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Showing content with the highest reputation since 08/14/18 in all areas

  1. 5 points
    Because the electron is not a classical particle (“little ball of mass and charge”), but a quantum object. As a first approximation, you can picture an electron as a 3D standing wave around the nucleus - you can only get standing waves of a given wavelength in specific places, which is why orbitals come in discrete levels. Crucially, there is a lowest energy level, which corresponds to the minimum distance an electron can be with respect to the nucleus (let’s assume here there is only one electron) - and that lowest energy level is not zero. Therefore the electron cannot fall all the way to the nucleus, it can only fall into its lowest energy level, which corresponds to an orbital that is still some distance outside the nucleus. This is a direct consequence of the laws of quantum mechanics, and coincidentally one of the questions that motivated the development of quantum mechanics in the first place.
  2. 3 points
    ! Moderator Note Posting to try and get others to do your work is getting rather tiresome. You have a question about a website, you go to THEIR help page and look for an answer. You want to know where to find information, use a search engine to find it. Stop posting crap like this here.
  3. 2 points
    After a long hiatus, nearly 7 years, I have returned. I went and joined the air force, got a bachelors of science, a minors in math and a minors in bio; and currently work in IT/ software engineering. Any of the old members still active?
  4. 2 points
    I don't think so. You can easily check this with your current configuration (without the tube blocked/sealed) if you put something that creates smoke (a cigar maybe) instead of that paper. The smoke would enter the tube in the center, along the rotation axis, where the air has a low presure, and exit near the walls, were the air/smoke is pushed by the centrifugal force (the rotation creates a vortex). Still, I recommend the wooden board I mentioned above, in order to block both air and electrostatic forces (if any). Gravity is not blocked by wood.
  5. 2 points
    The title says most of it, here is an inspiring extract Four years ago, Brian and his fellow students at Makerere University in Kampala, Uganda, came up with this low-cost, reusable device called Matibabu which detects malaria quickly without drawing blood. Although still in prototype stage, the society judges called his malaria testing machine "simply a game changer" in the fight against this deadly disease. Magnets and matiscope "Matibabu" means "treatment" in Swahili, and the machine uses magnets and a custom-made portable device called a matiscope. This shines a red beam of light on to the user's finger, detecting a substance called haemozoin crystals, the by-products of the malaria parasite. The makers believe Matibabu could transform the situation by speeding up testing times since it does not need to draw blood nor use invasive needles that children, in particular, can struggle with. https://www.bbc.co.uk/news/business-44484581
  6. 2 points
    Look man, I’m assuming you’re not some nutcase trying to hoax people on youtube and you’re genuinely interested in finding things out. Am I right assuming that? If that is the case, 1. Ground the pipe (if its metal, if its PVC you wont be able to) Tape a bare wire to the pipe and the other end connect to the ground (your vice or some other big chunk of metal should be enough for this purpose) You can also use an ESD set if you have one around the shop. 2. Use your multimeter to check for presence of static charge. Set it to measure „amperes” and be sure your meter has an option to retain a reading as the neasured discharge will take a microsecond or so only. Use tape to attach the myltimeter probes to the pipe. If the pioe is PVC it probably won’t work. Practise by rubbing a sweater or your bare feet on a carpet and measure that with your multimeter to get a readout by using the probes on your hands. 3. Use a feather instead of the paper to get a better idea of where and how much of air movement occurs. There might actually be both factors playing a role here at the same time - electromagnetism and air movement. 4. Read the wikipedia article I linked you to on gravity. Come up with questions and post them here, there are PHD physicists in this very thread who will answer all the questions you have, you can learn a lot from them. 5. Forget about hope you discovered how to „generate gravity” There is no way that could have happened, learn the basics of gravity what it is and how it interacts and you will laugh yourself a year later at this whole thing. I think its cool youre doing the experiments and I fully support you in this. Providing you’re not a nutcase or deliberately trying to find out how to hoax people.
  7. 2 points
    Do you know how CaO is produced? Mostly from CaCO3... CaCO3 + heat -> CaO + CO2..
