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Showing content with the highest reputation since 07/24/17 in all areas

  1. 6 points
  2. 5 points
    This would be very cool. Unfortunately, here in the USA, I don't see that happening any decade soon since there would be parental concern about the radioactivity as well as (unreasonable) religious concerns. * The discussion reminds me of a point I read once that if Darwin had been wrong, the discovery of DNA and how it works would have destroyed his theory and we would have been seeking an alternate mechanism. Instead the discovery of DNA lead to a refinement of Darwin's theory into the even more robust Evolutionary Theory. It is humbling to think of how Darwin, through observation and deduction, derived the process of natural selection and developed his theory and that we have only needed to refine it a bit in spite of more than a century of amazing discoveries. I used to believe in evolution but I no longer do after studying it – now I understand and accept it. I also now see three groups: those who believe in evolution, those who don't believe in evolution – but neither of those groups understand it – and those who understand and accept evolution. I have never met someone who understands evolution but doesn't accept it – all who claim to be such people show that they don't actually understand evolution and really they just don't believe in evolution.
  3. 4 points
    Thank you so much for your input! I was absolutely hoping for a response like this. I knew that there were inconsistencies, and I am glad that you pointed out and explained each inconsistency and flaw with this idea. When I say "independent research" I was mainly reading up on various reputable sources from various university websites that have certain topics that they have explained by lecturers posted online. I also have been listening to some physicists on youtube talk as well, but that can get a little sketchy, cause it's youtube after all. And then the chargeless and massless part I learned from cause I did not know that photons were massless and chargeless, but I did have "light" in mind because I knew that light was massless but didn't think that it was chargeless, but we are all wrong sometimes! I really am looking to get into this kind of field one way or another, but again, I gotta take baby steps. This was just an idea that I had that I wanted to bounce off already established laws and theories before I start doing anything serious with it! Thank you for that congrats! I like to try to stay humble with my ideas because I don't like to get cocky with this kind of stuff. I am completely unqualified and I really wanted to dive into the world of physics to try and better prove or disprove any ideas I may have. I do agree that I should get into some books and attend some courses but I gotta stick to my game design school so I don't fail it and miss out on a great opportunity like a B.S. in Game Design, you know? Both of you guys really helped me understand a lot! Thank you for your guys' inputs!
  4. 4 points
    Attenuated strains are simply viruses that have very low virulence in the target organism. They are produced by either by selection or, in some cases, targeted mutagenesis. They are typically propagated in vitro and quality control is quite complex and includes testing of the cultures (to ensure that they are still pure and only contain the virus), animal testing using susceptible models and so on. The theoretical risk is that somehow, attenuated strains may acquire further mutations that turn them virulent again. The only example I can think of where it actually has happened are the case of polio vaccines with something in the order of 20ish outbreaks in a decade throughout the world (interestingly, typically in regions where vaccination was inadequate). However, in order to allow transmission, the vaccinated individual would first have to become sick. But again, these are incredibly rare incidences, far outweighed by the risk of actual chance infection, especially in populations with low vaccination rates.
  5. 4 points
  6. 3 points
    Posting the same drivel on other forums does not constitute "publishing". But if you are unable to get this crap in a peer reviewed journal, then I suppose spamming it all over the Internet is the best you can do.
  7. 3 points
    There is a way to address the fact that violence from anyone is inappropriate that does not ignore the fact that there was a major white supremacist rally during which someone who was protesting against them was killed by a white supremacist when he intentionally drove his car into a crowd, which Trump did in his initial remarks. He then made a statement addressing those concerns days later which it later came out he was essentially forced to do over his own protestations by his staff, complained when the press coverage of his handling remained negative even after he made the statement everyone said he should have made in the first place and then the day after that he effectively repudiated everything he'd said the day before and went back to "Both Sides Are Bad." Trump's statement that there was violence on both sides is true in the same way that it is true that there were Jews who committed crimes against Germans in the 1930s: It might technically be true, but completely irrelevant in light of the larger discussion of what was going on and useful only as a tool to draw false equivalencies and distract from larger problems. Even if there was no violence at all from anyone on either side, the rally that happened would not be ok. Legal, but not ok, and the fact that deadly violence was used by that side on top of it makes any attempt to draw an equivalence between the two morally bankrupt in the extreme. A statement being literally true does not mean that it is not also Trojan horsing a lie by implication nor does it render the statement immune from criticism.
