Why do we need screen to see real images?

Question: As we know that concave mirror forms a real image when object is placed beyond focal plane.
This image can only be seen if a screen is kept at the point of intersection of rays(sharp image).If any screen is not kept then we are not able to see the image formed by meeting of rays.Whereas in case of virtual image we don't need any screen .Our eyes sense the rays coming (appear to be coming) from image source and we see image.so why do we need screen to see real image even though the rays are actually meeting at a point then also we are not able to see image without screen.In the following figure we need screen for a,b,c,d and e.
Comment: I think you've got it backwards: a "real image" is one that forms at a specified image plane (location).  Our eyeball, thanks to its own set of optics, can produce a real image on our retina for a variety of real or virtual object locations.
Comment: We only ever see real images - formed on our retina.
Answer: A real image can be viewed on a screen, a virtual image can not.   Rays from both types can enter your eye, be refracted by your eye's lens and form a real image on your retina as @CarlWitthoft points out.
So it is not the case that a real image must be viewed on a screen.  It can be viewed on a screen.
Comment: @GODPARTICLE   For a point source object forming a real image, all rays converge to a point image.  If you put a screen there, you will be able to see the convergence of those rays. If you don't put a screen there, the rays will continue past the image, and diverge.  Similarly, rays diverge from a virtual image.  Once the rays are diverging, there's no way to tell if the source is real or virtual.  It is possible to use a screen to find the real image, but you don't have to.  The image still exists whether or not you put a screen there to help see it.
Comment: I didn't understand your words *must be*, *can be*. I think you must need a screen to view a real image. Could you please elaborate. How do you think real image can be viewed without scree?
Comment: That means if screen is not there then also we can see real image, but I have never observed a real image without a screen during my high school practical. Why is it so please explain.
Comment: @user40999 If you've ever used a refracting telescope, you have.  Somewhere inside the tube of the telescope a real image is formed.  Rays continue past (or perhaps *through*) that real image, are collimated by the eyepiece, and then your eye's lens forms another real image, this one on your retina.
Comment: How will the ray diagram look like when one views a real image without a screen?
Comment: @Shub By "view" do you mean "look at the real image with my eyes"?  If so, then the rays continue beyond the real image.  Before the light gets to the real image the rays converge to form the real image in some plane in space.  Beyond that the rays would continue, so they would diverge from the real image.    Some of the rays would eventually  be incident on the lens of your eye which changes the direction of each ray so that they converge on your retina.  A second real image is formed on your retina.
Comment: @Shub [Real images and their formation](https://physics.stackexchange.com/questions/314519/real-images-and-their-formation)
Answer: The answer is that you do not need a screen to view a real image as is explained here.
A real image is there whether or not a screen is present.
The difficulty when trying to observe a real image without a screen is focussing your eye on the image which is located in a region (in the air) with no points of reference.
Answer: No, real images cannot be seen without a screen. in a refracting telescope after passing through the objective lens, the image is not seen as the eye piece lens forms a virtual image which does not require a screen.
Comment: Look at the concave surface of a spoon.  See that little upside-down image of you.  It's real.  No screen.
Comment: This isn't correct. While most compound optical systems *don't* have the user observe a real image directly, that doesn't mean it's *imposssible.*


Jittering cloth when simulating

Question: I have this problem where when the cloth plane falls onto the object (A smooth edge square)it jitters a lot similair to how elastic reacts when pulled and released. Im not sure what to do. Any advice?
Comment: please post some screenshots, and at the very least your cloth settings so we have a better understanding of what is happening
Answer: So Im sorry it took a while to get back to this question, I solved it by adding a ton of subdivisions which for whatever reason stopped the jittering.

Jittering cloth when simulating


Why do strange characters sometimes appear in PDFs on some computesr?

Question: I have seen this error occur a few times, where a PDF only appears correctly on some computers. Does anyone know what causes this and how to fix it? Is this some kind of encoding error?
Comment: Could you be a little more specific? Is the same software being used everywhere? The same OS? Do you know what software was used to create the PDF(s) in question?
Comment: @Frabjous: The question is general because I have seen this issue a few times. Sometimes it does seem to be OS related - but not the issue that I saw today
Comment: What did you see today? I really doubt that the question can be answered without more information.
Comment: @frabjous: Characters appeared weird on one Windows computer, but not another
Comment: On what? Adobe Reader on each? Save version? Different versions?
Answer: The question is too open-ended to be answered as is, but here are several things I've seen which have caused PDFs to render different in different software or different machines.

Fonts are not always embedded in the PDFs (-- usually they are, but not always --) and two computers have different fonts or different versions of the fonts installed.
Different PDF rendering engines are used, which support different features. Few PDF readers apart from Adobe support JavaScript, for example, and certain other features.
Different viewers, or different versions, support different PDF versions to different levels. E.g., there are features of PDF 1.6 not supported by Ghostscript based viewers like MuPDF.
Even for a given engine, sometimes not all components are always installed. Certain PDF elements do not appear correctly in poppler based PDF viewers unless the poppler-data package is installed, for example, and at least as of recently, this package is not installed on Ubuntu and other distros.
Different PDF software react differently to different methods of using basic unis of measurement when it comes to issues that are unclear in the PDF spec; for an example, see here.
Bugs, bugs, bugs!

I'm sure there are more!
Comment: Thanks, at least now I have a much better idea of what the errors could be
Comment: Also some PDFs are created with ANSI code pages, which don't translate very well when viewed on a different code page. Same reason some web pages are full of ????. There are utilities for the various platforms to let you read documents in their original code page, if you can figure it out.


Entropy and neutral charge

Question: If you have a system $a$ with $N$ particles with charge $+q$ and you put it in contact with a system $b$ that has $N$ particles with charge $-q$, i think the system will evolve to a neutral charged system. So my question is this, if the natural way on which the particles arrange themselves is the way of maximezating the entropy, is the charge neutrality a state of maxium disorder, or in other words minimum information?
Answer: The question is a bit vague but here is how to think about it. A spontaneous process always increases entropy. Hold the positive and negative charges at some position, then let them free. If they come to a new equilibrium position, then the final state has higher entropy.

Entropy and neutral charge


How to select a model based on statistical analyses?

Question: I've been statistically validating the performance of different Deep Learning models in classifying parasitized and normal cells. In the process, I could find that there is no statistically significant difference in performance between the pre-trained CNN models. In the absence of such significance, which model am I supposed to choose?
Answer: This is a very general question, since you are not providing any statistics, that one can comment on. But in general: yes, this can be the case. However, there is an interesting paper on comparing classification models with statistical tests written by Demšar (2006). He shows a way to vizualize the results of different models that do not significantly differ in quality.
Comment: This method operates on average ranks, which requires several datasets, but it seems like OP only has one dataset to evaluate on.


Can I claim the rent I pay as a business expense if the lease is in my wife's name?

Question: I have a mobile auto detailing business. I have an office at home with my computer where I do all my marketing/online advertising, calling customers, all that good stuff. The apartment that me and my wife live in is in her name but I make the rent payments. Can I claim a portion of those payments as a deductible business expense on my taxes ?
Comment: Tax questions need a country tag as the rules vary by jurisdiction.
Comment: If in the US - also what state it is? If it's a community state things may be easier to explain.
Answer: Assuming you are in the US, this should be standard home office rules.
You can claim only space you use EXCLUSIVELY for business -- if it's a corner of the living room, that means only the area occupied by your desk and chair, and even those only if you don't also use them for personal activity such as browsing Stack Exchange. Few people are really willing or able to carve out that space, but it can be done. (Easier if it's a separate room that you stay out of except when working, of course.)
Once you have established that space which is exclusively used as office, you can then pro-rate by the ratio of that space to the rest of the cost of maintaining the house or apartment... or you can use the Simplified Home Office rules, which don't require all that calculation and just say "deduct $5 per square foot of legitimate office space."
See https://www.irs.gov/businesses/small-businesses-self-employed/simplified-option-for-home-office-deduction and the documents referred to by that page.
Comment: I think the real question is whether they can deduct rental payments they're not legally obligated to pay
Comment: Transfers between spouses are not taxable and unless the spouses explicitly manage finances separately I doubt this would be an issue, but generally it would be easier to explain in a community property states.
Comment: I would assume that if transfers between spouses are not taxable, they're also not deductable. Seems too obvious a loophole otherwise. Which brings us back to one person being able to deduct the cost of each home office, however it gets paid for.
Comment: So can I make the deduction for that space even if the lease for the apartment is in my wife's name, but I pay the rent ? I can prove I pay it on my bank statements if it ever came into question
Comment: As long as only one of you takes the deduction, I don't think the IRS cares much about which pocket the money was pulled out of. If you were claiming a "real" office you might need to be more rigorous

Can I claim the rent I pay as a business expense if the lease is in my wife’s name?


Expectation of an exponentiated quadratic form

Question: Given a multivariate normal random $n\times 1$ vector $X \sim N(\mu,\Sigma)$, what is the expectation $$\mathbb{E}[exp(X^TAX+b^TX)]$$ where $A$ is a $n\times n$ matrix and $b$ is a n-dimensional vector? I know that $\mathbb{E}[X^TAX] = \mathbb{E}[X^T]A\mathbb{E}[X]+tr(A\Sigma)$, but how should I solve this problem?
Answer: $$
X\sim N(\mu,\Sigma)\quad\Rightarrow\quad \text{pdf}=f_X(X)=\frac{1}{\sqrt{(2\pi)^n|\Sigma|}}\exp(-\frac{1}{2}(X-\mu)^T\Sigma^{-1}(X-\mu))
$$
Therefore:
$$
\begin{split}
E[\exp(X^TAX+b^TX)]&=\int_{\mathbb R^n}\frac{1}{\sqrt{(2\pi)^n|\Sigma|}}\exp(-\frac{1}{2}(X-\mu)^T\Sigma^{-1}(X-\mu)+X^TAX+b^TX)dX\\
&=\int_{\mathbb R^n}\frac{1}{\sqrt{(2\pi)^n|\Sigma|}}\exp(-\frac{1}{2}(X-\Delta)^T\Sigma'^{-1}(X-\Delta)+\Lambda)dX
\end{split}
$$
where
$$
\Sigma'=(\Sigma^{-1}-2A)^{-1}, \Delta=\Sigma'(b+\Sigma^{-1}\mu), \Lambda=\frac{1}{2}(\Delta^T\Sigma'^{-1}\Delta-\mu^T\Sigma^{-1}\mu).
$$
Therefore:
$$
\begin{split}
E[\exp(X^TAX+b^TX)]&=\sqrt{\frac{|\Sigma'|}{|\Sigma|}}\exp(\Lambda)\int_{\mathbb R^n}\frac{1}{\sqrt{(2\pi)^n|\Sigma'|}}\exp(-\frac{1}{2}(X-\Delta)^T\Sigma'^{-1}(X-\Delta))dX\\
&=\sqrt{\frac{|\Sigma'|}{|\Sigma|}}\exp(\Lambda)
\end{split}
$$
Comment: Thanks for replying. I have two questions to ask you if you don't mind:     1. What is the explanation for the first line of equation you have written after "Therefore:"? I found a mention of a similar problem at this link http://goo.gl/fNqvoA and I can see that your answer can be simplified to the form given in this link, but I am having problem understanding the first step of your solution itself.      2. Can you suggest me a book to study this topic in detail so that I can solve the problems on my own?
Comment: @abbyj The link you gave refer to a completely different problem. Do you know what a closed form means?
Comment: yes and I guess you mean that the closed form expression here shouldn't contain any integrals over infinite space, right?
Comment: @abbyj multivariate normal distribution is much like the single variable one if you use diagonalization. What I did is basically completion of squares, which is high school math. The rest is utilizing the fact that probability density function integrates to $1$ over the entire domain $\mathbb R^n$. There are plenty of book on this subject, I didn't read a single one so I cant recommend you any reference.
Comment: Got your explanation. Thanks for helping.