  8. 2 points
    Distribution is still restricted there, from what I understand. Nonetheless I think part of the discussion seems to be based on the assumption that certain drugs are fundamentally (biologically) harmful than others. Thus, legislation is or should address that as a means to protect public health. The counter-argument do this are that evidence point to criminalizing drug abuse does not ameliorate the situation. Moreover, as the discussion with soft and hard drugs has been shown, it is not based on medical effects, either. Specifically alcohol seems to be seen as harmless (and ironically is a prime example how abolitionist movements did not work). Yet if scaled systematically it is on par with lots of other drugs typically seen as "hard" in common parlance. This does not come to a surprise to folks who work on physiological effects on drugs. Likewise, the dangers of tobacco are vastly underestimated, simply because we are used to it.' There have been efforts to use multiple criteria (which include harm to individual and harm to society) and according to one of the most cited study in the UK (Nutt et al. 2010 Lancet). The most damaging drug overall was alcohol, scoring higher than heroin or Crack cocaine. Of course one could surmise that the societal effects were driven by availability, but even on the harm to the individual user scale alcohol scores just behind Heroin, Crack Cocaine and metaphetamine. Drugs scoring lower than alcohol on the individual scale included cocaine and amphetamine. Tobacco scored close to cocaine and amphetamines. Tobaccos is a special case as it is generally not associated with overdose situations. However, if we include the increase in lung cancer, it suddenly becomes on of the deadlier drugs. Sure, it is less dramatic but lethal nonetheless. If we look deeper into the type of harm, alcohol and tobacco are drugs with some of the highest drug specific damages. When we look into drug specific mortality (which excludes e.g. violence), alcohol scores lower than heroin but higher than (crack) cocaine, methamphetamine etc. Especially the comparison between crack cocaine and cocaine is interesting. On the biological side, there is little difference in the damage they do bodily (mortality and damage are very similar). But on the overall damage scale crack cocaine causes more damage on the individual as well as societal level. A part of these different outcomes is based on the different policies surrounding those drugs, which, in my mind indicates that the additional punishment for crack cocaine is net harmful.In other words, the perception of what is considered a relatively safe drug (tobacco, alcohol) with actual medical data is quite different. Pretty much the only clear overlap are probably mushrooms. Of course, one could weigh different parts of the equation differently. E.g. focusing more on withdrawal, or availability of treatment options and so on. However, it does show our given perception not data driven but based on certain narratives that we built ourselves surrounding certain drugs. I found this argument, as well as your earlier approach to playing devil's advocate highly problematic as you tend to leave out so much nuance as to make the argument worthless. I have addressed what the difference between "feel good" and addiction or compulsive behaviour and that those require different approaches. Heroin itself was, for several reasons perhaps not the best example John could have picked. But what is clear is that alcohol is far from a safe drug. Yet we deal with it in a certain way that we find acceptable. It is certainly not based on the objective harm done to the individual. However, as a parent the answer should clearly be: don't give alcohol to them or any other drugs. If that is not possible than disapprove of dosages that can cause short or long-term damage. Clearly we do that for certain drugs. But for others we seem to be fine(ish) with the toll on public health. What you are advocating here, MigL is a full-on emotional response and I do not consider that a good foundation for policy-making. While I am far from being an expert in this area, it seems pretty clear to me that punishing users has almost only negative effects. The Portugal model (personal use is allowed, there is support to kick addiction, distribution and production is still prohibited) is not perfect and does not really eliminate drug abuse. However, it has also not lead to a surge of addiction. More importantly, indicators associated with drug addiction have improved. While certainly not perfect, it certainly seems a bit better than the decade old punishment route, which just made matters worse. @Koti, some of the references regarding cannabis and tobacco: Budney et al. 2008, Journal of Substance Abuse Treatment; Vandrey et al. 2008 Drug and Alcohol Dependence. Also note as per your earlier comment: there are no perfect policies. Every policy ever made is an empirical experiment. However, holding fast on wrong assumptions or not implementing changes once it becomes evident that they do more harm then good makes bad policies.
