "fitness" in evolutionary terms is discretely defined as genetic contribution to the subsequent generation. By definition, if a mutation is beneficial, it increases in frequency in subsequent generations (complications of neutral genetic drift aside). Therefore, "random" (they aren't actually random - only naïve with respect to fitness) explores significant portions of the human (or other species) total adaptive landscape every generation, and by definition, beneficial mutations, proliferate through the population throughout subsequent generations.
  17. 3 points
    “Sixty is the worst age to be,” said the 60-year-old man. “You always feel like you have to pee and most of the time you stand there and nothing comes out.” “Ah, that’s nothing,” said the 70-year-old. “When you’re seventy, you don’t have a bowel movement any more. You take laxatives, eat bran, sit on the toilet all day and nothing’ comes out!” “Actually,” said the 80-year -old, “Eighty is the worst age of all.” “Do you have trouble peeing, too?” asked the 60-year old. “No, I pee every morning at 6:00. I pee like a racehorse on a flat rock; no problem at all.” “So, do you have a problem with your bowel movement?” “No, I have one every morning at 6:30.” Exasperated, the 60-year-old said, “You pee every morning at 6:00 and crap every morning at 6:30. So what’s so bad about being 80?” “I don’t wake up until 7:00.” ---------------------------------------------------------------------------- A store that sells husbands has just opened in New York City,… Where a woman may go to choose a husband. Among the instructions at the entrance is a description of how the store operates. You may visit the store ONLY ONCE! There are six floors and the attributes of the men increase as the shopper ascends the flights. There is, however, a catch… You may choose any man from a particular floor, or you may choose to go up a floor,.. But you cannot go back down except to exit the building! So, a woman goes to the Husband Store to find a husband… On the first floor the sign on the door reads: Floor 1 – These men all have jobs, and will love their wife. She then goes to the second floor,… The second floor sign reads: Floor 2 – These men all have jobs, will love their wife, and love kids. She thinks for a while, and then goes to the third floor,… The third floor sign reads: Floor 3 – These men all have jobs, will love their wife, love kids, and are extremely good looking. “Wow,” she thinks, but feels compelled to keep going. She goes to the fourth floor and the sign reads: Floor 4 – These men all have jobs, will love their wife, love kids, are drop-dead good-looking and help with the housework. “Oh, mercy me!” she exclaims, “I can hardly stand it!” Still, she goes to the fifth floor and the sign reads: Floor 5 – These men all have jobs, will love their wife, love kids, are drop-dead gorgeous, help with the housework, and are excellent in bed. She is so tempted to stay,… But she goes to the sixth floor and the sign reads: Floor 6 – You are visitor no. 43,630,912 to this floor. There are no men on this floor. This floor exists solely as proof that women are impossible to please. Thank you for shopping at the Husband Store. Watch your step as you exit the building, and have a nice day!
  18. 2 points
    I'm not sure if D Trump was the useful idiot of the GOP, or if the GOP were D Trump's useful idiots. Those people in INow's photos are there for D Trump, not the GOP. If anything, he seems to have fractured the GOP into the group that wants to cut him loose ( including M McConnell now ), and those who cling to his coat tails in the faint hope of retaining power ( no matter how crazy, and illegal, he gets ). Maybe the Democrats should be thanking D Trump, he has exposed the craziness of the current GOP, and may well end up wrecking their current organization.
  19. 2 points
    @MigL Hope you don't mind, but I'm gonna take our PM exchange into the thread here (keeping your point unquoted, will share my reply here instead). We're still talking passed each other. While I said I can understand the underlying motivations, I have NOT made excuses for violence perpetrated in the name of BLM. There is violence happening as part of the movement. I don't agree with it. I'm not making excuses for it. I'm not pretending it doesn't exist. My primary point has been that the violence is the extreme outlier in BLM. It's marginal. It's super rare. It's uncommon. It's been inflated as a rightwing talking point. There has been violence. Some of it came from BLM protestors unprovoked. Some was provoked by police being too heavy handed and hitting peaceful protestors with clubs and firing tear gas into the faces of unarmed grandmothers. Some of it was rightwing extremists engaged in false flag operations. My primary point has been that it's a mistake to focus so much energy there... another example of of our white privilege. In these threads, people keep saying "it's horrible that another innocent black man was killed by another cop in another city, but destroying property has to stop." Yeah, okay... but try saying instead, "It's horrible that property is being destroyed, but these continued killings of innocent black men by police has to stop." See the difference? The pushback is saying you're prioritizing the wrong part... not that the violence is acceptable because it was done by "my team." Focusing so much on the tiny amounts of violence happening at the extreme margins of the movement distracts us from dealing with the issues motivating the movement itself. I'm not making excuses for the violence. I'm saying it's so rare that bringing up so often suggests an agenda, whether you're conscious of it or not. Please stop saying I support the violence. Please stop suggesting I'm making excuses for it. I'm simply not.
