How to fix iTunes wrong song time?

Question: My mp3 in iTunes shows a time of about 20 minutes, when it really have about 5 minutes. The VLC Player and the Windows Media Player shows the correct time for the same file, what's wrong with my iTunes?
Answer: How can I fix incorrect mp3 duration @ askubuntu had a couple of command line solutions.
For me, the ffmepg solution worked (ffmepg can be installed to OS X with Homebrew, for example):
<code>ffmpeg -i file_orig.mp3 -acodec copy file_fixed.mp3
</code>
Comment: This even fixed files that were generated by `ffmpeg`!
Comment: this worked but holy moly `ffmpeg` has a ton of cask dependencies!
Comment: Much better than letting iTunes transcode to AAC.  Thanks!
Answer: The incorrect time is most likely due to an error introduced by the encoding software. You can repair the problem by using the Convert to AAC feature in iTunes.
In iTunes 11 this feature can be found under the Create New Version → option of the File menu.
Comment: This is apparently no longer a solution in iTunes 184.108.40.206.  My song was in MP3, but the file menu had no AAC conversion.  Only convert to MP3, which it did, making two MP3 files, both still with the wrong length.  Deleting them from the library, closing iTunes, renaming the file, then opening iTunes and re-importing gave it the same wrong length as before.
Comment: Worked for me in iTunes 22.214.171.124 on Windows.
Answer: Mr. Van Cool's fix did not work.  Jaberg's suggestion worked, but I found an easier way to get to the "Convert ..." option.  From the songs menu, right click on the songs with the bad time & "Convert to AAC" is in the popup menu.  Fixed 4 songs in under a minute, added the M4A files to my playist, and burning to CD worked as expected.
Answer: The wrong time duration, is not solved with iTunes 11 and it's not depending from the encoding software (with the new releases of iTunes).
Even re-loading the file, deleting it form the device, often doesn't sovle the problem.
the only one effective solution I found (I got several times this issue) is:

Remove the file with iTunes form your device
Check if the song was really removed from the device, into the device
itself with iTunes on the iPhone or iPad. If not, touch the title,
shift your finger to left, and a red rectangle "DELETE" will appear
and touch it.
Rename the file of the song and re-upload it.

The reason of the 3rd point above is that: I noticed that often, even applying the first 2 points, for some reason (unknown to me), the device still put the old duration and/or old parameters. Changing the original file name, solves the issue.
Answer: I had the same problem. My track was more than an hour, but it only showed 1h04mins. Converting to AAC or apple lossless didn't work for me.
Fixed it by using this app called Tag Stripper, https://itunes.apple.com/us/app/tag-stripper/id432262744?mt=12

strip the track of its ID3 tags
import it fresh into iTunes. Track duration should be fixed now
cmd+i to edit the id3 tags.

Done.
There might be a simpler way, but this worked for me.
Comment: In my case it was a tag issue as well, and I was able to trace it down to the ITUNSMPB tag that iTunes uses for seamless playback. Removing just that one tag (Mp3Tag) and reimporting to iTunes solved the issue. I'm sure that tag is valid in many cases, but apparently not this one. (It had been included in a direct purchase from the author.) It might be worth trying to remove just that tag before wiping all of them.
Answer: What I did is pull up my editing software and cut out the length that was having the problem, and created a new file. Nothing else worked for me.

How to fix iTunes wrong song time?


A thick lens suffers chromatic aberration while a thin lens does not. why?

Question: I encountered this question and has put me into thinking that, "why does not our eye lens have any aberration?". I seem to be confused by optics. I also found that 'since lenses are made up of prisms, thick lenses have a greater angle of the prism than that of thin lenses'. Is that the answer?
Comment: The eye does have a lot of aberration. The retina and the rest of our nervous system deals with the problem.
Comment: @PM2Ring It is also true for chromatic aberration. Processing by neurons takes care of that.
Comment: You're on the right track. Think about Snell's law.
Comment: @Pieter That's true, but the OP is specifically asking about *chromatic* aberration. I guess the implied question is why don't we normally see coloured fringes on everything.
Answer:
The lens of our eye has aberrations, a lot of them, chromatic included. If we would take a photo of the image on our retina, it will look pretty horrible. We do not "see" those aberrations because the retina and the brain process the image so to hide the aberrations and present only a clean image to our subsequent processing and consciousness. We are interested in looking at objects, not at aberrations, so they are corrected/compensated by image processing.
We do see chromatic aberration from a telescope, a photo or underwater, because this aberration is much greater than what our retina is used to deal with.

By "thin" lens, we mean a lens with thickness much smaller than the diameter; not with small absolute thickness. For example, a lens of 1000mm diameter, 10mm thick, can say that is thin.  On the other side, a lens 10mm diameter, 10mm thick, is not thin.
The eye lenses are not "thin": the cornea is pretty curved; and the crystalline inside is more or less a ball.

Chromatic aberration depends only on material properties (and aperture). A super-thin lens will have chromatic aberrations too, same as a thick lens.
Your reasoning of "thick prism" makes sense, but, when you make the prisms thinner, also the power of the lens decrease. Given a fixed material (a glass, or our cornea) the chromatic aberration is proportional to how much the light gets bent. So, a thick and a thin lenses have different chromatic aberration, but also different power. But the ratio Chromatic/Power is the same.

Chromatic aberration of the eye is quite small, specially if compared to other aberrations. This is because the eye has small size, fairly large aperture, large angle of view, and actually it is not very sharp.  Chromatic aberration get somewhat lost in the blurriness of other aberrations.
Chromatic aberration become important for long lenses with small aperture, like telescopes, because the other aberrations are small, and the pixels are small compared to the telescope focal length, so the tiny chromatic aberration becomes evident.
A telescope lens is much more "thin" than the eye, but the chromatic aberration is more significant.

When the lens/prism gets really thick, and light is bent a lot, yes, the chromatic aberration gets proportionally larger, due to the fact that refraction is non-linear. This is evident near the "total internal reflection" angle, where the chromatic aberration becomes enormous. This happens in the eye at the borders of the field (far away from the center), but we have so poor resolution there that again we won't notice.
Answer: You are thinking in the right way!
A lens will not focus on different colors in exactly the same place because the focal length depends on refraction and the index of refraction for blue light (short wavelengths) is larger than that of red light (long wavelengths).
If the lens is thin, the effect will be small because the time is spent on the lens medium is small so there is not much difference in the focus point. But if the lens is thick, the difference becomes clearer. Like in the case of the prism, where one can see How the different color focuses at different points.
As for the Human eye, Its lens is about $4$ mm to $5$ mm (which is considered to be thin). More on this here. There other functions in the Human eye which help it to focus light at the same point.
The lens is a transparent biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. By changing shape, it functions to change the focal length of the eye so that it can focus on objects at various distances, thus allowing a sharp real image of the object of interest to be formed on the retina. This adjustment of the lens is known as accommodation. Accommodation is similar to the focusing of a photographic camera via movement of its lenses. More on this here.
Comment: You should also mention the benefits of the relatively small aperture of the iris, and the small angle approximation, $\sin\theta\approx\theta$.
Comment: OTOH, it *is* possible to get significant chromatic aberration when the cornea is not functioning correctly. Eg, if you wear contact lenses (that aren't the modern oxygen-permeable kind) for too long, the cornea gets water-logged, which changes its refractive index, and its dispersion. In that situation, the eye's lens has to work harder, but there's not much it can do about the dispersion.
Comment: A thin lens has chromatic aberration too.


Unable to access report created on account ,duplicate record item

Question: Created report for duplicate accounts, created on account and duplicate record item.
getting "You don't have sufficient privileges to perform this operation" error while accessing report
Answer: Insufficient Privileges error for Reports I have permission to read

There are a variety of reasons why you might receive an error message
  when you try to run a report that you should be able to access.

Possible causes might include

Field-Level Security
Profile and User permission

Check the Following

First, make sure your Report Type is in "deployed" status.
Verify that you still have access to the Report Folder.
Make sure you have 'Read' access to all of the objects that the
report references.
If it is an Administrative report, verify that the "View Setup and
Configuration" permission is on your profile.
Check the Field Level Security of the Lookup or Master-Detail
Relationship field to ensure that your Profile allows you visibility
into that field.
Check the Field Level Security for every field that is on your report
and in the object you are referring to.
Confirm that the 'Report Builder' is on the affected User's Profile.
If the report is built on multiple objects, make sure that a Lookup
Field between two of the Objects is not hidden by Field Level
Security.
If the Report Type is 'Opportunities with Products' verify that the
affected user does has at least 'Read' access to the Price Book
object.
For Communities, Customer Portal or Partner Portal Users, make sure
that appropriate Sharing Rules are defined.

Reference:- https://help.salesforce.com/articleView?id=000005189&type=1
Comment: Org wide defaults wouldn't cause that specific error, but the rest of this is good.
Comment: Thanks, @sfdcfox for your great suggestion. I will edit my answer.
Comment: @SarathBhusarapu Welcome :) You can mark it as your answer as it has solved your problem by checking the correct mark beside the answer.