How to allocate a process specific amount of CPU power?

Question: I would like to allocate certain number of CPU cores to a specific process for performance improvement.
How can I do this?
Comment: Same as http://stackoverflow.com/questions/4436422/how-does-java-makes-use-of-multiple-cores
Answer: There are many programs that allow you to take use of it already - for example compilers.
In your case , you should see whether your program is designed to use multiple cpu or cpu threads in parallel or not.
If your program (e.g. a java process) is single threaded and can't use multiple cores simultaneously, then you may just increase its priority only with nice command.
But you can write java programs that make use of multiple cores.
See this post
Answer: I assume the question is about a Linux environment and there's a competing workload in the system.
The easiest way to get some process separation at the CPU level would be to use taskset/sched_setaffinity and assign your process to a set of cores, and possibly exclude these cores from being used by other heavy CPU users on that system.
Another possibility is to use mechanisms like cgroups (manually or via container solutions like docker) to assign a majority of CPU time to the selected process (via shares).
If your workload is performance sensitive you may have to look at CPU used  by the OS itself, e.g. handling network packets. You may want to check which core does most of that processing, if any, which normally shows up as si (software interrupt) time in top. Making sure your process lands (or doesn't land) on that core may influence your results - unfortunately both ways. Look at irqbalance if it gets that far.
And finally, in attempts to lower external interference, you can try boosting your sensitive process's CPU scheduling priority by fiddling with its niceness using nice.
Comment: i think the question is about performance improvement of running a single process on multiple cores.
Answer: I'm not sure if you want to restrict a processes to a certain number of CPU cores or if you want to dedicate CPU cores to this process.
Dedicating CPU time
To my knowledge it is not possible to "give" a process exclusive access to a CPU, or at least it's very hard to do. If other processes are usng CPU time that you would rather have available to another process you should use nice. Nice is essentially a priority system for processes and is a number between -20 and 19 (0 by default). See man nice. Higher "niceness" means that the process gets less CPU time, it's "nicer" to the other processes. Lower the nice value and the process will be less nice and consume more CPU time. You could for examle run ls with the highest priority: nice -20 ls
Restricting CPU cores
On Linux you could use cgroups to restrict a process. I'm not sure about BSD other Unix variants, but I would assume they have similar functionality.
Comment: i think the question is about performance improvement of running a single process on multiple cores not about process isolation.


NEW MEMBER USER AGREEMENT

Question: I am fairly new to Microsoft teams.  I am wondering if there is a way to set up a user agreement form or page for new members/guests.  Ideally I would invite someone to a team and they would be required to read the terms and conditions and agree them before being granted access to the team.  Is this possible and if so what is the correct way to go about doing so?
Answer: Did you connect to teams from the SharePoint site? If so, you can try to add a member to the SharePoint site and grant him the corresponding permissions.

For more information about permissions, you could refer to SharePoint site permissions.
And here is a blog about Microsoft Teams and SharePoint permissions you could have a look:
Microsoft Teams and SharePoint permissions explained

NEW MEMBER USER AGREEMENT


What is a gentler word than "suspended" or "closed"?

Question: What word can show that an action is redeemable? Is there a synonym for closed/suspended that connotes a chance at redemption?
Comment: People are correct in saying that suspension is redeemable. If you want something that *sounds* gentler, though, you might say *on hold*.
Comment: In hockey, there is the "Penalty Box" where you are excluded from the game for a set period of time.  Maybe you could call your "mild suspension" something like "Penalty Box".
Answer: suspended should work for your purposes. This word indicates a temporary or conditional termination pending some future redeeming action.
Answer: Personally I see nothing particularly final about a suspension, or even a closing; otherwise a door would be a single-use object, after which it would become a funny-colored part of the wall.
If something is terminated, then it is well and truly ended with no opportunity for redemption.  If something is only suspended, it can be resumed or reinstated with little effort.  You can further emphasize that by declaring it to be "temporarily suspended".
Answer: If the context is what I think it is, you really ought to ask which phrase sounds gentler: "the question is closed" or "the question is suspended".  Neither sounds particularly kind to the person asking the question.  The first does carry a greater finality to my ear, however.
To answer the direct question, context is everything.  Pete Rose given a lifetime suspension from baseball in 1989.  A criminal sometimes gets a suspended sentence, which is gentler than serving hard time, but still a conviction.  Suspension in most social contexts, sounds like someone has done something very wrong.
As Hellion suggests, closed doors usually may be opened again.  A proposal may be closed for comments, which is usually final.  People sometimes say the "book is closed" on an incident to mean it has come to an end.  In social situations, "close" may be temporary or permanent depending on what rules are in force.
My suggestion for the particular problem of what to call a question that needs work in order to be open to new answers is (and was) "under construction".  Other suggestions that I like as both gentler and less final were "draft" and "needs work".
(You beat me to the idea of using this resource.  Great minds...)
Comment: "lifetime suspension" is just a euphemism.
Comment: Did this posting contribute to the "On Hold" change for newly closed questions?
Answer: I'm not sure of the context but would "deprecated" fit?
Answer: Two words, but my single word finding skills seem to be on hiatus this morning. Perhaps that subsystem's sabbatical will end as more caffeine is consumed?
Answer: Consider this non exhaustive list of synonyms for "suspended:"

adjourned: suspended until a later slated time.

tabled: US : (of a bill, motion, etc.) laid aside for future discussion, or for an indefinite period of time.

on the table: US : (of a bill, motion, etc.) laid aside for future discussion, or for an indefinite period of time.

pigeonholed: lay aside for the present; deferred.

on hold: Informal : into a state of delay or indeterminate suspension.

on the back burner: Fig. : on hold or suspended temporarily.

frozen: (of a process) suspended temporarily.


How do I get Lightroom to display AM/PM info?

Question: I switched the time zone on my camera -12 hours and I'm trying to fix the times of the photos before the switch; however, I can't figure out where Lightroom displays AM/PM - it doesn't seem to be in the metadata panel, nor in the cell labels in grid view, nor in the "edit capture time" dialogue.
Answer: This might depend on your locality settings. In mine it shows 6:15 PM as 18:15 (exactly how I like it).
The easiest way to see this is to press I. Going into Loupe view (E) in the Metadata tab, next to Capture Time there is a small button. Press it and you get "Edit Capture Time". There select Timezone Adjust to change by 12 hours.
The metadata panel has to be in "default" mode (others like IPTC and EXIF will also work).
To do the adjustment on multiple images, select them all and then go into Loupe view.


Issue Badges (ERC721) for ICO participants ; and based on that define reflection % in the ERC20 contract?

Question: I have unique requirements for a project. They are trying to issue ERC721 based badges/identities to the ICO participants. And utilize that identity/cert for sending reflection rewards via ERC20 contract. Say, there are 3 ICO phases : Phase A, Phase B & Phase C. Based on which bucket a particular user falls in, they will be getting bonus reflection dividends. Question I have is, how to reference the ERC721 badge/identity that are being issued during ICO and build a condition in the ERC721 contract (say If Wallet address was participated in Phase A then set reflection rewards as 1%)? If someone can explain this with an example, it will be greatly helpful.
Answer: It should be fairly easy for a contract to determine if an account owns any tokens. For example using balanceOf.
if (nftToken.balanceOf(msg.sender)) {
    // msg.sender owns at least one NFT
}

If you have the tokenId you could test for the owner
if (ownerOf(tokenId) == msg.sender) {
    // msg.sender owns
}

If you don't have the tokenId it is much harder to determine the tokens owned by an account. If the NFT supports ERC721Enumerable interface you could use it to enumera tokens owned by an account, but it will be expensive.
Probably the easiest thing to do if you own the NFT token is to add an explicit function to the contract and call it from the ERC-20 contract.


Any pantheist Buddhists?

