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July 26

Feynman Lectures. Exercises. Exercise 9-16 JPG. Lecture 9

. .

First there is a problem with question b). To find e.g. x(t₄) , we need v(t₃ + 0.5Δt). To find v(t₃ + 0.5Δt) we need a(t₃). To find a(t₃) we need v(t₃). But we are asked to calculate steps with time interval Δt. Even with interval 0.5Δt the errors appear xls png.

Second, there are two functions that are similar with Excel graph x(t) : $f_{1}(t)=-e^{-t}$ and $f_{2}(t)=-{\tfrac {1}{t}}$ . From different m and k , I see that when k=1 & m=2 max. x increases to 2 units , when k = 2 & m = 1 max. x decreases to 0.5 units. So equation must look like x = (m/k) f(t).

By means of guessing, from eq. ${\tfrac {d^{2}}{dt^{2}}}x=-{\tfrac {k}{m}}{\tfrac {d}{dt}}x$ , it seems that $x=e^{-{\tfrac {k}{m}}t}$ satisfies. Username160611000000 (talk) 10:17, 26 July 2017 (UTC)[reply]

It seems when I take double interval and arithmetical mean , I get increasing accuracy twice (during double time) : xls png . But it is not enough I think, as acceleration is changing with same rapidity as speed, and we maybe have to count this someway (maybe analogous formula 0.5at² for distance) Username160611000000 (talk) 14:50, 26 July 2017 (UTC)[reply]

The numerical methods that Feynman is illustrating in section 9-6 and 9-7 are the Euler method and the midpoint method. For an interval of size h the local error in the Euler method is order O(h²) whereas the local error in the midpoint method is O(h³). Gandalf61 (talk) 15:54, 26 July 2017 (UTC)[reply]

So for Δt = 0.1 the midpoint method is 10 times more accurate than Euler's one. But it's impossible to use the midpoint method in this exercise . Username160611000000 (talk) 18:20, 26 July 2017 (UTC)[reply]

Combining the graph and the formula F = -kv , I think eq. of motion must be $x(t)=-{\tfrac {m}{k}}v_{o}(e^{-{\tfrac {k}{m}}t}-1)$ $x(t)=-{\tfrac {m}{k}}v_{o}(e^{-{\tfrac {k}{m}}t}-1)$ . Is it correct? Username160611000000 (talk) 18:12, 26 July 2017 (UTC)[reply]

Yes, that is the correct exact solution. If

x(t)=-{\tfrac {m}{k}}v_{0}\left(e^{-{\tfrac {k}{m}}t}-1\right)

then:

x(0)=0

v(t)=v_{0}e^{-{\tfrac {k}{m}}t}\Rightarrow v(0)=v_{0}

a(t)=-{\tfrac {k}{m}}v(t)\Rightarrow F(t)=ma(t)=-kv(t)

Gandalf61 (talk) 12:48, 27 July 2017 (UTC)[reply]

- It seems that the simplest Euler method gives ( xlspng) much better accuracy than my attempt where I use v(t+ 2Δt) = v(t) + 2Δt a(t + Δt). I also noticed that if I calculate speed as v(t+Δt) = v(t) + Δt•a(t) + Δa•Δt•0.5 , where Δa = (-k/m)Δv = (-k/m)Δt•a(t) , then the accuracy rises xlspng, but not as good as with Euler method. Username160611000000 (talk) 18:36, 27 July 2017 (UTC)[reply]
  - Can't solve a) question. It seems that Feynman is expecting a formula $x'(t')=-v_{o}(e^{-t'}-1)$ . So we must have next relating formulas ${\text{sec'}}={\tfrac {k}{m}}{\text{sec}}$ and ${\text{meter'}}={\tfrac {m}{k}}{\text{meter}}$ .
    But combining $x'(t')=-v_{o}(e^{-t'}-1)$ and $x(t)=-{\tfrac {m}{k}}v_{o}(e^{-{\tfrac {k}{m}}t}-1)$ we can write $x={\tfrac {m}{k}}x'$ . It does not agree with ${\text{meter'}}={\tfrac {m}{k}}{\text{meter}}$ . Why?
    
    And also I am not sure should we convert $v_{o}$ and $k$ to different units. Username160611000000 (talk) 10:40, 30 July 2017 (UTC)[reply]

Where does this drop of water push down with a million-g force?

Fun article at phys.org about Buller drops (Reginald Buller) that launch fungal spores. They show an artificial system in which one drop of water joins with another and launches it into the air. The energy comes from surface tension. However -- there also has to be conservation of momentum, action and reaction. They say that the force on the drop is actually "a million g's". Yet it looks like only a tiny part of the drop touches the substrate. It's as if there is a truss inside the thing that would put a skyscraper to shame, and I can't even tell where it presses down. Wnt (talk) 11:08, 26 July 2017 (UTC)[reply]

The force is small. g is an acceleration. When you divide a small thing (force) by a tiny thing (mass) the result (acceleration) can still be high.

One of my favourite books is Pennycuick, C.J. (1992). Newton Rules Biology. Oxford University Press. ISBN 0198540213. It covers lots of this sort of thing about the fundamental and unavoidable scaling laws: why elephants can't jump (big things can't have legs strong enough), why fleas are so bad at jumping (when you're that light, jumping becomes so easy in comparison that fleas aren't actually that special) and why bees can't fly (at their scale the air is viscous enough to allow them to swim). Andy Dingley (talk) 11:27, 26 July 2017 (UTC)[reply]

I should have been more careful in my wording; yes, the force is a million g's times the mass of the drop. But that still implies that the drop can become, in a sense, one million times heavier than it normally is, yet it still does not wet or even deform to fit against the substrate! I suppose I am guilty of a scaling error in not appreciating that the force required to move a given volume drops per the square of scale, and I also don't know how small these drops really are. But it seems surprising that water drops could be so solid that they do not visibly react to the force. Also, I still don't actually know even which drop presses down. Wnt (talk) 12:53, 26 July 2017 (UTC)[reply]

Don't think about pressing down, it's done by pulling.