"Don't mistake me"

Question: Many times during conversation I hear the phrase Don't mistake me. Is it grammatically correct when used to mean Don't take negative connotation of my word. Shouldn't they say Don't take me by mistake?
Comment: They definitely shouldn't say *Don't take me by mistake*. That would only be valid in a couple of highly-contrived situations that I doubt OP has in mind. But *don't mistake me* doesn't always imply misunderstanding in a *negative* way - you could say it to disabuse someone of the misconception that what you'd just said was more *positive* than you intended.
Comment: @Jasper please dont take away my humour. I will die.
Comment: @bubble: I'm not sure I'd call them "doubts". I was just pointing out that - from your point of view, at least - it would probably be best to assume that *Don't take me by mistake* simply isn't valid English at all.
Comment: Related question: http://english.stackexchange.com/q/49679/14981
Comment: Is it really official when we try to hide our smile ? Let us have this smileys when we work officialy. Wont it be good ?
Comment: @Jasper I introduced that smiley to keep off the doubts like what FumbleFingers have now.
Comment: You can say "don't get me wrong" instead of saying "don't mistake me"
Answer: Don't mistake me is perfectly grammatical, but it doesn't mean anything like "please don't interpret my words negatively". When mistake is used as a verb, it means "identify incorrectly" or "misinterpret". Thus, you can get usages such as:

Don't mistake me for my sister.

or

Don't mistake me: I'm not disagreeing with what he said, but he could have expressed himself more politely.

I think the phrase you may be looking for is "take amiss" (like FumbleFingers said).

Please don't take my words amiss, they were not meant to offend.
Comment: +1 particularly because now I think about it, it seems to me that in fact *Don't mistake me*, and the related *Make no mistake...* are actually somewhat negative/confrontational in intent/perception. Clearly OP needs a less belligerent expression, so even if *take amiss* is very slightly dated/formal, it's a better bet here.
Answer: Don't mistake me is perfectly valid in certain contexts. It is usually used with an object that describes what you do not want to be confused with, as in

Don't mistake me for a fool.

Don't take me by mistake. can also be used, as in

Take the prisoner to jail. Don't take me by mistake.

In general, the prefix mis is used to change the meaning of a verb to one that implies that the action / state was somehow erroneous, incomplete, or bad. The reason there are different meanings for mistake is that there are different meanings for take.
Answer: Mistake can be used as a verb, exactly as you cite it in your example. The noun use is a lot more common.
Comment: Per my comment to the question, OP may be conflating the verb *to mistake* with *to take amiss*. If you say *"Don't take that amiss"* you're invariably trying to correct a potentially *unfavourable* interpretation of your earlier words. But *"Don't mistake me"* is essentially neutral - it just means *"Don't misunderstand me"*.
Comment: Yes, *mistake* can be used as a verb, but it doesn't mean what the OP wants it to mean, so "exactly as you cite it in your example" is incorrect.
Comment: @FumbleFingers: You're right, of course. But when I first saw the post, it ended: "Shouldn't they say 'Don't take me'" (probably OP pressed the wrong button and the question was posted before he had finished typing it). I didn't pay attention to the word "take", I had the expression "get me wrong" in mind, and I thought the post would be edited so the missing part of the expression would be completed. If you check the edits of the post, you will see. Funny how the mind works sometimes (my mind, at least).

"Don't mistake me"


Should we have "topic" tags like food, people, places, etc.?

Question: I see there is a food tag, which is sort of a general topic that many vocabulary or word choice/usage questions would fall into. That got me thinking whether we should have "topic" tags like food, people, places, transportation, etc. Does StackExchange have any guidelines on tags like these? What does English Language & Usage do? What should we do on SL&U?
Comment: A quick skim through EL&U's question list shows they really don't have "category" tags like this.
Comment: JL&U does though. EL&U doesn't have to be the leader, they definitely have differences from the non-English language L&U's. I personally like them and generally follow the food tags.
Comment: @hippietrail: Good point.
Answer: I like this idea.
The main caution I'd give is to be careful to avoid meta tags. That is, tags that either don't tell you anything about the content of the question, tags that mean different things depending on who's reading the question.
In addition to that, make sure you don't fragment things so far that you end up with a lot of small, ultra-specific tags. For example, parks is probably too specific and a more general places is better.
I think using the same categories as you'd find in a language textbook would be a reasonable starting point.
Comment: Sounds good. I'll start adding general topic tags when they seem appropriate.
Answer: I think such topic tags are a good idea, and I've tried to encourage them on French Language & Usage (and, in a slightly different but related setting, on Science Fiction & Fantasy). We have society, economy, dates, … (and similarly on SF&F magic, aliens, …) When you're looking for a vocabularly question, it's easier to locate it in food than in some generic tag like word-choice.


Why didn't Darth Vader's body disappear in Return of the Jedi?

Question: In the special edition, you see his one-with-the-force ghost, but he didn't disappear like Obi-Wan or Yoda. Any good explanations as to why this is the case?
Comment: Technically, you see it in the Original version as well, only he's played by Sebastian Shaw.
Answer: According to the canon reader Star Wars: The Story of Darth Vader Anakin's body did become one with the Force prior to the cremation of his armour.

As Anakin lay dying, he asked Luke to remove his helmet so that he could look at his son's face with his own eyes. When Anakin died, his body disappeared into the light side of the Force. Luke was sad that his father was dead but proud of him too. The light side of the Force had overcome the dark side and Anakin Skywalker had returned.
  On the forest moon of Endor, Luke burned Vader's armour. All around the galaxy, everyone celebrated the end of Palpatine and his evil Empire.

Note that this is a retcon. In the earlier film novelisation his body was explicitly stated to have been on the pyre.

Luke stood in a forest clearing before a great pile of logs and
  branches. Lying still and robed, atop the mound, was the lifeless body
  of Darth Vader. Luke set a torch to the kindling.
As the flames enveloped the corpse, smoke rose from the vents in the
  mask, almost like a black spirit, finally freed. Luke stared with a
  fierce sorrow at the conflagration. Silently, he said his last
  goodbye. He, alone, had believed in the small speck of humanity
  remaining in his father. That redemption rose, now, with these flames,
  into the night.

This is no longer considered to be a canon account of the funeral.
Comment: Or is the novel the oddball? I recall when I saw the original version on VHS the armor was clearly empty.
Comment: @Joshua - I don't think you can clearly make out that it's a body burning in the original; https://www.youtube.com/watch?v=bBMqJ9mQKpI
Comment: Oh my worse than I thought. The frames of the angle-shot on the helmet are clearly just the helmet there (if you get the right pause you can see all the way through the flames) and the sideways shots show the full suit.
Comment: @Joshua - I suspect you're mistaking the reflection of the flames for being able to see all the way though the helmet
Comment: Not see through the helmet. See through where the suit should be to the right of the helmet.

Why didn’t Darth Vader’s body disappear in Return of the Jedi?


Difference between "humble" and "modest"

Question: What is the difference between humble and modest? I saw one difference here. Is that true? Any other difference?
Comment: I intend to have "humble" carved on my statue after I'm gone.
Comment: @AndyBonner Are you not applying today's rules to the past? You should critique the answer you find inadequate, not the entire Q&A.
Comment: Don't be so modest @Optimal Cynic.
Comment: Voting to close this decade-old question as it never looked the two words up in a dictionary, and is attracting a slew of answers that don't either.
Comment: The purpose of closing is to prevent out-of-place questions from being answered. It is not clear what would be accomplished by closing a question that already has seven answers and has been seen 114K times.
Answer: Modest describes the personality trait or behaviour of not flaunting oneself, talking oneself up or putting oneself on display.
Modest behaviour can be a response to compliments, praise or follow an achievement. Modesty can also manifested physically (for example, "dressing modestly", "modest accessories", "modest smile").
In contrast, "humble" refers specifically to a person's inner state and feelings.  A humble person is willing to accept or respect another's authority, intellect and wisdom, or superiority without trying to challenge it or trying to assert oneself.
In summary, being modest refers to your behaviour, being humble refers to your ego.
Comment: Fantastic answer; while the words can obviously mean other things (as described in other answers), the "behavior" vs "innate quality" difference is crucial when deciding which word to use IMO.
Comment: Yes, very nice, succinct answer that cuts to the chase.
Comment: Humble can of course refer to behavior.  One definition is "having or *showing* a modest or low estimate of one's own importance".
Comment: so basically when I want to address someone and say, e.g." I really appreciate you being this modest" as opposed to saying "I really appreciate you being this humble " right?
Should we only use humble for ourselves? and modest for others?
Answer: Modest refers to a person's opinion of themselves.
Humble refers to a person's behavior with respect to others.
A person is modest when they do not boast or brag and when they tend to downplay their own abilities.
A person is humble when they show deference and a willingness to submit to others.
They often go hand-in-hand, but do not have to.
Comment: You and Raissa need to get together and work this out. Which of you is right?
Answer: The studies are part of a push to define humility, a concept more typically associated less with science than religion. (In Matthew 11:29, Jesus says, "I am gentle and humble in heart.") While research on narcissism—arguably the inverse of humility—has gained widespread attention, it's been harder to define and measure humility. Researchers do agree that it isn't just another word for modesty. A person who brushes off compliments isn't necessarily helpful, generous, respectful during conflicts, or accepting of criticism—all traits we can expect of the humble.
According to one model, the humble see their strengths and weaknesses accurately, and are inclined to altruism. Such people would be apt to treat romantic partners well, and to act in ways that support their bond. With that model in mind, a team led by Daryl Van Tongeren conducted three studies to test whether participants valued humility in a potential date and were more inclined to forgive a partner they perceived as humble.
Comment: So humble means  plus . Modest means  plus . If you accept neither criticism nor compliment, you are modest but not humble.
Answer: When one is modest, they have a moderate view of their own abilities. That is, they are not necessarily undervaluing themselves, but they would never overvalue.
When one is humble, they have a low view of their own abilities. They will always view themselves as weak in that area, even if they are not.
"Modest" is generally more suited to describe someone with a level-headed and accurate view of themselves, whereas "humble" is for one that is lower than it should be (to humble someone is to lower their own sense of value), though there is certainly a great deal of cross-over in modern usage of the two words.
Comment: Sorry, -1. I agree that the _verb_ "humble" implies lowering someone's self-esteem (thus carrying a negative connotation); however, the concept of _humility_ (and its associated _adjective_, which is what the OP asked about) is seen as a virtue in many societies. As @Raissa points out, it reflects a personality type that is not pretentious and is able to respect other opinions, irrespective of one's self-belief.

