Is there a shortcut to get to the bottom of a long email on iPad or iPhone?

Question: I get some long emails in which the important stuff is at the bottom after many pages. It is tedious to scroll down.  Is there a way to get to the bottom quickly? Either for iPhone iPad or both.
Comment: @lhf to go to the top of a page in safari is easy, just tap the bar at the top (where the battery icon lives)... going to the bottom, I'm in the dark there though
Comment: This is an issue in other applications in iPad and iPhone, for instance long web pages. I wish I knew a solution to both going to the bottom and to the top of a web page in Safari.
Answer: iOS does not provide a shortcut for skipping directly to the bottom of documents, but there is a reasonable alternative, if you're not already aware of it: scrolling views in iOS respond to swipe frequency, scrolling more quickly the more quickly and frequently you swipe the screen.
While swiping a long document, email, or webpage, try several long, quick swipes in rapid succession: you should notice the scrolling speed accelerate accordingly. This isn't nearly as elegant as a tap shortcut, but does let you quickly skip to the bottom of a long view.
Answer: I'm afraid no such shortcut exists.
Answer: You can create the following bookmark which will scroll you to the bottom of the page:
<code>javascript:scroll(0,document.getElementsByTagName( %22body%22)%5B0%5D.scrollHeight);
</code>
Source: http://www.ipadforums.net/ipad-help/69590-quickly-go-bottom-page.html
Comment: Welcome to Ask Different! While the link you provided may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. I've edited your question to include what I believe was the solution that you were referring to, however if it wasn't please quote the relevant section.
Comment: How does this help an iOS user?
Answer: Here's a workaround I just figured out:  Just make a comment at the top and bottom of the document.  When you view the top comment, you can then use the < in the comment navigation to quickly go to the bottom comment.  As mentioned before, you can quickly navigate to the top at any time by tapping the clock in the topbar.  Even if you make a lot of comments, you can always navigate < from the top to the very last comment.  You can also make comments as chapter, indexing, or placeholding markers and quickly navigate large documents.  Hope this helps!
Answer: Try double tapping at either side of the screen at the edge
Comment: Hi Kate and welcome to Ask Different.  In an effort to help improve your answer, you should consider adding some contextual information, explanations or links/references that give further detail as to why you believe your answer is correct.


SharePoint Designer 2010 Make Copy of NewForm.aspx

Question: How do you create a new copy of NewForm.aspx in SharePoint Designer 2010.  I would like to the customize  the copy.  I tried to copy the source code from the original to a new New Item Form, but that seemed to erase the original. Or, is there is a way for me to add fields to the New Item Form.  Thank you.
Comment: It is wise to fiddle with a copy of the form, good for you. But if you break it, don't panic. Copying the code from another list's form and substituting a few GUIDs sould help you out in that case. Just ask another question if that happens.
Answer: Open the file and then save it under a new name.
Comment: I have one more question please. Where do I save it to so that it will show up as an option under the appropriate list? Thank you.
Comment: Using this approach, the Save As dialog should default to the appropriate location.  You may then want to use the Forms list on the right side of the list properties page to set your default New form.
Answer: Alternatively you could use the browsing mode of SharePoint Designer and, at your preference, copy/paste or Ctrl+drag the NewForm.aspx file within the list's (or document library's) root (or Forms) folder. Then you could rename the files and in the list's properties choose the default item creation form as well as item display and item edit forms.
Answer: My personal preference is to create a new form from scratch -- leaving the original intact.  To do this, browse to your list in SharePoint Designer 2010, then click on "New" in the Forms list on the right.  It will ask you if this new form is for "New", "Display", or "Edit" and allow you to set the default form for each action.
A little additional info here.  If you want to customize the form (e.g. hide certain fields or change the order of the fields), I believe it is much easier to do that using a Data View Web Part on your New page or or a custom "Site Page."
Comment: Sometimes it's better to ask server or site admin to tune the fields and content types. Standard forms contain helpful html comments that might be of use when adding new client-side functionality using javascript. Those are lost when you use DataForm or DataView.
Comment: True, but since the poster asked if there was a way "to add fields to the New Item Form", I assumed he was needing something a little more than manipulating fields with jQuery.  I'm a big fan of jQuery on SharePoint pages, but there are definitely situations where a custom Site Page with a DVWP makes more sense.


How can I add another module to my existing Terraform deployment plan?

Question: I have deployed a project within Terraform. I need to add a 4th application module to my existing plan. How do I update my plan to include this 4th module and deploy the missing module without starting over? I thought terraform import might be an option, but I'm not understanding how it would be done.
Comment: @KamlendraSharma I have about 8 different applications (modules) I check out from Gitlab and I'm deploying different sets of them and I want to know how do I add to my existing plan if I do a terraform plan -target=module.nifi -target=module.kafka --out test1 - After it's deployed, how do I add another module to my plan and deploy just the new module?
Comment: Could you please provide more detail, what is your existing code state or how the code ( TF modules are ) is structured currently?
Comment: Why is adding a new module any different than adding a resource to an existing module?  In my view, there is no difference.
Comment: Terraform should handle this by default as it keeps track of deployments in a state file which is stored locally or in a configured backend so all you should need to do is run `terraform plan -target=module.nifi -target=module.kafka -target=module.other --out test1` and it should calculate the changes required based on the current state. Have you tried this? If so were there any specific errors?
Comment: You might want to include these modules in a top level module as using `-target=module` is not recommended as stated in the docs https://www.terraform.io/docs/cli/commands/plan.html#resource-targeting
Answer: Terraform is idempotent so will only change what needs to be changed.
So after applying your existing plan, if you add more modules or resources and run another plan and apply, it will add the new resources not the whole infrastructure.
Terraform import is used when you want to start managing a resource created outside your Terraform code for example created in the AWS console, AWS CLI).
It basically associates and existing resource with your new Terraform code, so that Terraform doesn't try to recreate it when you run the plan/ apply.
Comment: this should be accepted


Stock rom installation using twrp?

Question: I have a rooted Huawei G Play Mini. Boot loader is unlocked. Also, I have custom recovery (TWRP) installed. And, I need to upgrade my phone from lollipop to marshmallow. But, I do not have stock recovery back up. I can't find it anywhere. Tell me where to find it, or tell me how to how to install the official stock rom by using TWRP.
Answer: Before you do the upgrade, via TWRP, select backup> the select system, data (if you want yours apps), boot, and recovery. This will backup what is currently installed on your phone. Once this completes, go ahead and install the MM update for your phone. Do this within twrp as well to keep the custom recovery.
Comment: The thing is, TWRP doesn't acknowledge the `update.app` format of official updates.
Comment: You can use adb sideload in that case
Answer: Download the rom at http://download-c.huawei.com/download/downloadCenter?downloadId=79304
To install the rom follow instructions at https://huaweiflash.com/how-to-flash-huawei-stock-firmware-all-methods/

Stock rom installation using twrp?


Video encoders that display frame with most movement

Question: Are there any video encoders that can monitor multiple video frames and display whichever frame is the most active?  I would use this during a live streaming event and it would be great to automate the process.
Comment: Might be easier to suggest something if you explain the actual purpose?
Answer: This feature is called "motion detection" in the video surveillance jargon and can be found on most IP cameras and NVRs. There is a large variety of solutions out there depending on the level of accuracy that you need, the ability to divide the monitored perimeter into zones, whether the analytics run off a live or recorded feed, the OS that you use, and more.
If you look for something free and simple that just feeds you with XMLs then you might check Shotdetect. If you look for more of a "solution" then check motion, note that it is unix-specific.
It is also possible to use ffmpeg to extract thumbnails from your feed and run SNR comparisons on the fly, if you extract only I-Frames then the overhead is minimal. You are bound though to a detection rate that depends on your keyframe rate.
Try to provide some more detail regarding your operating system and overall use case for a more specific answer.
Answer: I assume you have multiple inputs and want some kind of automatic editing that will switch which feed is live based on what has activity at the time.  Unfortunately, pure changes in pixel values aren't really a super ideal way to tell what is interesting.
There are systems which handle automatic selection of the speaker such as Microsoft's RoundTable system which is able to recognize who is speaking based on position of the audio source and this kind of triggering is pretty common for source selection in things like WebEx and other meeting platforms.
You might be able to find something along the lines of what you are looking for in security software as well as security systems would want to display the most active frame.  In general, it probably isn't something you will find in most streaming systems though.  It would require a relatively high level of development to do well and the nicer streaming systems are going to be more about allowing an editor to directly control things as any high end stream is going to have a dedicated editor manning the console.


What is the purpose of the selected altitude/airspeed in ARINC 429?

Question: What is the purpose of the selected altitude and airspeed fields in ARINC 429?
Answer: Both labels are used to transmit the altitude and airspeed that are dialed into the Mode Control Panel of the autopilot. They are not necessarily the current altitude/airspeed, instead they are the target values that the autopilot is steering to.
Comment: so what is the altitude selected based on altitude? ground or sea level?
Comment: It is based on the barometric altitude of the pilot flying. So pressure altitude corrected for the altimeter pressure setting.
Comment: Thank you for help
Comment: @LeoAnggaraKrisna The current and selected altitude can be pressure (FL), true (MSL) or absolute (AGL). The autopilot doesn't care which; it will just fly the plane up or down as needed to make current equal selected.
Answer: DeltaLima very nicely covered the "what" of these labels. As to the "why", I have three examples of their uses:

Autopilot setpoints (altitude, airspeed, heading) are displayed on the Primary Flight Display for the pilot's situational awareness (and so that she knows when to stop when twiddling the autopilot control knobs)
They can be logged to a Flight Data Recorder for accident investigations, or a Quick Access Recorder for operational / maintenance purposes
They're transmitted by certain types of Mode S transponder with "Enhanced Surveillance" capability. If ATC is also suitably equipped (e.g. a lot of Eurocontrol airspace) the preselected altitude is displayed on their scopes and helps to prevent altitude busts due to miscommunication or pilot error.