Question: I know a lot of the Kyoto school were / have been defined as being as panentheists: but were there any pantheist Buddhists? And, has any comparative religion scholar defined it as pantheism?
Comment: Incidentally, there are also [atheist Buddhists](https://en.wikipedia.org/wiki/Secular_Buddhism)
Comment: yeah i had heard of him! @Codosaur
Comment: I was not aware that any Buddhists were theists of any sort. But if they are it would have to be panentheism since Reality would transcend space and time.
Comment: A "pantheist Buddhist" would be a Hindu, specifically an Advaitin.
Comment: @user14119: As I see it Buddhism should be described as agnostic, specifically not in terms of being uncertain about deity/ies existing but as declaring the question irrelevant to highest spirituality and how to live. See the discussion of Pali versiin of the Brahmajala Sutra, 'Teacher Of The Devas' https://www.accesstoinsight.org/lib/authors/jootla/wheel414.html wherein Buddha educates even Maha-Brahma on the history and nature of the cosmos.
Answer: Samuel Beal (1825-89), in his translation of the Fo-Sho-Hing-Tsan-King (A Life of Buddha), has defined the Vaipulya stage of Northern Buddhism as a pure form of Pantheism:

Northern Buddhism, again, may be divided into two, if not three, distinct periods of development, or epochs.
...
Thirdly, the 'indefinitely expanded' form, known as Vaipulya, which is founded on the idea of a universal nature, to which all living things belong, and which, by recovering itself in each case, secures for the subject complete restoration to the one nature from which all living things have wandered. This is evidently a form of pure Pantheism, and denotes the period when the distinctive belief of Buddhism merged into later Brahmanism, if indeed it did not originate it.
Source: The Fo-Sho-Hing-Tsan-King (A Life of Buddha)

The following Sutras are commonly defined as Vaipalya Sutras:

The nine Dharma Paryaya texts are otherwise named vaipulya sūtra, because vaipulya literary means 'extensive'. Nine Dharma Paryāyas are generally enumerated as follows:
Aṣṭasāhasrikā-prajñāpāramitā-sūtra
Saddharma-puṇdarīka-sūtra
Lalitavistara-sūtra
Laṇkāvatāra-sūtra / Saddharma-Laṇkāvatāra-sūtra
Suvarṇa-prabhāsa-sūtra
Kāraṇḍyavyūha-sūtra / Gaṇḍavyūha-sūtra
Tathāgataguhyka-sūtra / Tathāgataguṇa-jñāna-sūtra
Samādhirāja-sūtra
Daśabhūmīśvara-sūtra.
Source

According to the Dictionary Of Chinese Buddhist Terms:

Vaipulya is extension, spaciousness, widespread, and this is the idea expressed both in 廣 broad, widespread, as opposed to narrow, restricted, and in 等 levelled up, equal everywhere, universal. These terms suggest the broadening of the basis of Buddhism, as is found in Mahāyāna. The Vaipulya works are styled sutras, for the broad doctrine of universalism, very different from the traditional account of his discourses, is put into the mouth of the Buddha in wider, or universal aspect.
Answer: Yes, householder, the Buddha explained it to some of his monks who had been of Brahman origin. If remembering right, it is retold in Aggañña Sutta (DN27).
(Note that this gift of Dhamma is not dedicated for trade, exchange, stacks or entertainment but as a means to make merits toward release from this wheel)
Comment: If I might ask, please don't attach labels to people without a particular purpose in mind. The OP may not consider h'erself a 'householder,' and may not even know what the term means (since it isn't commonly used in Buddhist circles). The label adds nothing to the discussion, and sows seeds of confusion and discord. Thank you for your answer, though; I'll have to go back and reread that sutta.
Comment: I share Ted's view of this matter.
Comment: Being "of brahman origin" does not mean the person is a pantheist. Leaving aside the
 question of whether brahmans were pantheists , your argument can be extended to say that there are a lot of "christian buddhists" because they are "of christian background"
Answer: I feel pantheism is a bit of a slippery term, especially when applied far outside of it's monotheistic original context. There, it started as a kind of monotheistic non-dualism, drawing on monistic and mystic traditions. But it got widely used to describe animist traditions in the 19th century, and also -I'd say unwisely- to describe Hindu thought. And in modern usage, also now to describe the idea that consciousness somehow pervades everything, and is only concentrated in minds.
Taken as immanence of the highest principle, the Mahayana doctrine of the dharmakaya is a kind of pantheism.
In the sense of coidentifying the world with deities, Japanese Buddhist thought does not put itself in contradiction with Shinto practice which is called pantheist, and as I understand it many or most Buddhists in Japan also observe Shinto practices. See also tsukumogami, for how in a polytheistic context animism and pantheism are not fully distinguishable.
Yogacara or 'mind-only' thought can I think be understood as the idea that subjective experience and mental processes like thoughts are the most fundamental way to understand reality.
But at root, pantheism as a term is not a good fit outside of a monotheistic context, and the mix of uses is prone to creating confusion. I prefer not to use the term.

Any pantheist Buddhists?


Difference between "oeste" and "occidente"

Question: What is the difference between "oeste" and "occidente"?
Do they both mean the direction and the region?
Answer: Oeste is the cardinal point meaning West. Occidente is a synonym for Oeste meaning sunset, referring to the point where the sun sets, "por donde el sol se oculta". Nowadays, Occidente is a term used for "Western World".
The opposite for Occidente is "Oriente", for "origen", the place where the sun appears. In English, there is the same word "Orient" and is used for East, being the Eastern Culture, like Oriente Próximo (Near East), Oriente Medio (Middle East) and Lejano Oriente (Far East).
So, you see that for the direction, we use "Oeste" and "Este". For the region or area, we use "Occidente" and "Oriente".
Comment: Yes, but I didn't add these because they are a little bit offtopic. In Spain, Levante is usually Valencia region, though it can also be the Mediterranean Levant: Near East. Levant/levante means "rising", where the sun rises (East). Poniente "setting", where the sun sets (West).
Comment: I also see levante (E) and poniente (W) used to denote different parts of towns. (eastern Spain - Valencia region). Note that these are nouns whereas oeste / este can be used as adjectives western / eastern
Comment: @JouSauron: ya veo. Gracias.
Comment: In Chile use "oriente/poniente" to talk about local guidelines, for example, neighborhoods with respect to the center of town. We use "occidente" only for global locations, for example, countries. We never say "levante".


Android Studio waiting for build to finish

Question: I have a problem. When I start a new project in Android Studio and select a navigation drawer activity it happens. I don't have access to my activiy_main_drawer.xml on "Design" and it keeps saying "Waiting for build to finish.". I really don't know what I have to do. I tried to uninstall and reinstall Android Studio, and it didn't help.
Answer: I've just run into the exact same problem. I simply solved it by choosing Sync Project with Gradle Files. This will trigger a Gradle re-import and a build.
As of Android Studio v3.2, the icon is located near the top right tool bar. You can also find it using Find Action shortcut CtrlShiftA.
Comment: It worked... But after that i had to do Invalidate cache and restart too...
Comment: Thanks, in Android Studio 3.3.2 solved in the same way.
Comment: Restarting and and invalidating cache didn't work for me. Surprisingly this worked for me. My only regret is only having 1 upvote.
Comment: It worked, only Sync Project with Gradle Files and layout xml finisih to build
Answer: You can do the following:
"File > Sync Project with Gradle files" (worked for me)
File > Invalidate Cache & Restart > Just Restart
OR
File > Invalidate Cache & Restart > Invalidate & Restart
Close Project and Re-Import the Project
Answer: File -> Sync project with Gradle files
Answer: What worked for me was, from the top menu:
Build -> Clean
Build -> Rebuild Project

After that the xml design worked
Answer: Syncing gradle, reopening, rebuilding, invalidating caches and restarting, trying different Android studio versions. None of these helped. When I would open XML preview I would still see that damn issue.
What helped in the end is closing Android studio, going to gradle directory:
cd ~/.gradle/

And deleting caches folder:
rm -rf caches

After that reopening Android studio will take some time as it still has some rebuilding to do, but afterwards all xml layouts were being properly rendered again.
Comment: It has helped. I have had only to restart Android Studio again once it has rebuild the project. Thanks!
Answer: I am using Android Studio 3.1.3 (#AI-173.4819257), Android Build Plugin for Gradle 3.1.3 and Gradle 4.4. I tried all possible options mentioned on various posts but nothing worked for me. I want to use ConstraintLayout which is default with AS 3.1.3. My observation and workaround are as follows.
Observation: This issue occurs when a new project created with empty activity and default layout.  I also get "IDE Error Occurred" once Gradle sync finishes.
Workaround: Create an empty activity, activity class (MainActivity.java) and layout (activity_main.xml). Once it is done, create a new layout file (say activity_cltest.xml) using New -> Android Resource File after clicking right button on "app". Create new layout as per your requirements. Once done, update MainActivity.java by replacing R.layout.activity_main with R.layout.activity_cltest.
I also tried to copy content of activity_cltest.xml to activity_main.xml but still for activity_main.xml, error persists. Effectively, once a new project is created, activity_main.xml should not be used and deleted.
However, for some reasons, syntax highlighting of "R.layout.activity_cltest" within MainActivity.java doesn't work.
Answer: Just create a new XML file using the same name and copy paste activiy_main_drawer.xml file codes. It works for me.
Comment: Worked for me. Thanks
Answer: Have the save problem, the Android SDK was missing from my system.
After installation of this missing SDK, its running fine.
Answer: In my case it was because I specified recycler view's tools:listItem="<item_layout>" in body of <item_layout> (nested recyclerviews). Just removing this tools option solved it.
Answer: I uninstalled my 3.1.2 and installed version 3.2 Canary 18 from Android Studio download archives. Everything is fine now.
We welcome all constructive edits, but please make them substantial. Avoid trivial edits unless absolutely necessary.
Answer: Ah... I resolved it with the help on this page and a little bit more effort.
I installed Android Studio v.3.3.1 today on my Zenbook. I was stuck with the same error "waiting for a build to finish" and Display tab was not showing up for activity_main.xml
Here is what I did to resolve this error.
Step 1. I searched for SDK tools and downloaded required SDK versions.
Step 2. downloaded Gradle 5.2.1 and extracted the files in Program Files\Android\Android Studio\gradle
Step 3. File>Settings>Build..>Gradle and choose the local distribution of Gradle 5.2.1
Step 4. Go to File>Sync Project with Gradle files and allow some time to sync...
finish() :) developing android with Kotlin
Answer: My experience: I was accidentally importing "myself" into the view, creating infinite loop:
item_task.xml
<androidx.recyclerview.widget.RecyclerView
    ...
    tools:itemCount="3"
    tools:listitem="@layout/item_task" />   <---- circular dependency mistake

Setting a correct list item in the recycler view solved the issue.
Answer: I upgraded to AS 3.6 RC1 because of this time-waster but it still intermittently occurs!
Simply restarting AS has so far been working for me.
Answer: I've also faced this problem. The above solution wasn't worked for me.
I just restarted my Android Studio by closing the Android Studio application and opening it again from Start Menu. It works for me. Try this solution if the above not working. Hope this will helpful for you.
Answer: In my case, I was using an alpha version of material design lib, and it was not able  to render any view in the project. Solved by downgrading to a stable version.
Answer: Stuck w/ the issue for a month, got it after AndroidX update.
Tried to invalidate caches, manually remove them (project, grade, studio), re-install studio, re-import project - nothing helped.
This script resolved it finally (w/ -nuke option)
https://github.com/rock3r/deep-clean
Answer: Sometimes while converting the code from java to kotlin some library may get imported like import android.R
Just remove this library.
Check this tools:context=".MainActivity" in xml while copying another XML the class name will also get copy.
Else try File -> Sync project with gradle or rebuild the project.


