darklight03/StackMIAsub huggingface dataset:
I'm interested in learning about algorithmic trading, particularly in bitcoin. Looking at this chart, I can see that I could simultaneously offer a bid that was slightly higher than the highest bid, and an ask that was slightly lower than the current lowest ask. Whenever anyone bought or sold, that would mean that I would always be one of the people they bought/sold from/to. This would allow me to make a profit equal to the gap between the two. The problem I'm having is in calculating the risks. As far as I can tell the variables involved are: Variables out of my control Gap between highest bid and ask offered by others Average price paid for "pot" of BTC that I'm trading with Some measure of the volatility of prices over the preceding period (Risk) How much volume would move the market by a given amount higher or lower Variables within my control Maximum exposure in terms of money Maximum difference in ratio between GBP reserve and BTC reserve Size of the gap between my bid/ask prices (out from the exact centre as percentage of total gap) I'm struggling to figure out how to model this effectively though. I studied Computer Science and have a basic grasp of probability theory, but this is a bit beyond me. Any help, or pointers to the "proper" formula to model this would be greatly appreciated.
Of course a lot of people misunderstand the primary meaning of the adjective "moot" -- "open to question" or "argued about but not possible to prove" -- using the word only in the expression "moot point", which rightly or wrongly is often taken to mean "not worth debating". As a result the word is apt to cause confusion, even when properly used. So is there a better word to use for the minor meaning of "moot" -- "not worth talking about" or "no longer important or worth discussing"? A term which might be used in the sentence "The question of what color to paint the ceiling is _____ since we won't be adding on after all"? (One advantage of "moot" in this sense is that it's short and abrupt, which serves to enhance the meaning. Except that the wrong meaning may still be "heard".)
This might appear to be a bad question to some but i can't figure out the answer. While reading about an electric circuit, i found this on the web: Over the course of time, one could think of positive charges moving from the positive plate through the charge pipe (wire) to the negative plate. That is, positive charge would naturally move in the direction of the electric field that had been created by the arrangement of the two oppositely charged plates. As a positive charge leaves the upper plate, the plate would become less positively charged as illustrated in the animation at the right. As a positive charge reaches the negative plate, that plate would become less negatively charged. So my question is that why does only the positive charge flow? Since positive and negative charges attract each other, it seems to me that the negative charge can also move towards positive charge. Am, I wrong at some point? If the question is unclear, ask me to edit it in the comment.
Very soft question I admit, but it's something that's been bothering me for a while. I've been thinking that being self taught has the problem of accreditation. You can't evaluate a mathematician in a vacuum. You need an accredited mathematician to decide whether or not someone else is also a mathematician worthy of accreditation. Well, who evaluated the other mathematician? Other accredited mathematicians. It's sort of like becoming a member of an exclusive club. We put the job of accreditation on our universities. But what if some person was discovered, off-the-grid so to speak, who had taught themselves mathematics from library textbooks. How could such a person evaluate themselves? How do you know if you're making progress when you study? It's tricky. It's like language learning. Do I speak German more fluently now than I did yesterday? I've no idea. Who can say? It's like playing with Lego. How do you know if you're getting better with Legos? You build more complicated things. But who's to say one person's Lego helicopter is better than another's Lego Enterprise? What's the goal with Legos? Is there one? Should there be one? I know already that this question will be deleted almost immediately, but I think these are important questions and many people visiting this site are in fact self-taught and I'm sure these questions show up as massive roadblocks. Thanks for reading.
In English, a vector is said to have two properties: a length and a direction. The possible directions correspond to half-lines out of the origin (so that, eg, up and down are different directions). In many other languages, a vector is said to have three properties: directions correspond to lines (so that a vector pointing up and one pointing down have the same up-down direction), and a third property determines which way the vector is pointing along that line (up or down in our example). This may seem strange at first, but it's actually very useful to separate these concepts in mathematics. In fact, I need to do it in something I'm writing right now, but I can't find the right English words for it. Firstly, I need a word to indicate that third property. Is there any accepted term for it? In the wikipedia article on vectors, there is a picture where it is labeled as "sense", although the term does not occur anywhere in the article itself. Secondly, I might need a clear way to indicate which sense of the word "direction" I'm using (line or half-line). This does not need to be a single word, but it should be as clear and unambiguous as possible. It would be even better if any official references for this usage could be found. This problem is bound to have come up before in the translation of foreign scientific literature.
I saw on wikipedia that the shape of a raindrop is explained by using Laplace pressure. But why? Since the drop is in motion, we shouldn't be able to use an hydrostatic law, am I wrong? The bigger a drop of mercury is, the lesser spherical its shape is. Ideally, if we consider only the surface tension, the drop should be spherical. What energy should you take into account in order to understand the problem? I know the surface tension tends to minimise the fluid surface. I also know it will tend to minimise the potential energy of the drop. So we should take into account the gravitational potential energy. But how can we take the minimum of two different constraints (fluid surface and gravitational potential energy)? Is there a potential linked to the surface tension?