The spores are flat sided. That's energetically a poor shape for a surface (considering surface tension). Place a small drop alongside and lower than it, and the drop merges to the liquid layer covering the spore. The small radius sphere, and the constrained flat surface, are replaced by an energetically favoured larger radius. The attached drop CoG is pulled upwards by this shrinking surface. The overall effect is like one of those permanent magnet railguns (Youtube will have videos) where a magnet is accelerated by having others hit it from behind. By Newton there has to be a reaction force, but that's the spore pushing downwards, not the drop. Andy Dingley (talk) 14:20, 26 July 2017 (UTC)[reply]

The very nice video shows the water movement: you can see it first creep upward the spore (and it must push the spore downward meanwhile, but the spore just cannot go down because of the floor), then it continues to go up on its momentum, but pulling the spore upward with it.

1 million g is impressive, you can get it by accelerating a thing from zero to 1m/s (not a tremendous speed) in less than 0.1 microsecond, and for a 1 microgram thing it does mean that it gets 1 million time heavier that it is, but it still just endure a 1gram weight force, which is not a trouble even for soft substance (just imagine a 1gram pin standing on its point: it wont break your skin, you have to push much harder for that) Gem fr (talk) 23:43, 26 July 2017 (UTC)[reply]

Does quickly removing a plaster/band-aid/waxing strip result in quantifiably less pain than doing it more cautiously?

Does quickly removing a plaster/band-aid/waxing strip result in quantifiably less pain than doing it more cautiously? --129.215.47.59 (talk) 11:26, 26 July 2017 (UTC)[reply]

No-one seems to agree with a single, simple reason, but there are plenty of contenders.

Anticipation (waiting to do it is worse than doing it), duration and mostly speed - there's a limit on how much pain you can notice per second. If you exceed that, you don't feel it as any worse than you would by doing it slowly, but it's certainly over more quickly. Andy Dingley (talk) 11:30, 26 July 2017 (UTC)[reply]

What does your own experience tell you? ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:30, 26 July 2017 (UTC)[reply]

To answer this question, it is important to know that the only accepted way of quantifying pain is by a subjective scale, for example, "On a scale of 1 to 10, with 10 being the worst pain you can imagine, how would you rate this?" There is no objective tool available for measuring pain levels. So the question basically comes down to whether people say the pain is less; and the answer is yes, most people do. Looie496 (talk) 13:40, 26 July 2017 (UTC)[reply]

There are a number of Pain scales for self-reporting. The Wikipedia article about Pain notes that fMRI brain scanning has been used to measure pain, giving good correlations with self-reported pain. Blooteuth (talk) 14:22, 26 July 2017 (UTC)[reply]

On my own tedious/hate/pain scale ripping ecg patches off is less annoying than tearing them off slowly. The most important thing is shaving before they are applied. Greglocock (talk) 14:37, 26 July 2017 (UTC)[reply]

Quantifiably? No. It's not that Looie is 100% correct in saying that we lack all ability to examine this question empirically; his comment refers to the fact that pain, like all sensation, is a type of qualia, which is to say that it is an experiential phenomena and not a physical one, and thus there are no metrics to measure or even qualify an "amount" of pain in a scientific sense. That said, there have been many, many studies which attempt to measure pain via proxies which we intuitively associate with it. The methodologies vary from self-reports, to physiological responses, to direct examination of the neural networks known to be associated with pain. However, none to my knowledge has ever looked at the much narrower issue of comparing the fast vs. slow methods of band-aid removal, so you are out of luck for even this weaker form of analysis. There has been much research and speculation about the element of anticipation (and more general, the effects upon pain of mental focus), but it's far too generalized to be of much use in answering the question at hand. Snow ^{let's rap} 21:42, 26 July 2017 (UTC)[reply]
This assumption, " pain, like all sensation, is a type of qualia, which is to say that it is an experiential phenomena and not a physical one, and thus there are no metrics to measure or even qualify an "amount" of pain in a scientific sense" is based on a hidden and false dualistic premise. The hidden assumption is that there can be no physical explanation for the mental, but that simply represents our current state of ignorance, and a long tradition of assuming the soul is separate from the flesh as if we were ghosts trapped in zombies.

Vision expert Stephen E. Palmer has written on the phenomenon of reverse trichromacy (Color, consciousness, and the isomorphism constraint), where rare individuals have both red-green and green-red color blindness have the ability to distinguish all the hues normal trichromats do, but they see a very broad range of yellows with no unique focal yellow whereas their range of blues is extremely narrow. This is the opposite of normal trichromats, where pure yellow is unique, while a large portion of our color gamut is blue. This is a physically verifiable explanation for a difference in qualia.

It may be true that qualia can't be shared, but they are not inherently incomprehensible, just not yet understood. μηδείς (talk) 00:57, 27 July 2017 (UTC)[reply]

I've favored here a dualistic version of qualia based on causality violation, but even such a position is not inconsistent with physical explanations for every intermediate stage in sensation. And the general idea with pain scales is that even if qualia is unquantifiable, the way that people express reactions to qualia (such as rating on a scale of 1 to 10) is quantifiable in aggregate. Wnt (talk) 09:33, 27 July 2017 (UTC)[reply]

The issue is not that qualia are not quantifiable, it's that qualia are not transferable. That is, for the pain scale, a person can report their own pain as a "5" or a "2" on some pain scale, and for them that means something; but the physical thing causing the pain for one person to report a "5" is not consistent from person to person. Or for colors, for me red is always red, but I have no way of knowing that my red looks like your red. --Jayron 32 10:46, 27 July 2017 (UTC)[reply]

actually, the "red" example is very good, and just disprove your point: color and sound (Musical note) are qualia for lay people (those who don't use precise technical instrument able to measure frequency), but they are transferable nonetheless. It is true that you have no way to be sure that your red (your B flat) is the same as mine, but you do know that when i tell you something is red (my red), it will be red (your red) for you, too. You'd be surprised how well qualia scale are transferable, when properly done (if they didn't, they wouldn't exist). Gem fr (talk) 12:22, 27 July 2017 (UTC)[reply]

Pain is actually more complex than other qualities such as color, because in addition to its basic sensory dimension, it also has an affective dimension: pain is intrinsically unpleasant. The affective dimension is at least partly independent of the sensory dimension -- for example, opiate drugs act to reduce the unpleasantness of pain without greatly altering its sensory quality. Ronald Melzack argued that pain actually has three basic dimensions, which he called sensory, affective, and cognitive-evaluative. Looie496 (talk) 14:06, 27 July 2017 (UTC)[reply]

