What kind of knife is this?

Question: Found this knife in my Grandmother's collection. None of us can figure out what the semi-circle shape and slots are for (see attached picture).  Anyone have any ideas?
Comment: How sharply cut are the slots? I have seen multi-purpose tools with slots like that to be used as peelers/graters. The bottle opener at the hilt would also suggest a strange multi-tool.
Comment: @sobachatina, the slits aren't sharp at all, they're quite smooth. I guess multi tool makes sense, but I have no idea what the rest could be used for.
Comment: Is the spine sharp, making it usable as a mezzaluna?
Comment: @rackandboneman No, the spine isn't sharp. Good question though.
Comment: If the metal is tempered right to support a serrated edge well, it will probably support sharpening the spine ;)
Answer: It is a multi-tool, which appear to have been given out as novelties. The bottle opener and serrated knife are obvious, the slits are there to act as a pot strainer, the semi-circle shape and flat surface allows you to hold it against the edge of a pot and pour out the liquid while keeping solid bits in. I found a few of them on Ebay, the good links (as of this answer) are:
Vintage Farmers Co-op Creamery 1967 Bread Knife
Vintage Multi-Purpose Knife Bottle Opener Strainer Stainless Wood Handle Japan -
Given the nature of Ebay I can't guarantee these links will be good for long
According to the inscriptions on some they were given out by a couple of different Farmer's Co-ops and a Drilling company...does yours have any writing on it?

...and here is a picture of a pot drainer (single purpose) as it would be used.
Comment: Ahhh, a pot strainer. That makes sense. We tried a Google image search, but that failed. Guess our Google-fu wasn't as strong as yours!  It does have writing on the side, it says "Keller Grain and Feed."
Comment: As a 'novelty' item, I would not expect it to work particularly well. On the other hand it looks like you could get $14.95 off of Ebay for it if you want.
Comment: Looks handy for camping though.

What kind of knife is this?


What does the With Editor status mean for an Elsevier journal after being with the Managing Editor (ME)?

Question: I submitted a paper to an Elsevier journal, but it was not assigned to a reference number. They sent me a mail stating that the paper with the managing editor for initial evaluation . After tow weeks later, I got mail stating that the paper is with the Editor. And it was assigned to a reference number. What does this mean? Thanks in advance.
Comment: The Managing Editor handles technical publishing issues and record keeping (initial check in the chart), and is likely not an expert in the subject matter.  The Editor handles getting the paper evaluated, and is likely an expert in the subject matter.
Answer: "Managing editor" can mean many different things, e.g. for one of the journals I used to handle, the managing editors were effectively editor-in-chiefs using a different name.
In your case most probably the managing editor is some kind of gatekeeper to the journal. It could be the editor-in-chief, or it could be an employee of the publisher. They looked to see if your manuscript was within scope of the journal, and if it was, who the best member of the editorial board to handle it is. Then they forwarded the manuscript to that editorial board member.
There's nothing else to do except wait.


How can I remove odor of spilled sewage under the sink?

Question: My plumber did a really poor job when he replaced a pipe under my kitchen sink because he spilled the remaining sewage in the pipe all over the place. As a result it smells really bad under the sink (like ammonia and butyric acid), even though I have cleaned all surfaces thoroughly three times with various cleaning agents. The remaining smell comes from the surface of a corrugated PVC pipe and from the slits in the wood joints of the sink rack. Any idea how I can eliminate the remaining odor? Thanks.
Answer: At pet stores (and many other stores) they sell "enzymatic" cleaners that are made to destroy urine odor.  In my experience, they also work on other stubborn smells that can't be cleaned by ordinary cleaners since they work by actually breaking down the odor causing contaminates.
If that doesn't work, there's also a type of primer that you can purchase at a paint or home improvement store that will help seal in odors.  A shellac-based primer like Zinsser BIN will work well.  I've used it on paneling that reeked of smoke and on sub-floors where an animal died, and it worked well.  It dries very fast, so it's easy to use, but hard to clean up.
Answer: I would replace the contaminated wood.
If I could replace the corrugated PVC pipe without calling in a plumber or breaking any of the plumbing seals, I would do so.  If not, I would "entomb" the corrugated PVC pipe in a slightly larger pipe, and seal the ends with vinyl electrical tape.  I might need to cut the larger pipe in half in order to install it.  I would use vinyl electrical tape (not glue) to attach the larger pipe, and to seal the "seams" where I cut it.  That way, if my idea did not work, I could uninstall the larger pipe without damaging anything.
Comment: Good idea to completely seal it, this will be my last resort if enzymatic cleaners don't help. I've removed some of the wood and it makes a big difference already.


how can I download a file from a password protected folder in java

Question: want to download a file from a online server and I don't want it to be acessible outside my application so I have protected the folder using the control panel , now I need to know how can I acccess and download that file in my java program ? Its an android app that downloads a database. My situation is that I have two databases, one for the free app and another for the paid version.And I dont want people downloading the paid version to the pc and using them on the free version app.Is there another easy way ?
Answer: Please see the Apache HttpClient Examples, Client authentication. Android ships with these libraries by default.


Hopf Algebras and Quantum Groups

Question: I have studied graduate abstract algebra and would like to learn about Hopf algebras and quantum groups.  What book or books would you recommend?  Are there other subjects that I should learn first before I begin studying Hopf algebras and quantum groups?
Comment: I fear that a year long course covering the above-mentioned fields is, at best, an introduction. What you definitely will need in Hopf algebra theory is a good grip on tensor products, at least over fields (at the very least, the exactness properties and their consequences). Also, knowledge of representation theory a la http://arxiv.org/abs/0901.0827 is of much use; many Hopf-algebraic theorems generalize known facts of representation theory and seem utterly devoid of motivation if you don't know the latter.
Comment: Why the "suppose"? Have you, or have you not? (Also, since educational systems can vary, what have your abstract algebra courses covered?)
Comment: I did take abstract algebra. It covered Group theory, Rings, Field Theory, Galois Theory, classical Algebraic geometry, modules, vectors spaces. It was a year long course.
Comment: Related question: http://mathoverflow.net/questions/115231/expository-papers-related-to-quantum-groups "expository papers related to quantum groups "
Comment: This https://math.stackexchange.com/a/2191760/195021 answer might also be of some interest (although it comes ... years later !).
Answer: I don't think that you really need to learn much more algebra before you start on Hopf algebras.  As long as you know about groups, rings, etc, you should be fine.  An abstract perspective on these things is useful; e.g. think about multiplication in an algebra $A$ as being a linear map $m : A \otimes A \to A$, and then associativity of multiplication as being a certain commutative diagram involving some $m$'s.  This naturally leads to dualization, i.e. coalgebras, comultiplication, coassociativity, etc, and then Hopf algebras come right out of there by putting the algebra and coalgebra structures together and asking for some compatibility (and an antipode).
For the Drinfeld-Jimbo type quantum groups, it is helpful to know some Lie theory, especially the theory of finite-dimensional semisimple Lie algebras over the complex numbers.  If you don't know that stuff, the definitions will probably not be that enlightening for you.
There are a lot of books on quantum groups by now.  They have a lot of overlap, but each one has some stuff that the others don't.  Here are some that I have looked at:

Quantum Groups and Their Representations, by Anatoli Klimyk and Konrad Schmudgen.  They have a penchant for doing things in excruciating, unenlightening formulas, but this book is the first one that I learned quantum groups from, so it remains the most familiar to me.  This one has a lot more about Hopf $*$-algebras than any of the others.
A Guide to Quantum Groups, by Vijayanthi Chari and Andrew Pressley.  Has an approach based more on Poisson geometry and deformation quantization.
Foundations of Quantum Group Theory, by Shahn Majid.  Goes into more detail on braided monoidal categories, braided Hopf algebras, reconstruction theorems (i.e. reconstructing a Hopf algebra from its category of representations) than most other books, although some of this is covered in Chari-Pressley.
Quantum Groups, by Christian Kassel.  Focuses mainly on $U_q(\mathfrak{sl}_2)$ and $\mathcal{O}_q(SL_2)$, and does a lot of stuff with knot invariants coming from quantum groups.
Hopf Algebras and Their Actions on Rings, by Susan Montgomery.  This one is more about the theory of Hopf algebras than about Drinfeld-Jimbo quantum groups.

There are some other ones which I know are out there, but I haven't read.  These include Lectures on Algebraic Quantum Groups, by Ken Brown and Ken Goodearl, Lectures on Quantum Groups, by Jens Jantzen, Introduction to Quantum Groups, by George Lusztig, and Quantum Groups and Their Primitive Ideals, by Anthony Joseph.  Having glanced a little bit at the last two in this list, I found both of them more difficult to read than the ones in my bulleted list above.
So, as you can see, there is a lot of choice available.  I would advise you to check a few of them out of the library and just see which one you like the best.
Comment: Etingof also has a book on quantum groups. I haven't spent much time with it but it seems good.
Answer: I agree with MTS comment that you do not need much to start with. Whether you need more or not will depend on your focus: which part of the theory are you interested in?
Personally I would reccomend Serre's Complex Semisimple Lie Algebras as a must since you most likely will end up fighting with Serre's relations.
Also, classic books on Hopf algebras are not to be forgotten; here the choice is between Abe and Sweedler, if I remember correctly the title is "hopf algebras" in both cases.
As for the three books about which MTS does not add comments let me say something:
Joseph's book requires a solid background on Lie algebras and their reps, otherwise it's almost impossible to understand its directions. With this background it's a very intriguing, though demanding, reading.
Brown-Goodearl is a great book to start with. It's built from lecture notes of a course and therefore "learning oriented". It's much oriented towards the more algebraic part of the theory. I would reccomend McConnell-Robson book on Noncommutative Noetherian Rings at hand...
Lusztig's book requires feeling at ease with various categorical issues: definitely not a first reading. It is also uite narrowly focused on some specific aspects. I would not put it in any list: if that is your direction at some point younwill be forced into it.
I do not know about Jantzen's book.
Comment:  "Algebras of functions on quantum groups, Part 1"
 By Leonid I. Korogodski, Yan S. Soibelman
Comment: Yes, but that is the less algebraically oriented of all... I am still waiting for Part II
Answer: Thomas Timmermann's Invitation to Quantum Groups and Duality.
Answer: I think it is also worth to mention the book "S. Dascalescu: Hopf algebras. An introduction" as a suitable textbook on the algebraic theory of Hopf algebras. However, since it is not dealing with quantum groups, it could be timely to use it together with some books mentioned by MTS on this subject.