  20. 2 points
    This claim is not meaningless it is just plain wrong and arises from a basic misunderstanding of celestial navigation with a sextant, where the term 'arc of the sun or arc of other celestial body arises' It is not the altitude (which is the arc measured in degrees) but the plane from which is it is reckoned that changes with altitude and with altitude and other factors which have to be corrected for. This plane is called the true horizon and is not directly available to the observer so various 'observable horizons' are employed - marine navigators use the water horizon, aerial navigators use an 'artificial horizon' (yes aircraft still carry sextants for emergency navigation when the more modern electronic systems are broken). Clearly these calculations are correct since navigators do arrive at their destinations using them. The calculations and sight corrections can be quite complicated, here is a simple explanation. https://knowledgeofsea.com/correction-to-sextant-altitudes/
  21. 2 points
    Oh, but that's not because it's much worse than I pointed out. It's because it's bound to get worse if you make a notational blunder of that magnitude. If you want to discuss anything in terms of a 2-index tensor being diagonal in a certain point --o perhaps everywhere?, the OP didn't tell us--, you could arrange to distinguish this by using Latin capital letters, e.g., \[A^{BB}=\frac{\partial x^{B}}{\partial\bar{x}^{\mu}}\frac{\partial x^{B}}{\partial\bar{x}^{\nu}}\bar{A}^{\mu\nu}\] Meaning, \[A^{00}=\frac{\partial x^{0}}{\partial\bar{x}^{\mu}}\frac{\partial x^{0}}{\partial\bar{x}^{\nu}}\bar{A}^{\mu\nu}\] \[A^{11}=\frac{\partial x^{1}}{\partial\bar{x}^{\mu}}\frac{\partial x^{1}}{\partial\bar{x}^{\nu}}\bar{A}^{\mu\nu}\] etc. So it can be done, but not the way the OP is doing it. Not that it's very useful to consider tensors as objects that are or aren't diagonal in any invariant geometrical sense, as they are objects referred to two different bases. Absolutely. When I'm doing maths and I get to such surprising results as "the whole of tensor algebra/calculus is bonkers, because all tensors are null" --or something like that, I'm not completely sure if that's the point--, I try to retrace my steps and, sure enough, I can spot a silly mistake. The last thing that would cross my mind is to highlight the "result" and announce to the world, "hey, I've found an enigma".
  22. 2 points
    Again, this essentially comes down to the difference between topology and geometry. When we say the universe is spatially infinite, what we actually mean by this are three things: 1. Spacetime has no boundary 2. For any arbitrary pair of (spatial) points {A,B}, there exists another pair of points {C,D} the spatial separation of which is greater than that of {A,B}. 3. Spacetime is singly connected Herein, (2) actually implies (1), but I’m listing them separately for added clarity. These three conditions are true at all times t>0, including immediately after the BB, and at the present time; so this does not change, and it - roughly - represents an aspect of the global topology of the universe. On the other hand, when we say that the universe was singular at the BB, what we mean is that as t -> 0, the separation between any pair of arbitrarily chosen spatial points will tend towards zero; and it means that no geodesics can be extended beyond the hyperslice t=0, without them extending into the future again (so this is a bit like a “pole” in spacetime). It does not really mean - at the danger of straying into the disciplines of metaphysics and philosophy here - that only a single point existed; the spacetime manifold was already there in some sense, but there was no notion of “separation between events” yet. So it’s the geometry that was singular, but not necessarily the topology. Of course, this is the purely classical picture, it does not account for any quantum effects (which will likely change the story quite radically).
  23. 2 points
    That's not what MigL claimed though. He was suggesting that iNow was unfairly dismissing valid claims of Democratic/Progressive mis-steps. You'll need to show not that iNow said "false equivalency" but that he did it simply as a dismissal of a valid criticism. @MigL - I know you did not mention me specifically as someone who was dismissive of comments regarding poor 'Progressive' behavior but if you think I am guilty I'd honestly like to hear so. I don't think I am but of course it is sometimes difficult see ones own flaws.