There is some transferability in the sense that almost everybody agrees that getting kicked in the thigh isn't as bad as getting kicked in the nuts. So if you're marketing the Pocket Intimidator and you can point to a study where researchers hit a hundred people with it and most of them said "not quite as bad as getting kicked in the nuts", now you have something - and you can tell that it is sort of quantifiably less than the deluxe version that is "about the same as getting kicked in the nuts". Wnt (talk) 16:58, 27 July 2017 (UTC)[reply]

LOL. Gem fr (talk) 17:07, 27 July 2017 (UTC)[reply]

The problem is that my being kicked in the nuts may only be as painful to me as you getting kicked in the thigh is to you except there's no way to quantify such a difference; that is the comparison of pain between people is not possible in any way. I may be able to describe a pain as "getting kicked in the nuts" and you may imagine a pain fair worse, or far less painful, than I actually experience, and there's no way to know. It's the same with color; yes, when I describe red to you, we can consistently agree that red is red (in the same way that we all agree that genital injuries hurt more than muscular injuries), however there's no way to know that the way I experience red is the same as the way you experience red. That's the point of non-transferability, and it's a real problem with pain management; does a doctor prescribe powerful opioids because the pain is otherwise unmanageable for me, but open me up for a lifetime of brutal addiction, or do they prescribe less effective, but safer, pain killers because my pain would be manageable for me with them? --Jayron 32 12:17, 28 July 2017 (UTC)[reply]

Also, [1] --Jayron 32 12:21, 28 July 2017 (UTC)[reply]

Your alleged problem is true of just everything (cars, food, chicks, etc. Everything), leading to solipsism. it is a philosophical problem, but not a practical one: we don't need to be sure that your red and mine, your pain and mine, are exactly the same, we just need to know that when i tell red you won't tell green, and pain (or any other personal feeling, for that matter) is just perfect for that, BECAUSE you have no way tell otherwise (while you could, regarding a red). So, if i say my pain is a 4 on a scale from 1 to 10, it is a 4, period. And the doctor can and will assign me the painkiller associated with 4, not the one associated with 8 (higher, but not necessary double : the pain scale is not supposed to be linear), or just don't ask (my dentist don't ask, she just prescribe the usual painkiller for toothache). Any difference in result to what is supposed to happen will be attributed to individual difference in sensibility to painkillers, and adjusted accordingly, as is done for every other medication (you know : the doctor prescribe a pill a day, then tells you to modulate up to a maximum of ... if this happens, or down if that). In hospital doctors even went to quite simpler: ensure a quite safe maximum dose regarding addiction and other possible side effects, and let the patient auto-shoot himself as need be, as experience shows that most of them inject themselves even smaller dose, for enough (not complete) pain relief. Gem fr (talk) 15:04, 28 July 2017 (UTC)[reply]

If it were so simple, we wouldn't have the problem with the Opioid epidemic in North America we have now; self medication only works a) with highly adjustable dosing and b) in a managed care environment where doctors could intervene if needed. Most people hooked on opioids started taking them under a doctors advice, were not well regulated (i.e. self-dosed as needed using pills rather than injectables), and switched to non-prescription opioids when their addiction worsened. While it would be simplistic to lay the complex causes of such a problem to a single antecedent, certainly part of the problem is that the treatment of pain is not as simple as "He called it a "4" so I can just give him X drug and it'll take care of itself the same way every time" --Jayron 32 15:21, 28 July 2017 (UTC)[reply]

You cite a real problem - we are looking for a "standard candle" with pain, but how do we tell if the standard candle itself varies? But one can still make comparisons based on other outcomes. The most relevant article I can think of with this is Red hair, which summarizes some putative differences from the literature. It is, to be sure, not easy. But you can hand folks some whippets of nitrous and see how much they have to inhale before they stop complaining when you kick them in the nuts. (I really should look up how the scientific studies were done...) Wnt (talk) 20:15, 28 July 2017 (UTC)[reply]

Medeis, how on earth do you get "dualism" out of anything I said? The phenomena I described is one of the most pervasive and well-recognized issues in cognitive science (and ontology, theory of mind, and science broadly), known as the the hard problem of consciousness. It is widely accepted in the studies of neuroscience and cognitive psychology that no one, from ancient sophists through modern researchers with the most advanced contemporary technology and methodologies, has ever been able to explain how the experience of consciousness arises out of physical matter. Not only is that not dualism, it's the very definition of the diametric opposite of dualism. A dualist can always appeal to some mystic explanation, even if it is one that an empiricist can't accept. The hard problem is a problem for researchers specifically because of the assumption that consciousness should not be unique amongst observed phenomena in the universe in having no physical cause or explanation. You've got it completely backwards. Saying that we don't have the capacity (in terms of understanding, methodology, or even cognitive limitation) to quantify something, is not the same thing as appealing to the notion that it doesn't arise from physical matter. Utter nonsense.

There are many things that happen to be beyond the scope of our understanding--this happens to be chief amongst them, in terms of things humans have pondered for a long time and come up with very little to explain, but it's not in principle different from any other phenomena we lack the tools to explain or even properly define. The only caveat to that statement being that some cognitive scientists believe that the hard problem may be fundamentally different from even the most complex scientific problems involving the physical sciences because our brain evolved in a very specific context where it's perceptual and problem solving heuristics favour certain types of physical problems; put otherwise, we evolved in a context where spatial mechanics and principles of physical causality exerted adaptive pressure that gave us a cognitive array that could be leveraged to eventually understand certain kinds of complex questions regarding the nature of reality, while leaving us with blind spots with regard to certain aspects of our own basic reality vis-a-vis perception and cognition.

In other words, we may be smart enough to discover/infer the existence of subatomic particles ad-nauseum and still be destined to never understand why we perceive anything. Or more illustratively, we could capable of explaining every aspect of how the physiology of the sensory organs and our brains reacts to physical stimuli, and still not entirely understand how it gives rise to the experience of sensation. It's even entirely possible that we could stay in that state of ignorance forever, as a species. And there's absolutely no appeal to dualism, mysticism, or spirituality necessary to accept that basic status of this field of inquiry.