Where are the save files located?

Question: I was hoping to transfer my Knights of Pen and Paper save information between multiple Android devices.  Does anyone know where I might find the relevant files?  My devices are rooted.
Comment: which version of android are you on?
Answer: If they're storing them in their private data directory then it should be something like:
/data/data/your.package/files where your.package is the package name of the app.
If they're storing them in their external storage directory then it should be in:
/sdcard/Android/data/your.package/files where sdcard is your external storage device.
If they're not storing them in one of those places then it's in a custom file on the external storage device.
UPDATE: I believe the package name for the game is br.com.beholdstudios.knightspp
Comment: You must edit owner rights /data/data/your.package/files and set it to allow writes and reads before your copie the data.kopp file.
Answer: Please note, that you have to have root access to get to this file.  When you plug your device into the computer, typically you won't be able to see the root directory of the device, instead you will see /sdcard
I'm not aware of a way to view the root directory of an android device using Windows Explorer (I know there's a way, I just don't know offhand)
If you gain root access, and use a file explorer, the file explorer will be able to traverse up to the root directory or /
There, you will be able to navigate to /data/data/br.com.beholdstudios.knightspp/files/data.kopp
Answer: I found data.kopp under /data/data/br.com.beholdstudios.knightspp
I was able to copy it to my other device under that same folder path and it loaded up my chars+game on the other device.
I was using Root Browser and both devices were rooted.
Answer: This answer may be specific to Android 4.
Short answer: you won't be able to find them. The word from Paradox is:

The save file is called "data.kopp", and should usually be located in
  /data/app/br.com.beholdstudios.knightspp/files/
However, it seems really hard to find on some devices, as it's a Unity
  compressed data file. If you can find it, you should be able to
  replace the new save file on your new device with the old file.

After spending about 20 minutes looking I was unable to find any file that was even close to that. Showing hidden files didn't help. I looked for any file named data.kopp and didn't find anything (except my old save file from the previous install, which would've helped if I knew where to put it to overwrite the new save).

Where are the save files located?


Are quantum effects significant in lens design?

Question: Over on Photography, a question was asked as to why (camera) lenses are always cylindrical. Paraphrasing slightly, one of the answers and follow-up comments asserted that quantum effects are significant and that you need to understand QED in order to understand lens design. My intuition tells me that this probably isn't the case, and that modern lens design can be handled via classical optical theory. Is my intuition correct, or are quantum effects really significant in modern lenses?
Comment: @AlanSE: There are good classical explanations for the refraction of light. See http://physics.stackexchange.com/q/65812/ . You only need quantum mechanics if you want a detailed explanation of how the index of refraction varies with frequency, and even then, you don't need the full machinery of QED.
Comment: My first thought was that QED is necessary to explain the refraction index to begin with.  There was a recent video that covered how QED is needed for this, and how it's actually quite complicated and non-intuitive https://www.youtube.com/watch?v=CiHN0ZWE5bk
Comment: From the point of view of lens design, I think that varying refractive index with frequency is more of an input to the problem than anything else (I have these materials with these dispersion curves, how can I minimize chromatic aberrations?) - it's not something the lens designer needs to understand, just something that is. Still a worthwhile note that classical optics can't explain varying refractive index though.
Comment: That is total nonsense. How did Steinheil or Abbe design their lenses?
Comment: @Georg two possible answers: 1) The usual combination of experience, intuition, trial and error and a little bit of blind luck. 2) It could be the case that while the lenses of 100 years ago were firmly in the classical realm, the lenses of today have started getting into quantum behaviour. Note I don't believe either of those answers, but what I believe is pretty much irrelevant :-)
Comment: @PhilipKendall Welcome to Physics, by the way! Feel free to come by with any more physics questions arising in photography.
Comment: It was appropriate if someone could estimate the error of not using quantum mechanics to design a lens.(it's not that hard to do it, and it shatters all the clouds)
Comment: ""@Georg two possible answers:"" No, there is a third: You do not know who Ernst Abbe was.
Comment: @Ali That would be an absolutely wonderful answer to the question :-)
Comment: @Georg Actually, I do. My point is that saying "that is total nonsense" without backing that up with facts isn't a helpful contribution to the discussion.
Comment: Philip, why dont You ask the guy in "photography" for facts first?
Comment: @Georg largely because it seemed better as a separate question, and because the discussion on that answer had already degenerated into a sequence of "yes, it is", "no, it's not" posts.
Comment: Using QED to calculate lenses would be like starting out with GR to calculate the trajectory of an apple falling from a tree onto a head:=)
Answer: Stan Rogers' answer on photography.SE seems to be claiming that QED is not just sufficient but also necessary to explain the the effect of the lens's shape. This is wrong. Ray optics suffices at ordinary magnifications, and even at high magnifications, classical wave optics suffices.
Let's say you use a rectangular lens rather than a cylindrical one. First off, the shape of the lens won't matter at all unless you have the aperture all the way open; on any slower setting, the approximately circular shape of the diaphram will be the determining factor. Assuming that you do have the aperture all the way open, the main effect, which is purely a geometrical optics (ray optics) effect will be as follows. You will have a certain depth of field. If object point A is at the correct distance to produce a pointlike image, then this point is still a point regardless of the rectangular shape of the lens. However, if object point B is at some other distance, we get a blur as the image of that point. The blur occurs because there is a bundle of light rays, and the bundle has some finite size where it intersects the film or chip. Since the lens is rectangular, this bundle is pyramidal, and the blur will be a rectangular blur rather than the usual circular one. For example, say you're photographing someone's face with a starry sky in the background. You focus on the face. The stars will appear as little fuzzy rectangles.
At very high magnifications (maybe with a very long lens that's effectively a small telescope), it's possible that you would also see diffraction patterns. In the example of the face with the starry background, suppose that we change the focus to infinity, putting the face out of focus. Wave optics would now predict that (in the absence of aberrations), the diffraction pattern for a star would be a central (order 0) fringe surrounded by a ring (first-order fringe) if you used a circular aperture, but a rectangular aperture would give a different pattern (more like a rectangular grid of fringes). In practice, I don't think a camera would ever be diffraction-limited with the aperture all the way open. Diffraction decreases as the aperture gets wider, while ray-optical aberrations increase, so aberration would dominate diffraction under these conditions.
Quantum effects are totally irrelevant here.
Stan Rogers says:

It's difficult to explain without launching into a complete explanation of quantum electrodynamics, but all of the light that reaches the sensor "goes through" all of the lens, at least in a sense, even if we're just talking about a single photon. A photon doesn't take just one path (unless you make the mistake of trying to figure out which path it took), it takes all possible paths. Weird, but true.