  9. 2 points
  10. 2 points
    No, I remember history books stating the Nazis had lost the war. They lost territory as a result; what would they keep ? I'm not sure where you're from, but who were the original ( or at least previous ) peoples who lived there ? Should you leave and give back the land ? I live in North America,. Do I have to leave and give back the land to the native Indians ? Do all non-aboriginal Australians have to leave ? Do all white Africans have to leave ? Why are you applying this bizarre 'morality' only to Israel ? I don't think you're anti-Semite, because intelligent/educated people are not. And I respect your opinion, because Israel does do some things which are distasteful ( and don't help their cause ), but to liken them to the second coming of Attila the Hun is hyperbole. Especially considering the character of the neighbors they have to defend againts.
  11. 2 points
    The question was not about using computers to solve calculus problems anyway. Since computer science is mainly about proving asymptotic behavior of the maximal running time of algorithms, there are lots of results in computer science that cannot or only with some extra difficulty be proved without calculus, e.g. typically using that the limit behavior is given by a suitable Riemann integral. Generally you cannot escape using limits to get general bounds on running time.
  12. 2 points
    Considering a wasted education in my youth and the limited ability to remember that seems to come with my age. I like SFN, and several YouTube host, I also have an app that lets my download k12 textbooks, and I am not ashamed to download the lowest grade text I can find to try and get a feel for the basics. I'm not afraid of getting it wrong because SFN members are gratefuly quick to set me straight when needs be. Though at times I feel puzzled especially when I ask a question about spacial density and it seems I'm sent on a snipe hunt. I can only guess that my question was so far off the mark that they were trying to help me along by making it sound like I had asked an intelligent question. I read those articles over and over to the point that I should know them verbatim, Sadly the only thing I can remember about them is that I never did figure out what they had to do with my question. Pretty much everything is new to me. Sometimes even the answers I thought I knew, are new to me, like the conversation about why electrons don't fall into the nucleus. An amazing question followed by an amazing conversation. I wanted to upvote the whole conversation, and I'm glad you Achilles thought to ask the question, cause I was apparently clueless.
  13. 2 points
    Your imagination is irrelevant. There are people who use heroin (under it's more respectable name of diamorphine) regularly for years. In terms of toxic damage done to the body, alcohol is worse- simply because the doses (ounces rather than milligrams)are so much bigger. Of course there is. Several countries have relaxed the legislation on drugs- notably Holland and Portugal. There is typically a small increase in the number of users of pot (and a slight drop in alcohol use). There's a huge saving on police time etc. The problem isn't people using drugs. There is a problem with people how use them too much, or too often. But there's a huge problem with people who are injured- not by the drug use, but by the illegality of that use. The people killed in gang wars over drug territories are killed by the fact that the drugs are illegal. The people who die of overdoses from drugs that were sold with uncontrolled strength and make-up were killed by the fact that the drugs are illegal. The people who die from infections from sharing needles are killed by the fact that the drugs are illegal. We could save most of those people. Why are we not donig so?
  14. 2 points
    It seems to be a thing with the human psyche that self-righteous anger is often out of proportion. The idea that you are some sort of hero, putting less thoughtful or caring people to rights is very appealing, and often sends people over the top. Especially if you can picture yourself as some sort of heroic defender of the innocent. In the news recently, Disney cast a straight actor, Jack Whitehall, as their first gay character. There was a self-righteous clamour of protest, that they should have cast a gay actor. Stephen Fry popped up, and pointed out that he'd been playing straight parts all his career.
  15. 2 points
    Actually, this is not correct. The charge that is associated with the weak interaction is a quantum number called “weak isospin”. All particles possess this, and it is conserved in all types of interactions - unlike flavour, which is carried only be quarks, and is not conserved anyway. Thus, the weak interaction concerns more (elementary) particles than just quarks. To be honest, I don’t think there is an intuitive way to really understand the weak interaction. It’s really quite a complicated mechanism, and requires quite a bit of background knowledge in quantum field theory to fully understand.
  16. 2 points
    This is true, but it is not what the OP has asked. The original question was why the electron does not fall into the nucleus, i.e. how is an atom different from a purely classical system of a charge in free fall towards another (opposite) charge, which of course is not a stable situation in the classical domain. So the OP wanted to know how this is possible, so I have attempted to answer the question. The spontaneous tunnelling through the nucleus - or any other classically forbidden region - is not the same as the electron “falling in”.