There's even a (completely feasible) theory that no "thinking thing" can ever be able to completely understand itself, because systems can only be described fully by another system of higher complexity. Take a neural net, for example; it can't define the parameters of all of its nodes at once, because some of them would be used in the very process, leading to confused results. Another, slightly larger net could define the relationships and firing status of every node in that smaller neural net at any given instant, but then that larger neural net would need yet another, even larger one to define it. It's a "turtles all the way up" kind of argument, with increasingly complex forms of consciousness, each of which is nevertheless, by definition, incapable of completely understanding itself. Snow ^{let's rap} 01:08, 28 July 2017 (UTC)[reply]

Also, Medeis, your trichromacy example not only does not relate to your basic thesis, but actually reflects a fundamental confusion about the interplay of the phenomena here and how they are described in a scientific inquiry. Saying that a change in a physical mechanism involved in vision leads to an effect upon what is perceived is a trivial and obvious observation. Of course it does (assuming the difference is significant enough to not be filtered out by higher level processing in the visual cognition system); why on earth would anyone expect otherwise? Saying that changes to the physical system lead to a difference in perception get you not a bit closer to being able to explain the issue underlying the OP's question: namely how the experience of that colour arises from the physical matter that makes up the perceiving system. That's the entire reason we have the term "the hard problem"--to distinguish it from all other types of problems that arise from simply not knowing enough about the basic neurophysiological mechanisms. Some of these problems are not "easy" at all, and may take centuries more or concerted study with increasingly complex and precise techniques before we understand all of the biophysical and organizational properties of the brain that give rise to them. But they are still considered "easy" problems by comparison to the hard problem, which is considered so fundamentally difficult because it defies our capabilities to establish even the basics of how it (qualia) happens. Snow ^{let's rap} 01:55, 28 July 2017 (UTC)[reply]

There's no answer because "more" and "less" are subjective. Firstly, there are two distinct components of pain - intensity and duration. People make their own individual judgements over which they prefer. Many make choices much more consequential than band-aids based on these tradeoffs. Some people will live with chronic pain rather than surgery/rehab and vice/versa. It' subjective when a choice is involved. --DHeyward (talk) 18:16, 27 July 2017 (UTC)[reply]

The point of the reversed red/green trichromacy issue is not one of transferability, but a physically verifiable proof (two genetic mutations) can be shown to disprove the notion that one's colors could be "reversed" without it being verifiable. It has long been said that it would not be possible to tell if one's colours (red/green; blue/yellow; white/black) could be reversed without notice. But examples of such people have been discovered. Imagine pure lemon yellow, and then try to imagine "pure" blue. Yellow is the supposed opposite of blue, but there are only really two off-yellow shades (greenish or whitish) yellow while there are many more shades of pure and off-blue. For reversed-trichromats this is reversed. This can be tested objectively both psychologically and genetically, which disproves the dualistic dichotomy between qualia and the physical is not ontologically primary. μηδείς (talk) 00:41, 28 July 2017 (UTC)[reply]

People may have skin of greater or lesser strength, but I have found that if I pull off Bandaid type bandages, adhesive tape, or other medical adhesive pads quickly rather than pulling them off slowly, they take the skin with them, leaving a raw patch of the underlying tissue. This is painful for a long time, takes days to heal, has a risk of infection, and leaves a scar.I have typical skin so far as I know. Edison (talk) 17:14, 28 July 2017 (UTC)[reply]

Threshold of pain and Pain tolerance. Akld guy (talk) 20:10, 28 July 2017 (UTC)[reply]

I always do this cautiously such that no hair is put under tension, I can free the hair from the plaster and I avoid feeling any pain :) . Count Iblis (talk) 11:49, 29 July 2017 (UTC)[reply]

Note that the qualia we experience should be understood as the computational state of the software implemented by the brain. Any changes in the hardware that would render the same computation would leave the person and his/her experiences invariant. E.g. simulating Snow Rise's brain in a virtual environment where he is discussing things with Medeis would render exactly the same experience that Snow Rise would have if that were happening in the real world, even though there is now no brain involved, just the running of an algorithm. Count Iblis (talk) 12:16, 29 July 2017 (UTC)[reply]

Just so. Of course, there is the question of the necessary complexity which the alternative hardware would have to achieve in order to perfectly emulate every last biophysical variable which is involved in defining any one state of a brain at any one moment in time. The virtualization would be many more orders complex than most people would probably assume, based on the apparently speedy developments in brain science over the last half century. It may in fact be impossible. However, even in your brain in a vat + scenario (+ because you are talking about not just simulating the stimuli, but also the system that processes it), note that it would still leave us facing the hard problem. We've just supplanted one physical medium (some kind of designed hardware) for another (the brain). It still leaves us with this fundamental question we have never been able to even so much as scratch the surface of: why do we have the subjective experience of consciousness arising out of systems that we can only scientifically/empirically describe in terms of stimuli-response and other physical properties? We assume that virtual Snow would experience those thoughts and feelings exactly as I do, but we no empirical methodology to ever prove it (or for that matter, to know if you and I actually see remotely the same thing even if we both are looking at it). We tend to treat the idea as silly or the product of narcissism, or delusion, or overly-wrought sophistry whenever someone poses the question "What if I'm the only "real" person who actually thinks, and everyone else is a philosophical zombie?". But (counter-intuitive as it seems) the truth is that, insofar as what thousands of years of concerted examination (and now modern scientific research) can supply, there's not a person who ever lived who could be proven wrong if they made that assumption. We're just used to living with the suggestion that the physical proxies we associate with consciousness (similar brain designs, and so forth) suggest that if one of us is a conscious thing, then most or all of us are too. But insofar as we have not established the causal relationship between qualia and physical processes, that's actually a scientifically invalid assumption, not withstanding the fact that, impressionistically, it feels right. Snow ^{let's rap} 00:54, 30 July 2017 (UTC)[reply]

That's utter nonsense. The brain is not digital, does not run programs, is not itself mathematical, runs on no algorithms; there is no such evidence, and the notions contradict all we know about neurophysiology. Nerves and action potentials are not wires and currents. A simulation of consciousness is just as conscious as a simulation of a hurricane is wet. The brain is analog and dynamic in structure, and harmonic in function--it runs no programs. Any machine that could fully simulate a brain would be orders of magnitude more complex than a brain, just as any supposed machine that could run a simulation of the universe would be orders of magnitude more complex than the universe. Such fantasies explain nothing, they are as fruitful and naive as saying some guy with a beard on a throne in the sky created the universe. They simply beg the question in the literal sense of that phrase. μηδείς (talk) 01:13, 30 July 2017 (UTC)[reply]

Medeis, I suggest you read the link which CI included with his post, because I think you may have misread his point. Of course a brain is not analog; I don't see anything that the good Count said that would suggest it was. But with sufficient hardware, an analog machine absolutely can perfectly simulate a neural network (they've been doing that almost as long as we've had computers, as the term applies in general parlance). As you note (and as I went on about at length immediately above) the machine would have to immensely complicated (also in all likelihood, immense in physical size). Even at some speculative point of time far int he future where the human race is creating megastructures of astronomical proportions and other wonders, it could well prove to be a practical impossibility to create a machine capable of simulating a brain down to the atomic scale (which is what you would need to do in order to truly reflect all of the biophysical properties necessary to create an accurate model).