This is an OK description of why QED suffices for a description of the phenomenon, but it's completely misleading in its implication that QED is necessary. The word "photon" can be replaced with the word "ray" wherever it occurs in this quote, and the description remains valid.
Comment: +1 - I think this should be an answer to that question as well, as it's better than any answer currently there.
Comment: So, if the lens is not round, the world according to Stan Rogers explodes, because the single photon ends up out of focus with itself.  :) Thus, lenses must be round to protect the world. QED, by QED.
Comment: @Jens: The **diffraction** of light is explained by Maxwell's equations and the [Huygens–Fresnel principle](http://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_principle).  There is no need for QM.
Comment: I've seen it stated that the aperture when to small cause blur due to refraction. One source for this statement is here: http://www.kenrockwell.com/tech/macro.htm This would be an effect to be considered, that can't be explained by the ray model of light.
Comment: @JensSchauder I don't know how much of a camera person you are, but the general recommendation is to ignore Ken Rockwell entirely. He's very good at SEO and writing content which looks at first glance to be valuable, but not so good at actual correct information.
Comment: @PhilipKendall I'm aware of that, at least to some extend. But I've seen similar statements in other places. Obviously I haven't checked if they copied it from Ken Rockwell, nor if the statement is plausible. Although I should be able to do the later.
Comment: @JensSchauder: *I've seen it stated that the aperture when to small cause blur due to refraction.* This makes sense (assuming you mean diffraction rather than refraction), but with a small aperture, the noncircular shape of the lens would be irrelevant. I'll edit the answer appropriately.
Answer: Your intuition is correct, you don't need quantum electrodynamics to explain/model/engineer camera lenses.  When considering the propagation of light, the results of geometric optics can be interpreted in terms of path integrals, as Feynman does in his QED: The Strange Theory of Light and Matter, but this is not necessary for lens design.  Geometric optics itself suffices in most cases, but there are some design tasks which require an incorporation of the wave nature of light (or the application of empirical rules).  (Thanks @Matt J for this info)
Comment: This is mostly right, but geometric optics is not sufficient for designing a high quality lens (such as is routine in photography) with minimizes spherical aberration, chromatic aberration, coma, etc. These have to be explained with either phenomenological rules or (for a deeper explanation) with wave optics. That is why the last several editions of a very popular optics text (Born) have started out with wave optics based on Maxwell's Equations, leaving little or no time for geometric optics at all. But really, the rules suffice, there is only very rare need for QED in military applications.
Comment: @Matt J OK thanks for the input - I've modified the last sentence to reflect this.  But I'm curious - which military applications require the application of QED in optical design?
Comment: The example I was thinking of was with microwave optics -- and I didn't have the security clearance to hear much about it:( But you got the important point: such needs for QED in design are quite rare. Rare enough that we can be sure it is not needed for lens design. But I can't rule out the idea that reference to QED was needed to design the materials that go into designing stealth-technology either, since I don't know enough about how that is done. QED is the basic means of understanding the interaction of light and matter, after all. Yet phenomenological rules suffice for most engineers.
Answer: Well Phillip, I guess you ARE the original questioner on this site, and your real question seems to be is QED or any form of quantum mechanics needed in "modern" lens design.  So let me try again.
First some history. Significant lens design goes back certainly to the start of the 20th century; but the foundations go back much earlier.
Computation was an expensive chore, so "tracing geometrical rays" was time consuming.  Certainly, wave based diffraction theory was prohibitively expensive for "design" as distinct from research.
So much work was done on purely mathematical theoretical calculation of ray paths and aberration theory.   The Seidel aberration theory, was a great leap forward,
Now the actual math used is ordinary Algebra, and ordinary Trigonometry.  Euclidean Geometry of course.
Since ray tracing was time consuming; aberration theory was very important, so fewer rays needed to be traced.
Between WW-I and WW-II lens design was such that one could design an achromatic cemented doublet objective lens for a telescope or binocular, completely to manufacturing specs, by ray tracing just three special rays in two different colors.
That allowed correction for primary chromatic aberration, primary spherical aberration, and primary coma.
Eventually, this theory was condensed into a classic text book, that no optics designer should be without.  That is "Applied Optics and Optical Design."  By A. E. Conrady.  It is available in two paperback Penguin book for a few dollars.  The first volume material dates from his lecture notes from 1926.   It is an intensely equation filled text but as I said, simple algebra trig, and geometry, and he developed a formalism that many designers adopted even using it today (I do)
Now of course we have high speed computers in our pockets, and ray tracing is cheap.
Geometrical optics is a mathematical simplification that basically assumes that the wavelength is zero so diffraction wave effects don't occur.  So it breaks down when real practical wavelengths are used.   But the difference between the geometrical and the diffraction based calculations, doesn't affect many real cases, so the basic design is still done with geometrical ray optics, and the diffraction optics is used to polish things up, once a reasonable solution is reached.   And the mathematical aberration theory is till often used to establish a likely successful architecture.
The Seidel Aberrations; spherical aberration, coma, astigmatism, Petzval curvature, distortion, and then chromatic aberration, are all related, and you can specifically control each of them (given enough variables), but often, in modern design, the software can optimize spot sizes, or modulation transfer functions, paying no attention to the Seidel theory.   The successful result (if you get one) doesn't care whether you used aberration theory to achieve it, or whether you simply told the computer to find the best result.
BUT !  there are some serious "you can't get there from here" restrictions.  Little nuisances like the second law of thermodynamics, and failure to heed those will keep you from finding your answer, because you are asking for something that physics doesn't permit.
But I can't ever prove that you don't need QED to design any lens.  But as Einstein told us, you only have to identify A SINGLE CASE that does require QED, to prove me wrong.
Lens design is a very heierarchical discipline; so simple lens formulae, Seidel theory, geometrical ray tracing, and full diffraction theory, are used interactively.
It is well known at the university entry level, that geometrical optics predicts a different spot size from the true diffraction result, and moreover, the best spot image is in a different location.  But that is just icing the cake.
But get the Conrady books if you really are interested; I keep it at my elbow at all times.  Of course , Born and Wolfe is a well known text, and Warren J. Smith's "Modern Optical Design" is a must have text book.   I'll let you know if I ever have to use QED
Answer: Well camera lenses are NOT always cylindrical.  99.99999999 % of them are NEVER cylindrical.
They are usually rotationally symmetrical at least; but for the most part, it is the shape of the lens surfaces (which would be dead flat on a cylinder) which determines the optical properties.  Lens thicknesses are not unimportant, but the are secondary, to the curvature (1/r) of the surfaces.
As for QED, trying to use that for lens design, would be akin to making a hole in the garden to plant a seed, using a small nuclear bomb.
Geometrical ray optics suffices for 99 % of all camera lens design.   Very few camera lenses come anywhere near being diffraction limited.  A lot of them don't even get within a factor of ten of the diffraction limited spot size.   Telescope and microscope optics are a different story, and near diffraction limits is typical, specially for large telescopes.
Comment: I think you confused two meanings of lens: the more or less simple piece of glass vs the device attached to the front of a camera which is made up of lenses of the first kind + various stuff of metal, plastic, electronics. The later is in first approximation cylindrical.
Comment: What @JensSchauder said. I think everyone is aware that the actual bits of glass in a camera lens have curved surfaces.
Answer: You dont need QED because lenses can be any shape you want for example rectangular:
http://www.anchoroptics.com/catalog/product.cfm?id=20
Most important is a surface form not shape.
Comment: Sorry, I don't follow this. Why does the existence of rectangular lenses mean that quantum effects are not significant?
Comment: There is no restriction on the lens shape. That is why you do not need any theory for it. Only restricted parameter is form of the front and back surfaces. They are well described by classical optics.
Comment: But how do I *know* (other than your assertion) that the front and back surfaces are well described by classical optics? That's really the question here :-)
Comment: @PhilipKendall You do not know. There are tons of books on optics, you can create your own lens (there are many of enthusiasts in diy astronomy) and see that everything is fine :) Validity of the theory is about size of its objects -- "size" of visible light quanta is about 700nm so here you go. If you want lense that is 700nm small then you need to ask here again :)
Answer: On the one hand the answer is an emphatic no (in the sense that ray and wave propagation is valid). But ray optics and all the rest of it in a sense ARE quantum optics - Maxwell's equations are the first quantized description of one photon propagation through a lens system and raytracing / wave simulation are different approximations for solving this.
Although the equations are the same, it is helpful to think about this in designing things that transmit one photon states (or a sequence thereof) such as fluorescence confocal microscopy, see

J. Opt. Soc. Am. B/Vol. 24, No. 4/ April 2007 p 928
J. Opt. Soc. Am. B/Vol. 24, No. 4/ April 2007 p 942
J. Opt. Soc. Am. B/Vol. 24, No. 6/ June 2007  p 1369

These are paywalled, email me if you're interested.
Comment: Sure, everything is quantum if you look small enough. But if the classical approximations are good enough to design a modern camera lens, then it's not something the designer needs to know or worry about.
Comment: @PhilipKendal As someone who does actual design in this field, I would say that depends what you mean by a "camera". If you are imaging one photon sources or fluorophores, then it is very helpful to keep the basic physics in mind. In design of such things, it impacts more on the *specification* of imaging systems, rather than the model. Also, from a curiousity standpoint - haven't you ever wondered why raytracing is valid for one photon systems - not only is it a good approximation - but for some quantum states it is as good as anything else.
Comment: Fair point. I guess I'm primarily interested in what "most people" would think of as photography - visual spectrum imaging at focal lengths from a few mm up to maybe a metre or so. But I guess there's another interesting question along the lines of "are there any sorts of photography where quantum effects are significant?"
Answer: Besides classical optics, some high-end lens exploit (or suppress) wave effects, but no designs are influenced by considerations on quantum effects.
Answer: If you want to design lenses then no But if you want to understand how lenses actually work you would need to understand the QED theory of light. Also it is indeeed non intuitive but not very difficult.
Answer: The answer there seems to be a bit confused. It is true that you need to account for wave-like effects (i.e. interference and diffraction) to understand lens design.
However, these effects appear in both the classical field theory of light (Maxwell's equations/wave optics) and the quantum field theory of light (QED). Both classes of theories contain the basic phenomena of interference and diffraction, and the more subtle additional effects in QED don't play a role.


on 1989 f350, after turning ignition on to crank position, turn key to off and remove key, starter continues to crank . what is sticking?

Question: After inserting key and turning to start position, starter continues to crank after engine starts. You can turn ignition off and remove key and starter continues to crank. have replaced solenoid, ignition tumblers and starter. What could be sticking to cause starter to continue to crank?
Comment: If you disconnect the battery and reconnect it, does the starter run straight away?
Comment: yes, if you reconnect battery, the starter does run. i did not replace the switch, just the tumblers.
Answer: When you say you have replaced the ignition tumblers, I am presuming you have replaced the electricial switch on the back of tumblers, so let's forget about that.
Seeing as you need to initiate this by turning the key, it can't be a short somewhere.
If the starter is indeed being powered at this point, the only thing left that could cause this is the starter relay in the fuse box.
--UPDATE--
Since you didn't replace the switch, then the switch is also possibly faulty.  For simplicity I would first try swapping the starter relay in the fuse box for an identical one if there is one.  If that doesn't fix it, then the next thing to change would be the ignition switch.
Comment: @cloudnyn3  He said that he has replaced the 'tumbers', I am presuming he meant the whole thing including the switch.
Comment: I 2nd this. If the starter relay is malfunctioning, the circuit will be stuck closed so it will continue to try to engage your starter. Being an '89 it doesn't have any advanced computer systems to get in the way. Could it possibly be the ignition switch itself though??


Ball trapped without entering the hole

Question:
What rule should I apply in a situation like this. I know i very uncommon, but I should not touch the ball. Could be the plastic be considered a mobile obstruction? The ball is clearly inside the hole.
Comment: How does something like this even happen?!!
Comment: Reason # 123494 why those cup liners should never be used!  They are illegal to boot!
Comment: The plastic to support the border was broken. Don't have any idea how. It wasn't my problem either. Just looking for a solution..
Comment: Hilarious and bad luck. Never seen this happen before
Answer: Applying Decision 16/2 from the USGA Rules of Golf, this is considered holed (although it doesn't fit the definition of holed).

16/2 Ball Embedded in Side of Hole; All of Ball Below Lip of Hole
Q.A player's ball embeds in the side of a hole. All of the ball is below
  the level of the lip of the hole. What is the ruling?
A.The ball should be considered holed even though all of the ball is
  not within the circumference of the hole as required by the Definition
  of "Holed."

Definition of "Holed":

A ball is "holed" when it is at rest within the circumference of the
  hole and all of it is below the level of the lip of the hole.