Similarly, modesty does not necessarily stem from a moderate view of oneself. Modesty can be faked, which means one can hold themselves in high esteem while still _appearing_ modest.
Answer: Modest does not mean poor, but humble does.
For example: You can wear humble clothes that are old and cheap, which make you stick out like a sore thumb at a royal wedding; or, you can wear modest clothes that make you fit in and not stand out at a royal wedding.
Comment: I'd see 'modest' as meaning poor to the extent that humble does — people would often say "from a modest background" (like with "from humble beginnings") to mean "not well off".
Comment: Yes, it's a close call.  I am just referring to the frequency that I have heard/read one over the other for the same definition.
Answer: 'He is modest.' = He does not want to talk about his abilities or achievements. He is not boastful.
'He is humble.'= He believes that he is not more important, better, or cleverer than other people. He does not want to be treated in a special way.


How to see deleted comments in a Facebook group

Question: Is there a way for a Facebook group moderator/admin to see deleted comments or deleted posts?
Answer: If an administrator deleted a comment or post in a group, the comment and post are preserved for viewing and can be restored via the "admin activity log."
If a user deletes their own comment, as @serenesat pointed out, the post or comment is deleted permanently and is no longer visible by anyone including the user who deleted it. If the comment had replies after it, those replies are preserved and Facebook indicates these comments were in reply to a now-deleted comment.
Answer: No, once a post or comment deleted means it has gone. It does not matter if it was deleted by any admin or member who had posted. No one can see that. It also will removed from Activity Log.
Comment: This is no longer correct in August 2021. Comments and posts deleted by admins are preserved and logged in the group's administrator activity logs visible only by moderators and admins.
Comment: @glenviewjeff would be good if you can add any official link or screenshot to support your comment.
I see [Facebook help page](https://www.facebook.com/help/356107851084108/?ref=u2u) still says same thing as my answer.
Comment: see my answer, screenshot included as suggested.


Command+backquote (switch to next window) shortcut no longer works correctly in Mail after upgrading to Ventura

Question: This is a very strange one. I just upgraded to Ventura (13.0.1) and have discovered that for some reason the keyboard shortcut Cmd+`, which is supposed to cycle through windows of the currently active app, no longer works properly when the active app is Mail.
Specifically, Cmd+` will bring focus to the next window, but after cycling through all of the windows once, it will not return to the first window again.  So if I have, say, a draft open in a separate window, plus the Message Viewer in another window, I can't toggle back and forth between them using the shortcut — I can use it once, and it's effectively a one-way trip.  Holding down Shift+Cmd+` does work for going backward, but frankly, that's a pain, and it never used to work this way.
I have verified that in Finder and Safari, the keyboard shortcut still works the way it used to, so this seems to be specific to Mail.
Does anybody have any idea why this is happening, or if there is some way to fix it?
Answer: I guess I still don't know why this was happening, but I now know how to fix it:  just updated to Ventura 13.1, and the problem is solved.


HDRI is not showing correct color

Question: Currently I'm doing outdoor lighting in Blender using HDRI. I'm not really new to HDRI lighting, I usually done this kind of work in V-Ray Sketchup and the render output is quite correct (at least the dark area is pretty dark as the HDRI image), I just need to adjust the intensity and units in the V-Ray Dome Light (and 0-ing the highlight burn in Sketchup), like this.

And now, in Blender, my lighting is not really great. The Env. Map is just using a spherical image set to Non-color, with such configuration of Color Management. Not all HDRI being used is showing such incorrectness, some day light HDRI may light up the scene really well, but still I need to adjust the white value of materials color. This is what it looks like.

The looks in the photo viewer, blender texture editor, and the scene is just not right. The brightness seems shifted so much. The dark area of HDRI in photo viewer is blue-ish, but in the scene is very different, with no adjustment in the World node.
The HDRI is in HDR format, tried to convert it to EXR, but nothing changes. What should I do? What could possibly go wrong?
Answer: You need to play with gamma node after the hdri, sometimes you'd need to split HDRIs to camera and not-camera visible ones and fine tune them there. Blender Cycles doesn't use HDRIs the same way as Corona or Vray.
Check out tutorial on
HDRIs in Blender.

HDRI is not showing correct color


What is Landau theory, and why is it only valid within a region close to the transition temperature?

Question: I'm aware of the fact that first order and second order phase transitions are distinguished by at what order their free energy suffers a discontinuity as a function of a state variable, and I know Landau's theory deals, vaguely at least, expressing the free energy as a Taylor expansion in the order parameter (I don't actually know what an order parameter is), but I can't work out from looking at it online what it actually is, and why it's valid within only a region close to the transition temperature.
Answer: Loosely speaking, the order parameter is a physical quantity pertaining to the system, whose value allows you to distinguish between a state at $T>T_c$ and a state at $T<T_c$, ($T_c$ is the critical temperature or whatever quantity you're using to define the critical point), since it is $0$ for the former case and $\neq0$ (finite) for the latter. This "binary" behaviour makes it likewise useful to express other quantities of interest, such as the free energy, in terms of the order parameter.
For instance, in the Ising model - a lattice of up and down spins/magnets - the magnetization per spin of the system, $m$ (i.e., total magnetic moment divided by the number of spins), is typically used as an order parameter, as it is $0$ at $T>T_c$ (disordered phase - spins randomly oriented) and finite $\neq0$ at $T<T_c$ (ordered phase - all spins aligned). Another example of an order parameter is the difference between the liquid and vapor densities for a fluid - it is $\neq0$ for $T<T_c$, as both phases are present, and $0$ for $T>T_c$, as they "blend". Let's consider the spins example.
Landau theory kind of tries to "see the bigger picture". Upon realizing that symmetries of the system (which correspond to invariance of the Hamiltonian, $H$, for certain coordinate transformations) that are present when $T>T_c$ are no longer present when $T<T_c$, it considers a generalized free energy, $F$ that doesn't take into account the microscopic degrees of freedom of the system (i.e., it doesn't care if they are spins, magnets, etc), but only its symmetries. The way these symmetries enter $F$ is via the Boltzmann factor in the partition function, by means of $H$.
An example of a symmetry for the spins system would be the invariance of $H$ when switching up/down spins for down/up spins ($H$ has the same form when changing the values of the spins $s_i$ from $-1$ to $1$ and vice versa). Now, on  one hand, we know how to get $F$ from $H$ (assuming we know how to calculate the partition function) and so $F$ will have the invariances $H$ has. On the other hand, we'd also like to express the free energy in terms of $m$. The problem is $m=\sum_{i=1}^N s_i$ is positive if the spins are all up, and negative if they're all down - that is, $m$ is not invariant the same way $H$ is -, so we must be careful and expand $F$ in terms of $m$ retaining only those which keep this invariance intact. Thus, in this particular case, $F$ contains only even powers of $m$. Then, by analyzing $F(m)$ as we vary $T$, we're able to predict the behaviour of the system and all just by looking at its symmetries!
The validity of the theory being near the critical temperature has to do with the fact the order parameter is $\sim0$ at $T_c$, and we want to expand $F$ at $m\sim0$, because $F(m)$ will tell us what kind of transition it will be, and will allow us to calculate some quantities characterizing the transition / the critical point (e.g., critical exponents). Check this for more details.


What are the oldest living plants in the world today? What can you know about them? Why can some plants live so long?