Hopf Algebras and Quantum Groups


Still using texlive 2017

Question: I've just upgraded to Texlive 2018 via dnf and my Tex installation no longer works, using kile as the frontend. It is trying to use Texlive 2017
Comment: (1) welcome, (2) we need more information: what operation system are you using? Kile is mostly used on Linux, exactly what did you install and how? Is Kile explicitly configured to use full path when it calls latex? If so, adjust it to the new page.
Comment: The Linux distros tend to be a little behind with TeX Live. I always install TL via the TUG DVD rather than dnf but you could try to adapt [How to install "vanilla" TeXLive on Debian or Ubuntu?](https://tex.stackexchange.com/q/1092) if you need the dependencies.
Comment: see if your `$PATH` variable is set accordingly
Answer: I have fixed a similar problem by removing everything through

dnf remove texlive texlive* texlive-scheme-full texlive-collection-science kile

then

updatedb

Then

locate texmf

and remove every instance using rm -rf with real care. Especially, there may be a hidden directory - something like \home\bob\.texlive2017, visible via ls -al. Then updatedb, reboot and then install via dnf or the equivalent the sequence above.
Worked for me, though I suspect that the problem was the .texlive2017 directory.

Still using texlive 2017


What is the regulatory process of being able to produce and sell an alcoholic drink in South Africa commercially?

Question: We have started producing small batches of a unique honey mead that is doing well in small to large stall type markets. What are the steps that need to be followed in order to get a license to continue to produce and distribute an alcoholic beverage in South Africa?
Answer: A simple google search for "alcohol manufacturing south africa" turns up a lot of helpful results...
Essentially, you need to apply for a macro manufacturing and/or distribution liquor license. In order to do so, you will need to register with the National Liquor Authority (NLA) of South Africa.
The information you need to provide and requirements you need to meet include, but are not limited to: company information, financial interest in the liquor industry, obtaining a "B-BEE" Certificate (Broad-Based Black Economic Empowerment Codes of Good Practice,) projected annual turnover, and a registration fee.
Required documents include:

Applications should be accompanied by:

A business zoning certificate for industrial purposes or a consent    letter from the relevant municipality;
A comprehensive written representation in support of the application;
Any determination, consent approval or authority required by the Act;
Valid proof that the prescribed application fee has been deposited in    the bank account of the dti;
A valid certified copy of ID or passport of the applicant;
Trading business permit if the applicant is a foreigner;
A South African Police Services (SAPS) police clearance certificate    not older than three months from the date of issue;
If the applicant is a juristic person, valid copies of registration    issued by the Companies and Intellectual Property    Commission   (CIPC) or any other relevant registration authority    indicating the financial interest of all members, shareholders,    partners or   beneficiaries as the case may be;
A valid tax clearance certificate if the applicant is a juristic    person issued by the South African Revenue Services (SARS) within 12 months from the date of application;
Verification certificate issued in terms of the B-BBEE Act.

Considering that the sales and distribution ban in South Africa was recently lifted, I'd say it's a good time to get registered, if you have not already. ;)


What is the difference between 变 and 变得?

Question: What is the difference between 变 and 变得?
Is 变得 a word in its own right, or is 得 some sort of complement word?
For example, 眼睛变得亮晶晶。
Answer: 得 is some sort of complement word here. It tends to be some sort of comment or description of the action in the verb.
The basic structure is:
<code>[verb] 得 [description]
</code>
From your example

眼睛变得亮晶晶

变 is verb, 亮晶晶 is description of the eye.
Comment: Thanks. Is it a result complement or state complement? If it is a result complement, does it need 得? If it is a degree complement, doesn't it need 很 as well? Is there another type of complement it could be?
Comment: Is it the same as words such as 长得 and 觉得?
Comment: Is it a complement of state?
Comment: 长得,得 here use to describe the verb, same like the example I shown above.  觉得 is a word, you can't separate them, because  觉 has not meaning.  觉得 mean feel in English.


Difference between reference and instance in javascript

Question: Sometimes I hear people say "a reference to a object" and some say "a instance of a object"
What is the difference?
Answer: A variable will hold a reference to an instance of an object.
The actual object is an instance.
The variable/variables used to access the object hold the references to it.
Comment: Is the object Instantiating from the constructor that made it?
Comment: @James - in OOP that would be the case. A constructor would return an instance of a class.
Answer: Instance of an object (or, perhaps more accurately phrased when talking about languages that have the notion, of a class) is an object that has been created and exists in memory. For example, when writing
var obj = new Foo();

Then a new instance of an object has been created (with new Foo).
Reference to an object is some kind of handle that allows us to access an instance. For example, in many languages (including JavaScript) obj now holds a reference to the instance we just created.
There can be many references to the same instance, as in
var obj2 = obj;

where now both obj and obj2 hold references to the same object.
Answer: There can be many references to one instance. It's like, um, many paths leading to the same place.
var x="string object";
var y=x;

Both x and y are two different (but equal) references to the same instance of an object.
Answer: We always use a reference to an object and cannot use the object directly, we can only use the reference. Object instance itself is in memory.
When we create an object, we get a reference. We can create more references:
var obj = {}; // a reference to a new object
var a = obj; // another reference to the object

Answer: Object is an occupied memory for a class. Reference points to that memory and it has got a name (u can call it as a variable). For example,
A a = new A();
here when we write "new A();" some memory will be occupied in the system.
'a' is the reference(variable) which points to this memory and is used to access the data present in this memory.
Object is obtained when it has a life, means it has occupied some memory.
Reference points to the Object.
Instance is the copy of the Reference that points to object at a point of time.
Refrence is a variable that points the objects. Object is the instance of the class that have some memory and instance is a variable & methods that object have.
Reference means address of object or variable.
Object is instance of class and instance means representative of class i.e object
Instance is the actual object created at run time.
Comment: Just to be picky: `Reference points to that memory and it has got a name` : this is untrue. you can often have references without name. `var x = []; x[0] = {};`. Unless you call `x[0]` a name this reference has no name :)
Answer: In javascript a variable is a reference to the actual instance
    // create a new object from the Object constructor
    // and assign a reference to it called `firstObjRef`
    var firstObjectRef = new Object();

    // Give the object the property `prop`
    firstObjRef.prop = "im a property created through `firstObjRef`";

    // Create a second reference (called `secondObjRef`) to the same object
    var secondObjRef = firstObjRef;
    // this creates a reference to firstObjRef,
    // which in turn references the object

    secondObjRef.otherProp = "im a property created through `secondObjRef`";

    // We can access both properties from both references
    // This means `firstObjRef` & `secondObjRef` are the same object
    // not just copies

    firstObjRef.otherProp === secondObjRef.otherProp;
    // Returns true

This will also work if you pass a variable to a function:

    function objectChanger (obj, val) {
         // set the referenced object;s property `prop` to the referenced
         // value of `val`
         obj.prop = val;
    }

    // define a empty object outside of `objectChanger`'s scope
    var globalObject = {};

    globalObject === {}; // true

    // pass olobalObject to the function objectChanger
    objectChanger(globalObject, "Im a string");

    globalObject === {}; // false
    globalObject.prop === "Im a string"; // true

Answer: The actual English language definition of 'instance' and 'reference.'
instance: an example or single occurrence of something.
reference: the action of mentioning.
So taking these two definitions of the actual words into consideration and applying it to a JavaScript scenario you can understand how each concept fits.
Answer: Var a="myObject";
var b=a;

Here, variable a is an Instance and variable b is a Reference


Kotlin Function to return boolean between date/hour range (Android)

Question: I'm searching for an example with a function comparing a date and hours range for example in a restaurant for opening hours , the function return true if I put in parameters Sunday - Tuesday from 10:00 AM - 23:00 PM, What is the best way to do it? there is multiples date instances in Java/Kotlin I'm a little bit confused...
Comment: @Raman your answer was not complete, it didn't help me. now I have more questions about my problem...
Answer: The Kotlin-idiomatic way to do this would be to define your restaurant opening hours as a ClosedRange<T> (where T is some kind of date/time value, see further discussion below), and then use the in operator to determine if your given time falls within that range. See Ranges and Progressions in the Kotlin documentation.
To define the range you use the rangeTo function (or .. operator) e.g.:
val range = start..end

You can then use the contains function (or in operator) e.g.
anInstant in range

to determine if the given instant anInstant falls into the range or not.
As to the actual representation of the date/time values, it depends on your target platforms. If you are targeting JVM or Android, you can use any of the classes in java.time. For example, you can use a zone-aware date representation like ZonedDateTime, or one that ignores zones all-together like LocalDateTime, or one that represents a particular Instant in time regardless of zone, depending on your application's business rules for handling time zones.
If you are targeting multi-platform (e.g. native or JavaScript), then you'll probably want to look into a cross-platform library with date/time representations, like kotlinx-datetime.
Answer: I don't know if you no longer looking for an answer but this is the answer anyway
fun isNowInRange(start: LocalTime, stop: LocalTime, now: LocalTime): Boolean{
        return ( ! now.isBefore( start ) ) && ! now.isAfter( stop )
    }

and this is how to use it
isNowInRange(LocalTime.of(9, 0), LocalTime.of(23, 0) // opne

!isNowInRange(LocalTime.of(9, 0), LocalTime.of(23, 0) // closed

and if there is any restaurant that's open after 24 midnight you can write this
if (isNowInRange(LocalTime.of(9, 0), LocalTime.of(23, 0) && isNowInRange(LocalTime.of(0, 0), LocalTime.of(4, 0)){

// restaurant is open from 9am till 4am
// do stuff here

}else{

// restaurant closed from 4am till 9am
// do stuff here

}

Answer: fun checkIfInRangeOfHours(startHour: String, endHour: String): Boolean {
    val currentTime = Calendar.getInstance().time
    val currentDate = SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH).format(currentTime)
    val simpleDateFormat = SimpleDateFormat("yyyy-MM-dd hh:mm", Locale.ENGLISH)
    val startDate: Date? = simpleDateFormat.parse("$currentDate $startHour")
    val endDate: Date? = simpleDateFormat.parse("$currentDate $endHour")
    return Date().after(startDate) && Date().before(endDate)
}

Comment: Please, add some information, avoid to just post code without explanations


Check if NSDictionary is Null?