I was pondering about EM Waves and fields and felt that there is an inconsistency in the physical picture of EM waves that I have in my mind. For example let us consider a charge at rest . Now lets say we want to test the electric field due to this charge Q at a point P. So to do this we need to place another charge at that point and find if we can feel any force due to that charge. Now I think for Q to exert a force on test charge or an electric field to be established at that point there must be EM waves propagating from the charge Q to the test charge. However there are no accelerating charges which are the prerequisites for EM waves to be generated . So this brings in an inconsistency in the physical picture of EM waves I have in my mind. I believe that there is some misconception I am having and I am positively looking forward to replies to clear it out.
After a period in a .tex file, within a paragraph, should I use a space or a new line? I.e. like this: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec rhoncus vestibulum metus ut suscipit. Sed suscipit sem ligula, iaculis dignissim turpis ultricies vitae. Curabitur interdum lorem fermentum tellus blandit venenatis et et nisi. Ut elementum interdum nulla, at dapibus urna consequat ut. Nulla sodales in nulla et semper. Proin et consequat lacus. Nam faucibus, dui sit amet sodales cursus, nunc neque mattis eros, a pharetra purus elit quis tortor. Or like this: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec rhoncus vestibulum metus ut suscipit. Sed suscipit sem ligula, iaculis dignissim turpis ultricies vitae. Curabitur interdum lorem fermentum tellus blandit venenatis et et nisi. Ut elementum interdum nulla, at dapibus urna consequat ut. Nulla sodales in nulla et semper. Proin et consequat lacus. Nam faucibus, dui sit amet sodales cursus, nunc neque mattis eros, a pharetra purus elit quis tortor.
'George hasn't turned up,' said Nick. 'A nuisance his having to go back to Plymouth last night. He'll get over this evening sometime or other, I expect. In time for the dance anyway. I've got a man for Maggie. Presentable, if not passionately interesting.' A faint roaring sound drifted in through the window. 'Oh! curse that speedboat,' said Lazarus. 'I get so tired of it.' 'That's not the speedboat,' said Nick. 'That's a sea-plane.' 'I believe you're right.' 'Of course I'm right. The sound's quite different.' 'When are you going to get your Moth, Nick?' 'When I can raise the money,' laughed Nick. 'And then, I suppose you'll be off to Australia like that girl-what's her name?' 'I'd love to-' 'I admire her enormously,' said Mrs. Rice, in her tired voice. 'What marvelous nerve! All by herself too.' 'I admire all these flying people,' said Lazarus. 'If Michael Seton had succeeded in his flight round the world he'd have been the hero of the day-and rightly so. A thousand pities he's come to grief. He's the kind of man England can't afford to lose.' (Peril at End House, Agatha Christie) I suppose Moth here refers to an expensive brand/thing but can't figure out exactly what. The phrase in question is bolded.
Can anyone explain the essential difference between situations where nouns are used in a general sense and where they are used to indicate a specific type or instance of something? Specifically, I want to understand when to use a definite article and when to use no article at all. Murphy (fourth edition) give as an example of the specific type: When was the telephone invented? and as an example of the general type: Doctors are usually paid more than teachers. In some instances, i get a sense of why the noun is treated as it is, but not always. Moreover, in the above examples, it isn't obvious to me that the author means "telephone" exactly as a type of communication, and "doctors" may be defined as a particular profession (not in general, but rather precisely this class of workers who are paid better than others).
I've just gone through every google search I can think of without success. Is there an archive, database, list, or other compilation of LaTeX style files? I've found plenty of style files specific to certain journals or conferences, but are there any 'generic' themes out there? I'd like to make my document look a little different from whatever the out-of-the-box LaTex default, and more than just changing the font... I'm no pro, and don't have the expertise, time, or motivation to write my own style file. Also, I assume there are plenty of style files out there, analagous to the different 'Themes' or 'templates' used by microsoft products. Ideally there would be an image/example so that i could see what the style made the document look like. Where are they?
This is a phonetics question. I am teaching English as a Second Language. In phonetics, we all know the "i" in "think" is a "short i" sound. Additionally, the "i" in "bit" is a "short i" sound. However, when many of my students pronounce "think", "link", "stink", and so on - they pronounce the "i" in those words in an unnatural fashion (as if they are taking the "i" directly from other "short i" words and putting it into these words). To my ear, and my pronunciation, the "i" in "think" is far different from the "i" in "bit", even if it is short. In the same way, the "i" in "-ing" is different from the "i" in "bit" (or "sit", "grit", "fit", etc.). I believe this has a lot to do with the "n", but I'd like some technical explanation regarding the nuances of the system and how I can explain different pronunciations of a "short i" sound (instead of just having them listen and repeat).