  17. 2 points
    Most scientists do accept that we are probably not alone in this universe. Many reasons for that starting with the fact that Earth does not hold any privileged position. Along with the facts that the "near infinite" extent and content of the universe, and the stuff of life being everywhere we look, leads reasonable opinion to conclude that we are not alone. Still the fact remains that so far we do not have any convincing evidence of any life off this Earth, let alone any Alien visitations and anal probing on Earth. Those are the facts at this time, not withstanding the sensational claims of impressionable gullible folk who are so fascinated and in awe of mystique in the world around them, that it clouds any logical judgement on their part.
  18. 1 point
    Never forget your towel, wise words indeed...
  19. 1 point
    Although this is true.... what about drafts from open doors or windows or just air currents from around his workshop or his breathing even? Also, he is holding the towel with his hand - it would need to be clamped (his own twitching will/could move the towel even). He isn't even close to being able to understand what he needs to do to eliminate the effects of air currents and probably still doesn't believe that this is the cause of the movement of the towel. If I were serious about showing that it were not air currents I'd vac down a glove box and do it in there... although I probably wouldn't bother because it is obviously air movement from somewhere.
  20. 1 point
    I agree. And of course I do not think generated gravity is part of the explanation for the phenomenon in the movie (until all other causes have been eliminated by using proper scientific methods). Idea: If the machine generates gravity, it should have a greater effect on a massive object. If you test with a brick, does it move across the table?
  21. 1 point
  22. 1 point
    Insteresting. I’m observing the conclusions drawn from this research all my life all around me. Too bad they didn’t include a cure.
  23. 1 point
    It's more of a placeholder for the staff. We keep notes on all reported posts, and infractions we levy on our own. We have members who've tested lots of rules and gotten many points but are still here. On the other hand, if you keep breaking the same rule over and over, we're going to assume that will always be a problem for you, and you'll be banned. We normally suspend before we ban, to show the consequences of poor behavior. But we don't have a rigid system, and try to take context into account. Discussions lose their meaning if they aren't done right. The rules were designed to keep discussions interesting, meaningful, and civil.
  24. 1 point
    Let me wish you far greater success in your gardening thread (and gardening) than I had in my recent one, which received no replies.. As regards preparing a somewhat neglected patch for cultivation, don't expect too much too quickly. Yes you should most definitely dig over the proposed cultivated area before winter. I don't know if you have hard winters since you are a white bear, but frost action kills off many pests and breaks up large clods. You mentioned ploughing. Yes rotovating can relieve much of the work of digging. You don't need to achieve what is called a fine tilth before winter, just large clods will do. Cut back vegetation from around your area, and keep it cut back. Existing vegetation will harbour a source of pests next year otherwise. It will take 2 or 3 years to clean the csoil under cultivation of weed seed, roots and pest spores and grubs. So for the first couple of years you can expect lots of attacks on your plants. Birds help with the cleaning. Next sping turn the soil over and break down the remianing clods to a finer consistency (tilth) It is often said that potatoes are a good cleaning crop because the continual turning over of the soil promotes cleaning. Something to also consider is the cost of horticultural produce in your shops. Grow stuff which is expensive to buy, because anything that is 'in season for you' will also be in season for local commercial growers so will be at its cheapest then. For instance I grow soft fruit, particularly soft fruit, (strawberries, raspberries, gooseberries, blueberries etc). These are financially worthwhile. But tomatoes for instance are at rock bottom prices when mine would be ready, if I grew them. Capsicums and courgettes are a profitable crop too.
  25. 1 point
    The easiest is Cloud Chamber. https://en.wikipedia.org/wiki/Cloud_chamber If charged particle is flying through Cloud Chamber, there can be placed electrodes with uniform electric field, permanent magnet, or electromagnet, inside of the device. In external electric and/or magnetic field particle paths are bended. e.g. electron is attracted toward positive electrode, positron is attracted toward negative electrode. Electron has the same electric charge as pion-, muon-, or kaon-, positron has the same electric charge as pion+, muon+, or kaon+.. But their rest-masses are different.. So their traces look different in particle detector.. Same force applied to particles with different masses bends paths slightly differently, and they can be distinguished.
  26. 1 point
  27. 1 point
    When are you going to get it? the really bad shit happens because its illegal and criminals don't care.