  8. 3 points
    Moontanman, that reminded me of Bo Burnham's song, "From God's Perspective - You're Not Going to Heaven". ROFL!!!
  9. 3 points
    Just found something easy and useful. To quote extracts of a post: highlight the desired section and and a little "quote this" label shows up. Click that, you then have a a named and time-stamped quote in your input box.
  10. 3 points
    After a recent update to our forum software, typesetting equations on SFN has changed a little bit. Although we are still using LaTeX, for a variety of reasons, we've elected to shift over from our custom-written LaTeX generator to the excellent MathJax library, which will take your equations from post text and render them in your browser. Much as before, the idea is that in your post, you surround equations with special characters, and MathJax will convert the contained text into an equation for you. There's two types of equation that you can typeset: Inline math is displayed in the flow of a sentence, such as \( y= x^2 \). This example was produced by using the text \( y=x^2 \). Note that we do not support $ signs as most LaTeX users would be familiar with, since this occurs too frequently in text. Display math breaks up a paragraph and can be used for typesetting larger equations such as \[ y = \int f(x) dx. \] The text then picks up afterwards. This example was produced by using the text \[ y = \int f(x) dx \] , which we note is exactly what one would type in a usual LaTeX document. For reference, the old guide is still available and has a number of useful examples for those getting started. Finally, please note that for legacy posts, the old [math] [/math] tags will still continue to work and these will display equations as inline. However it's likely that older posts may look different to the way that they did before.
  11. 3 points
    So your going to rewrite physics and mathematics just because your too lazy to learn. Got it Thanks for wasting our time
  12. 3 points
    As it happens my father in law passed away two weeks ago and we had a celebration this past weekend in his honor. I bring this up because I was so impressed by the way he came to terms with his own end of life. He was 91 and recently diagnosed with a cancer that would end his life within months. His response was to ponder it for a moment, state that he didn't want to pursue any treatment, and then asked what time the baseball game was on. In order to make sure he looked his best he went out and got a haircut. He planned his memorial mass, a luncheon (including the menu, venue, and guest list), and paid up front for the party which included an open bar. About 150 people showed up. He scheduled the festivities for two weeks after his death so as to not cause anyone to have to make sudden travel plans. He also declined to have a funeral procession to the cemetery as he thought they were disruptive to traffic. The eulogy he wrote for himself was short and sweet because he said he knew if could be difficult for the person who has to read it. He went out with a smile and treated his last day no differently than he treated any other. I don't know how he did it, but his example of how to approach death is what I now aspire to.
  13. 3 points
    There is so much of this guff about, you have to develop a filter, or you will waste a significant chunk of your life debunking rubbish. Surely there is enough in what you have written to convince anyone that it's rubbish? You need to turn off your curiosity at the very first clue, because it's too valuable to waste on these con-artists. The time you waste on it could be spent on genuine science, which is equally amazing, and has the added bonus of being true and in line with the real world.
  14. 3 points
    Apparently every website now needs to be like a social network. Soon you'll be able to see pictures of every meal swansont has. I know, I don't understand it either. To make it a bit easier I added an "Unread Topics" link under My Activity Streams, which takes you to see all unread topics, condenses the list, and has links to take you immediately to the first unread post. Is that more helpful to you? I'll be sure to add a separate "Swansont's Lunch" feed later.