Question: What are the oldest living plants in the world today? What can you know about them? Why can some plants live so long?
Comment: please ask only one question and try to be spesific,what type of research has you done so far.you have multiple questions here.
Comment: Arguably Pando, an aspen grove that is a single connected organism: https://en.wikipedia.org/wiki/Pando_(tree)  But for the many plants that spread by vegetative methods such as root suckers, the question of what exactly an individual plant is becomes rather difficult to answer.  For instance, I have many varieties of roses in my garden, all propagated (for instance, by rooting cuttings) from plants that were in some cases bred a century or two ago.  Are they still the same plant?
Comment: Just to be clear; you are asking for oldest individuals of plants, right? Not the oldest still living species (~living fossil)?
Answer: Great Basin bristlecone pines (Pinus longaeva) have been known to live to be thousands of years old.
The oldest known living individual is named Methuselah and is estimated to be more than 4,800 years old. It's been credited as the oldest living non-clonal organism on Earth.
There are multiple other trees over 1000s years old.


20 amp circuit for lighting

Question: San Bernardino Ca. area. 20 amp circuit #12 wire, Can I use this circuit for Lighting? On this circuit 5  20 amp outlets and 6 LED fixtures 50 watts each. One outlet will be used for a refrigerator.
Comment: Where in the house are these outlets located?  Also, do you already have your two 20A kitchen small appliance branch circuits covered?
Answer: Yes, you can. Although I'd watch what you use with these receptacles as you could easily trip the breaker with the refrigerator on there too.
Also, I doubt those LED lights are 50W. They're probably much lower unless each fixture is like a chandelier with multiple bulbs.
Answer: If this is one of your 2 20A small appliance circuits the lighting should not be on it NEC handbook exhibit 210.28.
I think it is always a bad idea to have a refrigerator on a small appliance circuit but it is allowed by code.
If this is in addition to the 2 small appliance branch circuits for the kitchen countertop area it is legal.
Comment: You will need GFCI protection in the garage per NEC 210.8(2) all outlets now require GFCI including the Refrigerator.
Comment: This is a dedicated  20 amp circuit in garage for 1 refrigerator and 5 LED light fixtures @ 60 watts each. including 5 outlets.
Comment: Is it ok to have one GFCI to protect circuit (outlets) or GFCI at each outlet? Lighting need GFCI?
Comment: Just the outlets need the GFCI one at the first outlet can protect the string the lights dont require GFCI unless they have a outlet in the fixture.

20 amp circuit for lighting


How to add a modifier to many key frames?

Question: I have an animated armature that is a person walking, but the animation is too short. I would like to add a cycles modifier to my final keyframes to repeat the motion, but there are way too many keyframes to reasonably add the modifier to each one individually. Is there a way to add a modifier to many keyframes at once?
Thanks!
Comment: Thanks, josh sanfelici, I will try that. Just out of curiosity though, is there a way to add a modifier to multiple keyframes at once?
Comment: I updated my answer.
Comment: Okay, thank you!
Answer: You can copy and paste all needed keyframes all at once in the dopesheet or action editor, or you can use the repeat function in the Nonlinear Animation Editor.
Anyway, to answer the question, you can add a modifier to one channel, tweak its values then click its copy button, then select all the needed channels and click paste button.


Why doesn't Matt Smith's Doctor recognise Clara?

Question: If Clara went back in time to save all the Doctor's past incarnations through Trenzalore's TARDIS, why doesn't Matt Smith's Doctor recognise her when they first meet from all of their past encounters across time and space?
Comment: Because retcons don't *actually* ripple backwards in time
Comment: Because wibbly wobbly timey wimey.
Answer: From "The Name of The Doctor", in the montage that shows Clara saving several past Doctors:

CLARA [Narration]: I just know I'm running. Sometimes it's like I've lived a thousand lives in a thousand places. I'm born, I live, I die. And always, there's the Doctor. Always I'm running to save the Doctor again and again and again. Oi! And he hardly ever hears me. But I've always been there.

As I understood, Clara always saved the Doctor in his/her past incarnations, but kind of in a "behind the scenes" way. He hardly ever heard her, or saw her. In said montage, Clara was retconned with not very well done effects in past instances when The Doctor was in mortal danger, making it look like she saved him all along, without the Doctor knowing.
We see the first time he turns to see her is in "The Snowmen", and the Eleventh Doctor didn't even make the connection until he saw her grave saying Clara Oswin Oswald.
Oswin Oswald was the girl in the Dalek Asylum, and the Doctor never even saw her, he just heard her voice. That's when he finally put 2 and 2 together and set to solve the mistery of the "Impossible Girl", putting the time loop into motion.
Answer: The usual reason that the current Doctor doesn't remember some events that have happened to past Doctors is to do with time streams. This is the excuse used when a current Doctor event directly interferes with a past Doctor event. For example, the Doctor doesn't remember

 he saved Gallifrey rather than destroy it

until the events responsible for that were present in his time stream. From the TV episode The Day of the Doctor

WARRIOR: I won't remember this, will I?
DOCTOR: The time streams are out of sync. You can't retain it, no.

WARRIOR: So I won't remember that I tried to save Gallifrey rather than burn it. I'll have to live with that. But for now, for this moment, I am the Doctor again. Thank you.

Only the Doctor performing actions responsible for altering their own past can retain memories of those events.
The events that lead up to Clara going back to save his past incarnations, and consequently the Doctor recognising her and being aware of her presence in his life, begin with Asylum of the Daleks or there abouts (he realises who she is in The Snowmen). As such, even though he had met her previously (it's shown that he met her face to face while stealing borrowing the TARDIS, an event he remembers fondly and very well and would certainly remember the girl who helped him, as well as 10 and the War Doctor meeting her), he doesn't remember her because she isn't in the time stream of events that leads to her entering his past until 11's tenure as the Doctor. Essentially, he can only retain a permanent memory of her once the events that led to her spreading to his past had begun.
Presumably, the Doctor now does remember all of the times Clara had saved him/her in the past and that he/she met her, as the time streams have lined up now. Until that point when the time streams synched up though, any memory of her couldn't be retained.
Answer: The disconnect is between "she went back in time to save the Doctor" and "the Doctor had past encounters with her". The second does not actually follow from the first: she could have saved him without him ever seeing her, at least not to remember. A close analogy from real life would be EMT's/emergency room doctors: most people whose lives they save wouldn't give them a second look if they met in the grocery store.
Answer: The Doctor is able to change the past, even his own past (the events of Day of The Doctor, for example). When he changes history, events change around him - he retains the memories of what previously happened and what he changed. Even other versions of himself on those few occasions where he has met himself do not take the memories of changed events with them.
Clara may have gone into the Doctor's past and changed or influenced past events in his timeline, but as her entering his timeline was a direct result of Eleven meeting her and taking her to Trenzalore these changed events would have altered "around" Eleven so he would not "remember" the things that she changed as if they had happened to him.


why does ring flip of L-fructose occur?

Question:
when drawing the chair conformation for beta-L-fructose, I got the structure above (in the picture). The answer said that the conformation above had a ring flip. Why does a ring flip occur and how can we tell when it occurs?
Comment: For starters, this isn't fructose in the picture ^
Comment: ummm, what do you mean? I'm pretty sure it is beta-L-fructose
Comment: You are missing an OH on the terminal (exocyclic) methyl group.
Answer: These ring-flips are called 1C4-4C1 transitions and these happen to all of the pyranose sugars in solution when the conditions allow. However, the abundance of each forms depends on their energy. There is a so called 1,3-diaxial interaction between the axial substituents of a cyclohexane analogue. Two axial substituents on the same side are much closer than two equatorial substituens. If these substituents are relatively big, it will be energetically unfavorable to bring them close together due to steric effects. Therefore the molecule will "choose" the conformation that has less energy, so less "large" substituents on the same side. In your case the OH and Me groups are considered the "large" substituents, while the H atoms (undrawn) are the "small" ones. Therefore the conformation you drawn has an unfavorable Me-OH interaction, which will drive the conformation change from 4C1 to 1C4.

(source: prenhall.com)
Answer: Molecules vibrate and twist all the time, the energy they have is more than just zero point energy because they in a 'heat bath' of other molecules at, say, room temperature. In the case of (non-aromatic) rings such as fructose or cyclohexane the activation energy needed to move from the chair to the boat form is not much greater than normal thermal energy so both these forms co-exist in equilibrium with one another but with the chair being favoured do to lower steric interaction as described in the answer by @fasekaszs. The ring strain is particularly small in 6 membered rings.

why does ring flip of L-fructose occur?


How to change screen's in windows phone 7?

Question: Problem with the UriMapper. The flaw is when i am navigating to my EULA page which navigates to first page which navigates to Main Page.xaml but, this navigates back to EULA.xaml, here i mapped the MainPage.xaml and toggled between EULA.xaml and MainPage.xaml. So, the problem is after EULA->firstpage->EULA but i want it like EULA->firstpage->MaiNPage. How to achive this?
Regards,
Panache
Comment: possible duplicate of [On application launch show 2 different pages based on a condition?](http://stackoverflow.com/questions/4263039/on-application-launch-show-2-different-pages-based-on-a-condition)
Comment: looks like the same question... there's also an open question on this same topic here http://stackoverflow.com/questions/4438088/how-to-change-screens-in-windows-phone-7/4438227#4438227
Answer: You have a navigation loop.
Instead of mapping MainPage with UriMapper, map a virtual page eg. MainOrFirstPage.
Answer: Are you talking about a Navigation Loop ? I have this problem with a login screen : Remove a page from Navigation Stack
Answer: If you want a way to only show your EULA page once, have a look at these questions which all cover this issue:
Creating a Logon Screen
How do I clear navigation history in Silverlight/Windows Phone 7?
How to change the startup page of a WP7 Application
Windows Phone 7 Sign in screen redirect
On application launch show 2 different pages based on a condition?