Ball trapped without entering the hole


Showing cards head up

Question: One player goes all in one player  remaining the player turns his hand over before calling to try get a reaction out the player that has gone all in is this allowed
Comment: Mike Caro said that showing his cards at Showdown gets great reactions and has earned him tons of money. Explain that...
Answer: Depends on the game, customs vary between tournaments, cash games, location and  limits.
Answer: No. Players must not reveal their cards during a live hand unless a rule requires it.
A standard response is that any hand deliberately revealed when not permitted is dead. Further penalties can also be imposed.
Comment: Accidentally exposing live hands without permission, a warning and the opponent is not allowed to (re)raise. Nobody was ever daft enough to let it happen twice in a day. Deliberate exposure when not permitted? It never happened because players knew they'd be mucked. Not to mention the social stigma, let alone the chance of other formal penalties.
Answer: It is against the rules.  You cannot even announce your card(s) when the hand is live.
What I have seen with inadvertent is they can only call or fold. They cannot bet out or raise.
To award the hand is extreme.  It would be like a 1 orbit penalty.
There are dealers and floor men on this site that will hopefully weigh in.
Answer: In general it is against the rules ... I saw that at TV , not sure if it was EPT , but I think so , Hand was dead and penalty of 1 orbit .

Showing cards head up


How To Market A Series Of Books

Question: Recently, I have been browsing writing jobs in several renowned freelancer sites, and I often come upon cheap propositions for ghost-writing a series of books ...well if you like working for peanuts. I feel I can come up with a series of books, but what do they do afterwards? How can you market your own work?
Comment: Try getting an agent? Send your work off to a publisher, with the help of an agent.
Comment: This question is unclear to me; I'll put it on hold, and let's clean it up.
If I understand you correctly, you're considering going into ghostwriting? You ask "what do [the series of books] do afterwards," but I don't see how that applies if you're ghostwriting for somebody else? You ask "How can you market your own work"; how does that relate to the propositions you find on freelancer sites?
Comment: Also, can you tell us what kind of book you're talking about? Fiction, non-fiction, memoir, children's books, something else?
Answer: Reach out to book bloggers and offer them a free copy of your work in exchange for an honest review. If you have a series of books, offer the first one for free on Amazon whenever they allow it. This is an easy way to capture sales for the later books. You can also arrange a blog tour in order to promote your work, but if you are completely unknown you may have to pay for it.
Get involved in the community of authors and readers online. The challenge of self-publishing is always to get your book in front of it's audience. If you have a relationship with other fans, it's easier to do this.

How To Market A Series Of Books


Generating sleepers for railroad track

Question: Using this object as bevel curve, it is easy to generate railroad tracks. Now, how would you do add sleepers at regular intervals along the track?
Comment: with dupliframes for example?
Answer: Array modifier springs to mind as sleepers are somewhat of an array. It does however depend upon the way you want to extract (excuse my use of language, English is not my native language) your track.
If you intend to make some straight track, I would first create the tracks, 60 cm looks kind of right. Create a sleeper next and join it all as one object (sleeper as "root" works fine for me). I hope the included pictures enlighten you a little.

A straight track might look like this and can use an relative interval of 1:

To create a curve, this method is to crude: you get a lot of jagged connection, though if the track is only a very minor part of your scene, it might work. I reduced the interval to 0.95 to avoid gaps in the outside curve.

As you may see from my examples, I replaced your nice track-profile with a fairly crude modified cube.
I hope this helps you a little, kind regards, Christiaan
Answer: Chaining the "Array" modifier and the "Curve" modifier solves the problem. The sleeper mesh should be aligned with its longest side in the y direction.
Answer: If you're being picky, and want continuous track and no curve-distortion on the sleepers.. you could use Dupliframes.

Create the curve that will be the route
Create a single curve (with two identical splines) that will be the profile of the rails
Create a solid (cuboid) sleeper

Here, looking down in Z, the sleeper oriented as you would expect, with respect to the rail profile.
The objects are to scale with the route curve. Ensure CtrlA > all transforms are applied, and the objects therefore share a pivot point at the origin.

Now Set the rail profile as the Bevel Object for the route curve in
its Data > Geometry panel.
Set an animation length of the number of sleepers you want to lie along the track
Assign a 'Follow Path' constraint to the sleeper object Target: the route curve, 'Follow Curve' checked, Forward:Z, Up:Y. The sleeper should jump to the route. Do not hit 'Animate Path' for this method.
At Frame 1 of your animation, right-click > keyframe the 'Offset' field of the constraint to 0, and at the last, key it to the last frame number.
In the sleeper's Object > 'Duplication' panel set the duplication to 'Frames'.

Note that you can not key the 'Offset' field if the sleeper 'Duplication' is set; put it back to 'None' to make revisions.
You may need to  select a sleeper, and go into a Graph Editor window to set the animation curve of its constraint offset to Linear, to prevent an ease in and out of the number of sleepers at the beginning and end of the route. Select its 2 Keyframes, and hit T > Linear.

To make the Duplis into instances, you can hit CtrlShiftA > 'Make Duplicates Real'
It's possible this method is too much fuss for the difference it makes.

Generating sleepers for railroad track


Apollo CSM RCS maximum number of simultaneously active engines?

Question: Reading the RCS subsystem manual, it seems like each RCS quad of the Apollo SM consisted of four hypergolic engines. Am I correct in saying that all four engines of each of the four quads could be fired independently of one another, i.e. in any combination? Note that I am not asking whether the control software did it this way, but whether the physical RCS propulsion subsystem was capable of firing all four engines per quad, and all four quads (i.e. a total of 16 engines) independently and in any combination.
Comment: @space_voyager- mis-comm: **page** 2.5-5 is in section 2.5.1, specifically figures 2.5-2 (auto) and 2.5-4 (direct).
Comment: @amI: You are correct that figure 2.5-4 shows the wiring for direct control.  But look closely; *there aren't switches for each individual thruster.*  The lower-right corner shows the limit switches for the two rotational hand controllers.  The lower-left corner shows abort-mode logic.  Lower-middle is for the direct ullage manuever.  The "switches" in the middle are the transfer switch between SM and CM RCS.  At top is the SM separation logic. (cont...)
Comment: Note that the CM needed to purge (burn) its hypergolics during abort or normal re-entry (after parachute deployment at 24000 ft) which it did by firing 10 of its 12 jets simultaneously (which might take a minute and a half to deplete the fuel and oxidizer after firing valve squibs to join the redundant systems).  As for the SM, the automatic system's relays would never simultaneously fire opposing thrusters, but there was also full manual control of each of its 16 thrusters.
Comment: @amI: ... Also look at figure 2.5-5 on the next page, a table which shows which inputs fire which RCS engines.  You will see that everything is *exactly* as I describe in my answer.  You simply cannot fire both the +pitch and -pitch engines at the same time, because you can't move the control stick to the opposite extremes (up and down) simultaneously.  (Similarly with yaw and roll.)  So the best you can do is manually fire half the engines.
Comment: What documentation says there was full manual control of every individual thruster?
Comment: @space-voyager- https://history.nasa.gov/afj/aoh/aoh-v1-2-05-rcs.pdf  :
 SM2A-03-BLOCKII-(1)  Section 2.5-5  RCS Direct Control.
Comment: 2.5.5 doesn't seem to have direct control there?
Answer: Service Module RCS: 8 max

There are 16 engines total, arranged in four groups of four ("quads").
You can fire 8 of the engines by placing the Direct RCS switch to ON, and then turning either rotational hand controller to its extremes in all 3 axes (pitch, yaw, roll).  Each axis of a rotational controller has limit switches that are activated when the controller is twisted 11° from the center position.  These limit switches directly fire the corresponding RCS thrusters when Direct RCS is on, overriding the digital guidance computer and the analog stabilization and control subsystem.
Various programs of the guidance computer could theoretically fire up to 8 of the RCS engines at a time, but rarely did so in practice.
The stabilization and control subsystem also could theoretically fire up to 8 of the RCS engines at a time, but rarely did so in practice.
The 4 aft-facing engines could be manually fired as a backup ullage maneuver, using the sequential events control subsystem.
When the service module main engine was fired, the pilot could steer the craft using the rotational hand controller.  Rolls would activate 4 of the RCS engines.  Pitch and yaw was controlled by gimballing the main engine.
During SM jettison, the SM jettison subsystem fired the 4 forward-facing engines.
The minimum impulse control could disable (but not turn on) all of the RCS engines in a selected axis.
I haven't found any way to activate all 16 engines at once.

Command Module RCS: 10 max

There are 12 engines total: 3 axes x 2 in each oppositional pair x 2 redundant systems.  Two of these (the $-$pitch for both systems) are near the tip of the cone (fore), near the parachutes.  The remaining 10 are along the sides of the cone, near the base (aft).
The system was only used for launch abort and re-entry.  The fuel and oxidizer tanks were kept unpressurized until these events occurred.
A launch abort was initiated by turning the T-handle of the translational hand controller 17° counter-clockwise.  Among many other things, this would dump the CM RCS fuel and oxidizer out two blowout holes.
During re-entry, the rotational hand controller would control the CM RCS engines.  At 24,000 feet, this manual control was disabled.  After the parachutes were visually confirmed to be deployed, the RCS Dump button was pressed.  This fired the 10 aft RCS engines simultaneously, depleting the propellants.
Comment: What is your source? Your answer suggests that this is the engine count in "practical" application (by a human or an automatic control law). However, my question is not about whether the software ever fired 16 engines, but if the physical propulsion system is setup such that it could technically allow for it (wasteful or not).
Comment: SM is from filename "CSM19_Stabilization_&_Control_pp189-204.pdf", entitled "Guidance and Control", pages 189-204 of some larger document.  I downloaded it months ago and have lost the source URL.  CM is from the link in your question.  *Both* files appear to be sections of a larger document, probably the same document.
Comment: As far as if it is physically possible, one can only speculate, because there's no way to generate the control signals to fire all 16 engines simultaneously.  It would depend upon having enough pressure in the system to do that.  Considering that the CM could easily fire 10 of 12 engines to depletion, it's likely *yes* that the SM could fire all 16 engines.
Comment: Thank you. I accepted this as the answer based on your clarifications about @aml's comments
Answer:
Am I correct in saying that all four engines of each of the four quads could be fired independently of one another, i.e. in any combination? Note that I am not asking whether the control software did it this way, but whether the physical RCS propulsion subsystem was capable of firing all four engines per quad, and all four quads (i.e. a total of 16 engines) independently and in any combination.