  15. 3 points
    Imagine 2 satellites orbiting the earth very close to each other. Do you have any problem with that? (You need Newton's laws to understand this.) Now imagine that one satellite is bigger than the other, but both still orbiting very close to the other. Do you have any problem with that? (You need Newton's laws to understand this.) Now assume the biggest one is hollow, and the smaller one is completely inside the other. Both are doing their own orbit, which happens to be the same. Do you have any problem with that? (You need Newton's laws to understand this.) So the smaller satellite is 'weightless' in relation to the big satellite: it does not bounce any wall of the bigger satellite. Do you have any problem with that? (You need Newton's laws to understand this.) Now suppose the bigger satellite is filled with air, and the smaller one is an astronaut... Do you have any problem with that? (You don't need Newton's laws to understand this.)
  16. 3 points
    GeniusIsDisruptive has been banned. Was too little genius and way too much disruptive.
  17. 3 points
    I'm not sure if the OP is still around to see this, or if he'll even bother to read and try to understand it, but: Have you ever ridden in a fast moving car that reaches a dip in the road, and you get the "leaving your stomach behind" feeling? This is just a lesser magnitude example as to what is happening for the astronauts. At that moment, you are just slightly "lighter" with respect to the car than you are normally, and this is what your stomach is reacting to. If you where to be traveling so fast that the car's wheels left the road for some time, you would feel "weightless" and objects would "float" around in the car. This is because your "weight" is a function of gravity pulling down on you and the car, but the ground pushes back on the car and through it to you. When the car leaves the ground, both you and the car are still subject to the same force of gravity as before, but are both free to respond to it equally and are both in free fall. There is no force pushing up on you to resist gravity and you are "weightless". The "Vomit Comet" which is a plane designed to simulate this effect for longer than you could achieve in the car, does it by flying in an arc that follows such a free-fall path. Again, while following this arc, you, and object in the plane, float around in a weightless condition, even though the force of gravity on you has not let up one bit. The ISS is in a state of continuous free-fall. While near the surface of the Earth and at normal speeds, such a free fall path will always end up intersecting with the ground eventually, at the altitude and speed of the ISS, as it curves towards the ground, due to the spherical shape of the Earth, the ground curves away also. It basically end up in a state of constantly falling towards the Earth but it keeps missing it. Since both the ISS and astronauts are following the same free fall path, the astronauts end up in the same weightless condition as in the car in the air or the Vomit Comet during the arc, even though the force of gravity acting on them is not much weaker than it would be at the surface.
  18. 3 points
    A word isn't necessarily exactly the same as any of its synonyms: else why would the English language have such a diverse pool of words to choose from. I agree that faith and trust both require us to believe something. The subtlety here is that faith compels us to believe something regardless of the evidence. Science asks us to believe something so long as it accords with the evidence.
  19. 3 points
    I thought everybody knew by now that the answer to Life, the Universe and Everything is 42.
  20. 2 points
    This doesn't make sense to me. If people are starving it's because they can't afford food or because food isn't available. If it's the former, then they weren't customers in the first place, so there is no lost business. If it's the latter, then there is no business to be lost. You need to make contraception available, too. That's often a religion-induced issue. But That would happen even if they improved the water supply on their own, so I don't see how you can hang that on charity. This sounds similar to the common "poor people are lazy" propaganda, along with branding them as stupid, to boot. It's bogus.