  28. 1 point
    John, I'm pretty certain you drink alcohol ( from previous conversations ) When are you gonna give it up and switch to doing heroin ? Do your (adult ? ) children drink ? Would you prefer they did heroin instead ? And, if not, why not ? ( since its side effects are so much more benign )
  29. 1 point
    It's like a virus. Some get it worse than others. I know several people who don't really believe, and just "go with the flow" but they still indoctrinate their kids. Or agree to them being indoctrinated. And of course, going with the flow usually coincides with a mild level of indoctrination. The stronger the indoctrination, the stronger the beliefs. On average. That's why the Muzzies get their kids reciting the Koran over and over and learning it by heart. It works, and sticks for life.
  30. 1 point
    I'm really sorry about that late night rant, where I pressed 'submit' before engaging brain. It does, and I meant 'quoting only part of post', which is perfectly OK; I do that myself of course and sometimes don't quote a relevant part of the post, which I feel happened here - no bad intent by you. Inaccuracy by me again. You were, I thought rightly or wrongly, summarising my views in an inaccurate way and I should have said that or, better, nothing. Good we agree about tunnelling. Still apparently disagree here with you and others - precise terminology is a problem. I still maintain that per unit volume s orbital electrons are most likely to be found inside the nucleus. Since the orbital is much bigger than the nucleus that probability is still very low. Sorry again about my personal criticism, which was unjustified and should not have been posted. I've cancelled my downvote. Thank you for your excellent response.
  31. 1 point
    No. I'm stuck. I missed something else and now i think i am in a state beyond repair.
  32. 1 point
    Well, if you want to keep moving the goalposts and making logically incoherent arguments, I'm out. Just a reminder of what you asked, as you seem to have forgotten: You have gone off on all sorts of tangents since then. As far as I can tell, just because you want yet another thread to display your ignorant bigotry. I think I'll just put you on ignore. You clearly have nothing useful to contribute.
  33. 1 point
    How is information like new discoveries, quantum mechanic discoveries released into the public? Is there a main website where that happens, is it by law information must be released to public or do scientists have a belief information must be shared. How do we know so much about what scientists do and know, how is this information distributed to public and for even sites like Wikipedia to know about tons of stuff
  34. 1 point
    Well, it can't do. (After all protons are pretty large and yet they only contain three zero-sized marks.) For all sorts of reasons. For example, the Heisenberg uncertainty principle means that the momentum would be infinite if the distance was zero. (See the thread about why an electron doesn't fall into the nucleus for more info.) The weak interaction is not really a force and it doesn't hold things together. And it wouldn't be able to overcome the massive kinetic energy you would need to give things to get them that close together. And any such system wouldn't be stable (after allow don't see any of this around us). And gravitational singularities do not really exist. But apart from every single aspect of it being impossible . . .
  35. 1 point
    That depends on what you mean by "supports". I agree that they have legitimate grounds for complaint about the way in which Israel illegally grabs land and slaughters children. I can see how they feel that they have no viable alternative apart from resorting to violence- to match that leveled against them. Is that "support" or a simple recognition of the position in which they find themselves? That's a remarkably stupid assertion to make about someone who is a life-long pacifist.
  36. 1 point
    I would 100% agree with charge being neutralised pretty quickly, it was the static solution [zero angular momentum] that had me somewhat disturbed. But as you say, probably never been observed. OK, I believe I can live with that...thanks for the answers and clearing up a couple of misconceptions.
  37. 1 point
    I can't really speak for him - but I am guessing it is because he cares about what people think about him. He cares about how he behaves and self reflects and self monitors his own behaviours (much in the same way a Christian repents from wrongs). Basically he is a good guy who cares about people and the world and doesn't want to make bad judgements and is 'checking' his thoughts and reasoning with peers and people he trusts - like his pals on this site. Maybe - as I said I can't speak for him - but I think I get why he is self reflecting on the situation rather than just assuming he was in the right (which he is imo). I could be wrong - but he was the first person I ever 'friended' on here back when we had that facility - this is because I like the respect he treats everyone with... and he can be funny too. I was walking through the street late at night in Canterbury a year ago... I was a bit tipsy. I gave some homeless couple the rest of the money in my pocket... paper and coin. I was talking to them for a bit and some drunk guy who knew them came up and told them to be careful of me as I was "clearly a wrongun". He could see it my eyes apparently and was trying to start a fight with me. I thought about fighting him, but I had a bad back and didn't fancy it.... although I reckon he'd have been easy enough to deal with presuming he didn't have a knife tucked away. I am a pacifist anyway so wouldn't really have wanted to. It thoroughly depressed me - I try to be nice - I try to be a good person - I was Christian for many years - I was totally at a loss as to how my very appearance would cause someone to hate me so much - you just have to accept that some people are arseholes I think and write them off and move/drive on.