Question: I've tried multiple ways. I know the dictionary is NULL, as the console also prints out  when I break there. Yet when I put it in an if(  ) it doesn't trigger.
([myDict count] == 0) //results in crash
(myDict == NULL)
[myDict isEqual:[NSNull null]]

Comment: Then `myDict` isn't `nil`. Passing a message to `nil` should not result in a crash. Could it be that `myDict` is a invalid reference (for example, a reference to a freed object)?
Comment: Can you provide more detail? It's pretty bad if you're getting `NULL` for your `NSDictionary`, as opposed to the usual `nil` (for which `[myDict count] == 0` should be fine).
Comment: Don't merely describe what your console says; provide a dump of what you see in the console.
Comment: @JeremyRoman if myDict is `nil` then `[myDict count]` will cause an  `NSInvalidArgumentException` exception.
Comment: If you "NSLog("myDict: <%@>", myDict);" what is output? If that crashes then myDict isn't pointing to a valid ObjC object (ether bogus pointer or released object).
Answer: It looks like you have a dangling or wild pointer.
You can consider Objective-C objects as pointers to structs.
You can then of course compare them with NULL, or with other pointers.
So:
( myDict == NULL )

and
( myDict == [ NSNull null ] )

are both valid.
The first one will check if the pointer is NULL. NULL is usually defined as a void * with a value of 0.
Note that, for Objective-C objects, we usually use nil. nil is also defined as a void * with a value of 0, so it equals NULL. It's just here to denote a NULL pointer to an object, rather than a standard pointer.
The second one compares the address of myDict with the singleton instance of the NSNull class. So you are here comparing two pointers values.
So to quickly resume:
NULL == nil == Nil == 0

And as [ NSNull null ] is a valid instance:
NULL != [ NSNull null ]

Now about this:
( [ myDict count ] == 0 )

It may crash if you have a wild pointer:
NSDictionary * myDict;

[ myDict count ];

Unless using ARC, it will surely crash, because the myDict variable has not been initialised, and may actually point to anything.
It may also crash if you have a dangling pointer:
NSDictionary * myDict;

myDict = [ [ NSDictionary alloc ] init ];

[ myDict release ];
[ myDict count ];

Then you'll try to send a message to a deallocated object.
Sending a message to nil/NULL is always valid in Objective-C.
So it depends if you want to check if a dictionary is nil, or if it doesn't have values (as a valid dictionary instance may be empty).
In the first case, compare with nil. Otherwise, checks if count is 0, and ensure you're instance is still valid. Maybe you just forgot a retain somewhere.
Answer: if (TheDict == (NSDictionary*) [NSNull null]){

//TheDict is null
    }
else{
//TheDict is not null

}

Answer: To check if a dictionary has nil or NULL data, you can check for the [dictionary count] which will return 0 in all cases
Answer: All above doesn't work for me but this
if([mydict isKindOfClass:[NSNull class]])
{
   NSLog("Dic is Null")
}
else
{
   NSLog("Dic is Not Null")
}

Worked for me
Answer: if([NSNull null] != [serverResponseObject objectForKey:@"Your_Key"])
{
//Success
}

Comment: Could you include some explanation how this solves the problem?

Check if NSDictionary is Null?


How to upscale resolution / zoom screen

Question: When I connect my netbook to a TV via HDMI everything works fine, but because I watch it from a distance icons and fonts are too small. I'd like to either zoom it or set lower resolution that would just get upscaled to tv can show it correctly.
Answer: May I suggest an alternative approach: Make fonts larger and icons larger?
TTY font size is set with sudo dpkg-reconfigure console-setup as illustrated at How do I change the font or the font size in the TTY (console)?
Preferences | Appearance allows you to set the default font in the GUI as shown at How to change font size which can't be picked from 'Font' setting
GUI icon size is changeable as per How to resize the Unity launcher? by a right-click on the Desktop followed by Launcher Icon Size at lower right, unless you're using Classic, in which case see How can I make the icons larger and/or clearer in Classic Menu Indicator? for more.
Answer: When I needed to change my Ibuntu resolution in a non-standard resolution, I've found a useful program which is 'newrez'. It's not very user-friendly but it allows you to set resolution even bigger than your monitor native resolution.
You can also create simple scripts to quickly change resolution.
You can find newrez here:
http://linux-apps.com/content/show.php?content=134686

How to upscale resolution / zoom screen


How can install an app I purchased on the App Store which is no longer on the app store?

Question: I bought an app called Palua on the App Store a few years ago. Now I have a new personal Mac and I believe the app is no longer on the store. I know that it works on the latest version of macOS since I still use it on my work Mac. Is there a way for me to install it again, since I did indeed pay for it? I do not see it in my 'Purchased' apps in the App Store, which is where I hoped to find it.
Answer: Apps on the App Store (iOS, tvOS) and on the Mac App Store cannot be re-downloaded if

the developer removes the app
Apple removes the app for various reasons (e.g. violation of App Store policies, copyright infringements)

Since 2015 Apple removes apps from your purchase history as well. A well-known example is "Monkey Island 2" by Disney. It was removed with no option to re-download a copy of the game.
Try to contact the developer of the app. Maybe he/she can send you a copy of the app.
Answer: Actually, there may be another couple of ways for you to install the app in question. These are not definitive solutions as the success you have will depend on the specific apps in question.
Firstly, you may be able to re-install it if you have Time Machine backups that contain the app. If so, you should be able to use that (especially since you're saying it still works in macOS Sierra).
The second option is that you may be able to use the version from your work Mac, depending on what account it was downloaded under and whether or not you're able to use that account. Essentially you'd just copy the app from the work Mac to your personal Mac and try running it. You may be prompted to sign in to the account when you first run it.
However, some apps need to install support files in certain locations in order for them to work. If that's the case here, the second option isn't likely to work.
Other options
You may want to check out FNable as it offers similar functionality.
Note: I have no affiliation with this app whatsoever.
Answer: I had the same question, as I have been using a small freeware utility (autoping) from the Mac App Store for many years, which I install on every Mac. Recently this utility has disappeared from the App Store as the developer apparently stopped updating it. It does not show up in my Purchased list either. I also could not find the developer's website or any comparable alternative.
As Apple makes it impossible to re-download apps like that, my only option was to try to copy the App Store installed utility from another Mac. It does not seem to have any copy protection, as it is a freeware utility. After copying it, it works without having to sign in to the original app store account. Its appears to be self-contained in the app folder.
Therefore, for such apps its best to keep a backup copy around, in case they need to be reinstalled in the future.
Old description and link to the app


Macro lenses, what's the best  for quality and closeup?

Question: I want to do some extreme macro work, so which lens is best for this? I think the Canon 100mm macro isn't good enough. So which lens gives great low light work plus will get me right into the eye of an insect, for example?  Suggestions please.
Comment: @scb: It sounds like you have a distinct question to ask. I recommend using the "ask question" link in our header to ask a completely new question, allowing you to get the answers you need.
Comment: Hmmm, as I thought from my research, there isn't a good super macro lens on the market. why? I think the canon 100mm is, a great lens dont get me wrong, but 1:1 isnt enough. the DOF as you say with the MP-E 65mm isnt enough and also having to be so close to your subject really means it has to be inanimate or dead. can a teleconverter be added to the canon 100mm to give it a further edge? would this work? cheers guys!
Comment: You're almost getting into the range of photomicrography, and there is no lens that will help with that. Just adaptors. I've never tried this, but here's a link to a company that specializes in such adaptors: http://www.zarfenterprises.com/. And yes, the subject needs to be inanimate or dead. At many:1 zoom ratio, it's that simple.
Comment: Please don't post an answer unless you're actually answering the question. See here: http://photo.stackexchange.com/faq#deletion
Answer: Why do you think the Canon 100mm macro isn't good enough? Are you considering the L lens or non-L lens? If you are serious about eyes of insects, you probably want the Canon MP-E 65mm Macro Lens.
Comment: yes, do define "good enough" and why you think the Canon isn't.
Answer: No macro lens will do in low light. At macro distances depth of field is so scarce you'll probably be stopping down to f/11 or more. All macro lenses gather very little light at this setting so you'll most likely need an external lightsource.
To get up to photographing the eye of an insect you'll need to go way past 1:1 using something like the Canon MP-E 65mm. This lens is very difficult to shoot with due to the extreme magnification so don't expect results straight away, good macro photography takes years to perfect.
Comment: Actually some point-and-shoot cameras do fairly well in low light. They do not have a very good high-ISO performance, but one can shoot wide open at macro distances. The small sensor gives a lot of depth of field. Of course capturing the eye of an insect is far beyond their capabilities...
Answer: I shot with the MP-E 65mm lens (borrowed) and own both the 100mm macro lenses (L and "non-L"). Here are my insights:

100mm "non-L" lens: Great lens, autofocus can be a tad slow. Watch corners for chromatic aberration if you have very contrasty edges. Otherwise, well worth the money.
100mm L lens: Incredible lens. Autofocus is snappy and the lens is both clear and sharp from edge to edge of a full-frame sensor. If you have extra budget, this is money well spent.
MP-E 65mm: Pretty weird lens, in my opinion. It has up to a 5:1 magnification factor. You can read a nice write up here. The biggest challenge with this lens was wedging sufficient light in because the lens was pretty much touching the subject. I've included a sample shot with this lens. You'll note how insanely shallow the DOF is even though the image was made at f/16.