  21. 2 points
    I would like to address the issue of left(ish) and science-based privilege on this board. The science part is quite trivial. Due to the fact that most members are interested in science, certain basic aspects (evolution, GR, climate change) are con-controversially accepted as fact. Not everyone has the expertise to fully understand the concepts, but at minimum one accepts them as trivially true and gets suspicious when someone addresses these or similar topics in an adversarial manner. In the best case scenario, ignorance is countered by knowledge and hopefully leads to education, willful ignorance almost always leads to argument. Still, it is easy to suspect untoward motivation, when the subject matter and tone is more adversarial than potentially intended (and it does not help that there seem to be more of those not arguing in good faith). On policy sides thing are even trickier. I do not consider myself left leaning and I clearly do not associate myself with any party. However, I am very data-driven (in case you have not noticed, if so I am doing a bad job) and I tend to base my policy preferences on available data (even when imperfect) rather than a specific ideology. This results with me often agreeing with left-leaning stances, which on most issues is more dominant on this board. Although different members may have different reasons (ranging from evidence-based readings to ideological conviction) we do have a hegemony on many views (such as, I imagine, the utility of social intervention to solve crime rather than merely a punishment-based one). Especially for those that have done a lot of reading on that matter an alternative view based on demonstrably false assumptions can be seen as an attempt of trolling or the initiation of a discussion that is not considered to be in good faith. While many may reply that they do show evidence, it has to be acknowledge that long-held convictions cannot be overturned by single articles and it may be worthwhile to engage in a deeper conversation. That, unfortunately requires a lot of introspection from both sides. Although it is tempting (and I admit that I am getting annoyed at times, although no one forces me to participate here) I believe it is worthwhile to propose a conversation in good faith and at least acknowledge that deviating convictions, even if they seemingly clash with data or reality should be explored. Especially when one is part of the lefty-science hegemony on this board (a term I just made up) one should try to acknowledge not necessarily that the opposing view is correct. But rather we have to acknowledge that they feel that this aspect is important to them and if both sides agree to explore this, we may be able to find common ground. There is an inherent bias that we need to realize and acknowledge, as we are more likely to forgive someone using bad data to reach the same conclusion as we do, rather than someone who uses bad data to reach a different conclusion. On a different note, this feeling of marginalization is is similar to what it feels to be not on the upper side of racial or other privilege. The hegemony has behavioral rules and aspects that appear to be fair and make sense (based it on science, show the maths) yet may feel unfair on the receiving end. Opposition to divergent views appear to be amplified yet it is not acknowledged as such. People act as if they are fair and reasonable but why does it not feel that way? Why are my grievances not acknowledged? Why am I being marginalized for what I assume to be fairly reasonable? This intangibility of these dynamics that merely arise from group composition rather than of adversarial bias (people do not think that they hate people with differing political opinions for example) is at the heart of issue of privilege (and the subconscious elements of racism, sexism etc.). It is also more common than aggressive bigotry and requires introspection to be recognized. I like the concept of second thoughts that Pratchett mentioned: No one thinks that they are unfair or biases, otherwise they would behave that way. Left-leaning folks here do not think that they are being unfair to differing views. But for those on the receiving end it sure feels different, no?
  22. 2 points
    Apologies, i obviously missed it. But now i'm more confused: you insist that Christians must follow the bad bits (stoning an adulterer), and presumably the good bits (turning the other cheek - forgiving the adulterer in this case), but insist they must follow both to be classed as a 'true' Christian. Your definition leads to the absurdity that there are no Christians on this planet, since it is impossible to do both of these contradictory things. If even the Pope is not a Christian by your definition you've got to start questioning your definition surely?
  23. 2 points
    I don't know if I agree with your premise about a la carte beliefs being in conflict with categories of belief like, for instance, not believing in the resurrection disqualifying one from being a Christian. All beliefs are to one degree or another a la carte. You will be hard pressed to find to people whose beliefs are exactly identical on a wide range of topics. That disagreement means that there is rarely a set of canonical beliefs that fall under a single label which are not disagreed on at any point by people who take that label for themselves. As such, applying labels to any set of beliefs is not a practice of objective classification but really one of taxonomy. It is grouping non-identical things into categories of likeness. And any such taxonomic classification is going to, to some degree, be arbitrary and subjective with some blurriness on the edges. To describe yourself as a religious person, do you need to share all of your religious beliefs with every other person who describes themselves as religious? Of course not. Similarly, I do not think that one must share all of their Christian beliefs with other Christians in order to qualify as a Christian. Just like you cannot reasonably expect a person to defend the existence of Krishna just because they describe themselves as religious, I do not think that you can hold everyone who describes themselves as Christian to defend every belief that is common among some groups of Christians. Nor must someone who is a scientist defend every belief that is common in the scientific community. Nor must a conservative defend the beliefs and actions of every other conservative, nor liberals those of liberals. Such labels are names of convenience, not accurate descriptions of all of a person's beliefs. If a person decides to take a label on as part of their identity, then it is incumbent upon them to stake out where they differ from popular perceptions of the beliefs commonly associated with that identity, but they do not necessarily have to subscribe to every single one of those beliefs in order to retain that label for themselves, and expecting them to put up a universal defense of those beliefs or else admit that they don't really qualify for the label is generally unreasonable. A simple statement of "I am an X who does not agree with Y belief" should be enough.