What is so different about RTOS compared to normal programming?

Question: Classical programs run a loop with prioritized ISRs. How do RTOS do this differently of better?
Comment: Also, though not specifically your question, embedded OS applications tend to run in the kernel (mode) (and using single address space) rather than as user mode with multiple address spaces.  Paging is typically also disabled: no virtual memory -- everything runs from in real memory not just the kernel.
Answer: By not treating all Interrupt Service Routines (ISR's) as the highest priority.

The kernel of an RTOS is preemptible where as a GPOS kernel is not preemptible. This is a major issue when it comes to serving high priority process/threads first. If kernel is not preemptible, then a request/call from kernel will override all other process and threads. For example:- a request from a driver or some other system service comes in, it is treated as a kernel call which will be served immediately overriding all other process and threads. In an RTOS the kernel is kept very simple and only very important service requests are kept within the kernel call. All other service requests are treated as external processes and threads. All such service requests from kernel are associated with a bounded latency in an RTOS. This ensures highly predictable and quick response from an RTOS.
circuitstoday.com : GPOS versus RTOS for an Embedded System

People will make a fuss over things being "time critical" but there's really no such thing as anything that isn't time critical. What a Real Time Operating System (RTOS) really does is eliminate some of the random nature of scheduling in a general purpose operating system (GPOS).
Comment: The current Linux kernel is for general purpose operating systems, and is preemptable.


Document upload in sharepoint 2010

Question: When we upload any office  document in sharepoint document library do sharepoint make any changes or add properties to the document?
Answer: As far as I know SharePoint is not making any changes when you upload the document it just extracts the properties matching columns in the library, but when you access the document from a document library SharePoint will add/update these properties in the document.
But the result is the same.
Your document will not be unchanged when you retrieve it later.
Answer: It depends upon the SharePoint application and also the Office version (e.g., use of Document Parsing & Record Center Sites - where doc properties are related to the site content) - see this post for an example & more details: The Case of the Missing Office Document Properties in SharePoint 2010.

Document upload in sharepoint 2010


How to ensure that demesne holding are not lost on succession?

Question: Basically when ruling, it always says titles lost on succession. I am wondering how exactly you can ensure not losing demesne titles upon death, so that the heir to the kingdom keeps the same demesne holdings as his father did?
Answer: It depends on your succession laws. If you have gavelkind succession, your titles will be divided between your children. If you have primogeniture your eldest son will inherit all of your titles.
Now, lets say you rule more than one kingdom. In that case, each kingdom has its own succession laws. You can toggle between them by clicking on the respective coat of arms in the 'Laws' window.

You can read much more in the Succession Laws article on the CK2 wiki.
Comment: Isn't that screenshot from CK1?
Comment: It's quite possible. I was too lazy to actually open up the game, so I stole it from the CK2 wikia (see link). Either way, as the interface is very similar, I don't think it matters that much ... should I upload a new image?
Comment: @SevenSidedDie I uploaded a new image. :)
Comment: And a very nice one it is too!
Answer: gavelkind, gotta love and hate it.
but ye, as stated by other users, one of your kingoms still has gavelkind or another means of succession.
if i may give you a hint, you dont have to make all kingdom titles, and having only one top title prevents it from splitting up. eg: if you have 3 kingdom titles then those three titles can split, but if you have 3 kingdom titles and one empire title those three kingdoms will remain within the empire, even if someone else inherits them.
another way to make sure only 1 kid gets it all is to ensure only one kid is around to get anything at all!


Does Jesus command the Father to sanctify us in the truth?

Question: John 17:17 NASB95
"Sanctify them in the truth; Your word is truth."
The word "sanctify" here in the Greek is in the aorist, active, imperative. The Blue Letter Bible defines the imperative mood as "a command to the hearer to perform a certain action by the order and authority of the one commanding." I don't know too much about Greek grammar, but does this mean that Jesus was commanding the Father to sanctify us in the truth; not just simply requesting? Otherwise, the verb would be in the subjunctive or the optative mood correct?
Answer: Yes, the Lord Jesus Christ commands the Father in the same way that the apostles would command the Father in the Lord's Prayer.1 These imperatives were part of prayer and indicated earnest entreaty rather than an actual command.
As Dallas Burdette wrote,2

Even though Jesus utilizes the imperative in His prayer to the Father, we would not translate this as Jesus commanding the Father to do something, but rather Jesus' entreaty to the Father.

Furthermore,3

We do not command God to do something, but rather we entreat God. Another example of the imperative used in the sense of entreaty is found in the so-called Lord's prayer in the Gospel of Matthew. He writes, "Give (δὸς, dos, to give [in various sense literally or figuratively]) us today our daily bread" (Matthew 6:11). We cannot command God, even though the imperative is used in the prayer, but rather we beseech God to give us daily bread.

Likewise, Peter Perry wrote,5

On the imperative, William Goodwin wrote,5

Likewise, Moses Stuart wrote,6

Footnotes

1 "Give (δὸς) us today our daily bread."2 Burdette, p. 3853 ibid.4 Perry, p. 1015 Goodwin, p. 287, § 13426 Stuart, pp. 170–171, §49

References

Burdette, Dallas R. Bible Preaching and Teaching. Vol. 2. Maitland: Xulon Press, 2010.Goodwin, William Watson. A Greek Grammar. Boston: Ginn, 1895.Perry, Peter S. Brushing Up English to Learn Greek. Eugene: Wipf and Stock, 2014.Stuart, Moses. A Treatise on the Syntax of the New Testament Dialect. Edinburgh: Clark, 1835.
Answer: I want to start by looking at "Your kingdom come" Matthew 6:10. "come/eltheto" is a 2nd aorist imperative.
With "Your kingdom come" I think we do not have a request as in, "Please may your kingdom come". i.e there is no "please may".
Neither do we command God to make His kingdom come. We do not tell God what to do as a command. e.g. "Make Your kingdom come".
I suggest that what we do have is something like "come  on Spurs!". A strong statement of encouragement and identification with a particular cause.
But God is Almighty ; "all authority in heaven and earth has been given to me" Matthew 28:18. He will win; His kingdom will come; He will sanctify His people.
So if God is going to win anyway; if it is inevitable that the Father will sanctify [aorist imperative] His people; then Jesus can say [and those in Christ echo]:
"You are going to sanctify Your people; I/we are with You on this; go on do it; sanctify them!"
Beyond the Basics page 487:

"The imperative is often used to express a request".

Page 488 gives Mat 6:10 as an example. To which I add: It is a particular sort of request when what is requested is foreordained to happen, foreordained because of who God is.
Comment: Amen to that! "Your kingdom come" for example, affirms agreement.
Answer: The text in question makes no mention of any command. This text is not about issuing commands, but of speaking with a particular authority. In this case, it is words spoken by Jesus, while on earth, in prayer to his Father in heaven, with the authority of deity to deity.
The text in question likewise makes no mention of any request. Christians are encouraged to "present your requests to God" (Philippians 4:6) with thanksgiving, and although it's true that they can make statements to their Father in prayer (e.g. Thy kingdom come, thy will be done on earth, give us this day... etc), those are not commands from mortals to deity. Those are expressions of faith and assurance in the promises of God. They are uttered because Jesus told those ones to make such prayerful statements. They stand in contrast to doubtful statements, like, "Oh, I hope your kingdom comes, I hope your will is done on earth, I hope you'll give daily bread..." etc. No, Jesus had the authority of deity to know that God's kingdom shall come, his will shall be done on earth, and food shall be provided, etc. So, when believers pray like that, they are doing so on the authority of Jesus. They are not commanding God.
To know why Jesus spoke as he did in John 17:17, the need is for us to grasp the unique relationship between the Father and the Son, which was not diminished by the Son being on earth as a man. Jesus partially explained here:

"He that sent me is true; and I speak to the world those things which
I have heard of him. They understood not that he spake to them of the
Father... I do nothing of myself; but as my Father has taught me, I
speak these things. And he that sent me is with me: the Father hath
not left me alone; for I do always those things that please him." John
8:26-29

This unity with the Father, while the Son was on earth, was such that not only did he always do things that pleased his Father, he always spoke words taught to him by the Father. That would include words spoken in prayer.
Note that before he commanded dead Lazarus to walk out of his grave, Jesus prayed aloud, "Father, I thank thee that thou hast heard me. And I knew that thou hearest me always; but because of the people which stand by I said it, that they may believe that thou hast sent me. And when he had thus spoken, he cried with a loud voice, 'Lazarus, come forth'." John 11:41-43
Before speaking those words of command to a dead man, Jesus had ascertained the Father's will and knew that it was God's will, for then people would put their faith in him. Thus he commanded with the authority of deity.
Jesus confidently said, "Sanctify them through thy truth" because he already knew the Father would sanctify those ones through his truth. This was not a command to do something the Son had in mind. This was an emphatic declaration of the united will of the Father and of the Son, enabled by the Holy Spirit to work out in practice. So, yes, there is a sense in which the text shows Jesus speaking a command, but he is not commanding the Father. He is stating the known will of the Father, that those ones be sanctified by God's truth. This is deity speaking to deity, where one never commands the other because this is the one God here, who cannot be divided or disunited.
Answer: Why to be subservient to written definitions of grammar books that are sometimes too narrow and do not regard the entire spectrum of possibilities, for as mentioned by the earlier commentators, the aorist imperative can be used also for an entreaty and request, not only command; and psychologically speaking, is it always easy to distinguish between an entreaty and command? When a girl asks her lover who wants to depart for watching a football: "Stay with me!", will this boy understand it as an entreaty or as a command? Those grammar textbooks, without a nose to smell nuances!


Is it okay to switch narration styles towards the end of a story?