So, if you want to do super macro, go for it, but this is not an easy lens to use.
Answer: I think you're looking for a lens which simply does not exist.
The Canon MP-E 65mm Macro Lens can take photos up to the eye of an insect, but it's not intended for low light work.
Conversely, the Canon 100mm L IS USM is a lot more practical for low light (because of the image stabilisation) but won't take the photos you want with regard to the magnification.


How secure is it to use Tor on an outdated OSX

Question: Hi :) I'm unable to update my OSX and it needs to be updated.
Does the fact that my OSX is outdated make TOR less secure to use?
Answer: It makes your computer as a whole less secure because new security issues will not be patched.
Tor Browser will work the same as it always did but it won't change that fact that your machine is more vulnerable.
Comment: # JS Evans: Thanks for the reply! So while the computer is less secured in general, TOR itself is as safe as on an updated OS ?
Answer: Tor is only as secure as your OS is. That's why Windows users of Tor are usually targets for hacking. Windows is not as secure as linux or MacOS and thus is more vulnerable.
Since your OSX is outdated, you are more vulnerable to hacking since newer security patches haven't been added. Everytime your OS is updated, new bugs are patched and issues are resolved. Tor will have all its security patches to protect you, but if your system has security holes, then you are still susceptible to malware and hacking.


Capacity and BER as performance of transmission system

Question: We study the performance of the transmission system by channel capacity or BER/SER. If the system performance is studied as BER/SER, does it make sense to study a channel capacity?
Answer: Channel Capacity and Bit/Symbol Error rate are two different key performance indicators (KPI) of a system.
BER/SER, as it's obvious from its name, is  the number of Bit/Symbol errors divided by the total number of transferred Bits/Symbols. and you can use channel coding to improve it so it's not a fixed KPI.
while Channel Capacity is maximum rate that the system can achieve and it's a fixed KPI.
so it make sense to study the channel capacity of your system. by studying channel capacity you find maximum rate that can be achieved and by improving BER/SER you can improve rate of system to get close to channel capacity.
Comment: "number of errors per Bit/Symbol", typo? SER (or BER) is symbol (or bit) error rate, e.g. 1 error per 10000 symbols (or  bits(.
Comment: @P2000 I changed it. is it better now?


How can I rewire a three-wire ceiling fan installation where there is a two-wire set up?

Question: I installed a 3 speed ceiling fan with a dimmable light in the bedroom where a standard 2-wire light fixture used to be. After months of unsatisfied performance of these battery operated wall switches, I would rather have a full functioning wall switch. I have access to the junction box and all wiring for the fixture since the attic is above the ceiling. Is there a way for me to add a 3rd wire or change the wiring from the switch to the fan/light so I can install a 3 wire wall switch?
Comment: What model of fan remote control do you have?
Answer: pull the third wire (same gauge) through the same conduit from the fan to the switch. It possible that the conduit isn't large enough for another wire and you'll need to upgrade it. Use either red or black but make sure you can distinguish the 2 lives (like if you end up with 2 blacks you label that wire at both ends).
You then either need a second switch so one controls the light and the other the fan. Or if it is pullcord operated then the new wire will need to always live; just hook it up before the switch.
Comment: ...assuming there is a conduit there, which the OP didn't specify. I've never seen conduit used like this in residential situations, personally -- normally it's 14/2 NMD stapled to the framing.
Comment: There is no conduit. Just 14/2 loosely stapled.  What if I want to keep the remote control that I have to control the fan speed and the light, and have a 2 wire wall switch (dimmer) to only operate the light... How would I wire that up?


How do I choose which LED bulbs to put in my home?

Question: General purpose LED bulbs seem to vary a LOT in price... from $1 per bulb to $40+ per bulb... and there doesn't seem to be any tangible difference between them. I mean, some say they last longer, but it's never enough to justify 10-20x the price. And the lumens per watt are pretty much the same. Am I missing something?
Comment: In addition to quality issues, at $40 I suspect you are looking at some specialty bulb. (3 way, smart, etc). There still is quite a range though.
Answer: You're missing a lot, but you might not care. You indicated longevity is not a factor, so that takes care of one category of differences. Let's note a few other common differences between cheap and expensive LED bulbs, so that you might make an informed choice based on what's important to you:
Improvements in Expensive LEDs compared to Cheap LEDs

Efficiency: usually good bulbs are more efficient, in terms of lumens/watt. With a dramatic difference (say 55 vs 85), the saved electricity can pay for the differences in the bulb, depending on power cost and duty cycle of the product's lifetime, which as noted, also tends to be longer on higher-quality bulbs.
Heat: dirt-cheap bulbs use cheaper internal power supplies that tend to generate waste heat. Better bulbs use a fancy electrical driver known as a "switch mode power supply", which can be up to 90% efficient, compared to a resistive or capacitive dropper with as low as 50% efficiency. Heat lowers lifetime, so if your bulb will be in a globe, can, or other enclosed area, this is a factor worth considering.
Color Quality: Better bulbs tend to have both higher CRI, and less color variation within models. I've gotten two dollar-tree bulbs from the same peg, and one was about 250deg cooler than the other. I've gotten two different phillips bulbs months apart and they both have identical coloring. If you don't have a lot of bulbs going at once, this is more important than when a bad apple can hide in the bunch. There's also some health/wellness concerns about an over-concentration of blue light, and it's bio-rhythm effects, and in this regard, the more-balanced light of quality bulbs would reason to have less impact.
Light Quality: Cheaper LEDs (especially those with cheap capacitive dropper internal power supplies) tend to flicker at mains. This can be more noticeable at night, and in your peripheral vision. Prolonged exposure causes some people headaches or just distracting corner-of-the-eye rainbows or flashes. If all your bulbs are the same and they all flicker, the effect can be quite pronounced and annoying.
Performance: cheap bulbs can take longer to turn on, which is especially noticeable when one switch controls many lights. This can make a good automation system seems laggy, which nobody wants. Another performance factor is backwards compatibility with existing dimmers, dusk-to-dawn sensors, motion detectors, etc. The parasitic current of such devices often causes less sophisticated bulbs to dimly flicker when the switch is off. Better bulbs use a couple of electronics-based tricks to eliminate or reduce such an effect (sensitive gate SCRs, bleeder resistors across caps, post-DC switching, etc). Also, some cheaper drivers can create audible noise, either a hum or whistle (especially when dimmed), but I've not heard that on quality bulbs. Lastly on this point, quality bulbs last longer, so if the bulb is hard to reach, like an outdoor yard light, that could be a strong consideration.

Considering all that, you still need to consider your usage as well. Weight the factors important you you (if any) and shop armed with the knowledge to get the best deal for your needs. You don't always needs the best, and I use dirt-cheap ones in some places myself, even after noting all the above!
You can likely live with a cheaper bulb you use 2 mins a day in a closet better than you can cheap task lighting. If you don't have enclosed lamps, heat's not a big factor. If you lived happily for years with mixed CFL+tungsten lights you probably won't care about color temp differences or CRI. If you don't pay a lot for grid power, efficiency isn't as important as it is for those off-grid. If you don't have dimmers or other "fancy" switches, backwards compat doesn't matter, etc.
You be the judge. You can spend $5k or $500k and get a reliable car. Same with stereos, or anything really. How much you need depends, but now you know what to look out for...
Answer: A huge factor in LED pricing is local subsidy provided by the electric utility* or local government.
However, build quality is very important.  Items sold in big-box stores and dollar-stores are very heavily "cost-shaved" to make them a few pennies cheaper (on the production side).
The problem is, if you start with a quality LED and start shaving pennies, where do you cut?   The easiest place to cut costs is the electronic driver circuit which regulates power to the LED.

Use a cheaper capacitor-based driver circuit.  Unlike most electronic components, capacitors "wear out" like batteries so better LED makers avoid them.  (realistically the LED emitter will outlive all of us).
Worse, shabbily made or cheap capacitors are prone to  failing much sooner.
Fail to solve the crystallization problem in RoHS solder.
Design a system that runs hot and fail to cool it adequately, causing failure of the electronics.
LED emitters are manufactured and sorted into "bins" (the process is called "binning") based on their performance and light quality.  The bins are sold competitively, with top tier builders bidding top dollar for the best bins.  Buy from the cheap bins for worse light.
Buy from no-name LED manufacturers who make poor or unreliable emitters.
Use cheap plastic that deteriorates after a few years, causing the unit to fall apart
Fail to isolate the power supply, so the metal heatsink is electrically "hot"

The upshot is that discount vendor can do you a whole lot of damage.   And worse, big-box stores and dollar stores are the absolute worst at "shoving these products down your throat" to where it seems like nothing else is even sold.  Three brands that have given me nothing but trouble are Utilitech, Feit Electric and Lights of America - and all three are darlings of the big-box stores.
- Go for the lower "Energy Star 2.0" standard, which allows for a much shorter certified life (as opposed to the higher "Energy Star 1.1").
So it is very much a matter of "caveat emptor".  As a rule, I stick only to top brands and IKEA, which I have always had good luck with.  General Electric knows a  thing or two about how to make a light bulb.  (they were Thomas Edison's partner in initial production of light bulbs).

* Why would the utility pay people to use less of their product?  Because it costs a fortune to build a new power plant. When plants cost more than $1/watt, helping customers conserve makes sense when it can be done for less than $1/watt.  The government clears the way for this with supporting legislation.
Comment: Great checklist of failure modes and gotchas. about caps: you need capacitors to get DC from AC w/o moving parts. Not all capacitors wear out, it's mainly just electrolytic ones, and those are not as bad as they were 10 years ago (in terms of drying out). The tiny SMD capacitors used by most good driver ICs these days are actually ceramic, which are quite tough, and go up to dozens of uF. Just a few years ago, a 1uF ceramic was considered big, but now we can use them in bulk applications.