Type of residuals to check linear regression assumptions

Question: I would like to better understand some recommendations usually given to chose one or another type of residuals when checking the assumptions of a linar model.

Lets define the raw residuals as the classical errors $\hat{\epsilon}_i = \hat{y}_i - y_i$
The standardised residuals are defined by $\frac{\hat{\epsilon}_i}{\hat{\sigma}\sqrt{1 - h_{ii}}}$
The studentized residuals are defined by $\frac{\hat{\epsilon}_i}{\hat{\sigma_{(i)}}\sqrt{1 - h_{ii}}}$

I perfectly understand why standardised or studentized residuals are preferable to raw residuals when checking for outliers for example. But for other "post-fit checks", I do not always see the difference. Here are my questions:

When checking for normality of errors, does it make any difference to use one type of residuals or another? Some authors go for a QQ-plot of raw residuals against theoretical normal quantiles, other authors recommend a QQ-plot of studentized residuals against theoretical $t$ quantiles, but this sounds equivalent to me. (I cannot imagine any situation where these two plots would lead to different conclusions.)
When checking for constant variance, we can often read that it is slightly better to use standardised or studentized residuals rather than raw residuals. I guess this is because $V(\hat{\epsilon}) = \sigma^2 (I − P_X)$, i.e. the variance of raw residuals is non-constant by construction? Consequently, if a quick visual inspection of raw residuals (plotted against fitted values) reveals a slight heteroscedasticity, we cannot really know if it comes from the inherent nonconstant variance of raw residuals or from a true phenomenon in the data? Is this the reason?
Except for autocorrelation checks, is there any reason to prefer studentized residuals over standardised residuals (for normality, heteroscedasticity and outliers checks)?
Comment: Related (older) question: [When/why not to use studentized residuals for regression diagnostics?](https://stats.stackexchange.com/questions/406407/) with some links to other related threads.
Answer:
From my experience, you should not get different conclusions when assessing the normality of residuals.
Some authors note that standardized residuals z >|2.00| should be assessed. However, note that the calculation of standardized residuals (ZRESID) is based on the generally untenable assumption that all residuals have the same variance. To avoid making this assumption, it is suggested that studentized residuals (SRESID) are used instead. Essentially, you can accomplish this by dividing each residual by its estimated standard deviation.
To be frank, I am not sure, but I wanted to add a couple of notes for consideration. In terms of autocorrelation: it normally only makes sense to test for it, once your observations have some ordering (e.g. time, distance). Also, when checking for outliers and influential cases, you might think of using Cook's D (distance) instead (Cook, 1977). This measure was designed to identify an influential observation or an outlier whose influence is due to its status on the independent variables(s), the dependent variable, or both.

References:
Cook, R. D. (1977). Detection of influential observation in linear regression. Technometrics, 19(1), 15-18.
Pedhazur, E. J. (1997). Multiple regression in behavioral research: Explanation and prediction. Thompson Learning. Inc: New York, NY.


Old Western Guns Trademark

Question: I'm going to be making a computer game with a "western" setting and was wondering if it would be illegal to use guns from that era, like the popular Colt Single Action or the Schofield Model 3, and other weapons of course. I tried to look into it, but didn't find anything.
Comment: I've edited your question.  In general we prefer questions *not* to contain their history (the edit history is available if needed), so I moved the clarification directly into the question.  I also removed the introductory "hi" stuff.  Again, it's generally not the style here.  If you don't like any of these edits, feel free to revert them (and perhaps introduce your own).
Comment: Are you talking about a computer game or are you talking about real life?
Comment: Oh sorry, I'm talking about a computer game
Answer: I don't see a problem.
Colt may be a brand name that's still in use, but that's being used nominatively. Trade Marks protect abuse of a name, not the correct use. You may use Colt to name real Colts, not a cheap Chinese knock-off. In this case, it's an in-game virtual gun, but it still represents the original.
You might get into problems if you name your entire game something like 'Colt Single Action simulator 1848'. At that point you're using Colt as if it's a trade mark for the game, not the gun.
Answer: This article (warning: TVTropes) discusses several reasons why you might want to avoid this, as the name of the gun may be trademark, but the unique likeness of the gun may not be.  It's done with other products (Rock Star games for example, uses this with Guns and Cars, and Pokemon games do this with map locations) to avoid any unfortunate implications of players use of the products or story elements (For example, there are plenty of car manufactures that would like it if Rock Star would not let their cars run over hookers in San Andres... which is difficult to control.).
Most of the time, in this case, the names are going to sound like the actual product or make a pun off of them (Rock Star games loves it's dirty puns, most often featuring sexual or scatological humor... or both).  Others will just make cheeky references to the real product, and they can get pretty obvious if you know your stuff.   For example, instead of featuring the "Colt Single Action" or "Schofield Model 3", try "Bolt Single Action" and "Shoefield Model B" which when read out loud in English fast enough sound like the real world equivilent, but with the serial numbers filed off (figuratively speaking... don't literally do that, it's a good way to get your self into legal trouble unrelated to copyright infringment).

Old Western Guns Trademark


Frequent job switches

Question: I am in IT profession and have switched my job very frequently (maximum tenure 10 months others less than 10 months). If my future employer asks me the reason for a switch what convincing answers I should give? Would honesty be the best policy? I don't want to seem as a job hopper...
Comment: Why *did* you keep switching jobs? Answer that question and you have your answer.
Comment: possible duplicate of [How can I improve a resume to avoid looking like a job-hopper?](http://workplace.stackexchange.com/questions/1263/how-can-i-improve-a-resume-to-avoid-looking-like-a-job-hopper)
Comment: @Sonali: I think that's convincing enough. People switch jobs frequently, it's nothing you need to be ashamed of really.
Comment: first company shifted, second company had no work and third when i got it i got married n relocated..but this shoul b convincing..
Comment: Im technical. I job hop alot. My 2 favorite reasons are 'they are moving jobs to India' or when on a government contract 'the company lost the contract'. seems to work just fine.
Answer:
If my future employer asks me the reason for a switch what convincing
  answers I should give?

You should be honest about why you switched, but try to accent the positive aspects. Honesty is convincing. Optimism is convincing.
You might try something along the lines of "I know it looks unusual, but in each case there were strong reasons why I felt it was really important to leave sooner than I would have liked.", and then be prepared to tell the specifics about why you have left each former job.
Remember, the hiring company wants to be reassured that you won't leave them after just a few months. Companies invest a lot in bringing in new employees - salary, training, disruption in other workers' time, etc. I have hired many people over the years. Hiring is often a tedious, difficult process for a hiring manager. And I always want to make a wise investment in someone that will be around for the long haul, rather than someone who will be gone in less than a year.
Thus, you want to indicate to them that this time you plan to stick. Tell them what is different now (you are married now and settled in, have no plans to move, you are sure this company has plenty of work, etc). Tell them that one of the most important things to you for your next job, is one where you can stay a long time.
But only say all this if you actually mean it. If you really suspect that you might not be around for long, look for temp jobs instead. Continued short-term job hopping probably is not good for your reputation or your career. I know seeing many sort-term jobs on a resume is a major red flag for me when I'm hiring.
Good luck!
Comment: thanks a lot..actually am worried of this question more than the interview....:(

Frequent job switches


Does EOF actually exist?

Question: When I use file functions in PHP, I check for EOF. I wonder if EOF actually exist in a file. When I create an empty text file, it displays 0KB. How does EOF exist in a file with 0KB?
Answer: There is an end-of-file control character (in the ASCII character set it's CTRL+Z or 26 or 0x1A), but it hasn't actually been needed to mark the end of a file since OSes released in the 80's.  All modern OSes store the file size as metadata in the directory structure (exact format depends on filesystem) and high level file access functions will check the file size to decide when to indicate EOF to you, the programmer.
If there is an end-of-file in the data AND you have text-mode translations turned on (in most languages this is the same setting that controls NL <-> CRLF conversions), then the file access may stop when it hits that EOF character.  In binary mode, reads will keep going until the file size is hit.
Comment: Right, and other OSes used file separator (28) and so forth.  Just another reason we should be glad using a character to mark end of file is obsolete.
Comment: ^D is not EOF on unix. Rather, terminal devices on unix allow you to define a control character that generates an EOF condition on the device when pressed, and the default is ^D. But this does not mean the ascii byte for ^D ever appears in the stream of data from the terminal...
Comment: 'hasn't actually been needed' oh? What about for pipes?
Answer: In modern filesystems there is no actual EOF character on the disk. It's implemented in some file reading functions by returning a 4 byte value instead of a 1 byte value, but most functions don't use the concept.
Answer: it doesn't exist.. but file size does, and that's how you know where is eof

Does EOF actually exist?