  24. 2 points
    I found the paper to be an accurate representation of what I have read from other sources. Toward the end of the Carboniferous and the formation of Pangaea, combined with our fourth ice-age at that time, the atmospheric oxygen levels began to decline. When that ice-age ended approximately 270 million years ago atmospheric oxygen levels were already down to ~18% with atmospheric carbon dioxide levels between 250 and 350 ppmv. That is also when temperatures began to rise, reaching between 35°C and 40°C. Contrary to popular belief, there were three main extinction events between 270 and 250 million years ago, and each of those three Permian extinction events (spaced between 9 and 11 million years apart) were larger than the extinction event that killed the dinosaurs. When the Siberian Traps began erupting 248 million years ago the particulates in the atmosphere helped cool off the planet and increased carbon dioxide levels significantly (by as much as 1,200 ppmv according to some sources), but atmospheric oxygen levels would take longer to increase. While atmospheric oxygen levels has certainly determined the size of arthropods, I am not sure the same thing applies to reptiles or dinosaurs. We have evidence of large arthropods during the Carboniferous, when atmospheric oxygen levels were as high as 33%. Even during the Silurian and Devonian, when oxygen levels spiked to 24%, there were 3 meter long arthropods. The atmospheric oxygen levels would drop again towards the end of Devonian, which is also when the giant eurypterids went extinct. What seems to matter more, with regard to the size of reptiles, dinosaurs, and even mammals, is the amount of space they have, not the amount of oxygen. Reptiles, dinosaurs, and mammals get bigger and bigger the more space they are given, irrespective of the amount of atmospheric oxygen that is available. During the Triassic the massive Pangaea continent was beginning to break up, but the super-continents of Gondwanaland and Laurasia still existed so they could start getting large during this period. When Gondwanaland and Laurasia started to break apart into South America, Africa, North America, and Eurasia about 100 million years ago it also ended the rein of the large sauropods. Life on land would never again get that large, and it had nothing to do with atmospheric oxygen levels. See also "The Silurian-Devonian: How An Oxygen Spike Allowed The First Conquest of Land", from The National Academies of Sciences, Engineering, and Medicine, Chapter 5 - https://www.nap.edu/read/11630/chapter/7
  25. 2 points
    There is something interesting that points to a causal relationship between energy (mass) and entanglement. " In stark contrast to transport experiments, absorption of a single photon leads to an abrupt change in the system Hamiltonian and a quantum quench of Kondo correlations. By inferring the characteristic power law exponents from the experimental absorption line-shapes, we find a unique signature of the quench in the form of an Anderson orthogonality catastrophe, originating from a vanishing overlap between the initial and final many-body wave-functions. We also show that the power-law exponents that determine the degree of orthogonality can be tuned by applying an external magnetic field which gradually turns the Kondo correlations off."https://arxiv.org/pdf/1102.3982.pdf This wiki concerns Electronic correlation, interesting stuff.https://en.wikipedia.org/wiki/Electronic_correlation#Mathematical_viewpoint Maybe, If it's true that the breaking of entanglement creates energy or mass then that might be related to the way the observable universe is created...but it's a very big 'IF'. According to big bang cosmology there was a thermal equilibrium. Regions which today are out of causal contact were once in equilibrium with each other...https://arxiv.org/pdf/1205.1584.pdf Matter is any substance that has mass and takes up space. Mass is a property of a physical body. It is the measure of an object's resistance to acceleration (a change in its state of motion) when a net force is applied.
  26. 2 points
  27. 2 points
    You don't kill bad ideas by silencing them. You kill bad ideas by addressing them. These insecure, ignorant, inferiority complex ridden knuckle draggers should be allowed to share their views and march (and only a tiny insignificant few people are claiming otherwise). Likewise, people who wish to defend more forward looking inclusive values should be allowed to share their views and march in response. The scales will tip. The haters will retreat to the shadows. They won't be extinguished, but their embers contained. Let them proudly display their ignorance, and let us proudly display why it has no place in a modern society.