Yes, each of the four thrusters in each quad was independently controlled.
Some combinations wouldn't occur in practice, naturally (like firing the +X and -X thruster in the same quad, which would cancel out, wasting propellant to no effect), but the control software would dynamically activate whichever thrusters it needed to in order to orient or translate the ship. For example, activating the +X thruster on one quad and the -X on the opposite quad would turn the ship, while activating the +X on two opposite quads would move it forward.


What is the Latin and Greek phrase or word for golden chariot?

Question: I am currently writing about the ancient Greek and Roman gods, and I am looking to find the correct phrase for a chariot drawn by four horses made of gold. The closest I have come using google is khrūsoûs tethrippon (χρυσοῦς τέθριππον) /quadriga aureolus. Also, any help in a possessive adjective, such as Helios' golden chariot would be extremely helpful.
Answer: I think the Greek for Apollo's golden chariot would be ἅρμα χρύσεον Ἀπόλλωνος. I don't think Apollo's chariot would be τέθριππον, which means "four-horse," since it's actually pulled by swans.
I get the impression from WP that Helios was not really a big deal in classical Greek culture until the Romans exerted an influence back on the Greeks. But if you really want Helios with the iconography of the four horses, then I think it would be τέθριππον χρύσεον Ἠελίοιο. The word for the god is just the word for the sun, so this is "the four-horsed, golden chariot of the Sun."
Comment: For my purposes, I am treating Helios and Apollo as two separate deities, so both terms you shared were equally helpful. Apollo's chariot can be pulled by swans while Helios' can be pulled by horses.
Answer: aureus currus = golden chariot    (in Latin)
Answer: From Pausanias's Description of Greece II.3.2:

Ἐκ δὲ τῆς ἀγορᾶς ἐξιόντων τὴν ἐπὶ Λεχαίου προπύλαιά ἐστι καὶ ἐπ᾿ αὐτῶν ἅρματα ἐπίχρυσα, τὸ μὲν Φαέθοντα Ἡλίου παῖδα, τὸ δὲ Ἥλιον αὐτὸν φέρον.
For anyone leaving the forum on the road to Lechaeum, there is a gateway, and on top of it are gilded chariots, one carrying Phaethon son of Helios, the other carrying Helios himself.

(Translation mine.)
Which seems like good ancient evidence that Helios had a ἅρμα, not a τέθριππος. The real one, presumably, would be χρυσόν (gold) rather than ἐπίχρυσον (gilded).


My Citroen C3 2010 model has a problem starting all off a sudden

Question: It was due for service and i did not take it in, so immediately when it reached a 1000 km without service it stopped starting. i need to kick start it for me to start it. I'm not sure if its the battery or the starter because if the diagnosis doesn't show the issue at hand. can this mean if i take it in for service it will start?
Comment: Welcome to Motor Vehicle Maintenance & Repair!
Answer: The lack of service and it not starting will most likely have absolutely nothing to do with the other. There are no presets within the vehicle which tells the car to shut down when xxx amount of miles has accumulated. It is not the intent of a car manufacturer to leave you stranded because you didn't do the maintenance. Some people never do maintenance and they are still driving around in their vehicles (albeit doing tons of damage to their mechanical parts!).
Your problem lies elsewhere, though if you took it to the shop to get the service(s) done, they'd most likely be able to fix your car for you as well ... for a price.


How do I model a crumbling egg yoke?

Question: Does anyone have an idea how I can create a realistic looking hard boiled egg yoke, it has this rough and crumbling texture and if I were to model it by hand it would take forever and propably wouldn't look random enough. I can't find any egg yoke texture on the internet and don't know much about creating one on my own. Maybe on of you can help me with this, thanks.
Answer: I solved the problem by using using a texture made for clay and editing the colour to orange. I also tried some things out with the normal map, you could propably do a better job if you just create your own normal map and put an orange image texture on it.

How do I model a crumbling egg yoke?


Wordpress Bloated "session_token" in MySQL Database

Question: I'm running a wordpress site on a vps. My site has too many users using the wordpress login, so every couple of days the site login form stop working and keeps redirecting the user to the login form again and again (not to the dashboard).  After investigation and trying to figure out whats going on i logged into phpmyadmin and found out that the "session_tokens" field in "wp_usermeta" was getting bloated (i.e. too many connections/idle connections). I just cleared all values and everything started to work.
Now i'm looking for a way to clear that field from mysql db every 12 hour. I looked up Wordpress code reference (
https://developer.wordpress.org/reference/classes/wp_session_tokens/destroy_all_for_all_users/) and found a function that destroy all session tokens for all users.
final public static function destroy_all_for_all_users() {
    $manager = apply_filters( 'session_token_manager', 'WP_User_Meta_Session_Tokens' );
    call_user_func( array( $manager, 'drop_sessions' ) );
}

If there is a way to create a simple php file that i could run every time to clear this will be great (I can then create a cron job), but I'm not sure if that's possible or how it can be done. Any help is appreciated.
Thanks.
P.s.I did try a plugin to logout idle connections, but that didn't help at all.
Comment: Create a trigger in the db would be one solution, or an event set to delete the records every 12 hours
Comment: @RamRaider How can i do that? I sometimes use delete FROM `wp_usermeta` where meta_key = 'session_tokens' in phpmyadmin console to clear the values but how can i create an event to execute it every 12 hours'?
Answer: WordPress has the ability to schedule cron tasks built in, since there's a WordPress method to clean the sessions out it would make sense to use WordPress to schedule it as well.
https://codex.wordpress.org/Function_Reference/wp_schedule_event
The syntax of the function is:
<?php wp_schedule_event(time(), 'hourly', 'my_schedule_hook', $args); ?>

The method you need to call to clear your session data is:
WP_Session_Tokens::destroy_all_for_all_users();

Create a function with the logic inside and pass it into wp_schedule_Event along with when you want it to begin, how often you want it to occur and whatever other arguments you need.
Answer: An untested event as demonstration:
create event `evtDeleteSessionTokens`
    on schedule
        every 12 hour
    on completion preserve
    enable
    comment 'delete stale tokens every x hours'
    do begin
        delete from wp_usermeta where meta_key = 'session_tokens';
end


How are salt values more secure?

Question: If a database stores password encrypted by using salt values, how are they stored?

I read somewhere, it uses timestamps.
So is the timestamp also stored?

How about when a user tries to login next time, then how are timestamps considered?
Comment: I think this answer has what you're looking for: http://crypto.stackexchange.com/a/1772/17754
Comment: Note that "using timestamps" is very bad, unless the timestamp was an input to some function that generates the salt, then that is acceptable. A future salt should not be predictable to an attacker.
Comment: \$alg\$salt\$hash is a common way of storing hashes in a database, so a typical database field may look like \$apr1\$h7Fb0iS3\$24a7435b994b0bf6ea99155ac24747ec
Comment: think of a salt in terms of door keys; adding more "cuts" to the key makes picking the locker harder; even if the cuts aren't pinned, it still becomes harder to rake the back of the now-deeper cylinder.
Answer: Salts are generally stored in the database with the password.
They shouldn't be timestamps, salts should be random values of 128 bits or more (though this may vary depending on the hashing scheme used.)
Salts improve security by making brute force attempts single-use: a password of "password" is likely going to be used many, many times. If it's hashed without a salt, then an attacker will instantly know which users used "password" as their password when they hash it. By hashing it with a per-user random salt an attacker will need to try at least one guess for each user, and hopefully several guesses. So salts help protect users who reuse passwords (there aren't that many hashing schemes) and users who choose bad passwords (attackers have to try all the bad passwords with each salt, instead of just trying them once.)

How are salt values more secure?


Make a spherical background image

Question: How do I make a spherical background image from a Blender model, for example a city at night, rendered onto the inside of a sphere for use as a background?
Comment: Why do you not want to use a skybox? It gives you the same result http://math.hws.edu/eck/cs424/notes2013/webgl/skybox-and-reflection/skybox.html and is easier to setup.
Comment: This can be achieved with a Cycles equirectangular camera. I'm on a phone now—will post more info when I get to a real computer if this question is still open.
Answer: This is similar to the question asked here: How can an equidistance, spherical panorama image be generated from Blender Cycles? See the answer for information on setting up a Cycles-based equirectangular camera.
As Leander mentioned: If you prefer to use Blender Internal or the Blender Game Engine, a Skybox is probably your best bet (simply render six 90º FOV square images, then make a cube out of the results and use that to surround your scene.

Make a spherical background image


Is unemployment benefit part of national income measurement?

Question: Since unemployment benefit is a form of government spending, which is a component of aggregate expenditure, then shouldn't unemployment benefits be part of national income measurement?
Answer: It is included. It is a transfer payment, so the trick is to ensure that the income flow is only counted one time in the national accounting.
Statistics Canada, National Gross Domestic Product by Income and by Expenditure Accounts link to description

The Income and Expenditure Accounts record the distribution and use of
  income by the six main institutional sectors: households, non-profit
  institutions serving households, general governments, non-financial
  corporations, financial corporations and non-residents. These accounts
  articulate revenues to the sector (including current transfers from
  other sectors, such as employment insurance received) and current
  expenditures of the sector (including transfers to other sectors, such
  as income taxes paid to government).

("Employment insurance" is the Canadian equivalent of unemployment insurance.)