Question: I'm writing most of my book in third person omniscient, but I think it would be better if I put the last few chapters in first person, that way the readers can better understand what's happening at that moment. Would it be okay to do this, or should I keep a consistent narration throughout?
Answer: You can do anything if you can get away with it, but a shift in point of view is always tricky, and one that large is particularly so.  Worst of all, it comes near the end. That means the reader is expecting the constant use of third person omniscient.  There is no pattern.
More first-person sections earlier could establish a pattern of switching, but of course require something to say.
Answer: This is completely okay, as long as you do it right. First you should finish up your first person POV, maybe even at the end of a chapter or a cliffhanger, right before Bob hurls himself into the reactor core to overload the death star and save the galaxy, or at the start of a very fast paced and complicated scene or whatever else you need a POV change for.
Then you need to make it clear to the readers that the POV is changing. Don't say that the POV is changing, just put an extra line break or something that you can keep constant with any more POV changes.
Now that it's third person omniscient, you can just write it out and then when you need it switch back to first person POV using the method you decided on above. If you decide to end your book in third person, I don't think you need to do you line break switch at the end of this book or the beginning of the next book. If you end the third person at the end of a chapter, then you should probably put the line break switch although you could probably do fine without it.
Answer: "Jacob hurled himself off the [indoor] balcony and towards the bottom floor. 'here goes nothing,' he mumbled as he fell down, knowing that he may never come back up.
Chapter 25:
"The wind was strong, very strong. I could feel it blowing in my face as I fell down into the abyss. Looking down now, I wasn't sure if I'd ever make it back up. Far below me I could see Overlord Pai...
That was my pathetic and horribly written attempt at an example, but it's an example nonetheless. See how it switched POV's in a smooth and almost unnoticeable way? If you can pull something like that off than you can easily do this. It isn't breaking any rules, and your readers won't be confused if you can pull this off as/more smoothly as I did. (Mine honestly was not that smooth. Try to make it better than mine if you can. Although I think using one like mine would work without causing confusion, it would probably just sound a lot better if you did one better than mine).
If you can't pull it off smoothly, either don't switch POV's or study so that you can. It's less work for you and for your reader.


Can I say, "He goes on to say" in an academic paper?

Question: I have already used, "He states/asserts/postulates" in my paper quite a bit and I don't want to repeat myself again. I want to add another quote by the same author, but I'm not sure if this is acceptable: "He goes on to say, '......' ". Is this okay for an academic paper? What are some other common academic phrases we could use for "He said" and "He also said"?
Comment: "Johnson continues, 'blah blah blah'."
Answer: Some possible choices:

Johnson [thanks, Hotlicks] has been quoted as saying, "Yadda, yadda, yadda . . .."

According to Johnson, "Yadda . . .."

In the opinion of Johnson, "Yadda . . .."

From Johnson's perspective in his seminal work Yadda Yadda, "Yadda . . .."

Furthermore, from Johnson's perspective, "Yadda . . .."

Johnson's comments regarding _____________ are quite perceptive: "Yadda . . .."

Johnson delivered the coup de grâce to Smith's theory with this observation:  "Yadda . . .."

In Johnson's typically doctrinaire style, "Yadda . . .."

Lending a note of credibility to his argument, Johnson insists that "Yadda . . .."

On balance, Johnson is correct when he observed that "Yadda . . .."

Johnson sides with the conservative faction, as is evident in the following quotation:  "Yadda . . .."

Johnson evidently hews to the current paradigm when he says, "Yadda . . .."

The following quotation from Johnson's magnum opus Yadda Yadda serves to illustrate how behind the times he is regarding _______________: "Yadda, yadda, yadda . . .."

I could go on at length; I won't. This short list can serve, perhaps, as a springboard for coming up with your own ways of introducing a quotation. By the way, "He goes on to say" sounds fine to me.
Comment: @PatterEnglish: You're welcome! Best wishes to you. Don
Answer: You may also be creative and use ellipses to combine ideas.
In consideration of Senator Boyd's proposal, Judge Thomas explained, "The senator brings several poignant and provocative ideas to the court ... [however,] they are not supported by his data."


LED lights in bathroom

Question:
I have a problem in my bathroom with a switch and LED lights in the roof (6 of them).
The switch is double; the right switch is for LED lights in the roof with a dimmer and the left one is for a mirror light, also LED.
So, just by themselves, the LED lights in the roof turn off after few minutes (random time) after many, many years of working, and after that it was again turned on manually by the switcher and the LED lights in roof were just shining very faint (like when they are on the lowest level with the dimmer).
I took one LED light in the roof out, and also a transformator of that LED.
I checked the connections, checked the input in a 230V transformator, checked the output (it was something small, I don't remember exactly - 10, 12 or 24).
I took off the switch and saw everything was connected in the right way:
Comment: What country is this in?
What electronic stores are you familiar with?
Answer: Maybe the connection to the switch is broken and it is returning to what it thinks is the previously set dimming level?

Or maybe the overheating or short-circuit protection in the LED-driver is activating and turning off the outputs.

The correct wiring is as shown below

Note that the "switch-dim" connection should be connected to a momentary pushbutton switch - not to an external dimmer and not to a normal two-position lightswitch.
Comment: @toni_b: The HE2020 isn't simply a standard 230V to 75V AC transformer, it is a 350 mA constant-current LED-driver - these are very different things and not usually interchangeable. You very likely need something that rectifies AC to DC and provides a constant-current of 350 mA.
Comment: I was connected now without dimmer, and it is working good about switch and lamps with transformator, but it is just on half prosent of the power. ( lights are shining only half prosent of power), what i must to do it?
Comment: @toni_b: I'm not sure what you mean by "connected without dimmer" - are you using an external dimmer-switch? - The HE2020 is not designed for that. I would buy and install a 230V AC rated momentary push-button switch. See updated answer. To get light level to max, you need to use a switch to connect live to the connector labelled "switch-dim" for several seconds then disconnect (release push-button or turn off toggle switch)
Comment: It was working many years ago, so conections are good, somethink is burned or new problem with parts who break down after some time, like switch or transformator..
Comment: I was conected on switch L and L wire from swicher to transformator. And of course there is N, switch is working coreect, as transformator, input are 230v. And output os 75V*
Comment: My question is, can i now buy stadard transformator 230V to 75V (without dimmer), and conect that transformator.. and i will have then normal switcher for these led light?

LED lights in bathroom


Menus do not load on some pages

Question: I am attempting to correct an issue that has plagued me since setting up CiviCRM. The issue remains for me, even after upgrades. The issue is that on some pages within CiviCRM, the menu doesn't fully load, and ultimately renders a page useless. It occurs when I am going to the Civimail component and some other features. It isn't consistent. Here are two screenshots. The first shows the normal menu that appears on most pages. The second image is the image with the broken menu:
Answer: Sometimes it is worth visiting /civicrm/admin/menu?reset=1 and right clicking on any menu item, and then click Edit and Save so that you then get the message

Click here (/civicrm/admin/menu?reset=1) to reload the page and see your changes in the menu bar above.

Otherwise you can just visit that url directly. This may not help with your situation since it seems to be less consistent. But it may help others looking around for such advice
Answer: I've clicked around on the demo site (joomla.demo.civicrm.org) but I haven't been able to recreate the issue, sorry.
It could be a CSS/JS issue. Is there any custom CSS that could be interfering, or do you see any JS errors in the console when you encounter this problem?

Menus do not load on some pages


"Content types that are available to this Document Set have been added or removed" in SharePoint Online

Question: Question: I have a site collection that contains multiple sub sites with documents libraries inside. I need to update the documents set inside those libraries using code. It could be via CSOM, PowerShell or JSOM. I have tried multiples ways of updating properties of those Documents Set but it says  "Content types that are available to the Document Set have been added or removed". CSOM Document Set helper functions only work with SP 2010 ?How could I update properties on a Document Set targeting SP Online using code?
Answer: Using PnP PowerShell, I was able to update the properties of Document Sets using the following script. You can modify to suit your needs
<code>cls

Import-Module -Name SharePointPnPPowerShellOnline -Verbose

#Config Variables
$SiteURL = "https://mytenant.sharepoint.com/sites/SPOSite/"
$ListName= "SourceDocSet" #Name of the Library

#Connect to PnP Online - Use this for UserID/Password
#Connect-PnPOnline -Url $SiteURL -Credentials (Get-Credential)

#Use this to Login for multi-factor enabled tenant
Connect-PnPOnline -Url $SiteURL -SPOManagementShell

#examine the Internal names of the fields/columns
#Get-PnPField -List $ListName

#update the properties of a DocumnetSet by providing new values. Here, 4=ID
Set-PnPListItem -List $ListName -Identity 4 -Values @{"CustomDocumentType"="Health Record"; "_Status" ="Draft"}

</code>
Comment: Thanks , it works! Have a nice day
Comment: Glad to know that it worked for you. Please mark this question as answered if possible.


Value of gravitational constant $G$ and speed of light $c$

Question: In an Tolman Oppenheimer and Volkoff (TOV) equation of state for static equilibrium stars, if any one want to calculate pressure and density in $\mathrm{MeV/fm^3}$, then what is the appropriate choice for the value and the units of  constant $G$ and $c$. Are they both remain same as
$$G = 6.6743\times10^{-8} \quad\text{and}\quad c = 2.99792458\times10^{10}$$ as in CGS or $c=G=1$ as in geometrical units, or any other suitable value with their appropriate unit when Pressure and density is taken in $\mathrm{MeV/fm^3}$. (I think $\mathrm{MeV/fm^3}$ is a unit of pressure and density in Planck units.)
Answer: $\mathrm{MeV/fm^3}$ is a unit of energy density and a unit of pressure in SI-compatible units. In its full glory, it goes
\begin{align}
1\:\mathrm{MeV/fm^3}
&  = 10^6\:e \:\mathrm V/(10^{-15}\:\mathrm m)^3
\\ &  = 10^{51}\times1.602 \times10^{-19} \:\mathrm {C\:V/m^3}
\\ &  = 1.602 \times10^{32} \:\mathrm {J/m^3}
\\ &  = 1.602 \times10^{32} \:\mathrm {N/m^2}
\end{align}
If you want to calculate those quantities in that SI unit, and the rest of the quantities involved are in SI units, then you should use the SI values of those constants,
$$
G=6.674\:08\times10^{−11}\mathrm{ m^3\:kg^{−1}\:s^{−2}}
\quad\text{and}\quad
c=299\:792\:458 \:\mathrm{m \: s^{-1}}.
$$
If you want to start with CGS values and end up with an SI final quantity, then you should really convert the CGS values to SI and then work in SI, but you can also use $G$ and $c$ in mixed units (which is discouraged unless you know what you're doing).
Comment: If MeV/fm^3  is a unit of energy density and a unit of pressure in SI units then what we measure pressure in N/m^2 or kg/m*s^2.
Comment: @UmarKhan SI unit was perhaps a slight mischaracterization - the electronvolt is SI-compatible but not core SI. Note that $\mathrm {eV/m^3}$ is equivalent to $\mathrm {J/m^3}$ up to a numerical factor, and because $1\:\mathrm {J}=1\:\mathrm {N\:m}$, the units for energy density are identical to the units for pressure, $\mathrm {N/m^2}$.