  28. 2 points
    You are passively defending the Nazis by pretending their were other groups on non-bigots there whose focus was preserving history and by insisting bothsides were violent. Only ONE SIDE brought torches, shields, and helmets. Only ONE SIDE drove a car into a crowd of people. Only ONE SIDE killed someone. Only ONE SIDE is recognized as a hate group and on DHS domestic terror watch lists.
  29. 2 points
    "I can't remember where I heard this, but someone once said that defending a position by citing free speech is sort of the ultimate concession; you're saying that the most compelling thing you can say for your position is that it's not literally illegal to express." https://xkcd.com/1357/
  30. 2 points
    They don't behave as separate particles until you measure them, they are described by a wavefunction. The degree of freedom depends on the properties of the entangled particles..
  31. 2 points
    It really depends on selective force. Assuming no selection, the number generations required to fix an allele is: E(T) = -4Ne [p ln p + (1-p) ln (1-p)] With Ne being the effective population size and probability of allele frequency. The latter is important as in a large population p approaches the expected statistical distribution (i.e. 50:50 in case of two alleles) but with declining population sampling error occurs and you may have a skewed distribution, which is effectively what the drift is. As you can see, the time is maximized for p=0.5 and drops off it we see it skewed. However, if we add selection to the mix, it gets more complicated depending on how it acts on the population. It could accelerate the effect if the the particular allele is positively selected (and by how much depends on the selective force each generation). However, selection could go into the opposite direction (i.e. favoring the allele with lower frequency). In that case the balance of the two competing events would determine fixation rate.
  32. 2 points
    I don't know. But if Islam and only Islam was the sole determinant then we would expect to see all Muslim countries and populations adopt the death penalty for apostasy. We don't see that, therefore there are other factors involved. Which is not to say Islamic doctrine does or does not contribute, only that if it does contribute it is one factor among others.
  33. 2 points
    What are the error characteristics of your measurement system? You have 6 data points. Are they all supposes to be a repeat measurement of the others? With the information you've posted and only 6 data points it's impossible to give any good advice. (with the possible exception of repeat the experiment some more)
  34. 2 points
    Today I learned about the Hyrax. Although you can't tell from the picture, this rodent-like creature is actually more closely related to elephants!
  35. 2 points
    Seeing veins is neither paranormal or psychic. Phlebotomists do it every day. It's also possible your visual system is a bit borked and you're just more sensitive to the near-infrared side of the visual spectrum. Machines like those described at the following link would allow you to run tests to see if this is anything more than a delusion: https://www.cnet.com/news/near-infrared-makes-veins-easier-to-find/ Who knows, though. If you keep using meth, soon we'll be able to see gaps where your teeth used to be, tears where joy used to be, and potentially even graves where life used to be.
  36. 2 points
    Evgenia, Games are an interesting part of this. Are games practice, where you are learning how to fight an adversary by tussling with your littler mate, or an instinctual bonding behavior made to associate yourself with your littermates and thereby survive as a group, or are games something else? It seems games would be an indicator of a certain consciousness, because you have to know the difference between the effects on your littermate of having your claws retracted rather than out, as you would have them with an actual adversary. But perhaps games show an innate ability to "pretend" and this in turn would require an ability to tell when something was actual or not. And this would require some ability to remember the place and build an internal model of it. That is, be able to recognize a littermate as "not to claw" and something not a littermate, a potential enemy requiring a fight or flight response...that "same or different" ability talked about earlier. Also interesting about games in regards to instinct and consciousness is how, in a study I read years ago, female humans on the playground tended to play cooperative games where there is no winner or loser and males played team sports where a leader was chosen, teams picked and there was going to be a winning team and a losing one. I wonder if a recent study, after the last 30, 40 years in America have redefined learned gender roles, and different types of games are played by an even mix of girls and boys, or whether there is still certain innate tendencies governed by hormones (emotion). Regards, TAR
  37. 2 points
    Cats trained as spies, DrmDoc ? interesting but unworkable, I'm afraid. I don't see a problem with the black tux, Omega Seamaster or even the Walther PPK. But shifting gears in the Aston Martin would be a problem.