We know that neutrino eigenstates are not mass eigenstate and this therefore produces neutrino oscillations. This is, however, deduced from the fact that the neutrino of one flavor produces the corresponding partner lepton of the same flavor (electron neutrino only produces electrons, etc.). My question is : how do we know that this is indeed the case experimentally? I know that the standard model predicts that it is the case, but how can we verify that, if the only way to tell that there was a neutrino of a given flavor is to detect the corresponding partner ? EDIT : To give some precision about the kind of answer I'd like : Saying : we know the flavor of a neutrino by the lepton it produces is not enough. In that case, we could imagine that a lepton does not always produces the corresponding neutrino (say, an "electronic neutrino" is by definition a neutrino that creates electrons when it interacts with a nucleon, but we could imagine that an electron could produce half of the time a "muonic neutrino" (always producing muons) and half of the time an "electronic neutrino"). I know that's not what predicts the standard model, but has it been verified experimentally ? If so, how can we do that, as we don't know what is produced before detecting it... I ask that because we could imagine that it could be another way to "explain" at least part of the neutrino oscillations physics.
"You just won the lottery? Chapeau!" This is the first time I have seen such usage in English. Literally 'Chapeau' means 'hat', but the intention (that I get from the internet) is something like 'My hat is off to you' or 'Hats off!' or 'Congratulations!' or 'Mad props!' or 'Good for you' or 'Cheers'. The primary question is: What is the provenance of this in English. And secondary questions: - at what point did it enter English? Is it direct to British English from across the channel? Or is it North American only, borrowed from French-Canadian? - And what is the feel of it? Is it mostly ironic (as 'good for you' often is)? - Is there a difference in English usage between the French singular 'chapeau!' and the plural 'chapeaux!' (or is it meaningless distinction in English). I've seen both usages.
A different question about truly spherical objects in nature (Do spheres exist in nature?) made me think of a lecture I had been at where, as I recall, it was mentioned that the most perfectly spherical object in nature is in fact (the event horizon of) a black hole. In the comments of the aforementioned question, I was informed that any deviations from a spherical shape of such an event horizon would be damped out within a very short time, related to the characteristic timescale of the system. So I was wondering what order of timescales exactly we're talking about here, I would appreciate some elaboration on this. And something I thought of just now: would it be possible for some wave (periodic) phenomenon to occur in this horizon, periodically distorting the spherical shape?
Does speed of pressurized gas escaping through a narrow nozzle into vacuum depend on the pressure? I've asked a question on Space.SE regarding utilizing gas at extreme pressures for propulsion. My idea was that the higher the pressure of the gas, the higher specific impulse would be achieved, because it would increase speed of the escaping particles. An answer cites the Choked Flow article, claiming The exhaust speed of a rocket is limited by the speed of sound. The answer was criticized as the linked article only gives the case of atmospheric pressure on one side and vacuum on the other as where this would apply, and my question was about way higher pressures. I'm finding this answer difficult to accept too, because speed of sound should be relative to the medium; a co-pilot of a supersonic plane can still communicate with the pilot, because the air enclosed in the cockpit moves with them. So, in a long pipe, speed of sound in decompressing gas should be relative to the local speed of the gas. Still, I don't have any solid background or source to back it up - thus the question. Is the speed still limited to speed of sound in case of very high pressures? If so, what effect limits it?
Heat can be evolved or absorbed when two dissimilar liquids are mixed together at constant temperature and pressure. This is called the heat of mixing of the mixture. I'm trying to understand the molecular "picture" associated with this process. Here is my current attempt: Initially, there are two pure substances each with its own "like-like" intermolecular forces. During mixing, these forces have to be overcome in order to "break-up" the similar molecules to "make way" for the dissimilar molecules. This requires energy and so is endothermic for both pure substances, correct? It would be like boiling the liquid (energy input) to achieve an ideal gas (no interactions) of each pure substance. The second component of the net energy change is the release of energy when forming the mixture. Now, we have to accomodate both the "like-like" interaction forces (presumably at different intermolecular distances than the pure substance) and the "like-unlike" interaction forces. Overall, this direction is exothermic since formation of the solution with interaction forces is lower energy overall than the non-interacting ideal gas mixture, right? So I have two offsetting directions in the two components of energy change associated with mixing. The net effect (endo or exothermic) obviously will depend on the quantitative forces associated with the each component of the process. Do I have the basic molecular picture correct?