  24. 2 points
    Having taught math successfully in Junior High and High school I though I would have a lot of great examples for you-- but on further reflection realized my best ones were not something that could be generalized. I had the greatest success when I could connect the math lesson to the students' experiences. For example, in my rural area the vast majority of the students have experience with guns and many also have reloaders in their families (people who make their own ammunition). When I first tried to teach statistics I got blank looks from many students, So that weekend I took my test equipment out to the rifle range and measured velocities of 10 rounds of ammo I had built. On Monday I put the data up on the screen and asked the students if the load I had developed was consistent enough for hunting. This lead to a successful lengthy discussion and the development of the idea of mean and standard deviation. The lesson I learned and applied from then on is this: The goal is not so much to make the students think differently, but rather to create a use for the math knowledge in a way that connects to their experiences. I can think back to lots of examples of good teaching tricks, but realize they are were specific to a certain student or group of students. Not much help to what you want.
  25. 2 points
    OK so I will try to discuss communication of Mathematics, rather than principle of Mathematics. I can't see where you have mentioned any basic Maths, computer code is hardly basic if it is indeed Maths at all. However I beg to disagree with your outright rejection of History. Perhaps your experience of History at school was of the sort "History is a list of dates of battles, deaths and treaties to be learned by heart and regurgitated for the examiner". History actually offers many lessons for those that care to peer into them. Not the least being concerning computer code. Coding languages have a very short lifetime; I have seen them come and go and stopped bothering to learn the new fashion decades ago now so I have little idea of the meaning of your example. The last serious program I wrote was PFortran TRIP (Trigonometric Intersection Program). British schools went through a phase of demanding that every child learn 'programming'. This mean resources were wasted on teaching first, different versions of BASIC, then PASCAL, then some early scripting. None of which are current today. History also tells us that the basic mathematical operation of counting is at least as old as writing, probably much older. Now schools used to teach using the old fashioned balance scales. Good schools would actually get the pupils to set up pretend shops acting as customers and shoperkeeps. They would weigh out amounts of materials, say potatoes or sand and also practice with pretend money. This allowed a method of counting by the custemr presenting say a half crown coin and the shopkeeper saying That's one and fivepence and then making up the one and fivepence to half a crown with coins to provide the change. Instant communication of arithmetic and fractions. For those who were a dunce at school arithmetic there was the joke, you say you can't do maths but you can still instantly recognise that you need a treble eighteen, double top and single nineteen to finish in a darts match when you are on 113! Would these be the sorts of examples you are looking for ?
  26. 2 points
    Yeah the poll is obviously made with a very specific viewpoint in mind. How about you are sexually abused but no one believes you? Or you are sexually abused, and report it but lose your career over it? How about you are sexually abused and have to explain your browser history in front of a jury? Or you are sexually abused and folks tell you not to be a slut? Or you are sexually abused and folks try to help you but you cannot overcome the resulting psychological problems? I mean, some things happen more commonly than others.
  27. 2 points
    Look at this EM chart: Wifi. and mobile wavelengths are around 3metres long and the lowest level of ionizing radiation is just into the uv range many, many times shorter. Look where visible light is, I don't think that causes ionizing radiation, so how can microwaves cause the purported issues if ionization starts and increases to the right of the uv segment?
  28. 2 points
    I would guess that any hard right ( or hard left ) Government that has aspirations of dictatorship ( Poland maybe ? ) would be trying to force established social media out, so that a Government run/controlled media can more easily disseminate Government propaganda. Makes it much easier to control the people.
  29. 2 points
    GASOLINE contain hydrocarbons. These are able to work as a sweller. The fuel compounds petrate the molecules of the plastic and expand them. In some cases it can dissolve them. Alcohol would be the better choice. Because it solouble in water. Or any commonhoushold cleaner based on water.
  30. 2 points
    I have studied GR in some detail, so I am aware of all these possible scenarios; by personality I also tend to be a “natural worrier” who easily gets anxious even over minor things and life events. In addition, I am an Aspie too. Yet I feel no sense of depression, worry or anxiety over the possibility of a cyclical cosmology. Furthermore, you need to remember that the observational evidence we have at the moment is much more consistent with other global topologies, and not a cyclical universe. I believe you when you say that you yourself might find such an idea depressing, but remember that this does not imply that others necessarily relate to the concept in the same way. Most of us here understand the notion of a cyclical cosmology well enough, but don’t find it depressing. I find that people often tend to miss the salient point of Schopenhauer’s philosophy - he did not advocate despair, depression, or absolute nihilism. The main point he was trying to make was about acceptance. It is strictly necessary to fully understand and acknowledge the inherent limitations of the human condition - such as the impossibility to permanently satisfy desires and craving, and the futility of constant strife towards some ideal utopia -, but then it is also necessary to accept them for what they are, and thus arrive at a position of peaceful coexistence with those limitations. Philosophical pessimism does not imply despair and meaninglessness. And of course, philosophical pessimism is only one possible life philosophy, which is by no means shared by everyone.