Is Obama's support of Trudeau's re-election "foreign interference"?

Question: There have been concerns that the 2019 federal Canadian election might be the target of foreign interference.
Former U.S. president and current American citizen Barack Obama issued a public statement:

I was proud to work with Justin Trudeau as President. He's a
  hard-working, effective leader who takes on big issues like climate
  change. The world needs his progressive leadership now, and I hope our
  neighbors to the north support him for another term

Prominent figures have put forward arguments from both points of view.
Here are some individuals and bodies who have said this doesn't constitute foreign interference:

Elections Canada said that a foreign citizen speaking about the Canadian election doesn't  "constitute an instance of undue foreign influence under the Canada Elections Act," and that factors considered before determining if "undue foreign influence" has taken place would include who incurred expenses and for what reason.
The "Critical Election Incident Public Protocol," the panel of senior public servants responsible for deciding when and how to inform Canadians about concerning behaviour or content that comes to their attention: as of Wednesday, 16 October 2019, the panel has not come forward with any potential meddling efforts.

On the other side, here are some individuals and bodies who have said that it does:

Ian Brodie, who was former Conservative prime minister Stephen Harper's chief of staff, said "I await a response on the Obama tweet from the federal government's rapid response team on foreign interference..."
a spokesperson for U.S. President Donald Trump's 2020 reelection campaign called it "foreign election interference,"
Globe and Mail columnist Lawrence Martin wrote "The Obama intrusion, unprecedented even for a former president, constitutes unjustified meddling."
National Post columnist Kelly McParland wrote "Former president Barack Obama is not nearly as distasteful a person as the president of Russia, but he was engaged in a much more open case of intrusion when he urged Canadian voters Wednesday to vote for the Liberal leader over other candidates."

Does this constitute foreign interference?
Comment: There is a difference between a foreign leader openly stating their opinion, and covert activities. If President Putin had limited Russian involvement in the US election to a statement saying, for example, that he wanted Trump elected because he would be easier to manipulate than Clinton I don't think there would be any problem.
Comment: @PatriciaShanahan While it certainly has led to some controversy over who has given candidates their endorsement in the past, it's true that foreign leaders are largely allowed to endorse who they like - let alone former political leaders. https://www.washingtonpost.com/news/worldviews/wp/2015/12/17/what-happens-when-certain-foreign-leaders-endorse-american-presidential-candidates/
Comment: I would really advise against reopening the question in its current state, because it will lead to conflicting answers which come to different conclusions just because they interpret "foreign interference" slightly differently. The votes on these answers will likely be heavily impacted by the political leanings of the voters and what narrative suits them the most. But if you really want to overrule me on that, so be it.
Comment: I'm sorry, but we generally don't answer questions which ask for the personal opinions of the community. This is a Q&A site, not a debate site. But maybe this question could be made on-topic by framing it differently. How about asking how common such election endorsements by foreign (ex-) politicians are and how diplomats usually react to them?
Comment: This stuff is common. Trump also said BoJo would make a good PM etc.  Nobody heckled him for that. https://www.dw.com/en/us-president-trump-backs-boris-johnson-as-next-british-prime-minister/a-48998921
Comment: I really want to re-open this question because I also would like to know if there is a dividing line, but I understand Philip's point. I would have no hesitation to re-open if the question was not specificly about this instance and more broadly about when the line is crossed between "free speech" (for instance) and "election interference". That though would probably invalidate the current answer.
Comment: @JeffLambert The dividing line is money. Saying "I support X" is one thing. Many world leaders and celebrities do that and, while it's free advertising, it didn't cost the supporting person any money or work. Giving money or equivalent work to X is another matter. In my understanding, Russian interference was criticized, because it was equivalent to paid advertising and paid opposition research (ignoring the hacking of servers, which might also be considered criminal). There might also have been financial contributions to the campaign, though I've not really kept track of the whole thing.
Comment: @Morfildur Quite possibly that should be its own question and/or answer; in any case, it's not obviously relevant to Canadian politics.
Answer: It depends how you define "foreign interference" (but also no)
If you are using this term to mean any non-citizen having any impact on the result of an election, then yes, this is clearly foreign interference.
If, however, you are using something more akin to Wikipedia's definition of Foreign electoral intervention as "attempts by governments, covertly or overtly, to influence elections in another country", then it seems pretty clear that this does not qualify. It's true that as a former president, Barack Obama has closer links to the US government than many others, he is speaking here as a private citizen. The term "foreign interference" usually means a state trying to influence the politics of another state, so this is not "foreign interference" as most people understand it.
The slight ambiguity of terms is what provides the opportunity for people to accuse him of this if it suits their political aims.


explanation for cross entropy for logistic regression

Question: as far as I know, cross entropy of two distributions is:
$$
C(p,q) = -\sum_{s \in classes}p(s)\log(q(s))
$$
however, the loss function for logistic regression (called "crossentropy loss") it's defined as:
$$
J(\theta) = -\frac{1}{m}\sum_{i=1}^my^{(i)} \:\cdot\: log(h_\theta(x^{(i)}))+(1-y^{(i)})\:\cdot\:log(1-h_\theta(x^{(i)}))
$$
as far as I know, $y$ and $(1-y)$ are just term to handle the error in case of miss-classification in both ways, and this makes me really miss the connection with the crossentropy definition, ergo, I don't see why it's called like that, even though i don't see any connection between the 2 formulas
Answer: In the crossentropy loss, $y$ is either $0$ or $1$.
It can be seen as the exact probability of an example belongs to class 1 or class 2
So $\mathbb{P}(w=1|\mathbf{x}) = y$ and
$\mathbb{P}(w=2|\mathbf{x}) = 1-y$
Identically $h_\theta(\mathbf{x})$ is the predicted probability of an example belonging to class 1 or class 2.
So $\mathbb{P}(w=1) = h_\theta(\mathbf{x})$ and
$\mathbb{P}(w=2) = 1-h_\theta(\mathbf{x})$.
This should make clear the connection with the definition of cross-entropy.
Note that your second definition is a kind of average cross-entropy (you are summung over examples, but your indices seem wrong)
Comment: sure, I was missing the indices.... but I don't get which are 2 distributions on which we are calculating the crossentropy ($p,q$)
Comment: p,q are probability mass functions that give the probability that a discrete random variable (the class) is exactly 1 or 2 (these numbers are arbitrary)
Comment: So our $\frac{1}{m}\sum...$ is just a "estimation" of the $p(t)$ of the first formula (ergo, the probability is the proportion of elements)?


Are animal fats cooked with dairy issur hanaah

Question: According to Leviticus 7:24 forbidden fats from non shechita'd animals may be used for any purpose but eating. Therefore, is it permissible to cook them with dairy and/or sell them mixed with dairy? Or is that still issur hanaah despite this Passuk saying it can be used for non eating purposes? What is the Halacha regarding this?
Answer: Aruch HaShulchan Yoreh Deah 87:12 (basing himself on the opinion of Rambam) writes that it is forbidden to cook chelev (forbidden animal fats) with milk, but that after the fact one can derive benefit from such a mixture.
However, Peri Megadim in his introduction to Basar BeChalav, while noting this opinion of Rambam, writes that he believes that one may not benefit from chelev cooked with milk.
Comment: The halacha here is what underpins this Purim Torah, by the way: https://judaism.stackexchange.com/a/26216/21 . (Generally we say that one prohibition can stack onto another if it broadens it, however the Rambam's "wondrous point" is that if the prohibition on benefit is essentially a form of a prohibition on eating, then you can't stack them. The more common question is beef that wasn't kosher slaughtered, which was then cooked in milk. (Not everyone agrees with the Rambam on this.) Just because the Torah said "it can be used", doesn't mean you can't then mess it up further.
Comment: Certainly if you took that animal fat and then put it in a city which was then condemned for worshiping idols, it becomes prohibited from all benefit, as the latter prohibition isn't about "eating."


Is the study of logic a part of mathematics?

Question: I know that there are different subfields of logic, but I am talking about the kind Kurt Gödel studied, that is,symbolic and mathematical logic. Why is he considered a logician, mathematician and philosopher (according to Wiki) and not only a mathematician ? I don't understand how the philosophical questions raised in such enquiries are not mathematical in nature, why it is separate. Why is George Cantor not considered a philosopher and logician(according to Wiki), but only a mathematician ?
Comment: This sounds like a question for the corresponding Wikipdedia talk page.
Comment: The [SEP article on Gödel](http://plato.stanford.edu/entries/goedel/#GodPhiWor) discusses his contributions to philosophy.
Answer: The reason is quite simple.
The impact of Cantor's work on math and phil of math was very high, but he published only mathematical papers, without explicit contribution to the (current in his age) discussion about the philosopical issues of mathematics (due mainly to kantian school).
Godel published (in addition to fundamental mathematical papers) a couple of papers with interesting contribution to the (current) discussion about the foundations of mathematics :

Russell's mathematical logic (1944)

and

What is Cantor's continuum problem? (1947)
Answer: My guess is that there's no rationale behind this. Why Kurt Gödel can be called a philosopher is because many of his works deal with problems that are identical to those within the philosophy of mathematics. It doesn't seem to me that calling Cantor a philosopher would be bad either, but I also think it's unimportant.
Adding to what someone mentioned about Gödel writing papers, Gödel collaborated with philosophers in his later life. For example, with Hillary Putnam and Hao Wang.
Answer: Cantor can certainly be called a philosopher, whether or not Wikipedia agrees. Cantor published in philosophical journals (Zeitschrift für Philosophie und philosophische Kritik) philosophical and theological questions. Zermelo's edition of Cantor's collected works (Springer, 1932) has the title "Collected works of mathematical and philosophical contents".
Cantor himself mentioned various philosophical roots of his work: Ebenso finde ich für meine Auffassung Berührungspunkte in der Philosophie des Nicolaus Cusanus. Man vgl. R. Zimmermann, Der Cardinal Nicolaus von Cusa als Vorgänger Leibnizens (Sitzungsberichte d. Wiener Akademie d. Wiss. Jahrg. 1852). Dasselbe bemerke ich in Beziehung auf Giordano Bruno, den Nachfolger des Cusaners. Man vgl. Brunnhofer, Giordano Brunos Weltanschauung und Verhängnis. Leipzig 1882.
He had correspondense with many, many philosophers and theologians, see for instance
Georg Cantor: Leben, Werk und Wirkung, Herbert Meschkowski, 2. Aufl. BI, Mannheim (1981)
Georg Cantor 1845 - 1918, W. Purkert, H.J. Ilgauds, Birkhäuser, Basel (1987)
Georg Cantor Briefe, H. Meschkowski, W. Nilson (Herausgeber), Springer, Berlin  (1991).
Further he speculated about the real father of Jesus Christ and the real author of Shakespear's works. Of course these topics are not sufficient to make him a great philosopher. But his set theory is enough to make him great - and in fact it is pure philosophy as far as he is concerned: The belief in the possiblility to finish infinite sets, based on the holy bible and the teachings of S. Augustin and other fathers of the church.