If we have a perfect Schwarzschild black hole (uncharged and stationary), and we "perturb" the black hole by dropping in a some small object. For simplicity "dropping" means sending the object on straight inward trajectory near the speed of light. Clearly the falling object will cause some small (time dependent) curvature of space due to its mass and trajectory, and in particular, once it passes the even horizon, the object will cause some perturbation to the null surface (horizon) surrounding the singularity (intuitively I would think they would resemble waves or ripples). Analogously to how a pebble dropped in a pond causes ripples along the surface. Is there any way to calculate (i.e. approximate numerically) the effect of such a perturbation of the metric surrounding the black hole?, and specifically to calculate the "wobbling" of the null surface as a result of the perturbation,maybe something analogous to quantum perturbation theory? Or more broadly, does anyone know of any papers or relevant articles about a problem such as this?
Recently I was told of a job offer to analyse astronomical data. The job offer states that they want somebody with knowledge of astronomical data analysis software and it will be a plus somebody who has experience with programming languages, giving as examples: IDL and Fortran. My first question is: Is Matlab a good programming language? I mean, to treat astronomical data and any other things that they might want? From what I see IDL is comparable to Matlab, both have pros and cons but basically they both do the job. For my second question, and I'm sorry if I should post this on a different post but are very closely related, the selection for this job will be made by analysing data from some surveys on the optic, millimeter and infrared frequencies from the Hubble, Spitzer, Herschel and Apex telescopes. My other question is: what kind of data is this and what kind of treatment I may have to do? If somebody could indicate me somewhere online where free data is available I would be deeply thankful. My experience on this kind of job is, clearly, limited, but I believe I have all the theoretical knowledge to tackle the problem, I just need to know what to study and train.
As an example of someone who has discovered maths at a later point in my life than average, and who has (perhaps unusually?) proven the point that it is perfectly possible to study undergraduate mathematics with almost no prerequisites, I am now having to accept that fluency in mathematical techniques is in the end extremely important in the long run. I am curious about the extent to which having a rich exposure to elementary maths techniques must influence creativity in research later on? At the moment I have taken on a full-time programming job, and I am looking for optimal methods for improving fluency in elementary maths, that could work in such a limited time frame. Any suggestions? Could it be feasible to multi-task- say, for example, practice methods of mental arithmetic at the same time as doing something else?
Consider these two sentences, one with a contraction, one without: I didn't check my voicemail. I did not check my voicemail. didn't is expanded to did not. Now consider: Why didn't you check your voicemail? If you want to write this without a contraction, you must write it as: Why did you not check your voicemail? The word you comes in between did and not when didn't is expanded. This: Why did not you check your voicemail? is probably not correct at all. I've never heard anyone speak like that, and never seen that written, even though didn't is expanded directly into did not. This came up during discussion the other day, and I was wondering if there was a term for this situation where a contraction cannot be expanded into what might seem the most obvious form.
So I was trying to figure out the reason why my old (and probably sufficiently damaged) needle on my phonograph (turntable) was not working like it was a little while ago. With my headphones on, I was playing around with it and happened to touch two of the leads on the underbody of the needle. All of a sudden, a man's voice was speaking to me in a muffled, mid-pass tone, slightly audible but definitely discernible (talking about the "nightmares of the Obama regime" or something odd like that). The voices only occurred when I was in contact with both leads. Why is this? Did I turn myself into a giant watery antenna? I know phonographs have some interesting physics to them, but this is a new one. Why is it so clear? I can hardly get old analog radios to focus cleanly, let alone my own body. Is there a natural resonance that caused such a clear audio frequency to be heard?
In Texmaker, I like using the shortcut to enter math mode. This shortcut creates two dollar signs, and allows you to immediately type text in between the two. My problem is that I would like to be able to continue typing outside of this block immediately upon finishing with my math text. I would like to, say, hit "tab" and be able to start typing outside the math block, one space after the latter dollar sign. How do I do this? Is there a shortcut for this? If not, can I create one? Alternatiely: Can I edit the Math shortcuts that come with Texmaker? I don't mean that I want to edit the keys I press to obtain the code -- rather, I would like to change the code that is available from the Math menu.
Let's suppose you go to Ikea to buy a wardrobe, but you have to make sure it fits in your room. You find two that are really nice and since you like them so much you decide to buy both of them. So you measure their length, width and height (just to be sure they fit in your room). For the width you have no problem: They could be thicker or narrower and would still fit. However the first wardrobe length is not good. It's too long so you write in comments: Please provide a shorter one. The second wardrobe length is good but its height is not. This one is too tall so you write in comments: Please provide a shorter one. Wardrobe A is too large so it must be shorter. Wardrobe B is too tall so it must be shorter. Because shorter has two meanings you end up receiving both wardrobes with incorrect sizes. Now the question: Is there a pair of words for length and height that avoid using the same word to mean less magnitude?