Protecting Password in Code

Question: I am writing a program in Processing (which is basically java), that (amongst other things) downloads files from a FTP Server. To connect to the Server the program needs the correct FTP-password, which is currently saved as plain text in a String in the source code. The program should be given out to other people later, so I'm guessing this is not a very safe way to store the password.
What would be a good way to protect the password?
Comment: Without the user providing input, and comparing it to a hash I don't think there's a secure way to do what you want.  Encrypting the password means you have to store the encryption key in plaintext somewhere, which is as good as storing the password in plaintext.  From a security perspective anyway.
Answer: I think your effort is broken by design. You want to install a program at someone's machine that connects to an FTP server via password, but you don't want the user to know the password. No matter what you do to protect it, the user can easily intercept the network traffic comming from the program. For example, the user could set up a proxy and just dumping everything that runs through it - the password will be somewhere in this dump. Encrypting the password at the user's side and decrypting it at the server will just delay the problem - the user will just send the encrypted password.
I would rather set up an extra FTP account with an extra directory just for this user. There he cannot hurt anything, because anything he sees is generated by his own actions.
edit It's true that with FTPS the user wouldn't be able to extract the password. But who is setting up the encrypted connection in the first place? The user's machine. So the certificate is sent to the FTP server before the encryption is done, which can be intercepted again and used to decrypt the whole communication.
Answer: You can't.
FTP is a plain-text protocol.  No matter what you do to slow down reverse-engineering the password from the program code, an attacker can always get the password just by using a network sniffer to watch what the program is sending out over the wire.
Edit: In response to your comment, FTPS is a bit harder to break: an attacker can't grab the password with a network sniffer.  The password still needs to be present in RAM at some point, so the attacker can look for it with a debugger, or they can still reverse-engineer your program to extract the password.
Comment: Or if it would be encrypted connection, by using a debugger to trace what the code is doing. No need to analyse all of it, just get to the step where it deobfuscates the password and print it.
Comment: @BigAl A network sniffer won't see it. But anybody who's running the application on their own machine can still extract the password.
Comment: I forgot to mention it's actually a FTPS connection. Is it still possible to just get the pw using a network sniffer with FTPS?
Comment: No FTPS is secure.  Mark is saying FTP is a plaintext protocol, and you would be able to see the password in network traffic.
Answer: Store the password in source code is the worst approach. But the right approach is not easy to define and depends on chosen procedures.
A better approach could be:

Ask the user to insert the password every time (console/gui interface)
Save the password to a text (property) file, in this case other users with right permissions could read the file with the cleartexr password. You can still encrypt the password(s) with a master password and an cipher like AES. In this case every time the user needs to insert the master password but you can protect many password with the master one at the same time.
Comment: I can't ask the user to insert the password bc the users are not supposed to know it.
Comment: @BigAl So you want the user to use a password without knowing it. Sounds pretty impossible...
Comment: if the user should not enter the password, because he should not know it, you can only obfuscate it. To do it one option is to encode it in AES with a fixed password. You also need to take the risk that the user discover the password anyway, and it is not that difficult!
Answer: What platform is this being run on?
Ideally, you should use something like an encrypted password store, or a password manager which supports APIs or command line utilities.
On linux, I use a tool called 'pass' which uses gpg encryption to store passwords.
When I want to use a password from my password store in one of my scripts, I simply send the output to a variable and assign that variable as the password.
Here's some documentation for pass:
http://liquidat.wordpress.com/2013/03/27/pass-a-perfect-shell-based-password-manager/
I also make use of Password Manager Pro from ManageEngine - they have a great SSL API for retrieving passwords. XML-RPC is also available. They provide java libraries for doing this. PMP is not free though - but it's probably one of the best password managers I've seen for the price you pay.

Protecting Password in Code


Clip slope raster for values outside of percent grade range

Question: I have a slope raster, but I would like to remove values (or make them no data value shading) outside a range which makes them too steep. I tried looking at the raster calculator, and I am not sure how to use it if it can. I keep getting an invalid expression.
An example is a slope percent grade raster, anything over 60% grade is not safe, so I would like to finish with a raster showing this remaining white/gray area.
How would I do this and what tools are needed?
The projection is in UTM meters, but I would also like to do degrees, however, in 4326 the percent grade slope values are extremely high and hard to interpret. So I am starting with just UTM meters.
Answer: I found the processing toolbox raster calculator in QGIS 3.16.15 works but not the calculator in the menu bar. I got valid expressions from this.


AngularJS + Phonegap app: Views fill 100% height

Question: I'm building an android app with phonegap using angularJS + topcoat. I managed creating the index page, views and all the basic structure. My question is, there is some pages(partials) that doesn't have data to show. In that case, the view does not fill the height of the page. That makes a problem because I have a drawer menu hidden usin angular-snap. Because the page doesn't fill all the available height, the menu that is supposed to be hidden is visible. Does anybody know how to handle this situation? I'm attaching a image to examplify! app-example
Thank you!
Answer: Why don't use the css min-height property. Assume every page of your app is wrapped inside a div as follow :

  //your page content
  ...

You can then create the following CSS rule
.page {
  min-height :100%;
}

that will ensure that even if the height of your content is less than the total height of your screen it will occupy 100% of the page's height.
Comment: Thanks for your help. I tried that already and it didn't work. I also tried setting the min-height:100% on the body and html, also didn't worked.
Comment: Nicolas I solved the problem. I was setting the class on the partials div instead of setting on the "main" div with the ng-view directive. Now it works. Thank you for your help!
Answer: I managed solving the problem with Nicolas help. It didn't worked in the beginning because I was setting the new style on the partial's div. After trying for a while I set the class on the "main" div which holds the ng-view directive and it worked. Just an example in case others have the same issue:

.page {
   min-height :100%;
   background:inherit;
}

Note: I had to set a background for the page class otherwise it won't work.


Does each ROM has its own boot?

Question: At the moment, I have Redmi Note 7 on Pixel Experience. I do not like the kernel it has. As a result, I tried to change it by flashing the boot.img of the stock ROM. Unfortunately, it remains stuck at the splash scren.
I also formatted the /Data partition, but it did not solve my problem.
Comment: basically , yes
Answer: Yes, each ROM has its own boot unless the ROM is explicitly build keeping the stock kernel. SO to able to boot your device again, unzip your PixelExperience ROM file, take boot.img from it and flash that.

Does each ROM has its own boot?


Perturbation Theory for the Hydrogen Atom

Question: The full Hamiltonian of the hydrogen atom (including fine structure) is $$H = H_0 + H_{rel} + H_{s.o},$$ where $H_0 = \frac{p^2}{2m} -\frac {e^2}r$, $H_{rel}$ (resp. $H_{s.o}$) is the relativistic (resp. spin-orbit) correction ( I did not include the Darwin correction, since degenerate perturbation theory needn't be applied in that case). The corrections are defined by ($V(r) = \frac {e^2}r$) $$H_{s.o} = k \frac 1 r \frac{\partial V}{\partial r}L\cdot S$$ where $k$ is a constant, and $$H_{rel}= -\frac {p^4}{8m^3c^2}.$$The eigenstates $|nlm_lm_s\rangle$ of $H_0$ are $n^2$-fold degenerate, so we must use degenerate perturbation theory. However, it doesn't seem like the degeneracy will ever be lifted completely, as none of the fine-structure corrections involve the magnetic quantum number (that is, states with different $m_l$ but equal $l$ or different $m_s$ (equivalently different $m$ and identical $j$, using total angular momentum) will have equal corrections.) How is it that we can get away with using 1st order degenerate perturbation theory on the hydrogen atom, when the degeneracies aren't lifted to 1st order (or possibly any order)? Is it just by using the $|nljm\rangle$ basis which diagonalizes each perturbation that everything works out?
Comment: @RogerVadim I added the explicit expressions.
Comment: I suggest writing the expressions for the corrections and/or their matrix elements explicitly, since otherwise the question lacks the essential information (which likelyreadily answer it).
Answer: You answered your own question already: "Is it just by using the $|nljm⟩$ basis which diagonalizes each perturbation that everything works out?" Yes, indeed. The whole purpose of perturbation theory, degenerate or not, is to try to diagonalize a Hamiltonian to a given order. If you work with a basis in which $H$ is already diagonal, you essentially bypass perturbation theory.