Tomato plant-Yellowing of older leaves with necrosis of green leaves- flowers falling off without fruiting

Question: The Internet has led me to suspect this is a nutrient issue but I can't figure out which nutrient or if that's true. This is a cherry tomato plant. It gets moderate sun- direct sun for about 3 hours per day in Southern California. It has been chilly here lately (~65 day, ~55 night) and randomly ~75ish. This plant was last fertilized 3 weeks ago with Jobes tomato spikes. Brand new leaves show no sign of disease- new leaves at base of plant show no sign of disease. Some flowers fruiting, others drying up without fruit. The lower leaves yellowed completely in 3 or 4 days. Upper leaves appear dry and have small light brown thin spots- not concentric circles. Other leaves have holes- usually the holes are in the center areas of the leaf and do not affect the tips of the leaf.

[![leaf damage][3]][3]
Comment: 75% humidity today. Weather has been pretty stable recently.
Comment: Something eating/attacking the roots?
Comment: @SuzanSucro What kind of humidity or aridity do you have?
Comment: [detailed pictures](http://m.imgur.com/a/FYZLK)
Comment: @SuzanSucro I made some more important additions to my answer.
Answer: I don't think it's the temperature. Colder temperatures (50F) stunt a plants growth. A deficiency/excess occurs when a plant is growing and there is a nutrient imbalance within the uptake. 55+ is okay (not great) for tomatoes, 60+ is better.
That amount of pest can't be ignored, it is certainly affecting your plant's overall health.
Yellowing of older, bottom leaves on a tomato plant is typical. Yours are yellowing a bit too far up to be considered normal.
Brown spots can mean a variety of issues. Typically nutritional problems affect leaf tips before they spot, but in seedlings it's not uncommon for spots to occur and in established plants it's not unheard of either. Still, brown spots on established plants, not on the leaf tips, is usually fungal.
It could be the pests alone, or it could be the double whammy of pests and fungus.  (This is assuming the tomato spike is doing its job).  There could even be some underwatering at play, which would bring in issues of nutrient uptake. Tomatoes are on the far spectrum of water-lovers - if grown in bags, the bags can be set in 2" of water all season and the plants will love it.
I wish I hammer down definite answers for you. Good luck. Keep the soil very moist. If bent on saving the plant, pesticide and a soil test might serve you well.
Answer: It's likely too cold for your tomato plant.  The roots need to be kept above 60 deg F in order to be metabolically active and absorb nutrients.  Below that you get functional deficiencies, with typically phosphorus being the main one which causes a blue/tinge to the leaves.  You might also be over watering the plant.
I'd bring the plant inside until the weather gets hotter, or stick it in a greenhouse.  A temperature probe might also show you what the roots are experiencing.
Also that pot looks too small for a tomato plant, so you're going to need to repot it.
Answer: Edit: I didn't notice your mention of fertilization when I wrote my answer below. Jobe's Tomato Spikes are a 6-18-6 fertilizer. That means they're mostly phosphorus. Depending on your soil, that could be a good or a bad thing. I still think your plant is nitrogen deficient, and that the soil is drying out too quickly. It may also have other deficiencies. The roots could be damaged, but I wouldn't count on it. Most plants planted in containers in random unamended potting soil where I am exhibited strange issues like this (including the dry spots on the leaves), even without being root bound. I think the soil is the main problem. I'm guessing you have enough phosphorus, however! :)
Bringing it in the house will probably improve the plant in some regards while in its current soil, but the same thing will likely happen again within a week of putting it outside again, even if warms up. I might say, especially if it warms up. Putting a humidity dome around it with a UV filter would probably have a better result, but I still don't recommend that because it'll have to leave the dome some day. So, I would still recommend pre-fertilized Miracle Gro soil for vegetables, and/or topsoil, instead (and more soil). Or, if you don't want to repot it, I'd give it more nitrogen and potassium (without giving it more phosphorus), and a little rockdust, as well as something to make it not dry out as quickly (like compost, maybe peat moss, greensand, clay or something).
It's possible that Miracle Gro soil might dry out fast, too, if your area is dry or windy. So, adding some clay or something to it may or may not still be beneficial.
Edit (again): In light of the humidity you mentioned (if that's typical), unless it's pretty windy, I wouldn't be worrying about the soil drying out too fast. However, I'd still be worrying about minerals, nitrogen, and maybe potassium.
When plants are nitrogen deficient, it affects the lower leaves first (because it's a mobile nutrient, nitrogen from the lower leaves can be moved to new growth). Nitrogen deficient leaves are yellow, including the veins. Magnesium deficiency is similar, but the veins don't turn yellow. Iron deficiency causes new growth to be yellow, as does sulfur deficiency (but it looks different). Phosphorus deficiency makes the leaves have purple on them. Potassium deficiency makes the edges of older leaves turn yellow; it can also result in weak plants, smaller fruit, less heat-tolerance, etc.
Phosphorus toxicity is a possibility, too. The soil may have had enough already before the fertilizer spikes. This would reduce available zinc and increase available manganese. In this case, adding peat moss would be a bad idea, because it's acidic and more acidic soil has a higher availability of manganese. Overwatering can also increase available manganese. Manganese toxicity may be what is causing the dry spots. Adding rockdust would assuredly help it several ways, if this is true. It would increase the soil PH (due to the calcium in it). It would increase the need for phosphorus. It may also increase the need for potassium, though.

Original answer:
It looks to me like your plant has nitrogen deficiency. It also appears to have insect damage on the leaves (maybe from a caterpillar or something).
I wouldn't worry too much about the insect. There doesn't seem be enough foliar damage to merit much concern. I think Paul Nardini may have thought there was insect root damage, but I don't think there's sufficient evidence that the roots are damaged.
I definitely don't think you should bring the plant inside or put it in a greenhouse, in my opinion, unless it's a particularly sensitive variety (cherries are usually pretty hardy to weather, though), but maybe not even then. Bringing it inside will shorten season considerably, and you may need to harden it off again. In my experience, tomatoes aren't bothered much by those temperatures. It just needs fertilizer and/or better soil, in my opinion. The yellowing lower leaves indicate nitrogen deficiency. The insect damage indicates that the plant could use some more potassium, as well as perhaps calcium and/or silica. Healthy plants don't get eaten as much, normally. Extra phosphorus should make the plant more cold-tolerant. All three fertilizer components should help your flowers: Phosphorus is most known for it, but nitrogen plays a role with higher numbers of fruits (not higher total mass of tomatoes harvested, though); so, nitrogen may help with those extra flowers.
The container looks quite small. That's probably one reason you're getting deficiencies so early. I recommend giving it much more soil, if you can (5 gallons or so). You might try some pre-fertilized Miracle Gro meant for vegetables or some such. Since it's not a seedling, buying pre-fertilized soil should be safe. Don't transplant it while the sun is shining, though, or it could get bad transplant shock, depending on several factors.
It looks like the soil might be drying too quickly for the plant's tastes.
A little rockdust or something should help with calcium and silica, but the Miracle Gro pre-fertilized soil likely has enough of everything. I've heard of someone getting about a hundred tomatoes on an Early Girl plant in Miracle Gro soil in a container (I don't think she even added extra fertilizer later in the season, but I could be wrong). So, it should be okay for your cherry tomato.
I personally like to use our topsoil in outdoor containers where I live, though, but a lot of people seem to think that's taboo for some reason. Nevertheless, the plants don't suffer in it, in my experience, so far.
Comment: Thank you so much for giving such a detailed answer. This is my first vegetable plant and first year with really any plants so I don't know much. I repotted the plant into a much larger container with 5 gallons of miracle grow. Here's the condition of the roots: http://imgur.com/a/s1IvW
Comment: Since the OP has fertilised the soil, it's not an actual nutrient deficiency but a functional one.  I looked at the original pictures and the whole plant looks very blue.  I still say bring the plant inside and repot it.
Comment: the root ball looks small so hopefully you'll be able to resuscitate it.  I also noticed you were using plastic zip ties.  Don't do this as the ties will strangle the plant. You need to use something that will allow the stems to thicken, like cloth or loosely tied twine.
Comment: @SuzanSucro Awesome. Watering many hours before transplanting and immediately after transplanting is a good idea. Adding a little wood ash should help, too. It'll add extra calcium (if the soil in the root ball is too acidic, it should help to make it less acidic), and potassium (which should help reduce transplant shock and encourage root growth). Too much wood ash can be very bad, though (it can raise the PH too high and too much potassium can inhibit the positive effects of nitrogen). There might be enough potassium and calcium already in the Miracle Gro soil, though.


Arduino Micro 5V Vin and 3v3 pins

Question: I am very confused with the pins on the arduino micro. What are the 3v3, 5v, and Vin pins used for? Are they for power input, or power output, or both?
Answer: Vin is a power INPUT. It is connected to the input of the voltage regulator, which enables you to power the Arduino with voltages between 6V and 12V, while the Arduino itself is running on 5V.
The 5V pin can be both an power INPUT and OUTPUT. It is connected to the general 5V power rail inside the Arduino and thus to the power inputs of the microcontroller. This rail/pin needs to be provided with 5V power to let the Arduino work. Where this power comes from (from the voltage regulator, from USB or from your own external 5V power supply connected to the 5V pin) is irrelevant for the Arduino. The 5V pin can even be used to provide power to other components in your circuit (though with certain limitations, see below).
The 3V3 (meaning 3.3V) pin is a power OUTPUT. It is connected to the output of another voltage regulator, which brings the 5V from the 5V rail down to 3.3V. It can be used to power external parts, that need 3.3V to work.