Connecting Ceiling Fan

Question: Power source in fixture. Two 3-way switches. How do I get constant hot to ceiling fan and work the light with both switches.
Comment: We're going to need a fe pictures of the switch boxes and the ceiling box.
Comment: Can you post photos of the interiors of all boxes involved please? Are you limited to the cables that are there, or are you running new cabling?
Comment: I'm voting to close because OP is so vague that we can't possibly answer, and isn't adding the detail that is needed to help.  Also since the constant hot is already at the fixture, I suspect OP self-solved this with other resources on the Web. If not, OP please [edit] and it'll be reopened.
Comment: I understand exactly what he is asking. What we don't know is what he has available. Existing switches?... # conductors present?... Is this a new install?... 3-way already affecting both?... etc... Personally, I put mine on two sets of 3-ways; one for each circuit.
Comment: I got it figured out... thanks a lot....
Answer: If both switches are not working correctly someone messed up the wiring! We will need a schematic to figure it out.
A schematic is a explanation of the wiring in each of the switch boxes and at the light fixture.
Many times it is a simple screwup when a new switch was installed the person swapped the common with a traveler .
We need pics or a full description, but can help, @harper has some good 3 way posts if you don't want to provide photos reading up on one of these will give you a path forward.
Comment: I have a feeling that's what OP did... self-solved.

Connecting Ceiling Fan


Rap, R&B, Rock, and Pop (mixed together in a song)

Question: Is there a name for the genre that mixes Rap, R&B, Rock, and Pop together (in the style of Vanilla Ice, Lil Wayne, Metallica, and Michael Jackson... ), all in one song?
Are there significant artists working in that genre?
Answer: The fusion of rap and rock is called, pretty predictably, "rap-rock."  Some of the better known artists who work primarily in that style are Rage Against the Machine, Limp Bizkit and Kid Rock.
The fusion of hip-hop and R&B represents a large percentage of contemporary black American music (see my answer to this question), so much so that it doesn't make sense to pick out individual artists.
For artists who are known for combining that entire range of different styles with a pop sensibility, you might try Outkast (Bombs Over Baghdad), Janelle Monae, Red Hot Chili Peppers, the Offspring, Beck, the Roots (The Seed 2.0), Mary J. Blige, Frank Ocean, Beyonce and Kanye West.


Is it fine to slightly overfit, if its giving you good predictive power?

Question: I have 2 variables which have a correlation of about 0.51. In the test dataset the estimate of one is changing from +ve to -ve. But keeping both of them in model is giving me good predictive power. Is it fine to keep both of them in model? or it might to lead to some wrong results?
Comment: How do you know that your model is overfitted? If an "overfitted" model is giving you truly better predictive power (no cheating, honest out of sample assessment) than some benchmark "non-overfitted" model, I would suspect that the "overfitted" model is actually non-overfitted but rather the "non-overfitted" benchmark model is actually underfitted.
Comment: "In the test dataset the sign of one is changing from +ve to -ve" - what do you mean exactly? A little more detail about the process you're following might be helpful.
Comment: If it's improving your predictive power then it's not "over"fitting, *by definition*...
Comment: Colinearity is your problem not overfitting?
Comment: overfitted, because the estimate sign is becoming -ve with other variable, while actually in partial regression with only that variable it holds a +ve sign. or in other words, with that variable, it holds a -ve estimate, but if removed holds a +ve estimate!
Comment: Partial regressions are invalid when regressors are correlated.
Comment: @user1320502. doesn't collinearity leads to overfitting? is 0.51 correlation is high enough to be considered as colinear?
Answer: How do you know that your model is overfitted? If an "overfitted" model (let us call it model A) is giving you truly better predictive power (no cheating, honest out of sample assessment) than some benchmark model that you think is non-overfitted (call it model B), I would suspect that model B is actually underfitted while model A is

less-underfitted than model B or
non-overfitted or perhaps
slightly overfitted (but not as severely as model B is underfitted).

So I would say it is fine to use model A in place of model B if you have to choose one of the two.
Regarding whether to keep both predictors or drop one, I would suggest making the choice based on out-of-sample performance assessment. If a model containing both of them gives better forecasts, choose it.
Answer: Sounds like your issue is collinearity rather than overfitting, as user1320502 suggested in a comment.
Do you know where these two variables came from? For example, if one is $x$ and one is $x^2$, centering the variables may help.
If all you care about is predicting, collinearity is not a direct problem. But if you look at other things (confidence intervals, etc), collinearity will affect things.
You might look at similar questions like:
How to solve collinearity problems in OLS regression?
How to prevent collinearity? (the question is about preventing collinearity, but see Aleksandr Blekh's answer which talks about dealing with collinearity if you didn't prevent it in the first place.
Importance of multiple linear regression assumptions when building predictive regression models (see the OP's comment on Michael Bishop's answer: nested CV)
Comment: so the one variable is x and the other is (x+y),where y is not a constant.  The VIF is around 1.6,  when only those 2 variables considered, but goes up around 2.1 when other model variables are considered.


Help in composing music for spa or relaxation

Question: What are the important elements of harmony, rhythm and orchestration in composing relaxation or spa music?
Comment: Your question might not be answerable here. That said, there are many universal or near universal aspects to human psychology, which means the things that you find relaxing will probably be relaxing to many other people. Experiment and imitate music that you find relaxing.
Answer: Try sustaining the 1 and 5 of the key while you change the bass note.  Or try sustaining the tonic in the bass while the right hand changes chords.  Lots of sustaining things, lots of repetition.  Find a simple repetitive motif and repeat it o. Every chord change.
Here's how to know what chords go together.  Usually stick with the 1 2m  4. 5  and 6m
https://wordpress.com/post/ofonechord.wordpress.com/76
(I'm speaking from the perspective of a keyboardist, but you can take these concepts to other instruments.)
Answer: My immediate thought for archetypal 'relaxation' music would be the 'Ambient' genre.
a few tips if following this style:
harmony : you may want to avoid 'chord progressions' in the traditional sense. Exploring the possibilities within a single scale, but with a fixed harmonic root note or drone is common. It's often good to have some interesting and dissonant moments to prevent the music being too saccharine.
rhythm : you may want to avoid a strict pulse or percussive rhythm, but still have some sense of cyclic movement within the piece. Try to create patterns that are natural and unsurprising without being too predictable and oppressive.
orchestration : effects like reverb and delay, and synthetic sounds can help in transporting the user to 'another world', as can foreign / world instruments.
All this might sound like a complete cliche and a recipe for 'cheese' but it does somewhat depend how well you do it!
FWIW if I were going to a spa now I think I would like them to play me some Charles Mingus, which is a bit different to what I've described!
Answer: Anything using the major pentatonic scale as your melodic lead should come close to the relaxing compositions you're looking for


Signing transactions using metamask provider

Question: I would like to sign a transaction using the metamask provider so that the transaction can be sent later as a raw transaction. Is there any way to implement this in code? I believe that a metamask pop up would appear for the user to confirm signing the transaction
Answer: You can construct the transaction object and pass in the data to Metamask for signature via eth_sign. You can refer docs for more info.
Comment: Would provider.signTransaction work with ethers? Also web3?. I have some difficulty differentiating with eth_sign and the provider.signTransaction these would do the same thing?


How to calculate the minimun of Average Fixed Cost knowing the Average Fixed Cost

Question: Given the Average Fixed Cost, how does one calculate its minimum?
Comment: I'm voting to close this question because no effort and unclear about production and market structure leaving the question impossible to answer
Answer: As the quantity of output of a good increases, fixed cost (by definition) remains the same and therefore average fixed cost per unit of output continuously decreases.  Therefore the average fixed cost curve does not have a minimum, except in the sense that it is asymptotic to zero.
A much more important concept than average fixed cost is average total cost, that is, the average of the sum of fixed and variable costs.  This often has a minimum, but can be continuously decreasing when there are significant economies of scale.
Comment: This is what I had thought too, but an answer to one of the questions in a questionbook that I'm using says that  for AFC = Q^2 -10Q +50 + 72/Q the Average Fixed Cost is minimum when 2Q - 10 - 72/Q^2 = 0. This is odd to me because fixed cost doesn't depend on the quantity produced. Does the book mean ATC instead? Would you please tell me how it had calculated its minimum? Thank you.
Comment: @asdfghjkl  Finding the minimum from the given formula for AFC is a straightforward application of calculus, setting dAFC/dQ=0.  The problem is that the given formula for AFC cannot be correct (72/Q on its own would be fine).  Not having seen the book I can't tell, but it does seem likely that the formula was meant to be for ATC.  Fixed cost 72 together with variable cost Q^3 - 10Q^2 + 50Q would imply ATC = Q^2 - 10Q + 50 + 72/Q.


Is it better to call the doppler effect a change in wavelength or frequency?

Question: Why is it preferable to say that the doppler effect causes a shift in frequency rather than a shift in wavelength? I often read on websites that they define the doppler effect as a change in frequency.
Comment: Frequency is preferable as it doesn't change when the wave changes medium.
Comment: thats why as a counter example Stefan-Boltzman law and Weins law are in terms of wavelength.
Answer: The doppler shift causes a shift in wavelength at the origin of the wave (the frequency of the source never changes).  This results in a shift in frequency for the observer.
In the link below you can see the emission of the wave for a moving source causes the wavelength to be shorter in front and longer behind.  The actual source isn't changing in frequency.  So it's a matter of relativity.  To the traveling observer (in the source), only the wavelength is changing, to the stationary observer (experiencing the doppler shift) both frequency and wavelength have changed.

 Lookang, Wikimedia commons. More simulations and applets here.
Comment: In the case of a travelling observer is there any change in observed wavelength?(when the source is stationary)
Answer: For waves that are carried by a medium (sound waves, ocean waves, ...) one has to distinguish two cases

fixed source, moving observer : the wavelength is unchanged, but for the moving observer, the frequency is different because in his point of view, the velocity of the waves is not the true one.

moving source, fixed observer :  the wavelength is different, and the frequency is also different, since the velocity of the wave is the same.