"The general set theory [...] definitely belongs to metaphysics. [...] and the fact that my presently written work is issued in mathematical journals does not modify the metaphysical contents and character of this work. [...] By me Christian philosophy is for the first time confronted with the true teachings of the infinite in its beginnings." [G. Cantor, letter to T. Esser, February 1896]


If I fits on the Board, I sits on the Board

Question: I recently saw text on that picture, over the reddit. It says "If I fits on the Board, I sits on the Board". Since that looks like official and formal signboard, I am curious as to why authors used "fits" and "sits" instead of "fit" and "sit". Are there any suggestions ? Thanks a lot.
Answer: This is a "meme" based on videos of cats sitting in boxes that seem to small with the quote "If I fits I sits". This is incorrect language and is intentionally incorrect to sound "cute", perhaps mimicking the way the cat would talk if it could.
Answer: It is a very folksy and informal way of talking, as in

If I sees it, I eats it.

usually associated with a form of northern rural speak (Maine, Minnesota) which has been adopted by certain feline dialects.
You also need to consider this is in Minnesota (read: long cold winters leading to cabin fever) at a famous liberal arts college (read: creative types) and they are trying to give the cat a certain personality.
Also, notice the punning in the comments.


Emergency Brakes feel like they are set but are not

Question: When driving my 2006 Pontiac Grand Prix Wide track, it feels as if the emergency brake is on even though it isn't. What is causing this?
Comment: Can you give us more information? Has any work been done to the car lately? Is the gas mileage down? Does the engine rev but the car doesn't go forward? How many miles on the car? Which engine in the car? Which model of the car? *Anything*?
Comment: Do you use your emergency brake when you park?  The caliper could be stuck (you released the brake lever, but the part on the wheel is still sqeezing).
Comment: Check to see if your rear wheels are hot after driving.
Answer: I have the same problem with my 06 G6. The pins in your calipers are likely seized. Try cleaning or replacing the slide pins. If that doesn't help, it's probably time for calipers.


Connect two sharepoint lists

Question: I do not know programing, but I can use SharePoint for my requirements. I want to connect two SharePoint lists in to one. Lookup column is not enough to meet my requirement, is there any way to link two lists ?
Comment: Can you explain why a Lookup is not enough?
Comment: If a lookup field is not enough you can try to get information from one list via Microsoft Flow to the other list (SP list create/update trigger)
Answer: Look up column connection is a straight way to implement this but as you said lookup column didn't work for you, not clear on this why didn't work.
Similar question already has been discussed here:
Is there a way to link two SharePoint lists together?
Follow this link to do some work around - same implementation is done here:
https://www.nhaustralia.com.au/blog/link-two-lists-microsoft-sharepoint/
If you are ok to buy some third party tool to implement this, you can go with the boostsolutions integration, just plug and play :-)
http://www.boostsolutions.com/blog/how-to-integrate-multiple-sharepoint-lists-into-one-list/
Comment: I created two lists for two groups which have different permission levels 01 Group - Contribute without edit & Delete 02, Group - Contribute without delete, both groups use same ID for their works & I want to show comments updated by group 02 to group 01 - hence I want to update the list which is used by group 01 automatically (Like Excel) based on 2nd list which is used by Group 02
Answer: To merge two lists in SharePoint Online, you can create Linked data source in SharePoint Designer.
Refer to the following article about how to link two lists and create a combined view in SharePoint 2013 (Which is also works in SharePoint online):
https://www.ignatiuz.com/blog/sharepoint-2013/how-to-link-two-lists-and-create-a-combined-view-in-sharepoint-2013/

Connect two sharepoint lists


How to copy files with an option for skipping stuck files?

Question: I have a corrupted CD from which I want to copy files. The problem is that the default Windows 7 copy utility gets completely stuck when it encounters a corrupted sector of the CD. Can you recommend utilities with an option to manually skip certain files on-the-fly, or with option to specify a time out for every file copy?
Answer: Robocopy, which is built into Windows.
To copy files from a CD-ROM, assuming drive D:\, you'd do something like this:
robocopy D:\ C:\ThisIsTheTargetFolder /MIR /R:1 /W:1

D:\ means the source, which in this example is the D: drive.
C:\ThisIsTheTargetFolder is obvious, but you need to set the correct target path.
/MIR mirrors the folder structure.
/R:1 means retry once for each file. You can change this.
/W:1 means to wait 1 second between retries. You can change this too.

Type robocopy at the command prompt to see more options. You would be interested in the Exclusion List options, which are /XF and /XD. Very powerful stuff.
Hope this helps!
Comment: My experience indicates that when robocopy encounters a difficult to read file, it's output includes a percent complete, but it still "hangs" for quite some time before it moves on, even with /R:0.
Comment: Warning: before transfer it will delete content of `C:\ThisIsTheTargetFolder` if any exists
Comment: But I am definitely upvoting this for the /XF option - I can iteratively exclude the ones that get stuck by adding them after the /XF flag
Comment: I can also confirm that Robocopy still hangs on the problematic files:  0.0%      New File               6.2 m        20170921_130000.jpg
Answer: Teracopy may be worth a look.
Comment: to add, this'll skip bad files, iirc prompt, and carry on
Answer: You could also try RichCopy

RichCopy is a free utility that comes to us from Ken Tamaru of Microsoft. The tool was first developed in 2001 and has been updated regularly to keep pace with evolving needs. Trust me when I tell you, this is the answer to all your file copying needs. What you'll find most striking the first time you take RichCopy out for a spin is that it's a multithreaded copying tool. That means that rather than copying one file at a time in serial order, RichCopy can open multiple threads simultaneously, allowing many files to be copied in parallel and cutting the total time required to complete the operation several times over. You can also pause and resume file copy operations, so if you lose network connectivity at any point, you can just pick up where you left off.

It is like a super-charged GUI for Robocopy if you don't want to dig into the command line.
Answer: Try Unstoppable Copier

Recovers files from disks with physical damage. Allows you to copy files from disks with problems such as bad sectors, scratches or that just give errors when reading data. The program will attempt to recover every readable piece of a file and put the pieces together. Using this method most types of files can be made useable even if some parts of the file were not recoverable in the end.
Answer: "CBD (Copy Bad Disk) - like Unstoppable Copier" was offered as an 'answer' designed to test whether reviewers were paying attention, I failed because it seemed to me worth mentioning at least: (i) that is not free, though a trial is here and (ii) seems to be relevant to HDD only and (iii) some details.
BUT I would agree, it would have been an answer to a (slightly?) different question! (Isn't that often the case on SU?)
Answer: Another simple utility is CopyFile: http://yurichev.com/copyfile.html


Is there a good and easy paper to code policy gradient algorithms (REINFORCE) from scratch?

Question: I am interested in learning about policy gradient algorithms and REINFORCE. Can you suggest a good and easy paper that I can use to code them from scratch?
Answer: this is maybe not a paper but this article is dope.
I got 2 link in below to help you understand about policy gradient algorithms especially Reinforce Learning. Both article have a good explanation about that algorithms and not only an explanation, also contain a good example about that. They really put their effort into it so i'm sure if you've read it and really understand it, you can code from scratch. Hope this is help you.
If you think this answer is helping you, i will grateful if you make my answer as accepted. Just kidding, have a nice day....
(no i'm not kidding)
https://towardsdatascience.com/policy-gradients-in-a-nutshell-8b72f9743c5d by Sanyam Kapoor on Towardsdatascience.com
https://medium.com/@jonathan_hui/rl-policy-gradients-explained-9b13b688b146 by Jonathan Hui on Medium.com
Comment: I'm leaving this open b/c you got an upvote (so presumably helpful to the OP.  But could you please excerpt a relevant passage from each article and provide some context?  Otherwise, someone else might come along and delete this answer.


Is this a Calvinistic or Arminian statement of faith?