But that doesn't mean the speculation isn't useful. In fact, exactly the scenario CI proposes has been pondered by serious cognitive scientists for a long while. When you're dealing with phenomena that advance so far beyond the horizons of our technical ability to measure or even model, thought experiments are often one of the few tools which open the issues up to examination, however imperfectly. Scientists do this all the time with physics and cosmology, and I can assure you, it's not uncommon in cognitive psychology/theory of mind discussions between leading experts. Those experts find the discussion quite "fruitful", whatever your impressions as an enthusiastic amateur. And I can tell you this much for certain, your statement that "A simulation of consciousness is just as conscious as a simulation of a hurricane is wet." is about as unscientific as they come. In order for an empirical claim to have any kind of validity, it must be falsifiable, which your statement decidedly is not.

And the brain absolutely is mathematical, as is any physical system. It may not run all of its operations through straight forward arithmetic, but given sufficient time and processing, you could explain all of the activity of its constituent parts in mathematical terms (it is, afterall, a network of nodes, however complex it may be). There are in fact entire subfields of neuroscience devoted to analyzing the brain on exactly this level. Further, one of the leading modern theories of cognition is the computational model of the mind. Snow ^{let's rap} 02:13, 30 July 2017 (UTC)[reply]

And since we're on the topic, you might be interested in Functionalism (philosophy of mind) and multiple realizability (particularly the details on functional isomorphism), because plenty of researchers believe that it's very much possible that you wouldn't even have to replicate an identical brain state to arrive the same mental state. I am agnostic as to this view, personally, neither convinced that it is likely nor that it can be disproven. But it remains a live debate. Snow ^{let's rap} 02:38, 30 July 2017 (UTC)[reply]

I don't see much point in further argument. When you say the brain is mathematical because aspects of it can be measured mathematically that does not mean it works by sending numerical symbols or using mathematical equations. Computational models of the mind are very popular with non-biologists, but they lead to fallacies such as the Turing Test (which says nothing about the machine, just the gullibility of the interviewer). I am with Searle; the Chinese Room is not conscious. See also the homunculus argument. μηδείς (talk) 03:01, 30 July 2017(UTC)

No, your wild supposition (presented as knowledgeable insight) is again wrong; the computational model is in fact favoured by researchers working in biopsychology, and in evolutionary psychology in particular. In fact, it was most famously popularized by some of the leading figures of that field. Not the other way around, as you suggest. And you seem to be deeply confused by the superficial use of the word "computational" here. It does not in any way reflect the notion of a digital machine processing arithmetic logic; the theory merely postulates that the mind is interstitial phenomena produced by the brain processing input, and input does not need to be bussed into a system via symbolic logic or arithmetic calculation--a neural net is fully consistent with that theory (again, a very popular theory with researchers working on the biophysical side of things and less popular (traditionally) with those working from the analytic end of the spectrum, not the other way around). And...it has absolutely nothing at all to do with Turning tests...

Also, you were the one who raised the notion that the brain is "non-mathematical" which is a more or less nonsensical statement. I merely pointed out that it is as "mathematical" as any other physical system. Nobody here has suggested that it arises from arithmetic or symbolic logic, or that it is digital. Those are straw man arguments you have brought into the argument yourself, but in each case, the assertion itself does not support your larger conclusions. Snow ^{let's rap} 06:14, 30 July 2017 (UTC)[reply]

Unidentified seashore life (San Diego)

I saw this odd pink seaweed and these tiny shells on a kelp float at the beach yesterday. I haven't gotten a response on iNaturalist; does anyone here know what they are? 2602:306:321B:5970:D9:F312:FC8A:C37C (talk) 13:50, 26 July 2017 (UTC)[reply]

I'm not 100% certain, but I think the tiny shells are a type of Spirorbis worm. Even less certain about the "pink seaweed", but I suspect it's actually a piece of a coral colony, perhaps Leptogorgia chilensis? ---Sluzzelin talk

(OP) Spirorbis looks correct for the first one, and I looked up relatives of the coral you suggested and it seems plausible. Thanks! 2602:306:321B:5970:F947:D46C:8DE9:5D7F (talk) 17:13, 26 July 2017 (UTC)[reply]

Novice magnifier question

I've noticed that the more powerful a magnifier glass the smaller the lens is and the closer to the subject the lens has to be. Is there any way to overcome this? I need a free standing 10x strength magnifier similar to this but with a wider field of view and increased distance from the subject from 5cm tall to 15cm tall. Basically imagine the picture I linked but scaled three times bigger. I can't seem to find anything available with these specs. Is it impossible?

Hopefully a better answer is on the way but I think it might be possible with more than one lens. Loupes for medical professionals allow higher magnification and at an increase focal distance than any single lense I could find and I think it's enabled by the use of compound lenses. I'll be interested in the answers to your question also. --129.215.47.59 (talk) 16:36, 26 July 2017 (UTC)[reply]

There is no way. Magnifying glasses are typically placed at about their focal distance from the object. For 10x magnification the focal distance is 2.5 cm. Ruslik_Zero 16:44, 26 July 2017 (UTC)[reply]

What you really need is something like an operating microscope or jewelry microscope -- but they aren't cheap. Looie496 (talk) 18:17, 26 July 2017 (UTC)[reply]

I like QuickTest in the UK (http://quicktest.co.uk) as an honest vendor of magnifiers. They sell a range, at a range of prices, and they're refreshingly open about the limitations of what you're buying at the cheap end - you have to love a vendor with a section called Do Not Buy. Some of their background articles are worth reading.

Eye relief is important for some tasks. It's easy to design a high magnification magnifier at the cost of shortening this eye relief, much harder to do so but still leave long relief. Andy Dingley (talk) 20:36, 26 July 2017 (UTC)[reply]

Forget about lenses - try a high resolution camera and a screen. Wymspen (talk) 20:48, 26 July 2017 (UTC)[reply]

If you need really high magnification, that can be a very good approach. Andy Dingley (talk) 21:05, 26 July 2017 (UTC)[reply]

A plastic Fresnel lens sold as a TV-screen enlarging device.