The exact expression of the Doppler shift in terms of the velocity and the speed of the moving "partner" is not the same. I'm giving the expression for the frequency $\nu$ in terms of the original $\nu_0$ for speed $v$ of the moving partner and velocity $V$ of the wave
-Fixed source

observer moving towards the source $$\nu=\nu_0\  {\frac {V+v} V}$$
observer moving away from the source, $v\le V$ $$\nu=\nu_0\  {\frac {V-v} V}$$
observer moving away from the source, $v\ge V$ $$\nu=\nu_0\  {\frac {v-V} V}$$
provided the source has started emitting long enough before the observer overtakes it, and the observer has not yet reached the first wave emitted by the source

Wavelength unchanged
-Fixed observer

source moving towards the observer $v\lt V$ $$\nu=\nu_0\  {\frac V {V-v} }$$
observer moving away from the source,   $$\nu=\nu_0\  {\frac V {V+v} }$$

If the source moves towards the observer with $v\ge V$, the wave has not had time to reach the observer yet.
In all cases the wavelength is $V/\nu$. (Sorry that the character $\nu$ for frequency is so close to $v$.   ;)   )
The situation is different for light. The speed of light is always the same. The changes in frequency and wavelength are always reciprocal. But the expression of the Doppler shift in special relativity is still a third one !
For light, the velocity of which is always $c$, relativity tells us it does not matter which moves and which is fixed

observer and source getting closer $$\nu=\nu_0 \sqrt {\frac {c+v}{c-v}}$$
observer and source getting further away $$\nu=\nu_0 \sqrt {\frac {c-v}{c+v}}$$

In both case the wavelength is $c/\nu$
In the case where $v$ is  much smaller than $V$ (or $c$ !!) the three expressions for the frequency are very close, whether for source and observer getting closer or farther. Wavelength, on the other hand, changes in the same way for light and fixed observer, but of course does not change at all for fixed source.
Hence it is better to think in terms of frequency. For $v$  much smaller than $V$, the relative variation ${\frac {\Delta \nu } \nu}= {\frac \nu{\nu_0}}-1$ is always very close to $v/V$ for getting closer and $-v/V$ for getting farther. For light $V=c$.
Answer: In case of a travelling observer , there is change in wavelength,and the magnitude and sign of change in wavelength depends on the velocity of the observer. Let's say an observer moves towards a stationary source emitting pulses with a frequency of 'f' with a velocity vo . A pulse reaches the observer and by the next time a pulse reaches the observer, the observer will have traveled a distance 'vo/f' towards the pulse. Here , relative velocity comes into picture and so the wavelength changes due to the doppler effect.
Answer: The wavelength does not change but the relative velocity of sound changes so the frequency changes. When an object is moving, the velocity of the sound wave from the object is different for the observer and it is not anymore 330 m/s.


Local File Support Detection in JavaScript - Windows Phone 8 Bug

Question: I have a question about <input type=file> HTML element -- specifically, why all signs point to it being supported on Windows Phone 8 (IE 10 Mobile), yet it really doesn't work.
I have been working on a photo uploader project, and in the Javascript development, I have logic in place to check for File API support, so I know if I can support local file selection. Surprisingly, the code I have in place is returning a true value on Windows Phone 8. This shouldn't be an issue, however the <input type=file> element isn't really supported for WP 8 (as noted on the Windows blog in an article about IE 10 for Mobile). The result on a WP 8 is if an <input type=file> element is on the page, it shows up just fine, but nothing happens when clicking the "Browse" button.
My JS code to check File API support is:
function checkLocalFileSupport() {
   if (window.File && window.FileReader && window.FileList && window.Blob) {
       return true;
   }
   return false;
}

I'm hoping someone could shed some light on how to better check and confirm if local file selection is available on a specific device/browser. As I said, my current solution returns true on WP 8. I've been trying a variety of different methods to see if an <input type=file> is enabled (snippets below), but all of the other solutions still return true for WP 8.
One caveat is this: I really want the code to be device-agnostic. As such, I don't want to have to sniff for a browser user-agent. In my mind, user-agent sniffing is a fallback that I'd rather not have to implement.
Here are a few solutions I've found and tried, yet still return true on WP 8:
Referencing the disabled attribute on the input element:
function isInputTypeFileImplemented() {
    var elem = document.createElement("input");
    elem.type = "file";
    if (elem.disabled) return false;
    try {
        elem.value = "Test"; // Throws error if type=file is implemented
        return elem.value != "Test";
    } catch(e) {
        return elem.type == "file";
    }
}

Using jquery.support:
var support = (function(undefined) {
    return $("<input type='file'>")    // create test element
                 .get(0)               // get native element
                 .files !== undefined; // check whether files property is not undefined
})();

Hopefully someone can help shed some light on how to accurately get WP 8 to return a false value for local file support.
Thanks in advance!
Answer: According to this blog post some systems return false positive support and you can overcome this by checking them with RegExp such as
if (navigator.userAgent.match(/(Android (1.0|1.1|1.5|1.6|2.0|2.1))|(Windows Phone (OS 7|8.0))|(XBLWP)|(ZuneWP)|(w(eb)?OSBrowser)|(webOS)|(Kindle\/(1.0|2.0|2.5|3.0))/)) {
   return false;
}


Is there a bowler without a wide or no-ball in their international career?

Question: Is there any bowler with a minimum of 5000 delivieries in international cricket who has never bowled a wide or no-ball in their entire career?
Answer: When you search for this question the answer you will likely to get is Michael Holding bowling 5473 (900 overs) without a single wide and no-ball, and also Joel Garner who bowled 5330 deliveries without a wide (or a no-ball) in ODI.
From ESPN Cricinfo article:

Derek Underwood (21,862 balls in 86 Tests) and Garry Sobers (21,599 in 93) never bowled a wide or a no-ball. (It's just possible that some of these players delivered no-balls which were scored from, which would not have counted against them at the time so might have escaped notice; the practice of debiting no-balls and wides against the bowlers' analyses started in the early 1980s.)

But one week later another article from cricinfo clarifies that Michael Holding and Joel Garner do have bowled a no-ball and wide ball. But also states:

Charles Davis, the Melbourne statistician, believes the leader in Test matches is probably the Australian legspinner Clarrie Grimmett (14,513 deliveries in 37 Tests), who never bowled a no-ball or a wide.

So neglecting Michael Holding and Joel Garner other three may have bowled without no-ball and wide.


Underweight. What should I do?

Question: A girl, 16 and BMI is 16.8. I'm underweight and I really blank what to do since I cant really gain weight even if I eat A LOT, all that it does is making my belly bloat. I have a really tiny frames and my wrist size is just as big as my little finger (exactly). I have this problem when I only have appetite only and only if I'm surrounded by a lot of people, which makes it harder. I'm a muslim, so I cant really go to the gym. I have a bar but I cant even do one pull up :( Limited time and fasting month is just around, lesser energy :/
Comment: you say you don't gain weight, even if you eat "A LOT". How much is a lot (in kcal per day)?
Comment: Did you use the [BMI calculator for teens](http://apps.nccd.cdc.gov/dnpabmi/) or for adults?  If you are underweight you should make sure that your doctor has checked to see if there is a medical reason.  Your doctor may decide that you are healthy and your weight is appropriate for your size of frame and age.  Or they may do some tests.  Also consider not only how much you are eating, but what you are eating that causes your belly to bloat.  Ask your doctor for a recommendation for a dietician to help you set up a healthy diet.  Good luck.
Answer: Look you need to get more weight or add more mass to your body but it must not come from fat. Fats are terrible for you health. Muscles are great for your health, give you more strength and make you look better.
You will need both exercise and diet to get healthy weight:
To gain healthy weight you must start eating healthy. Eat more protein fibre and good carbohydrates. Eat fruits and veggies, and a lot of meat. expecially in Ramadan when you are not eating anything during day. waking up more at night and eating at night is good. Try napping during day and waking up much more early during ramadan. Eat some healthy food and then do some exercise like jogging before morning supper and then eat a lot of meat during morning meal.
You must do little running or walking to increase your metabolism and improve your bowel movements so you can eat more. And then you need to do a lot of exercises. Buy light dumbles, around 2 KG and do the exercises to target different muscles at home. You can find many videos on youtube showing easy/beginners' exercises to get beefed up.
n.b: I am talking about all-day long fast. During fast the asker can not eat anything during day.

Underweight. What should I do?


How can I reset my iMac G4 to factory settings without the startup disk?

Question: I currently own an iMac G4 that I bought from someone online. But now that I try to update it, it won't let me. The Safari doesn't work and I really just want to clean it up and really start from fresh.
Answer: You need to contact the seller and see if they have the original OS install discs, as they'll have iLife and a correct version of OS X. Barring that, try to get ahold of a set of retail OS install discs for anywhere from 10.3 (Panther) to 10.5 (Leopard). I'd suggest you get the newest your system will support. (It's important to look for retail discs so you don't have to spend extra energy trying to match your Mac's exact specs and model with the one the discs were shipped with.)
How to choose which disc to get if you can find multiple OS versions?

10.2 - iMac G4s shipped with as low as OS X 10.2 (Jaguar), but an OS install/upgrade disc won't necessarily have the drivers to support your machine, and some iMac G4s may simply be too new for 10.2 to support them at all.
10.3 - This is the lowest you should go if possible. Look for install DVDs (rare) or packs of install CDs. (I think there's two or three CDs to install the OS.)
10.4 - Make sure you get a retail version of 10.4. This is when Intel Macs were introduced, and an Intel Mac's OS install disc will simply do nothing in your PowerPC iMac. Look for DVDs. (Code-named Tiger.)
10.5 - Not all iMac G4s support 10.5 (Leopard). Anything with a processor slower than 867 MHz won't get Leopard. If you have an 867 MHz or faster CPU, you can use any retail Leopard DVD (these discs are for both Intel and PowerPC). As with Tiger, be wary of system-specific install discs, as most (if not all) Macs that shipped with Leopard were Intel Macs.