Up to this point I only wrote about voltage. But depending on your circuit you also need to consider the current. The different electrical parts on the Arduino can only handle a specific power (measured in Watts). Thus with a given voltage you can only draw up to a specific amount of current through them, before you destroy them.
As an example, let's assume you provide the Arduino with 9V through Vin and you want to drive a middle sized motor. Motors in general can draw a lot of current. When you now drive the motor from the 5V pin of the Arduino, the motors current will flow through the Arduinos voltage regulator. Thus the regulator will go into emergency shutdown and cut the power (applies for a genuine Arduino) or it will get destroyed (applies for most cheap Arduino clones). To prevent that, you need to connect the motor directly with the power supply (or through an extra voltage regulator, suitable for the needed current), so that the current for it is no longer flowing through the Arduino.
This explanation is only to prevent you from destroying your board. That is always very annoying, when it happens.
Comment: Ahh, this makes much more sense! Thank you very very much! :)
Comment: Upvoted (also because of the last line, which is quite an understatement).
Comment: Excellent answer. One point I would add is that if you are going to supply 5V to the 5V line, you need to make sure it is regulated 5V. If it strays too far from 5V it will cause the board to malfunction and may damage or destroy it.
Answer: VIN is power input. IN means INput.
Generally 5V and 3.3V are used for power output, but the 5V one can also be used for power input if you want to power the board from 5V.
But since they are just power they have no "direction" as such, only a voltage level.

Arduino Micro 5V Vin and 3v3 pins


GDPR: Is only a birthday personal identifiable information?

Question: I wonder if only a birthday is seen as personal identifiable information according to the GDPR, so no usernames, passwords, emails, phone numbers are present in the system. Literally only a birthdate. And if someone can answer this it would be great if you could link the source as well since I can't seem to find this.
Answer: This depends on the context – GDPR rarely restricts the use of specific kinds of data (see Art 9) but instead regulates the processing of this data, and the purposes for which it is processed.
Personal data is any information relating to an identifiable person (Art 4(1)). So to show that some information is not personal data, you must show either that it doesn't relate to the identifiable person, or that it's not possible to identify the person.
Whether a person is identifiable depends on the means of identification that are reasonably likely to be used, taking into account the cost and effort of these means (Recital 26). This recital also mentions that singling out a person is a kind of identification.
If you have lots of birthdays so that there are no unique birthdays, or if the birthdays are stored without contextual information that would allow identification, this can indicate that it's not personal data. Some examples to illustrate my views:

Scenario 1: you are collecting statistical data in a shopping mall and are collecting birthdays from passer-bys, without any additional information. This information is anonymous and not personal data, since you have no reasonable means to identify the persons.
Scenario 2: in an office, there's a publicly visible calendar on the wall with the birthdays of all staff members. However, the calendar doesn't say whose birthday it is. This information is likely personal data, since it's reasonably possible to infer the correct person based on contextual information. At least HR would also have the birthday for all staff members on file, so that the company clearly has the means to identify anyone. (This doesn't mean such a public calendar is illegal, just that there must be a legal basis.)

It is more difficult to determine whether information also relates to an identifiable person, i.e. whether this information is about that person. This depends not just on what the information is, but how the information is used. AFAIK there has yet to be EU-wide guidance by the EDBP, but the ICO has listed some hints. I think that a birthday of an identifiable person will almost always relate to that person.
Answer:
Is only a birthday personal identifiable information?

It depends, as pointed out by Greendrake. See the definition of "personal data", article 4(1) of the GDPR. I will assume that the scope of your question is not restricted to a small population, and from there you can contrast it with any unspecified particularities you might have in mind.
There are thousands (perhaps millions) of births every day where the GDPR applies. This implies that many, many people have the same birthdate (and even more people have the same birthday). Therefore, a birthdate is useless for identifying a natural person.
Furthermore, neither birthdate nor birthday fits, or gets close to, any of the categories of identifiers listed in article 4(1) and other reasonable alternatives. Although birthdate determines a person's age, the latter is not a factor "specific to the physical, physiological, [... or] mental, [...] of that natural person" because people's aging and said factors depend on the person's lifestyle, life events, and other factors which are not captured in the person's age or birthdate.
Comment: Depends on the context though. Within a relatively small group of people, a birthday can perfectly identify a person (especially if birthdays of all persons in the group are known).
Comment: @Greendrake If the OP had in mind only a relatively small group of people, I am confident he will discern the extent to which the criteria in this answer are applicable to his general question. He obviously knows that criteria are more meaningful than a bare 'yes' or 'no', which is why he asks for the source as well. I can change the 'no' to 'it depends', though, if that helps highlighting the importance of the criteria.


How do we calculate the speed of an air bubble rising in water?

Question: We all know that an gas bubble expands as it rises through a liquid due to decreasing pressure.But at what speed does it rise? if we make a bubble of unit volume filled with a gas of given density at the bottom of one meter deep liquid container (liquid's density is also known), then how much time will the bubble take to rise? We also have to incorporate the continuously increasing volume of the bubble.
Answer: As this is marked homework, I'll only give some rough ideas.
You need to find the Volume depending on the height, that's straightforward as you can calculate the Volume from the ideal gas law and the pressure that in turn depends on depth. I would assume equal temeprature between gas and liquid - though that does not always hold.
From the Volume the buyoncy is straight forward - so you arrive at a formula that gives you buyoncy in depency of height (or rather depth).
On the other side you need the viscous forces - those are dependent on speed and size of the bubble, so again dependent on depth.
So, with x beeing the height (positive upwards), B buyoncy and D drag forces and m mass of the bubble, you get something like:
$$m \ddot x = B(x) - D(\dot x, x)$$
This does not look easy. Also note: I assume that the time the bubble takes to expand is negligable
Comment: You also have to keep in mind what shape the air bubble has. This will also be affected by the surface tension. I think that this will be very hard to calculate for bigger bubbles (for very small bubbles the drag forces will be very small compared to the surface tension and the shape will approximate a sphere).
Comment: I agree, @fibonatic.  Small bubbles are spherical, so a drag coefficient is known.  As the small bubbles rise, they continuously expand, and their shape changes into something that looks more like a pancake.  It is also practically certain that as the bubbles grow past a certain size, they break into 2 or 3 smaller bubbles.  Unfortunately, I don't have any "feel" for what parameters (surface tension, liquid/vapor densities, etc.) lead to bubble breakup.
Answer:
Determine the bubbles buoyant force in the Y direction. This can best be analyzed by looking at the relationship between volume and density of the bubble in relation to the surrounding viscus fluid.
Determine the general shape of the bubble, oblong, elliptical shape, and its coefficient of friction with respect to the fluid it will be flowing through. You may need to determine if the bubble will be laminar or turbulent to further investigate the friction factor.
Multiply the force created by the buoyant force, by the frictional losses to get your applied force.
Once you have applied force, given (Displacement x) (initial condition $V_0$) (Mass) you should be able to figure out the speed, given one of the velocity equations.


How to Migrate Magento 1.9 Module into Magento 2

Question: I use some extensions, such as the extension Alpha search module in Magento 1.9 but this module does not exist for Magento 2, so I need to convert the module to Magento 2. Can you suggest any tool or tips so I can easily convert a Magento 1.9 extension to a Magento 2.0 extension?
Comment: it is possible, but not easier, try follow this: https://github.com/magento/code-migration
Comment: Hi @MichaelHa
Thank you give me suggestion.
But can I know how can I use?
Answer: You can use code-migration tool: https://github.com/magento/code-migration
To use it, follow the below steps:

Download code from the above link. unzip and upload it to your home/user/ directory, not in public_html or another root doc directory.
login to your server via shell
Now go to the "code-migration-develop", where you upload the migration tool code.
Run the following command in the root directory of this toolkit
composer install
now go to the bin directory: cd bin
Execute command: php migrate.php migrateModuleStructure /home/YOUR_USERNAME/public_html/MAGENTO_DIR ../
It will convert the structure and you will see these converted
structure in the directory: code-migration-develop/app/code

Run below commands to convert Layout & Php code
Run php migrate.php convertLayout ../

Run php migrate.php convertPhpCode ../

your code converts complete.
Hope it helps!


Shower Plumbing or Concrete pan

Question: We were having a frequent drip show up on our stairs from the master shower above.  The tiled floor of the shower (over concrete pan) had mildew in the corner, so I cleaned out the corner and found water between the tile and shower pan membrane.  So, I pulled out the lower rows of tile and water came out.  I also took up the showers tile floor.  We've been just ignoring the shower fix for awhile, but today, I realize that if I hold a bucket under the shower and run it, a dark damp patch appears and grows on the concrete.  I also opened a hole in the wall of the bedroom and the vertical pipes are not leaking.  Did I mention that I poured water down the drain to see if that caused a leak.  It didn't.  SO what is happening?  It's obviously with a pipe, but what pipe?  Do I have to take out this concrete shower pan?  Thanks.
Comment: There shouldn't be any pressurized water lines embedded in the concrete pan. Are you able to see if the supply lines do go into the concrete?
Answer: I think the fact that a "dark damp patch appears on the concrete" when you open the shower valve(s) yet catch the water in a bucket points directly to a leak from the plumbing. You need to open the wall from behind to gain a view of the shower valve body, and also remove all trim on the inside. Use the handles to open the valves and find the leak source. Water may be running down the interior of the enclosure wall. The fact that you have a plumbing leak does not mean that your shower pan is in good shape; if it is old, since you have removed the tile, this is an appropriate time to break out the concrete and have the pan refurbished (hot-mop, vinyl liner, fiberglass pan, etc...)
Answer: I agree with Jimmy Fix-it. Until the leak is remedied, I'd just caulk under the valve to seal water out from getting between the tile & wallboard. Your bigger problem is why wasn't the water draining under the tile or pan & simply finding its own way out.
Consider yourself lucky. You need to rip out the pan. First, water shouldn't find any way out. And Second, your pan's membrane should be emptying into your drain's secondary inlet that the membrane is supposed to be applied up to & is there for this exact purpose.

Shower Plumbing or Concrete pan


How to find expiry date without whois?