  38. 2 points
    Some great answers were already given. Yes, it might seem hard, but would you refuse to go to the movies, just because you know the movie will end? And that after a year you might not remember much of it? I could give an answer in a Buddhist spirit: first realise that everything is changing, and therefore also will come to an end. Secondly, realise that you, as an autonomous, independent object, do not exist. You are the sum of all your biological and biographical factors, which include decisions you made yourself. Thirdly, realise that you are not the only one: every conscious being is in this situation. If you can really feel this, it can increase your compassion with other beings. When you feel this, and can act accordingly, such questions will not bother you anymore. Read this comic for another view on this. I am glad to hear this from you.
  39. 2 points
    Mike, you seem to be entirely missing the point. You have not demonstrated that any part of your heirarchy is valid. You just keep repeating what it is and what you believe about it. That is about as useful as a chess set in a rugby game. If you cannot at least make a serious attempt to justify your claims I shall have to conclude you are just trolling and I really will be out of here.
  40. 2 points
    Resignation is the answer. Whenever something bothers you, there are two, and only two, options: 1) do something about it 2) accept it and move on Since death is inevitable, there is nothing you can do about it, so just forget about it and go on enjoying your life. You can of course do some things to prolong life, such as not smoking and eating healthy, but those fall under category 1 (unless you choose to forget about that too). (there is of course a third option, which is often taken: fear, anger, resentment, jealousy, despair... none of these leads to nice places) I think your feeling describes nicely why religion is so popular.
  41. 2 points
    No. The given radius gives an orbital speed of 7673.556779 m/sec. At that speed and radius, the centripetal force would be 7673.556779^2 x 50/7=6,771e6 = 434.8211... N The force of gravity would be 3.987e14 x 50/6,771e6^2 = 434.8211.. N They are equal to the same degree of accuracy we have for the given parameters The 3.9987e14 is the "gravitational parameter" for the Earth which is equal to GM,where M is the mass of the Earth. This gives a more accurate answer as we know it to a better accuracy than we know either the gravitational constant or the mass of the Earth separately.
  42. 2 points
    You want to click the little dot or star next to the title of each thread, which takes you to the first unread post in that thread. It's not particularly well labeled. Also, under the Activity Tab, My Activity Streams, there should be an Unread Topics stream which is condensed and easier to follow. I wonder if I can adjust the defaults.
  43. 2 points
    There is a rich treasure trove out here. First this 2008 paper acknowledges Gorierly's proposal, but attributes the high speed particles, which generate the short lived isotopes, not to the actions of the magnetic field, but to a companion neutron star. I find this unconvincing, but that is based on my ignorance of the ease or difficulty of detecting neutron stars. I imagine that if there were a neutron star companion it should have been detectable by now. No subsequent papers citing this one discuss the NS hypothesis further. It seems that HD101065 is not the only star with transuranic content in the photosphere. HD465 is also anomalous. This is mentioned in passing in a couple of papers. I have not yet tracked down the original research. In an earlier post I mistakenly stated the half life of Technetium was 17 hours. I should have referenced the half life of 145Pm as 17.7 years. (How time flies when you are having fun.)
  44. 2 points
    Cladking - why do you insist on trying to explain the scientific method and modern scientific thinking when you clearly have no idea and have had this shown to you on multiple occasions A scientific model is an attempt to provide a rigorous and self-consistent mathematical and theoretical system which produces results which mirror those we find through empirical observation. An experiment does not reflect reality - it is reality. Models do impart understanding - that is they do unless you are using some mad definition - which is quite possible. They might not impart understanding of some platonic underlying schema - but then nothing does. You do realise that many scientific models are created before any specific data really becomes available - the scientists extrapolate from more general data and other models, guess, and create maths which looks beautiful and fitting. They then work out how this would be manifest in experiment. They then go looking for 27kilometres of superhard vacuum to smash protons together.