You might consider a Fresnel lens. I'm not sure if it can do what you want, but they are quite different from simple lenses, so it may be possible. Note, however, that this type of lens does cause some distortion due to the sharp discontinuities on the lens. As you can see, the large size of the lens and distance from the subject may be in the range you want, but 10x might look rather distorted with a Fresnel (the example shown seems to be about 2x). They typically magnify less than that, except for when a blurry image is acceptable, as in magnifying a light. StuRat (talk) 23:54, 26 July 2017 (UTC)[reply]

i'll go for Wymspen advice, or, if this doesn't suits you, try to find some dusty Overhead projector (they use a fresnel lens, as suggested by StuRat) Gem fr (talk) 00:11, 27 July 2017 (UTC)[reply]

Overhead projector lenses are there as condensers, not imaging lenses. They can be used as magnifiers, but they tend to have very coarse lines and so give a lot of distortion. Andy Dingley (talk) 09:26, 27 July 2017 (UTC)[reply]

Another mysterious San Diego sea creature

What is this transparent, tubular, gelatinous thing? I think it's a pyrosome but I'm not certain. 2602:306:321B:5970:E590:A039:83E2:D9A9 (talk) 20:46, 26 July 2017 (UTC)[reply]

Resolved

Figured this out myself, it's a Corolla spectabilis pseudo conch.

If you're sure that's correct, would you care to upload/release it to Commons? We don't seem to have a reasonable picture ourselves. Matt Deres (talk) 14:51, 29 July 2017 (UTC)[reply]

July 27

Television (What is the relationship between QLED and Quantum Mechanics?)

What is the relationship between QLED and Quantum Mechanics? 196.192.183.14 (talk) 20:29, 27 July 2017 (UTC)[reply]

Not sure offhand for modern QLEDs, but in the mid-80s I worked (briefly!) as a quantum mechanic (tiny, tiny spanners). I designed a laser diode. Specifically a quantum well heterostructure. It's not hard to make "a laser diode". You look up the properties of some semiconductor compounds, brewing up the mixture to give band gap energies that you like, and a frequency

f

(thus implicitly the wavelength

\lambda

) that depends on the photon energy

E

produced by jumping between those bands, according to Planck and

E=hf

, where

h

is Planck's constant.

Now the problem. Sometimes you want a particular wavelength (we wanted one that was minimally absorbed by glass optical fibres). Maybe you're making LEDs to make a coloured display. Maybe you just want a precisely monochromatic colour to be a more efficient way of generating useful light. But no matter how hard you look, you can't find any combination of chemistry that delivers what you need.

Enter the quantum well. This is a structure made of less-fussy materials, where its quantum behaviour (i.e. the band gaps) are controlled by the dimensions of the well (and the effects of QM behaviour), not just the chemistry. With a precisely controlled manufacturing process (difficult back then, but achievable) you can control these thicknesses. Voila, a metamaterial with effective properties of whatever you like (within limits). Now you have a choice of wavelength, not just a choice from a few naturally available ones. Andy Dingley (talk) 20:50, 27 July 2017 (UTC)[reply]

See quantum dot and quantum dot display. Gandalf61 (talk) 20:52, 27 July 2017 (UTC)[reply]

Note that all LEDs, and for that matter all semiconductor devices, involve quantum mechanics. Quantum mechanics is required to explain most of the properties of semiconductors. --47.138.161.183 (talk) 23:12, 28 July 2017 (UTC)[reply]

There is an important difference though between QM as a description of naturally occurring semiconductor materials, and as a means of designing new metamaterials with previous unattainable properties. Andy Dingley (talk) 14:14, 30 July 2017 (UTC)[reply]

July 28

Where to find timelapse images of Sun (ultraviolet, I suppose but I don't know)

This video is a timelapse of the Sun from the NASA SDO (solar something observatory) but it's missing the lower half and some of the solar flares etc are cropped off. Where in NASA's archive can I find the original images to see if a better video can be constructed from them? I was hoping to make a nice animated desktop wallpaper --145.255.246.166 (talk) 19:46, 28 July 2017 (UTC)[reply]

The "something" is the Solar Dynamics Observatory. That article includes this nice 7-year timelapse video of the full sun in the 'Gallery' section: [2] — The SDO image gallery is here, and this Helioviewer might be useful if you are ambitious enough to attempt creating your own video. — 2606:A000:4C0C:E200:E465:CA4F:4607:5398 (talk) 22:04, 28 July 2017 (UTC)[reply]

Thanks very much; that link to HeliosViewer is very much appreciated since it looks about perfect for what I want. Here is an image made from two different sources and you can see there's a black border around the Sun. Is that because the information is unattainable due to the glare from the Sun or is there a way to get this filled in? I'd like to make a video without any missing information like that. I found this link to a heliosviewer forum but it doesn't seem to be working at the moment. Do you know whether it is still active? --145.255.241.195 (talk) 12:06, 29 July 2017 (UTC)[reply]

Some parts outside the shield are so bright the expensive modern detector is overwhelmed. They go full white. Imagine the parts near the surface! This doesn't mean that the stuff outside the disc is bright in everyday terms - little or none of that would be visible to the naked eye in a solar eclipse. The Sun's atmosphere is millions of degrees - hundreds of times hotter than the surface but it's at least 300,000,000,000,000 times thinner than air so it ends up very dim (a thin layer (only a few thousand km) of the Sun's atmosphere is different but it's almost literally apple vs skin thin). The Sun's outer atmosphere never really ends till several times the distance of Pluto, it just gets dimmer and dimmer and SOHO has a camera that shows 16 Sun widths from the center and can see parts 100,000,000 times dimmer than the inner corona (and 100,000,000,000,000 times dimmer than the surface). The C1 camera could see 0.1 Sun widths from the Sun before it broke and 3 corona cameras of different sensitivity were needed to cover that brightness range. (you can see movies of those online but only in 1K, at a decent frame rate the flares move so fast in C2 that they look like explosions (only 5 frames per hour)) Sagittarian Milky Way (talk) 17:05, 29 July 2017 (UTC)[reply]

Best source i know for such stuff is here, the image- and movie- archive of the webpage of the Solar Influences Data Analysis Center (SIDC) of the Royal Observatory of Belgium. --Kharon (talk) 18:36, 29 July 2017 (UTC)[reply]

July 29

Is sneezing after the first sip of a stiff drink a thing?