Question: After GDPR shutting down the whois protocol, how can i get information relative to the expiry date to any domain?
Comment: The WHOIS protocol isn't being "shut down". ICANN administrates reporting under the WHOIS protocol, and what's under consideration, and currently in the German courts, is how they should adhere to the GDPR in countries regulated by it. On May 25th 2018, they issued a  [Temporary Specification for gTLD Registration Data](https://www.icann.org/resources/pages/gtld-registration-data-specs-en) that details how registrars should report this data, which only pertains to contact  information, not the expiration date and other required data for Registrars to be able to function.
Comment: The only mention of "expiration date" in that specification is in [Appendix F](https://www.icann.org/resources/pages/gtld-registration-data-specs-en/#appendixF), and states that registry operators must provide it.
Answer: What needs to change with WHOIS
At the moment the private details of registrants are included in the publicly accessible WHOIS data.
The argument for nobody having access is that people like their privacy, and do not like spam and unwanted phone calls. This is covered by the GDPR, as users have the right to object, which the ICO describes with regards to direct marketing like this:

Individuals have an absolute right to stop their data being used for direct marketing.

Source
The argument for governments and copyright holders is that they want to be able to find out who runs sites that are illegal, and shut them down quickly.
Will this affect the accessability of expiry date information
At the moment, the full changes are not fully clear, but the main consideration is who, if anyone, should be able to have access to the personal details held in WHOIS.

The GDPR changes will, in a sense, shield every registrant from disclosure almost as fully as proxy registrations. Under the GDPR-compliance program currently being implemented by the Internet Corporation for Assigned Names and Numbers (ICANN), full information will be collected by the registrar when a domain name is sold. But the WHOIS database available to the public will show the registrant's name only for organizations, not for natural persons. Instead of physical address, the public database will show only State or Province and Country. And instead of the registrant's true email address, an anonymized email will be displayed to allow the registrant to be contacted.

Source
Short of if WHOIS was scrapped entirely, which does not seem to be suggested at the moment, expiry data would still be publicly accessible, the changes would only affect the fields which are considered personal data.
Comment: "At the moment the private details of registrants are included in the publicly accessible WHOIS data." - FWIW, since GDPR "most" of my domains now suppress the "private details" from the public WHOIS records. Either because the Registry (eg. Nominet) now suppress this information or because the Registrar has implemented "privacy protection" (at no additional cost and opt-in by default). Namecheap don't appear to have done anything for existing domains, but have stated that all new registrations/renewals will get free privacy protection as default.
Answer: GDPR is not shutting down the whois protocol, this is a far fetched idea. They will be changes to whois for sure, and this was long due. It may get replaced by RDAP.
The whois protocol does not define in any way the content received, nor its format. Per the protocol the server replies with a bunch of lines, that is all.
GDPR may have consequences on the content of the reply and/or who can access what, but technically the protocol could work as is. However RDAP is a far better alternative nowadays because it is built on HTTP and hence delivers immediately features about authentication and authorization which are sadly missing in whois (because these were not problems at the time the whois protocol was defined).
Also the expiration date is something you can today only get through whois (be it at registry whois or registrar one, in gTLDs that are thick registries) as a public. The registrars have privileged access to registries, typically using the EPP protocol and through it they can get access to expiration times, at least for the domains they sponsor and sometimes for others too.

How to find expiry date without whois?


Term for someone worried about health after reading health information online

Question: Is there a term to describe someone who becomes very worried after reading health
information online? They think they have developed those health problems and are always on edge.
Comment: Nothing against this question, but why does everything have to have its "cyber-" variant these days? It's like the internet has an ego of its own and needs to have its own flavor of every disease, syndrome, crime, habit, etc. People used to browse the ICD or other medical coding book for the same purpose./curmudgeon mode>
Comment: @JeffSahol let's call that **cyberfication**
Answer: That person would be a hypochondriac.

The persistent conviction that one is or is likely to become ill,
  often involving symptoms when illness is neither present nor likely,
  and persisting despite reassurance and medical evidence to the
  contrary. Also called hypochondriasis.
  2. Plural of hypochondrium.

If you fear that you might be a hypochondriac then click here.
Answer: It's called cyberchondriasis - combination of cyber and hypochondriasis.
http://www.ncbi.nlm.nih.gov/pubmed/22137465

A type of hypochondriasis that develops in a person who, while on the Internet, identifies one or more personal symptoms—e.g., tachycardia, dyspnea—and ties that to one or more conditions; the individual then convinces himself/herself that he/she is suffering from these conditions (freedictionary).
Answer: This sounds very much like a variant of the condition known as medical student's syndrome or medical student's disease

Medical students' disease, also known as hypochondriasis of medical students, medical student syndrome, medical student disorder, medical school syndrome, third year syndrome, second year syndrome, or intern's syndrome, is a condition frequently reported in medical students, who perceive themselves or others to be experiencing the symptoms of the disease(s) they are studying.


Delete background, change color of video

Question: Is it possible to take, for example, this video

 and somehow make dr. Manhattan's skin yellow/white? instead of blue? Is it possible to take out his figure/delete the surroundings? If yes, then how?
Comment: Since there is *heavy animated glowing* around him going on, I don't think that this is possible (in this case).
Answer: You can also use DaVinci Resolve.
First node: You can use a qualifier to get the basic outline of Dr. Manhattan (not the glow around him, but the darker blue parts).
Second node: You can feed one output from that first node through hue vs. hue to convert blue to yellow.
Third node: You can feed another output from the first node to a mask.
Fourth node: You can then then blur the mask (outside only, not inside and outside) and tint it to make your yellow glow.
Fifth node: you can use the mask of the 3rd node to select the output of the second node and composite that with the output of the fourth node to get a yellow body with a yellow glow, and no background.
Answer: One way to achieve cutting out the background is by using after effects and rotoscoping Dr. Manhattan out - there are many tutorials online on how to rotoscope. Adobe After Effects CS5- Rotoscope with Rotobrush
Once you've done this, grade Dr. Manhattan to your liking by using a colour correction tool such as levels, and hue/saturation. You may have to rotoscope in/out the colours you want to keep.
Hope this is helpful.


Child theme within a child theme?

Question: I'm developing a child theme, but also want to make it possible for that child theme to have a custom functions.php file that won't be overwritten during theme updates .. is this possible in any manner?
Answer: You can add a custom functions.php to your child theme. As long as it's in the child theme folder, it will not be overwritten when you update the parent theme.
See http://codex.wordpress.org/Child_Themes. Read the section "Using functions.php"
Comment: But is there a workaround for preventing overwriting a file in the child theme when the child theme is automatically updated? Basically treating the child theme like a parent theme as well.
Comment: I'm not sure. In my mind, the child theme is the "static" element where you actively are preserving and protecting the settings/options from being changed when the parent theme updates. After the design is complete, what would precipitate a child theme upgrade?  If you want to preserve functionality, independent of what happens with the theme, why not create a plugin that is not theme dependent?
Comment: In the instance of designing/selling a child theme, having the ability to update the child theme while also providing a place for the customer to make 'static' changes that wouldn't be overwritten should an update need to be pushed out for the child theme.

I guess it would be something like a grand-child theme, but what I've found in searches says it's not currently an option? I guess a separate plugin to provide customizing outside of the child theme would have to be the best option for now.
Comment: This is growing outside of my knowledge, but I believe you should be able to create a library folder for your child theme that would contain the changes that you would normally put in function.php, which would leave the child theme's function.php available. When you provide the update, overwrite all of the files in your child theme with the exception of the functions.php.

Child theme within a child theme?


Is there any way that I could find out the market share of each miner manufacturer?

Question: I am considering getting into mining myself. And I would like to compare different mining equipments and how many people are using each of the equipment. It seems like it is really hard to find the data on the market share of mining industry. If anyone knows or has any recommendations on which miner would be best for serious miners, please let me know. Thanks :)
Answer: I found this site: https://bitcoinwisdom.com/bitcoin/calculator that enables you to input your electrical costs, your computation rate, how much you paid for your mining hardware and the bitcoin value to calculate profitability. there is also: https://en.bitcoin.it/wiki/Mining_hardware_comparison which is worth a look. I'm hoping to find out if mining is worth it if you cannot make an initial investment over 4-500$. Still working on it, haven't started yet.
Comment: It is not clear to me, whether you are asking a new question or attempting to answer this one. If the latter, your answer appears to miss the main point, as it doesn't address how to find out the market share of different manufacturers.


Is it possible to learn violin by yourself?

Question: I currently want to learn violin. I already have some background in music (but not classical). I can play piano and guitar too. So, is it difficult to learn violin by yourself even with some background in music?
Answer: I doubt that this is a good idea and it even might be an unhealthy idea, but of course the answer depends on what you want to achieve.
If you develop wrong habits they will stop you from making progress.
Violin is an especially critical example, because it´s very un-anatomical. Wrong habits in holding and using the instrument might damage your motion apparatus.
To play a note on a violin you need to hit the finger on exactly the right spot and move the bow at exactly the right speed and pressure in the correct way and at the correct position, to be able to play the next note you will to have to be able to do so fast and with the right technique and of course you need to be able to choose the right position for your finger out of the handful of possibilities.
That is to much to figure out for yourself, I think. You are likely to develop "alternative" techniques, improper shortcuts to solve the vast amount of problems and you will probably end up being able to play something but in a dead end. Further progress will be hindered by the wrong habits and shortcuts.
One obvious little example is the pinky finger. You don´t need it to play easy pieces, so folk tend to roll it in, which makes movement of the other fingers faster and easier. But of course you need the pinky for a little bit more advanced pieces or to avoid the change in timbre involved in using empty strings. But when you rolled your pinky for two years it will never ever get the flexibility it would have had when doing it right right from the start.
tl;dr
You need a teacher to find a learning-path for you or your journey will come to an premature end and you won´t be able to travel to the really cool sights.
Answer: Sort of.. I have seen some Youtube videos of people who are doing just that.  My son also just got a violin and spent about a month trying to learn himself (he has trumpet and some piano experience).
Simply put, the results aren't very good.
So I think that maybe it's possible, but a teacher will pick up no mistakes in technique that you are going to have a difficult time self-diagnosing.
Good luck!!