  31. 2 points
    I demonstrated the concept of subtraction to my children by eating their French fries. It worked quite well, and served the parallel purpose of being an education in social interaction with people more powerful,than you... that life isn’t always fair. Sorry... yours is a weird OP
  32. 2 points
    It’s an amplifier, not a root cause. Lies and disinformation and absurdities spread in nazi Germany, too... well before social media. Schwarzenegger put out a good video today speaking along these lines and how the siege on the capitol was like Kristallnacht. This is a much bigger conversation. The question is not if the law should change, but how. Here’s what protects them today: https://www.law.cornell.edu/uscode/text/47/230
  33. 2 points
  34. 2 points
    ! Moderator Note Nope.Your “new model of the universe” discussion was closed. You don’t get to invoke it here - you used up your chances to support that idea already, and you didn’t.
  35. 2 points
    Because there is a general principle in nature that says that all systems will always tend towards that state which represents the lowest energy level, and/or the most stable configuration (in technical terms, the “least action”). This is called the principle of least action, and it is a formal mathematical statement that underlies both the macroscopic world (GR) and the microscopic realm (quantum field theory). The principle of extremal ageing is just a special case of this. In the case of test particles under the influence of gravity, the resulting world lines are the simplest possible ones (so it isn’t “elaborate”) - they are geodesics of spacetime, i.e. world lines where proper acceleration vanishes at every point (hence “free fall”), or equivalently the “straightest possible” world lines. Because it is mathematically inconsistent. The object that describes the curvature of spacetime, and hence gravity, the Riemann curvature tensor, can be thought of as “made up of” two parts - its trace-free part, the Weyl curvature tensor (which roughly speaking encodes tidal effects, i.e. distortions in shape of a test volume in free fall); and its trace, the Ricci tensor (which encodes the volume itself). If you have only 3 spatial dimensions, the Weyl tensor identically vanishes (a basic result in differential geometry, which can be straightforwardly proven), so there’s no tidal gravity. In fact, since in vacuum the Ricci tensor vanishes as well due to the Einstein field equations, you would have no gravity at all in the exterior of massive bodies - which is clearly not consistent with what we observe. So the universe cannot have only three spatial dimensions, since this is logically at odds with what we see in the world around us. I can easily formalise this argument mathematically, but I think you understand what I am trying to point out, so there shouldn’t be any need. Nice one 😄
  36. 2 points
    Today I learned the US Civil War was not as far back in history as I thought. https://www.yahoo.com/huffpost/civil-war-veteran-widow-helen-jackson-030518406.html
  37. 2 points
    No. What actually happens is that the relationship between these frames in spacetime changes - clocks don’t “slow down”, and rulers don’t “shorten”, only the way they are related changes (in the case of SR, that’s mostly just a hyperbolic rotation in spacetime about some angle). All clocks always tick at “1 second per second”, and all rulers always measure “1 meter per meter”; its only when you compare two of these in relative motion, that you find that they no longer share the same concept of simultaneity, and thus that their frames are rotated with respect to one another. But because the laws of physics precisely are about relationships between events in spacetime, this has measurable physical consequences, which are quite real. Also no. Experiment and observation tell us precisely the opposite, namely that Lorentz invariance is a fundamental local symmetry of the world; this has been so thoroughly tested (see above) that it is beyond any reasonable doubt. Given this, spacetime has to be locally Minkowskian, which implies that the metric is invariant. Therefore the “number of events” - which is the geometric length of the clock’s world line in spacetime - is also invariant. It does not change and cannot change, and all observers agree on it - this is mathematical fact, and not subject to any “interpretations”. The only thing that changes with relative motion is the way two frames are related to one another.