A quick search on google was unhelpful, it referred to wine allergies and runny noses due to dilation of the blood supply to the sinuses. But my mother and I both sneeze once on the first sip of a hard drink. (I also sneeze when I go out into bright sunlight, which I know is a common reaction.) Mother judges her gin and tonic that way, and complains at restaurants that the drink is too weak if it doesn't make her sneeze. Neither of us gets a runny nose or continues sneezing. Is this a known phenomenon? Thanks. μηδείς (talk) 00:13, 29 July 2017 (UTC)[reply]

Our article Photic sneeze reflex covers the sneeze due to sunlight, and also mentions that eating spicy foods can cause sneezing. The linked article Gustatory rhinitis redirects to an article covering only sneezing due to the stomach being overfull, but this source says gustatory rhinitis can be caused by alcohol as well.-gadfium 02:22, 29 July 2017 (UTC)[reply]

Thanks, but actual rhinitis is not relevant in this case; there's no runny nose, just a single sneeze, as in the photic sneeze reflex. μηδείς (talk) 03:43, 29 July 2017 (UTC)[reply]

My son sneezes after taking liquid medicine. When I looked up the reason why (some time ago), I got to this page. Yahoo answers are obviously not reliable, but the comments there make sense - and would also apply to liquor. There's no answers here, but should at least make it clear you and your mom are not alone. :) This seems a bit more reliable; in your case the takeaway might be that histamines could still play a part, with a note that it's experienced at very different levels for different people. You didn't mention what kind of stuff you're quaffing, but quick Googling suggests that some people only sneeze from wine, others just from beer. Presumably there are other specific sufferers. Time for science! Matt Deres (talk) 15:03, 29 July 2017 (UTC)[reply]

Neither wine nor beer causes the sneeze, which is immediate upon the first sip of a strong drink. There's no time for an allergic reaction, and no runny nose or continued sneezing. I suspect it's the same as the photic sneeze reflex, which I have, just caused by alcohol absorbed through the palate. μηδείς (talk) 00:15, 30 July 2017 (UTC)[reply]

Scale of everything

Can I get a rundown of the scale of everything from the smallest thing, such as a quark, or possibly a string, to the biggest thing, the universe, or multiverse? I would want this to be presented in "levels" (e.g. atom, planet, galaxy). — Preceding unsigned comment added by AHumanEditor (talk • contribs) 01:55, 29 July 2017 (UTC)[reply]

How about orders of magnitude and its associated category? --47.138.161.183 (talk) 02:57, 29 July 2017 (UTC)[reply]

Thank you! — Preceding unsigned comment added by AHumanEditor (talk • contribs) 04:07, 29 July 2017 (UTC)[reply]

Orders of magnitude (length) and maybe Orders of magnitude (volume) are more specific to length. Graeme Bartlett (talk) 04:16, 29 July 2017 (UTC)[reply]

This Video on YouTube may help. (The second half zooms in to small things.) Mitch Ames (talk) 06:13, 29 July 2017 (UTC)[reply]

Why would you want to try the impossible? This is way beyond our imagination. You cant even imagine the scale of our Solar system, not even if it is scaled down (correctly!)! Dont belive what i write? Go check out this very well done "staggering" prove Video: [3]. --Kharon (talk) 18:16, 29 July 2017 (UTC)[reply]

Memory - remembering but not knowing it

Just recently, I was thinking of the cortex of the brain that deals with error detection, and somehow I thought of the anterior cingulate cortex for some reason. Then I looked it up, and it was exactly what I was looking for. Weird. Does anyone else experience this? 50.4.236.254 (talk) 02:29, 29 July 2017 (UTC)[reply]

This isn't the place to ask people about their personal experiences. --Jayron 32 03:13, 29 July 2017 (UTC)[reply]

However, if there is a name for this phenomenon, then there probably is an article on it. — 2606:A000:4C0C:E200:E465:CA4F:4607:5398 (talk) 04:11, 29 July 2017 (UTC)[reply]

See confirmation bias, Implicit memory and deja vu. Graeme Bartlett (talk) 04:12, 29 July 2017 (UTC)[reply]

No one else. You're the only one. But you may find Memory useful. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:47, 29 July 2017 (UTC)[reply]

Source amnesia may also be of interest. Deor (talk) 15:38, 29 July 2017 (UTC)[reply]

July 30

Steam train

What wheel arrangement is best for a steam train whose main task is bringing minerals from mines in the mountains to the mainline in the valley (the line over which it operates is NOT a narrow-gauge or rack railroad, but does have at least some tight curves and steep grades)? The parenthetical phrase was added after the first response. Would that be the same 4-8-4 arrangement which is best for heavy mainline trains, or would some other arrangement work better? 2601:646:8E01:7E0B:298A:91F:6885:FC (talk) 00:34, 30 July 2017 (UTC)[reply]

You really have to mention a lot more factors. For example, if you have lots of tight curves, an articulated locomotive with two sets of drivers (e.g. a Mallet locomotive, with wheel arrangements like 2-6-6-2) has an advantage over locomotives like a 2-10-4, while if you just have a lot of straight stretches, that specific advantage disappears. Also bear in mind that many such railroads were narrow-gauge railways; such routes typically were built on a lighter strength than full-size railroads (they were narrow because of size restrictions that also would prevent the use of heavier trains), so wheel arrangements with lots of wheels might be a very bad idea simply because such locomotives would be a good deal heavier. Nyttend (talk) 01:20, 30 July 2017 (UTC)[reply]

Clarification: the line is NOT a narrow-gauge or rack railroad, but does have tight curves and steep grades; also, the trains are very heavy (as is often the case with mineral traffic). 2601:646:8E01:7E0B:298A:91F:6885:FC (talk) 01:51, 30 July 2017 (UTC)[reply]