  38. 1 point
    I'm not sure I agree with that. The electron was discovered long before quantum theory was developed.
  39. 1 point
    There are existing such applications. How is that different from e.g. video conference.. ? One smartphone/tablet is recording video from front, back or both cameras, and sending through Internet, to yet another smartphone/desktop/FTP server.. Your application would have to be special with unique features for specific client, to be worthwhile purchase.. ps. Don't waste time on asking these "questions". Better buy C/C++, Java, PHP, Perl, Python books, read them, and learn programming.. During reading and learning you will see what is feasible to be done.
  40. 1 point
    It sounds like Phi encountered what we in the UK call a nutter. Personally, I would avoid all eye contact, or just give him a smile and thumbs up. American nutters carry guns. It's in the constitution. Every nutter has the right to bear arms.
  41. 1 point
    The strong force is what holds quarks together inside protons and neutrons. It is mediated by (virtual) gluons and is defined in terms of the "colour charge" of quarks and gluons. A proportion of the strong force "leaks" out of protons and neutrons and acts to old those particles together in the neutron. More here: https://en.wikipedia.org/wiki/Strong_interaction#Behavior_of_the_strong_force
  42. 1 point
    Just goes to show, not all sheep behave like . . . . . . well . . .sheep
  43. 1 point
    It is more that there are conditions that may be associated with larger adenoma growth (e.g. genetic factors). Those prone to increased growth are also seem to be at higher risk for cancer (even if the growth is removed).
  44. 1 point
    Many people wrote it. Even people who are fairly sure Jesus existed don't think he wrote any of it (as far as I know).
  45. 1 point
    I opened new private session window in Firefox. Then visited www.google.fr and changed options in either language and regional, and voila. Each website that you will visit, can have independent region and language detection mechanisms though.. They can Geo-localize by IP address. So even exclusive French native speaker could have problems, if he/she will visit foreign country, buy new SIM, and try to connect (as he/she will have IP address of foreign country). Try searching for French proxy server, and use it instead. IP will be in France.
  46. 1 point
    When you have two rotating objects orbiting one another, then each of them will have an influence on the geometry of spacetime. But this combination will be a highly non-linear and complex affair, so it’s not possible for me to tell exactly how this would look like. The dynamo effect is a mechanism by which magnetic fields are generated in the interior of rotating bodies, such as planets. I do not see the connection to frame dragging.
  47. 1 point
    Did anyone say it would? The distinction between "hard" and "soft" drugs is not based in science, it is largely political dogma. It was observed during the Vietnam war (among others) that soldiers used a lot of drugs to get through the experience. Most of them quit taking the drugs when they got home. That's because their "home" environment was supportive. If you want to reduce chronic drug use, what you should do is make everybody's "home" supportive. The "war on drugs" tends to do the exact opposite. This fact is known to the politicians.
  48. 1 point
    Airbrush, I think your post was less about the Fermi Paradox than about your (leftist) politics. Get a life. However, Gutfeld should have spoken about something he actually had reasonable information on rather than just dorky blather. EW
  49. 1 point
    Here is the paper: http://vixra.org/abs/1703.0073 Also testing if the "lol XD you so fahnny posting you schizo viXra maymays xD XD XD" people are active in this forum.
  50. 1 point
    If this idea that you won't bake a cake due to religious belief then any business that does this should be required to list the parts of society they will not serve plainly some place like the front door so the rest of us can know who these bigots are and not patronise them if you disagree with them... Personally I think this is just a way to bring back the ideas prevalent in some areas where they used to post signs proclaiming no negroes or asians. You can use this religious excuse to bar almost anyone from your business. Everyone should have the right to know who your bigotry encompasses..