  38. 2 points
    There are countless observations of natural selection in so called "higher organisms". Many feature as model organisms for natural selection - stickleback fish, toads, anoles, killifish, guppies, monkeyflowers, grasshoppers, Drosophila, jellyfish, lycophytes, to name a few. There are dozens of well known manipulative experiments that have comprehensively demonstrated natural selection in populations of relatively long lived, multicellular organisms, and thousands of population genetic studies on natural populations which do the same. Natural selection in modern humans is also directly observed. The best example that immediately comes to mind is the Framingham Heart Study. I think the concept that you're missing is that selection is dependent on population size. In small populations, genetic drift can overwhelm selection, leading to the loss of beneficial alleles and the fixation of deleterious ones. Conversely, the larger the population size, the lower the selection coefficient required to lead to fixation or extinction of a given mutation. https://www.nature.com/scitable/knowledge/library/natural-selection-genetic-drift-and-gene-flow-15186648/
  39. 2 points
    Looks like somebody trashed the memory crystals in Superman's Fortress of Solitude. No seriously … very nice !
  40. 2 points
    Can't Believe I forgot about these. Cave of the Crystals
  41. 2 points
    They'd be there for a porpoise... Happy New Year everyone!
  42. 2 points
    Well, this wasn't at all related to New Year's eve ...
  43. 2 points
    The full energy-momentum relation (which is simply the relationship between the temporal and spatial parts of the 4-momentum vector) is \[E=\sqrt{m^2c^4+c^2p^2}\] For massive particles at rest you have p=0 and thus \[E=mc^2\] For photons you have m=0, and thus \[E=pc\] Particles do not need to be stable in order to be elementary. For example, the muon is elementary, but has only a short lifetime. Protons don't decay, so it is "more stable" than the neutron - even though both of them are quark triplets. Neutrinos naturally arise from the way the weak interaction works, since energy and momentum need to be conserved. Protons are not fundamental, they are composed of quark triplets, same as neutrons. They do interact with matter, it's called the Mikheyev-Smirnov-Wolfenstein effect. They also interact gravitationally, if you have enough of them. Gravity is not a force (though it can be approximated as such in the Newtonian limit) - as is easily seen by going into free fall while carrying an accelerometer.
  44. 2 points
    Here is what looks like the same passage from English wikipedia. https://en.wikipedia.org/wiki/Michelson–Morley_experiment Note that the above is a full section showing more context and interpretation. Looks like the results of that experiment showed a different outcome that you try to argue?
  45. 2 points
    ! Moderator Note Enough! We ask you to clarify what you're talking about and support it adequately, yet every new post makes everything less clear. It seems clear you can't understand the explanations the other members are giving you because you can't see beyond your own concepts. Your style of argument is polluted with conspiracy fallacies, and somehow you think questions you can't answer but also can't be bothered to research properly are interesting and meaningful. You clearly are not ready for the type of reasoning science requires. Please don't post any more threads where you suspect cosmology of some kind of intellectual coverup. This is a place of knowledge and learning, not pitchforks and leeches and ignorant fears. We wish you well, but you don't listen, and that's required in discussion. Maybe you should start a blog somewhere? If you stay, please read more than you post. You have a LOT to unlearn. Thread closed.
  46. 2 points
    Yes, that means they will float. But the downflow of water exerts a force as it strikes the beads, so initially the buoyancy can’t overcome this. But the flow rate near the beads decreases after the top fills up, so this force decreases, and then the beads can float upwards.
  47. 2 points
    Two things are clear to me. 1) All other participents understood the gist of what you said the first time round so there was no need to repeat it. 2) You didn't listen to anything others said, since for instance you repeated your valence electron error (underlined), which is probably why you didn't respond to anyone.
  48. 2 points
    So … impossible to prove or detect. That means it has no affect on anything else, or it could be detected indirectly. And if it doesn't affect anything, what is the point of having it in the model ? Maybe you should post your ideas in the Religion section. God is also impossible to prove or detect, and why so many people have no need of Him. Just like the aether.
  49. 2 points
    The fitness effects of a mutation are a moving target in a variable environment. While a mutation may be deleterious or neutral in one environment, it may be highly beneficial in another. E.g. antibiotic resistance in bacteria. Further, even if the net number of deleterious mutations outnumber the beneficial, the process of selection increases the likelihood of fixation of beneficial mutations. This seems to be a version of the irreducible complexity fallacy - of which this is a good discussion of. As pointed out above, mutations do not need to be of benefit in the current environment to be prevalent or even fixed in an environment, so a trait can exist that has no contemporary function or benefit. Also, intermediate phenotypes are often more prevalent than many expect - as an example there are both air breathing fish and amphibious fish that can't breathe air that are extant today. Epigenetics and gene interactions may well be associated with beneficial mutation, however neither process could be described as effortful or interactive.
  50. 2 points
    They aren’t. The premise of your question is false.
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