Imagecache_external: Thumbnails of external URLs aren't accessible

Question: Modules:
Imagecache External, Media, Remote Stream Wrapper
Scenario:
I created a content type, in which I want to collect Movie Actors. My aim is to add images of those actors which arent hosted on my drupal site itself. They are being linked via Remote Stream Wrapper but RSW doesnt allow to use Image Styles on those external images (for example thumbnails). The solution is Imagecache External, which allow Image Styles even on external hosted images.
Problem:

Imagecache External returns Image-URLs which ends with a cryptic snippet, which resolves into an error message: Access denied

localhost/drupal/sites/default/files/styles/cover/http/img4.picload.org/image/acdcwwi/imagestyle_examp.png%3Fitok%3DAyQfRnDQ

Thumbnails are being saved in a directory, which represents the URL of the external image:

drupal\sites\default\files\styles\cover\http\img4.picload.org\image\acdcwwi\imagestyle_examp.png

Detailed Problem Description:
Imagecache External creates thumbnails with such URLs:

localhost/drupal/sites/default/files/styles/cover/http/img4.picload.org/image/acdcwwi/imagestyle_examp.png%3Fitok%3DAyQfRnDQ

If I open this URL directly, I get an "Access Denied" error because I dont have permission for that page (-> even as an admin!?). If I remove this cryptic snippet at the end of the URL (%3Fitok%3DAyQfRnDQ), the Thumbnail is accessible.
The other problem is that the thumbnails are saved in a directory, which is equal to the external URL:

drupal\sites\default\files\styles\cover\http\img4.picload.org\image\acdcwwi\imagestyle_examp.png

This will result in a not overviewable directory tree.
The external image I linked externally for example is this one:
http://img4.picload.org/image/acdcwwi/imagestyle_examp.png
I hope anybody has a solution to my problem. :-/
Greetings,
KG
Answer: I think it is a bug in imagecache external when there are special characters in the URL. Try to file an issue on the module queue on drupal.org to see.
About the "cryptic" end, it's http://drupal.org/node/1934498.


What are the connotations of the word "Greetings" when used as a greeting?

Question: What are the connotations of the word "Greetings" when used as a greeting? I am British, and I have rarely heard "Greetings!" used as a greeting in the UK. I associate it in my mind with Commander Data in Star Trek: The Next Generation, because I seem to remember he used it a lot. So to me it connotes geeky, formal and stilted. However, I appreciate this may not be accurate.
Comment: Greetings earthling, take us to your commander
Comment: See also: http://english.stackexchange.com/questions/49454/would-greetings-be-a-better-word-to-greet-someone-any-time-than-the-word-hell
Comment: I believe that the answers on Hugo's linked page address the thrust of this question. Marking this as a duplicate ...
Comment: It is sometimes used as a salutation in letters, usually when you don't know the name of the person you're writing to, such as a letter addressed to an organization. Normally we write "Dear Bob" or "Dear Mr Jones", but of course we can't do that if we don't know the person's name. "Dear Service Department Person" is just awkward. It used to be the convention to write "Dear Sir", but that implies the reader is a man. Thus "Greetings" is good and general and vague.
Comment: I was taught as a child to use "Dear Sir or Madam", instead of "Dear Sir", in such situations.
Answer: I doubt there was ever a time when "Greetings!" was a common salutation. Because it's perfectly comprehensible, some people might assume it's a "dated" usage - and by association, perhaps they might therefore assume it's formal/stilted, but I don't think that's really accurate.
In "real-world" contexts today, it's usually (but not always) used facetiously. But because it's a relatively uncommon non-idiomatic form, it's often used in contexts where the intention is to convey that the speaker is somehow "exotic" and far removed from everyday life as we know it.
Consequently, it's often used in science fiction/fantasy novels, movies, etc., which is why OP also perceives geeky associations. It might also turn up in "historical fiction" - but again, I think that would be because the writer wants those exotic/distant connotations, rather than because they've researched the matter and are accurately reflecting the usage of a bygone age.
So if a native English speaker greets you with "Greetings!", you can usually assume he's being flippant/jocular. With a non-native speaker, you could perhaps infer he's not fully fluent.
Answer: Several dictionaries don't agree with the notion that it is somehow facetious or jocular. It may be, but I would definitely say that it is normally used as a formal means of acknowledging someone.
The Cambridge dictionary, for example, has this to say...
<code>greetings [plural] a message that says you hope someone is well,
                   happy, etc birthday/Christmas greetings
            formal My father sends his greetings.
            formal Greetings to you, my friends and colleagues.
</code>


Orthonormal Basis for $[5,1+t]^{\perp}$

Question: Consider the vector space $\Bbb{V}=P_3(\Bbb{R})$ of the real polynomials of degree less or equal 3, with the inner product given by
$$\langle f,g\rangle=\int_0^1f(t)g(t)dt,\forall f,g\in\Bbb{V}.$$
Find a orthonormal basis for $[5,1+t]^{\perp}.$
I've some ideas of how to do it by finding the expression for a vector from $[5,1+t]$ and then yielding a basis for $[5,1+t]^{\perp}$ and so using the Gram-Schmidt Orthonormalization Process. But I'd like to know if there is some way of avoid this, saving effort. Has anybody some hint?
Answer: Either apply Gram-Schmidt to $\{1,x,x^2,x^3\}$ or search through some known http://mathworld.wolfram.com/OrthogonalPolynomials.html.

Orthonormal Basis for $[5,1+t]^{\perp}$


How to get information from ERC1155 token metadata in Solidity?

Question: How to get data from token metadata in contract? It is ERC1155 token, metadata json stored on ipfs
Answer: With ERC-1155 you must know the id of the token, it doesn't matter if that's an ERC-20 Token (Fungible) or an ERC-720 (Non Fungible), you must provide an id.
Assuming for the example that the id is 0 and that the contract you are interacting with supports the optional ERC1155Metadata_URI (You can check that through ERC-165):
You need to call the uri function with your token id 0 which may return one of two things :

a specific token uri that you can use right away
a generic token uri containing the substring {id} which you will need to replace.

In the second case, with the result after calling contract.uri(0) you should see that {id} substring that you must substitute for your specific id.
As the EIP states :

The string format of the substituted hexadecimal ID MUST be lowercase
alphanumeric: [0-9a-f] with no 0x prefix. The string format of the
substituted hexadecimal ID MUST be leading zero padded to 64 hex
characters length if necessary.

so in our example, you'd need to substitute {id} for : 0000000000000000000000000000000000000000000000000000000000000000.

Additionally, make sure to look for other {id} substring in the resulting json metadata file as it is possible other substitutions are required there too.

If the string {id} exists in any JSON value, it MUST be replaced with
the actual token ID, by all client software that follows this
standard.
Comment: Thank you @hroussille but I want use data from metadata in contract that mint this tokens, e.g. function that returns name of token or other information stored in metadata
Comment: Ah okay, that's not possible straight away http or ipfs are outside of the Blockchain context which is the only one you have access to with solidity. Maybe some oracle service could provide that but I have not heard of it at least...
Comment: You may extend the contract definition to include your metadata in it or maybe use chain link oracles to fetch those values for you but it goes against the definition of metadata then.. you are not supposed to use them in that context , they are purely informative. Everything you need for logic should be contained in your contract(s)


Why the "meat" in "sweetmeat"?

Question: This has always confused me.  Dictionary.com doesn't help at all.  Candy and meat just don't go together that well.
Answer: The key is that meat used to just mean "food". The first entry under meat at Merriam-Webster has exactly that definition, though of course the primary sense of meat today is  definition #2, which specifically refers to animal flesh. However, the older, broader sense of "meat" still sticks around here and there, such as the practice of referring to the edible part of a nut as the "meat", and in compounds such as "sweetmeat".
Comment: Ok, now explain "sweetbread" meaning meat o_O
Comment: @Karl Knechtel One of the meanings of _bread_ is "a piece or morsel of food."
Comment: @kiamlaluno and *brede* means "roasted meat" while Old English *bræd* means "meat" or "flesh",
Comment: My grandmother would make "mincemeat pie" which confused us (her grandchildren) when we were little, because it had no meat in it...
Comment: @GEdgar a seasonal classic, though still (unless matters changed recently) illegal to eat around late December under laws passed during the Interregnum banning many Christmas traditions and later ignored rather than repealed.
Answer: The OED reports the following definitions for meat (I report the first two):

Food; nourishment for people or animals; especially solid food, as opposite to drink. Now archaic and dialectal. OE.

S. Johnson: The horses could not travel all day without rest or meat.
    Shelley: He had… meat and drink enough.
    Proverb: One man's meat is another man's poison.
A kind of food, an article of food. Obsolete except in sweetmeat. OE.

Why the "meat" in "sweetmeat"?


Programmatically Create Record Type

Question: Is it possible to programmatically create a record type in Apex to be used in a test?
Answer: No, it's not possible to create RecordTypes from Apex, since RecordType doesn't support DML.
It's likely possible to achieve your ends some other way - for example, see this answer to a similar question.
Answer: Create a record type manually like this:

Setup -> Customize -> Accounts -> Record Types
Click 'new'.
Specify your record type.
Click save.

Assign to a user the permission to view and assign a record type:

Setup -> Manage Users -> Profiles -> choose a profile
Under the category: "Record Type Settings" choose edit field, next to Accounts.
Under "Available record types" select your record type.
Press 'Add' to add the record type to the selected record types.
Specify a default record type, click Save.

Programmatically Create Record Type


Should we have an animal-ethics tag?