Question:
We believe in the Holy Trinity consisting of God the Father, Jesus Christ, His only begotten Son, and the Holy Spirit. We believe this triune God to be perfect in every way and worthy of our complete devotion and worship. We believe that all mankind is born into sin, separated from God and destined to an eternal destiny apart from God. We believe that God, in his infinite love, has provided a way for us to attain relationship with Him, by sending His son to be born as a man, to suffer, and to die in our place. We believe that on the third day after His death, Jesus Christ was resurrected and now sits at the right hand of God, interceding for us. We believe that we are saved by faith in Jesus Christ and that faith will be manifested thru obedience to Christ. We believe the bible to be the infallible Word of God and the final authority on all matters. We believe that God has called us to live holy lives, as He did, and desires us to honor Him by caring for the poor and needy and by setting free those who are held captive by the devil. We believe that when life on earth is over, those who have repented of their sins, accepted Jesus Christ as their savior, and have strived to walk as He did, will be united with Him forever in heaven.
Comment: It can be *either*, since the author took pain to *exclude* from the statement of faith the elements of disagreement between a Calvinist and an Arminian such as the role of free will and predestination.
Answer: The disagreement between Calvinists and Arminians are over the precise nature of predestination and election. The traditional Arminian position can be seen in the Five Articles of Remonstrance. The key difference between an Arminian and Calvinist position is that of free will: Arminians believe that human beings are born with free will, and can therefore resist God's grace. Salvation is, from this perspective, conditional on whether a man or woman accepts God's grace.
By contrast, the traditional Calvinist / Reformed view is that mankind does not have free will, we are incapable of accepting salvation unless God himself enables us.
This is how the 39 Articles of the Church of England puts it:

X. Of Free-Will
The condition of Man after the fall of Adam is such, that he cannot turn and prepare himself, by his own natural strength and good works, to faith; and calling upon God. Wherefore we have no power to do good works pleasant and acceptable to God, without the grace of God by Christ preventing us, that we may have a good will, and working with us, when we have that good will. Source

The statement of faith you cite does not actually take a position on these things. I would suggest this is almost certainly intentional. Some denominations or churches do not want to take a position on this, for fear that they will alienate some people. Many churches simply want to focus on what unites, rather than what some say are more contentious issues.
There are no doubt arguments to be had of the wisdom of such an approach, but perhaps to go into it would be beyond the scope of this answer!
Comment: I would further clarify your statement that "traditional Calvinist / Reformed view is that mankind does not have free will".  It depends on the precise meaning of "free will".  Like you said, when it comes to accepting salvation, our "free will" is defective, but in other areas there are still some freedom which makes us responsible for our choosing to sin.  See https://www.thegospelcoalition.org/article/did-john-calvin-believe-in-free-will/
Comment: @GratefulDisciple Yes, there are nuances. I remember learning about the liberty of spontenaity vs the liberty of indifference. That is, human beings have freedom to do what we want to do. We don't have freedom to change what we want to do. But I didn't think in this particular case going into the finer points of free will would have added much. That's a helpful article you linked to.
Comment: @Phill Sacre - From reading your profile and this answer, I wondered if you might be able to contribute an answer from an Anglican/CoE perspective to this question I asked:  https://christianity.stackexchange.com/questions/74667/what-is-the-anglican-and-episcopalian-basis-for-viewing-the-trinity-as-a-family
Comment: @Lesley - sorry, I don't have particular expertise about whether there would be an Anglican answer to your question. This is what I wrote a few years ago, which probably doesn't add much to what you ask: http://phillsacre.me.uk/2015/06/on-god-herself/
Comment: @PhillSacre - Thanks for the link.  Most interesting.


Air velocity through a tunnel 5,000 feet long and 30 feet in diameter?

Question: I am an architect in need  help with an aerodynamics problem for a design that I am developing. I need  to know the  the potential velocity of air moving from one end of a pipe to the other if any with a constant  20° difference in temperature. The temperature at one end of the pipe would be uniformly 20°F colder than the temperature at the opposite end.  I'm assuming the temperature difference would cause warm air to move to the cold end. The pipe /tunnel would be 30 feet in diameter and 5000 feet in length. I am interested in using any potential work or force from this volume of air, moving due to temperature difference. Thank you for any help that you can provide.
Comment: Natural Ventilation of a Tunnel is the topic you're looking for. You'll need to determine if it is something you're competent to conduct the analysis or you'll need to hire an engineer who has this within their competency.  You also will need to figure out how exact of a figure you will need. dependent upon how exact of a velocity you need the construction of the tunnel could be very important, concrete vs steel, D shape vs round vs square, etc.  But as far as internet answers I can tell you the velocity will be somewhere between 2 ft per second and speed of sound.
Comment: @Ken_Miller: warm air rises. Your assumption about warm air flowing to the cold end of the tunnel is not valid. The opposite will occur, if there is a sufficient difference in air pressures between each end of the tunnel. You need to consult a ventilation engineer, preferably a mine ventilation engineer.
Comment: As Paul says, you need to know the boundary conditions at the two ends. So you're missing either the density or the pressure at each end. If the ends are open to the atmosphere, you can just use the standard atmosphere values as a first approximation.
Comment: Then you need to make some assumptions about the tunnel and compute the pressure drop due to friction. Then you have to solve for the velocity in the tunnel, provided you have enough equations.
Answer: First of all, the flow of air is caused by the difference in pressure, and not in temperature, although they are related. So you need to know the pressure drop. You have to guess the pressure difference, or use the ideal gas law for finding the pressure at the ends:
$P=\rho RT$, where $\rho$ is the density of air at that specific temperature (see here), $T$ is the temperature that you must know and $R$ is a gas constant for air ($R$=53.35 ft lbf/lb/$^{\circ}$R).
There are many ways to find the velocity, but that would require to know the roughness of the pipe, flow regime etc. I recommend that you do your calculations for velocity here once you know your pressures.
And use the properties of air from here.
You can fine the conversion in velocity (from Imperial to SI) here.


Can I mix waterbase Behr wall paint with waterbase deck stain/sealer?

Question: I had some clear Waterguard exterior deck stain/sealer which is water-based. I got them a while ago so I cannot return them. The problem is I like to cover the deck with opaque color. Is it possible and a good idea to mix the Waterguard sealer with Behr water-based wall paint?
Comment: No personal experience or much knowledge of this topic, so just a comment: I have a feeling mixing them would end up with something that doesn't seal well and doesn't look good either. I would try (maybe try on a small piece of wood) a two step process - seal, wait a day or two to dry, then paint - and see how it looks & feels.
Comment: This is hard to answer because it depends way too much on the formulation of the particular products.  "Water based" covers a pretty wide swath, and that alone does not make the products compatible.  *The factory would know*.
Answer: First, are the products chemically compatible?  The mere fact that they're water-based does not make it so.  The best place to ask is the factory.
However, there's a bigger problem.  Even if they're compatible, a colored paint diluted (what, 2:1?) with a clear coating will have very poor coverage.  If it's going to take 6 coats to get decent coverage on the deck, then why not just paint 4 coats of clear stain, and 2 coats of paint?
The third problem is that floor paint is a very tough service.  I don't have confidence in any water-based product, but you certainly don't want to use wall paint! For best use of the materials, you might try 1 coat of sealer (to actually seal), 2 coats of wall paint (to color), then more coats of sealer (to provide a durable coating over the color).   That's a stupid amount of work, and I still wouldn't have high hopes.
If it goes wrong, you may have to remove the failed paint.  That will be far more tedious and expensive than any savings you might have had on paint.
Believe me, I get it.  Nobody wants to waste paint.  I have tens of gallons of paint I have no use for (I am a fastidious color matcher, and I buy a lot of quarts just for color tests).  But my problem is, everything I might paint is too valuable to risk a failed paint job and the huge amount of work to recover from that.
There's one more problem with newer water-based paints.  The paint industry has done their level best to reduce VOCs, especially toxic VOCs.  The result is nothing poisons the paint from growing microbes or mold.  There have been many cases of people finding paint that's stinkier than normal, painting their walls, and finding the stink won't go away. Covering it with fresh paint doesn't work, their only option is to peel off all the layers of paint down to the failed coat. This is a staggering amount of work that can go into hundreds of hours.  That makes me very reluctant to use old paint at all.  Again, most of my projects are too important for that kind of risk, so I find myself just buying new to avoid any chance of a big problem.
Answer: you can add pigment to the paint ("sealer"). Oxide pigments are sold for tinting cement but also work on paint.  In fact this is the same stuff paint manufacturers use to colour their paint.
Or you could take it to a paint shop and ask them to tint it for you... a clear paint will need a lot of tint to make it opaque and will be diluted by the liquid part of the liquid tinting compound used in retail, and you'll probably have to pay for the service.


Are there any currently studied or hypothesized crewed Mars missions that utilize the Space Launch System?

Question: Space Launch System is finally beginning to see the light at the end of the tunnel. If everything goes smoothly (fingers crossed!), we should see the Artemis program kicked into full drive by the end of the decade. Post (or even during) Artemis, are there any studied, planned, or theoretical crewed martian missions that utilize the Space Launch System Architecture?
Comment: Mars missions are ostensibly part of the rationale for the Gateway station, does that count? Pretty much any beyond-LEO effort proposed today is going to involve the SLS purely for political reasons, though its low launch rate will realistically limit its role. (Again, look at Gateway...two modules of which are now being launched together on a Falcon Heavy instead of on two SLS/Orion flighs.)
Comment: It would not be practical to use SLS for a crewed Mars mission. The very low launch rate will prevent it from lifting sufficient tonnage to be useful. If (or more likely when) Starship becomes operational SLS will be obsolete. It might continue for years for political (jobs) reasons, but it would only be able to make a token effort in any such Mars project.
Answer: There's always plenty of studies.
NASA Mars architecture presentations always use SLS. There's a diversity of them, from the DRM that Fred mentions, to the variations, to the bat**** crazy. There's more of course; this google search will provide reading to your fatigue. The architecture that Boeing likes is the Deep Space Transport SEP setup. Aerojet Rocketdyne of course has a couple of studies/presentations on the topic; focussing in on NTP and the DST SEP setup.
There are also presentations like these from JPL Lads at ExploreMars sessions about pure chem architectures.

^this image would likely give Robert Zubrin a heart attack.
With that I supposed we should also consider OG Mars Direct, which baselined a vehicle similar to modern Day SLS, with it's 2 launch chem-ISRU approach. Zubrin has since moved on however.
The crux of SLS use cases in these architectures is to launch Orion or large elements; with refuelling/tug stages being given to CLV. Given that 2033 is out for a DST setup and that 2039 is about the earliest for NASA humans to Mars assuming conventional means, by which point SLS's future is looking dodgy; eh...
Comment: I was actually in a room with Robert Zubrin when this was presented. Can confirm that he did not have a heart attack;-) It's still a bit silly, but...
Comment: Your "2033" link to ida.org is giving me "Access denied". Is that some classified info that I'm not supposed to see as a non-American, or just a broken link?
Comment: @TooTea This link should be better; https://www.ida.org/idamedia/Corporate/Files/Publications/STPIPubs/2019/D-10510.pdf      and if not just download it from here;
https://cdn.discordapp.com/attachments/922737781237768202/922737871356559440/Evaluation_of_Humans_to_Mars_in_2033.pdf
Answer: Yes, there are.
NASA has a long running series of studies for a Human Mars Mission.   These have traditionally been referred to as Design Reference Missions (DRM).   A good summary of all the DRMs can be found here
https://en.wikipedia.org/wiki/Mars_Design_Reference_Mission
The very latest addendum to the DRM 5 mentions SLS 322 times.