  45. 2 points
    Doesn't the "point" of nukes depend entirely on who you ask in what context?
  46. 2 points
    ! Moderator Note Bringing up speculations in someone else's thread is hijacking, a rules violation. (And, should one be tempted to do so, responding to a modnote is off-topic)
  47. 2 points
    Just to elaborate on the answer already given. Gases are just collections of fast moving particles bouncing off of each other. The pressure of a gas is a result of the collision of those particles. If you were to have a container, divided in two with a vacuum on one side and a gas under pressure on the other, The pressure on the dividing wall by the gas is the result of the constant collisions of those fast moving particles with the wall. If you cut a hole in the wall, the vacuum does not "suck" the gas from its side of the container, but rather, the particles that would have collided with the wall where the hole is have nothing to stop them from passing through to the other side so they will cross over into the vacuum side. Eventually (how long depends on the size of the hole) there will be just as many particles on one side as the other. Of course now the same number of particles will be in a larger volume with a larger inner surface area. While this will not change the force of collision for any given particle with the wall, it does decrease the frequency of collisions with the wall. This, in turn, decreases the net pressure felt by the wall. Now the Earth's atmosphere doesn't have a wall to hold it atmosphere, but here is how gravity does the trick. Take a ball and throw it upwards. It leaves your hand at a certain speed, slows as it climbs, and then eventually comes to a stop and falls back down. Air molecules are no different, They are bouncing off of each other at high speeds, but in order to escape into space they have to climb just like the ball, and just like the ball they lose speed as they do. Eventually they lose all their speed and can climb no further. Now if They had started with enough speed (known as escape velocity), they could have kept going, as gravity gets weaker the higher you go, and it would never be able to rob it of its last bit of velocity. However, the typical speed for air molecules are much lower than this required speed. (except in the case of light elements like helium and hydrogen, the Earth has a more difficult time holding on to these.) The speeds of the air molecules are a function of their temperature. With hotter gasses the molecules have faster speeds. If you were to heat our atmosphere considerably, you could cause it to lose its atmosphere. (Going back to hydrogen and helium, the reason the outer gas giants atmospheres contain them is bot because the planets are large and have strong gravity and they are further from the Sun and thus cooler. The Sun, on the other hand, which is mostly made of hydrogen, is very hot, but is also very massive, on the order of 1000 times the mass of Jupiter, and it only needs its gravity to hold together. In fact, if it weren't for the heat generated by fusion at its core, its gravity would compress it even smaller than it is.) Attempting to invoke buoyancy as an explanation for the effects we attribute to gravity is a bit of a non-starter as buoyancy relies on gravity to work. It works on the comparison of different weights and volumes of the object and fluid involved, and you can't have different weights without gravity. It also fails to explain why our space probes follow trajectories influenced by the gravity of the various bodies in the solar system while traveling through a vacuum, which has no buoyant effect. Nor does it explain why object still fall in a vacuum chamber, such as shown here:
  48. 2 points
    What is best in life? To crush your enemies, to see them driven before you, and to hear the lamentations of their women.
  49. 2 points
    I didn't really understand your question. And shouldn't it be the other way round, that virtual games imitate (or should I say recreate) reality?
  50. 2 points
    Searching for Cavendish on Wikipedia (which is what I assume you mean) brings up several possible pages. Only one of which looks like it might be relevant: https://en.wikipedia.org/wiki/Henry_Cavendish The words "2 micrograms" do not appear, and there is only a passing reference to the force of gravity. Perhaps you could be a little more specific than "here are some numbers I read somewhere or made up". OK. I guess this is what you are referring to: https://en.wikipedia.org/wiki/Cavendish_experiment#The_experiment So that summarises how the necessary accuracy was achieved. What is your question? And where does your value of the measurement uncertainty being "one milligram" come from? Is that what you think the likely error in the mass of the balls was? Which would be an error of 1 part in 158,000 or 0.0006%. That sounds impressive. Do you have a source for this?