Thank you for the clarification. Side note, if you're in a really tight environment and can't build heavy lines, I suppose you just have to run lots of smaller, lighter trains to extract the heavy minerals. You need to read up on the history of the Chesapeake and Ohio Railway in West Virginia and southeastern Kentucky, as they had to handle precisely the kind of situation you describe. (Here is a short discussion of the subject, and this article would probably be really useful to a magazine subscriber.) For a quick glance, go to 37°52′48″N 81°59′12″W / 37.88000°N 81.98667°W and look around: this is their huge Peach Creek coal marshalling yard near Logan, West Virginia, out of which they sent coal trains of 160 loaded cars out of the mountains, and a quick look around the area will show you the topography they had to handle. In most of this region, mines were served by Mallets (primarily 2-6-6-2), with 2-8-8-2s for full-length trains before the development of the 2-6-6-6. The railroad's smaller locomotives and larger non-articulated locomotives were generally used in less mountainous regions (for example, their 2-10-4s were used for faster freight), although late in the steam era, they employed 2-8-4s in the mountains. Nyttend (talk) 02:23, 30 July 2017 (UTC)[reply]

PS, this book, about locomotives of the C&O 1900-1965, would be particularly helpful to you (my parents have a copy, which I frequently read when growing up), although as your WHOIS suggests that you're in California, it's likely to be a good deal harder to obtain than if you were here in Virginia. Contact your local library about interlibrary loan, if it looks interesting. Nyttend (talk) 02:27, 30 July 2017 (UTC)[reply]

Assuming 1930s technology, probably some big Garratt design, like a (2′D1′)(1′D2′). Garratts were commonly used for such tasks in many parts of the world, although for some reason they were never very popular in Europe and North America. More recently, one wouldn't consider using a steam train. Around 1890 one would expect a 2′D1′ or something similar.

Note that in your case the loaded trains are going downhill and the empty ones uphill, so you may not need a very powerful locomotive. Electric trains using regenerative braking could turn your railway into a power generator instead of power consumer. After 1920 this may be the best option.

For your mainline trains, you have less tight curves to deal with, less severe gradients and you may want more speed to mix with express passenger traffic. The same Garratt could do the job, but you may consider a non-articulated design instead, like a 2′E1′. Also note that steam locomotive design was often more an art than a science. PiusImpavidus (talk) 08:59, 30 July 2017 (UTC)[reply]

"It depends". The best wheel arrangement is an 0-4-0, because it's simplest and it puts all the loco's weight onto the drivers. Everything else beyond this is a complication.

You probably need more power, so that means more weight. That needs more wheels to keep individual axle load from overwhelming the track, so it becomes an 0-6-0 or an 0-8-0. This is a mineral railway, so it may involve hill climbs (even going "downwards" it might need to cross a ridge), the track could be lightly laid, cheaply maintained and in poor condition. Tank locomotives might be favoured because they keep useful weight over the wheels, giving better adhesion.

The loading gauge could become an issue in the UK, so fitting a large enough boiler in place could be an issue, especially with a tank locomotive. UK minerals were hauled by the Hunslet Austerity 0-6-0ST which was a small, powerful loco, but the size of the boiler limited its speed and sustained output. Heavy loads could be drawn by working multiple of these together.

If the rear of the loco becomes heavier, owing to a larger firebox or more bunker capacity (thus greater range), there may be a need for a carrying axle behind the firebox. This gives an 0-6-2T arrangement, such as the South Wales types, which were another stalwart of UK coal working.

There will be two cylinders, as the speed and budget is against any more. Early British practice was for inside cylinders, but eventually they are too large and move outside. This gives a 2-8-0 layout, such as the GWR 2800 and GWR 4200 Classes. These were a tender and tank locomotive version of originally the same engines, the tender version with greater capacity and range, the later tank version having detail changes and a slightly shorter boiler to allow tighter curves.

As bunker capacity again increases, there may be a need for a 2-8-2T class, as was found with the GWR 7200 Class - converted from some of the earlier 2-8-0T.

British distances were short, so there was little need for the large tender locos with high fuel and water capacity used elsewhere, or for the huge boilers to supply steam across such a prolonged climb as the Rockies or Andes. So British locos never grew much beyond the 2-10-0 arrangement of the last large mineral locos and the BR Standard Class 9F. This was such a sophisticated design that it was also one of the fastest express passenger locos of BR, owing to the sophistication of its suspension and wheels. Still a single axle front pony truck was enough to carry the front cylinder weight and to guide it at speed, without requiring a 4-wheel bogie. The rear, owing to the small wheels and the shallow firebox, could be carried over the driving wheels and so not needing a rear bogie or truck at all.

In general, mineral locos were slow and so 4 wheel bogies were avoided in favour of 2 wheel trucks. This kept more weight on the drivers, where it was usual for adhesion. There were of course exceptions.

Articulated locos were primarily needed when either a narrow gauge limited the width of a locomotive and required it to be extended lengthways, or when the boiler or grate capacity needed to be very large. The Garratt design in particular places the boiler in isolation, with neither wheels, cylinders or water tanks around it, allowing it to expand as much as possible. This was often used when a wide grate was needed to fire with poor quality fuels. The Mallet, as favoured in the US, had the advantage of compound working, but it is harder to fit a large boiler in there too. Only the large US loading gauge really allowed this for very large locos - most other countries went for the Garratt. For narrow gauge, where the loading gauge can be far larger than the track gauge. the Meyer or Kitson-Meyer layout has advantages and is better articulated than the Mallet, so was popular in South America.

There is far more to this question than could be answered here. Andy Dingley (talk) 12:21, 30 July 2017 (UTC)[reply]

Identifying a butterfly

Hi all, I photographed this butterfly in the Butterfly House in the Melbourne Zoo on 16 February 2015. Can anyone help with identifying it? The rest of the butterflies there were native to Australia, so I would suppose this one is too. Thanks, --SuperJew (talk) 13:28, 30 July 2017 (UTC)[reply]

Outdoor thermometer time delay

In case of an outdoor thermometer for air temperature how much time elapses until measurement after a particular temperature actually sets? Is there a significant delay and if yes, are mercury-based thermometers inferior or superior to other types? Brandmeister^talk 14:56, 30 July 2017 (UTC)[reply]

The delay will depend mainly on the design of the enclosure, the windspeed, and the rate of change of temperature, but it should normally be measured in seconds not minutes. The Volumetric heat capacity of mercury is not significantly different from that of ethanol, but perhaps non-fluid thermometers might respond slightly more quickly? Dbfirs 15:10, 30 July 2017 (UTC)[reply]

Influence and borrowed content

How much from the scientific content of Luca Pacioli's work Summa de arithmetica, geometria, proportioni... is taken from his predecessors going back to Fibonaci and even earlier?(Thanks!)--82.137.13.229 (talk) 15:49, 30 July 2017 (UTC)[reply]