Reset Windows Spotlight

Question: I am using Windows Spotlight on the lock screen of my Windows 10 laptop, and I have accidently liked some photos, and the keep coming up. is there a way to 'change your mind' about a photo, or just reset the whole thing?
Comment: Have you tried simply switching windows spotlight off, restarting the machine and the on again??
Comment: help pretty please?
Comment: no I didn't, and I don't have spotlight anymore so I cant test it sorry :)
Comment: I have provided this feedback to Windows - please upvote: https://aka.ms/Qjjldf
Answer: I was also frustrated by this very same issue with the Windows Spotlight Lockscreen image on Windows 10.
Being unable to "change your mind" after having previously selected either "I want more" or "Not a fan" is a real pain. I've described below what worked for me. It may not be a full solution, especially if Microsoft change the way Spotlight works, but for now it seems to be a good enough work around.
WARNING: This involves changing values in the Windows Registry so be warned that it is generally considered a dangerous practice if you're not sure of what you're doing. Proceed at your own risk. Don't hold me liable if you break your machine.
The basic idea is that the current lockscreen image is stored at the following registry path:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Lock Screen\Creative

Open the Windows Registry
Follow the registry path:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Lock Screen\Creative
Find the key "CreativeJson" and double click on it. The 'Edit String' dialog will open.

Go to the 'Value data' field. It contains a rather long json string with parameters affecting how the lockscreen image operates.
Start scrolling through the json string from the very left and you'll find a lot of key-value pairs in there including: "creativeId", "placementId", "impressionToken" among others. (These are not very useful for what we need, but i've pointed them out just as a check-point to see if you're on the right track)
The important ones for this process start approaching when you see "onHover", "onPositiveFeedback", "onNegativeFeedback" and the one that will solve our problems 'feedbackProvided'.
If you've previously given feedback it will have  value of "true". If you have not it will be "false". So in our case where we want to change the decision we made, it should already read "true", so it will involve changing the value from "true" to "false".
Change this particular value and it should read now "feedbackProvided":false (NB: Don't change anything else. The entire rest of the string should remain the same)

Once you've done this click "Ok" and you can close the registry.
If you lock your screen now the current image should now allow you to make a choice again.

Note: As this registry path holds the settings for the current lock screen image, several parameters will obviously change when the Windows decides to change the lock screen for you. I think among these many parameters they have some sort of "Time-to-Live" for the current lockscreen.
Note2: The location of where the images are stored is also found at the registry path mentioned above, but at the Registry Key "HotspotImageFolderPath". On most Win 10 machines at the moment, the default should be:
C:\Users\[USERNAME]\AppData\Local\Packages\Microsoft.Windows.ContentDeliveryManager_cw5n1h2txyewy\ LocalState\Assets
Update: Here is a Powershell script to update the feedback flag:
$creativeJson = (Get-ItemProperty 'HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Lock Screen\Creative').CreativeJson | ConvertFrom-Json
$creativeJson.cdm.feedbackEvents.feedbackProvided = $false
New-ItemProperty -Path 'HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Lock Screen\Creative' -Name CreativeJson -Value ($creativeJson | ConvertTo-Json -Depth 100 -Compress) -Force

Comment: In Windows 10 v1709 (build 16299.19), the "Creative" registry key does not exist anymore.
Comment: Hello from 9 months later. I ran into this issue and went into the indicated registry key, but I am unable to edit it! I have tried to run regedit as Adminstrator (although my account is already admin...it's my personal laptop). Clicking Modify on CreativeJson shows me an empty box. Other keys that I've spot-checked do appear to be editable, however. Any idea why this might be? Also, is it safe to edit via the Edit Binary Data option? I can find the spot in that box that I need to edit...I changed it to see if I could but didn't click OK.
Answer: I just encountered the same issue as described by Blazinator. And note: This is after having previously been able to view and edit the string..
However I can inform that THE STRING IS ACTUALLY THERE! It is just invisible, for some reason: But you can highlight and copy it: Here's how:

Press the [home] key to place the cursor at the start of the string.
then press both the [shift] + [end] keys to highlight the whole
string (you can't see it's highlighted but it is).
Press [ctrl]+[c] (or right-click and select "copy" from the menu").

Then you can paste the whole string to notepad and edit it there (Note: It'll be a good idea to de-select Word Wrap in the "Format" menu, or it might spur in some carriage return chars). And when done editing then copy and paste the whole string back (make sure to overwrite or delete the original (invisible) content).
In response to the original post, however: The "feedbackProvided" part of the string, reads "false" even though I have clicked the "like".. So my alternative solution for now is to simply replace the image file with a different image of the same filename. - Here's how:

Find the image file in the folder specified in Note 2 above and
copy it to a convenient location.
The images are .jfif format; simply add .jfif as extension and open
with some graphics program. (Tip: if you copy all the images and add
the .jfif extension to them all then you can easily spot which one
it is).
Then paste a different image over it and save.
Then remove the .jfif extension again, and copy it back to the
images folder, thus overwriting the original file.

That'll work too.
Comment: The 'Creative' folder at the end of the path 'HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Lock Screen\Creative' doesn't exist for me!

Windows 10 Professional (10.0.19042.662)

Reset Windows Spotlight


Blender 2.8 transparency & volumetrics?

Question: Can somebody walk me through the process of getting volumetrics and transparency working in EEVEE.
I recently hopped on from 2.79 but all my glasswork just isnt working.
I tried all the alpha channels and spent a lot of time searching but i can't find the thing im missing or doing wrong.
Included is a simple set-up that works in 2.79/2.80 cycles but not in 2.80 EEVEE.
Answer: Answer has been found here.
https://blenderartists.org/t/transparent-materials-workflow-from-cycles-to-eevee-from-2-79/1129207/5
TL;DR
Enable screen space refractions in your material under options.
Leave blend mode on opaque.
Ënable screen space reflections in your render settings under screen space reflection.

Blender 2.8 transparency & volumetrics?


Kirchhoff's second law intuition

Question: So Kirchhoff's second law states the sum of the emfs around a circuit is equal to the sum of potential drops. All explanations point to the conservation of energy. Fine. But why do electrons have to lose all their gained energy from batteries to the components. Conservation of energy would still hold if they lost a bit of the energy to components yet retained the remainder as kinetic energy as it passed back through the battery?
Comment: Intuitively, note that a battery has a fixed voltage. Thus, it theoretically always maintains the same difference in potential energy between its terminals. By definition, circuits just don't function in the way you described. The electrons will always lose the same amount of energy by virtue of the fact that they are traveling from one terminal to the other, but the way this is manifest varies based on the components they travel through.
Answer: $\newcommand{\vect}[1]{{\bf #1}}$
More than conservation of energy, this law is related with the fact that electric field is a conservative one, indeed, if $V$ is the electric potential, then in a static situation
$$
\vect{E} = -\nabla V
$$
therefore if $a$ and $b$ are two points and $\gamma$ is a path connecting these points, the work to move a charge $q$ from $a$ to $b$ is
$$
\int_\gamma{\rm d}\vect{l}\cdot (q\vect{E}) = -q\int_\gamma{\rm d}\vect{l}\cdot \nabla V = -q\int_a^b{\rm d}V = -q(V_a - V_b)
$$
If $\gamma$ is a closed curve, then this last term vanishes and
$$
\oint_\gamma{\rm d}V = 0
$$
And this is actually the reason behind Kirchhoff's second Law. Imagine that you split the path $\gamma$ into a bunch of segments $p_1\to p_2 \to \cdots p_N \to p_1$. This last equations ensures that after you measure the potential between consecutive poitns $p_i p_{i+1}$ and then add the values up, the result should be exactly zero

Kirchhoff's second law intuition


Is the blink drive essentially 'folding space' like in Dune?

Question: Although there are physical differences between the 'blink drive' used in the Dark Matter TV series and 'folding space' in Dune, are the concepts not basically the same?
Answer: Not especially, beyond that both are fictional methods of faster-than-light travel.
The Dune series does not focus on the exact mechanics of space travel -- it is not a work of hard science fiction, after all -- but the semi-canonical Dune Encyclopedia gives some tantalizing details. (Note that some of these details conflict with the Brian Herbert sequels, making this answer somewhat specific to the Dune Encyclopedia canon.)
To summarize:
The Spacing Guild implemented space travel using a form of the Holtzman suspensor-nullification effect -- part of the same set of fictional forces that were used to implement defensive shields and suspensors. Activation of the suspensor-nullification effect causes a large sphere ("no more than a kilometer across") to enter "the Void", a sketchily described extradimensional space.
Space travel took place on large spherical ships (presumably sized to fit within the range of the suspensor-nullification effect) called heighliners, under the control of the Spacing Guild. The heighliner is controlled by a group of Guild Navigators. They use the prescience provided by large doses of melange spice to predict and correct for disturbances in the heighliner's course.
I can't find much detailed information on the Dark Matter "blink drive" online, but from what I gather, it's unlike space travel in Dune in several crucial ways:

The "blink drive" is technological in nature. Space travel in Dune requires a biological element (the Guild navigator) to safely complete travel throughout most of the series. (The Dune Encyclopedia mentions that a computerized navigation system was eventually developed, but only in 14132, after the time period of the series.)
The "blink drive" is instantaneous. Space travel in Dune is not instantaneous -- it is faster-than-light, but still takes time.

 The "blink drive" can lead to time travel. No such effect is attested anywhere in the Dune series.
Comment: Looks like there is something missing at the end of the first bullet point :-)
Comment: the space drives in Dune do not require a biological element. Navigation however is the other side of things. The Butlarian Jihad outlawed thinking machines. A thinking machine could manage the navigation.
Comment: @Darren _Dune Encyclopedia_, under HEIGHLINER: "The neutrino circuitry, mandated by field mechanics, relied much more on sheer power than on the elegant geometries characteristic of modern craft. For this reason a heighliner was a simple, featureless globe."
Comment: The blink drive may not have been intended as a time travel device originally. It would seem that it was intended as a means to travel instantaneously to other regions of the galaxy and to explore the folding or warping of time and space (time-space continuum).
Comment: Are the Guild ships described as spherical in the encyclopaedia? I don't remember them being described in that much detail in the book (didn't really read many of the sequel/prequels). I recall them being cylindrical in one of the screen versions.
Comment: @Naib The _Dune Encyclopedia_ states that computerized navigation was not developed until 14132 -- after the death of Leto II.
Comment: @duskwuff that doesn't dispute what I said ... the actual drive does NOT require a biological element. The navigation does
Comment: @duskwuff thanks. For the record, I wasn't disputing what you said, was merely curious. I wonder if there is a canonical source for the claim the ships are spherical.