Question: This question:
When is declawing a viable option for cats?
May be the beginning of more of these types of questions. Should we have an ethics or animal-ethics or pet-ethics` tag?
Comment: If at all I'd go with ethics. Prepending 'pet' or 'animal' on a site about pets seems a bit redundant. (applies to most but not all tags of course)
Comment: I got it back to front? @Baarn feel free to edit
Answer: No. I don't think so. The ethics you are referring to are human ethics.
Your answer on the linked post lists countries where declawing is illegal (one of them being mine) but in other places, I suppose it is an option.
Another example of a possible ethics related question would be the anything related to the differences between livestock and pets with regard to consumption.
The answers would most likely be "localized" to the specific region of the user so the highest voted community answer may very well be considered un-ethical to readers not located in the same region.
Answer: I don't think that ethical discussions are appropriate here. What I consider ethical is going to vary greatly from what someone else thinks, and we risk having rants and arguments instead of solid questions and answers. I know it is difficult when we are talking about the welfare of the animals we love to put aside our feelings in these matters, but like I said in my other answer regarding g ethical matters, I think it is important to assume good faith and good intentions, and also remember that other people's opinions and ideas may not match your own, but that doesn't make them terrible people.
You also will never get a consensus on what is the correct or most appropriate answer in these cases, as it will vary greatly from place to place and person to person
In general, SE is a place for concrete, factual answers, and ethics runs too close to opinion and such for it to really be viable.
I would hate to see fights or arguments break out just because two people disagree about what is ethical, as there are so many factors that go into those sorts of personal ideals that we really shouldn't try to take a solid stance on it as a site, because there will always be people who may not be on the same page, and it is a very complex and I feel also a personal issue.
Answer: As I tried to mention in my answer to Questions of moral, ethical and legal nature, this is one of the things that is really going to be a problem because of the international nature of the site, and what is considered proper or normal in one culture, may not be another.  Even in my own country (the US), the laws pertaining to some of the items I mentioned are mixed, so you are not going to get a consensus answer to an "ethical" question.
To quote myself:

I think it is important to avoid reacting with our personal opinions on such, especially in the answers. This simple fact is someone might not actually understand why such a practice is not good for the animal and a calm and objective answer giving the facts is appropriate.

The point I was trying to make here is that the answers need to be based on facts or at least experience based observations to get a point across as to what the proper course of action is, so dragging ethics into the question is inviting an opinion based answer because my ethics might be different than yours.

Should we have an animal-ethics tag?


Can't we stop the time?

Question: Time is called as a measurement of difference between two or more incidents. So if we stop happening incidents can't we stop the TIME? Eventhough it's impractical, I mean if we reduce the temperature of earth to absolute zero.... isn't it stop the motion of matter and stop the time? When we start increasing temperature again isn't the time starts from where we stopped?
Comment: It's something came to my mind recently
Answer: Even if you stop the time, quantum mechanically, the energies of systems are not zero. The simplest example would be quantum harmonic oscillator which has a ground state at $E_0=\hbar\omega/2$.
In any case, Heisenberg's uncertainty principle also prohibits to completely stop the movement of a particle as that would mean we have absolutely no idea where that particle is in the entire universe.
Answer: According to the special relativity, if you are able to move close to the speed of light then time might be slow down because in your frame of reference the speed of light also be speed of light we can not allow the relative velocity. The event horizon of a black hole is one of the closest place for almost completely stop of time...

Can't we stop the time?


How to add code to custom field to every blog post via php?

Question: I have a custom field value in every post. I need a rule to automatically add code to that custom field in every blog post. How can I do this ? thanks :)
Comment: Need clarification - you are saving code (what kind?) as custom field values on every post? Do you need this done in a batch or whenever posts are edited?
Comment: the custom field display just html code, it is a value. I need to envelope it with a script in every post. It should work this way :
- user write a post using a front end post editor, giving the custom field a value
- after post is sent, the custom field should be automatically enveloped (I guess via php) with a script that makes that field visible only for registered users. Actually I add manually the shortcodes of a content locker before and after the custom field, but I would like the procedure to be automated. Thanks
Answer: You can use the update_post_metadata hook to edit any custom field value right before it's saved to the database. For example:
function update_my_post_metadata( $check, $object_id, $meta_key, $meta_value, $prev_value ) {
    if ( $meta_key === 'MY_META_KEY' ) {
        $meta_value = 'BEFORE' . $meta_value . 'AFTER';
        update_post_meta( $object_id, $meta_key, $meta_value );
        return true;
    }
}
add_filter( 'update_post_metadata', 'update_my_post_metadata', 10, 5 );

In that example you would replace MY_META_KEY with your meta key, and BEFORE and AFTER with whatever arbitrary HTML or shortcode you wish to wrap the meta value in.
Alternately -- looking at the details in your comment -- if you're just trying to make it so that only registered users can see it, you can do that when you're outputting the meta value, like this:
if ( is_user_logged_in() ) {
    echo get_post_meta( get_the_ID(), 'MY_META_KEY', true );
}


Angles in Ptolemaic Model

Question: I am about to work with Ptolemy's Model for the motion of an upper Planet (Mars). I use a epicycle rolling on the deferent. As a first step, I am just interested in the shape of the trajectory, which is why I can ignore the equant, because the uniform motion arount the equant does not change the fact, that the epicycle rolls on the deferent, which is why $\phi_0^*$ can be expressed in terms of $\phi^*$, $r_A$ and $r_a$. I want to express the angle $\phi^*$ or $\phi_0^*$ in terms of $\gamma$. I assume $r_A$, $r_a$ and $c$ (distance from Earth A to the center of the deferent $B$ and distance from this center to the equant as well). How can I express $\phi^*$ geometrically?
Answer: You misunderstood Ptolemy's model: The epicycle doesn't "roll on" the deferent; rather, the epicycle's center is on deferent. Mind you, it's only a minor detail in this situation.
In the diagram you drew up, it is impossible to know φ* in terms of γ alone, as φ₀ could take any value. Also, in Ptolemy's model, φ₀ does not depend on φ*, so φ₀ ≠ δφ*. However, both vary uniformly, by quantities that we will here call ωₐ and ωₜ after Pedersen.¹ For example, in the case of Mars, ωₜ = 0°;31,26,36,53,51,33/day and ωₐ = 0°;27,41,40,19,20,58/day.
You are correct to presume that c, rₐ, and rA were known and specified in Ptolemy's model—a good part of the Almagest is spent determining such values for rₐ and rA supposing that c = 60 units.
Finally, nowhere in the Almagest are φ* or φ₀ expressed in terms of γ, as both of them, as hinted two paragraphs above, are only time-dependent. Because none of the angular speeds given for ωₐ and ωₜ is a factor of 360°, this means that for a given γ, any value of φ* and φ₀ is possible, depending on how long has elapsed since the reference date (the "epoch"), which Ptolemy chooses, for historical reasons, to be February 26, −746 (aka 747 BCE), Noon Alexandria true solar time (Julian Day 1448637.91666…).
If you understand the language, I have translated the Almagest to French, with some diagrams animated or interactive. It's freely available at https://ecliptiqc.ca.

¹Pedersen, O. A Survey of the Almagest. With Annotation and New Commentary by Alexander Jones. New York: Springer, 2011, 480 p., ISBN 978-0-387-84825-9.

Angles in Ptolemaic Model


ODEs whose finite-time solutions are not L^2 on their interval of definition

Question: Let $f:\mathbb{R}^n\to\mathbb{R}^n$ be analytic and consider the ODE
$$x'(t)=f(x(t)).$$
It is well-known that if $(t_{min},t_{max})$ is the maximal domain of a solution $x$ and $t_{max}<\infty$, then
$$\lim_{t\to t_{max}}|x(t)|=\infty.$$
Let $t_0\in(t_{min},t_{max})$. What conditions on $f$ (appart from linearity) ensure that
$$\int_{t_0}^{t_{max}}|x(t)|^2dt=\infty,\quad\text{when }t_{max}<\infty?$$
Answer: This  is  not  an  answer, but  is  a  comment.  (I  can not  give  comment  since  I  am under  50  reputation).
Linear  vector  fields  are  always  complete  vector  field  so they  do  not  satisfy your  condition.
But for  higher  order  polynomial  vector  field, I  guess that the  solutions  which are  not  a  complete  orbits, are  not  in $L ^2$.  My  motivation is  that according  to  an interesting  Paper  of  Chicone and  Sotomayor, the  solutions  escape  at  infinity  very  fast(exponentially)  since  there  is  a  hyperbolic  singularity  at  equator.
On the  other  hand   your  question is  very  interesting  for  me  since it  implicitly   suggests  to  consider  some  different  function  spaces to  be  acted by $D_f$,  the  derivational  operator  associated  to  the  vector  field  $f$.
The  motivations  for  study of  this  derivational operator  is  explained in the  following  posts:
Does this function belong to $L^2(\mathbb{D})$?
Codimension of the range of certain linear operators
Answer: Consider the case $n=1$ (and, say, $f>0$, wlog), then $t_{max}<\infty$ iff $\int\frac{dx}{f(x)}<\infty$. Then $\int x(t)^2\ dt=\int\frac{x^2}{f(x)}\ dx$.
Since you didn't mention that simple case, I hope it may help.