What are languages spoken in only one country called?

Question: English and Spanish (castellano) are the official languages in several countries. Mexico, Spain, Argentina, Costa Rica speak spanish (albeit with some differences, people from these countries can communicate with each other). United States, England, Ireland, South Africa speak English. Languages such as Korean and Finnish are not spoken in countries outside of their place of origin (at least, not by a sizable majority). Is there a terminology for languages such that aren't widely spoken outside their place of origin?
Answer: There is the pair of terms monocentric vs. pluricentric describing the situation whether only one cultural or economical centre is responsible for the definition of a standardised language or Hochsprache, or whether there are several centres (e.g. in the case of High German Germany (Berlin), Austria (Vienna) and Switzerland (Bern)).
However, this does not necessarily matches political boundaries, A language still may be monocentric and be spoken in several countries, or one country may host more than one centre of langauge standardisation.
Maybe one can borrow the term endemic for a language only occuring in one country from biology.
Comment: And would English then be *nullicentric*?
Comment: It is not correct to say that Berlin speech was "responsible for the creation" of the German Hochsprache. Standard German is based on the bureaucratic language (Kanzleisprache) of the Habsburg court in Prague. Berlinerisch is a low German dialect.
Comment: @fdb In fact, standard German is based on the Luther bible and Luther used the bureaucratic language of the Meissen chancellory as a model. But this is a historic fact, today the most influential political leaders and journalists of Germany gather in Berlin. Hamburg (hosting *Der Spiegel* and *Die Zeit*, two influential and wide-spread weeklies) also has a non-neglible contribution to German German. A Berlin dialect word has a better chance of spreading into High German than words from other dialects.
Comment: "the creation of a standardised language" : your words, not mine. Berlin dialect did not play any substantive role in the "creation" of Hochdeutsch.
Comment: @fdb Thanks for the remark, I am not a native speaker of English and I have now replaced creation by definition. I hope this reflects the dynamic nature of the standard language better.


text document shows random characters

Question: I had a text document notepad file in my windows7 with some text written in it then I wrote some more text in ubuntu in that file but now it seems that I have lost all the texts since it shows random characters mostly like /00/00/00/ do you have any idea how I can recover my information again?tnx
Comment: This can sometimes happen if the page coding is set to different settings. I'll look around and see if I can find an answer.
Comment: Can you tell me the text editor you are using in Ubuntu, please.
Comment: I used Emacs23 but it was no use it still shows mainly /00/00
Comment: Can you try to open the file with gedit, vi or another text editor? Just to see if the same thing happens.
Comment: it's still the same result :(
Answer: You see random characters when trying to read the text document back in Microsoft's Notepad, right?
Did you trying reading it back from Ubuntu? (if this works, then it's probably Notepad's fault) If you can't check from Ubuntu, try installing Notepad++ in Windows, and reading your text document with it.
As a general rule, I would recommend avoiding Microsoft's Notepad in Windows, and using a more serious alternative, Notepad2 or Notepad++ for instance. (Notepad2 is easier to get into, but replaces Microsoft's Notepad in Windows' menus) It will save you from a lot of pain when being in non Windows-only environments.
Comment: I can't read it even from ubuntu and I have notepad++ but it still shows /00/00/ ...
Comment: Could you give us a link to a copy of the document? (if it doesn't contain anything private)

text document shows random characters


What information about a house is required to get a quote for a fire sprinkler retrofit?

Question: So, I have the crazy idea to give my grandparents what could be the ultimate Christmas present -- having their house (they own it outright) retrofit with fire sprinklers.  It's a single-story ranch with a one-car attached garage and full basement of about 1100ft^2 finished area, fed by municipal water -- so on the face of it, a retrofit appears feasible.  However, the house was built in 1947 -- so there are no blueprints for it.  What information, other than a reverse-engineered floorplan of the rooms of course, would the sprinkler contractor need for a quote on the retrofit?
Answer: Floorplan is not enough. They need to visit and take extensive measurements to engineer the system.
If you want "bells and whistles" (there's lots of options) you need to decide on those too.
They will need to investigate the location, size, and routing of the service main as well. They should be able to determine minimum requirements for your locale by contacting the AHJ. NFPA has specific requirements too, but they only matter if adopted by your building code. This could be a very expensive gift. Significantly cheaper to get a high-end alarm system.
Comment: I'm already pegging it at several thousand dollars -- (the house already has an alarm system, btw)
Answer: I'd say you have everything you need for a quote. As long as you know where they live is all that's needed for a quote visit. Other than that, you need to find out what they want to save. For example: Grandpa wants himself, the TV & the cooking & cleaning wife & Grandma wants everything but the husband.
But, it should be cheaper to run & drop it from the attic, they just fill them with anti-freeze for the appropriate situation. From the basement might limit the throw of each sprinkler as affordability may stop the install at wall heads instead of ceiling heads.


How to send ether on Ethereum main net avoiding all middle men

Question: Is there a way to send ether from my address to another address on ethereum main net without using any intermediary tools or services. That is, I don't want to use third party wallets or web sites or exchanges. Interact directly with the ethereum network. Is there a way to do that?
Answer: Assuming that you're defining "middle men" as "third-party wallets or web sites or exchanges", then you can avoid all middle men by broadcast your signed transaction directly to a bunch of live Ethereum nodes.

Using existing Ethereum implementations
If you're willing to not consider geth (or some other Ethereum implementation) as a middle man, then you can use the implementation to sign and send transactions. Here are some docs on how to do this.

Not using existing Ethereum implementations
You may consider geth (and other third-party implementations of the Ethereum protocol) as falling under the "middle men" definition here. In that case, you'd want to construct and broadcast the transaction over the wire yourself to live Ethereum nodes.
Describing exactly how to do that is beyond the scope of this question, but here are some good resources: devp2p, this, this, and this.
You'll probably end up needing to implement some of the Ethereum protocol; notably you'd need to implement parts of the Ethereum Wire Protocol and the Node Discovery Protocol if you don't already know the IPs of some nodes, you'd also need to implement the relevant parts of the protocols that the previous protocols depend on like RLP, JSON-RPC.

Ramblings
This question begs a more philosophical question of "who do you trust?" and "who really are the middle men you want or need to avoid?". Here is an incomplete list of pieces of the puzzle we often implicitly take for granted as middle men:

Coinbase, Binance, or other centralized exchanges.
MetaMask, MyEtherWallet, Trust, or other software wallets.
Trezor, Ledger, or other hardware wallets.
Infura, Alchemy, or other centralized Ethereum gateways.
Etherscan, MyCrypto, Blockchair, or other websites that let you broadcast transactions directly.
geth, OpenEthereum, Py-EVM, or other Ethereum protocol implementations.
Any of the numerous open-source libraries that these implementations use.
clang, rustc, CPython, or other language implemenations.
Linux and GNU, Windows, MacOS, or whatever other OS.
Wi-Fi or Ethernet implementations.
Software or hardware of the internet router or modem.
ISPs.
The physical wires, relays, and other networking equipment that make up the internet.
The hardware that all this stuff is running on.
Yourself? It's not unlikely that you'll make a critical mistake implementing complex protocols on your own.

I realize this is a bit pedantic, but it is worth defining explicitly and exactly (and I do mean exactly) who the middle men you are willing to keep as middle men are, if that is something you care about.
But I think for the purposes of this question, the answer is probably "you can use geth directly".
Comment: Thank you very much. This pretty much answers my question. Thanks for your time answering this query.
Comment: No problem! It's an interesting question!


Blender keeps flashing not responding

Question: I am using windows 10 and the latest version of blender and even tried to reset windows however blender keeps flashing not responding and the complete UI flashes.
Please help
Comment: If you can add which package version are you using (.msi - installer or zip version)? If using the .msi, try the zip version (ie: simply unpack thew zip and run blender.exe) since "blender is installation free" (copyright Ton Rosendaal https://youtu.be/spKJ2jbnVI8?t=929)
Comment: Tech support is outside the scope of this forum. You'll get better answers from BlenderArtists.org That being said, I'll try to help out.
Comment: Most of those errors have to do with the drivers for the graphics card. Update to the latest version at the manufacturer's website.
Answer: There are a number of things that could cause this problem. It could be an old video driver. It could be a corrupt download.
The first thing I'd try is browse to C:\Users[user]\AppData\Roaming and delete the folder called "Blender Foundation." This is where Blender keeps all kinds of caches, settings, configurations, etc. Deleting this folder is like resetting Blender to the factory default configuration.
If that doesn't help, post your problem on BlenderArtists.org with a bit more detail about what "flashing" means, what GPU you have, when you last updated your drivers, and whether you're on a laptop or desktop.
Hope that helps!
Answer: There should be a problem with your video driver.
Do install the driver using disk you've got when buying it or go to the website of your graphic-card and download the latest driver available.

Blender keeps flashing not responding


How can I write if conditions on quantum registers using qiskit

Question: There is a quantum register measured to state $\left|00\right> $ How can i write a code to check weather the first qubit in measured state is 1 or zero and if 1 do some operations or if 0 do other operation (example).
Answer: If "some operations" in your question means quantum operations, then you can use Gate.c_if() to apply a gate based on a value in a classical register as follows:
qr = QuantumRegister(2, 'q')
cr = ClassicalRegister(2, 'c')
circ = QuantumCircuit(qr, cr)
circ.h(0)
circ.barrier()

# Measure first qubit to cr[0]
circ.measure(qr[0], cr[0])
# Apply X-gate to second qubit if the measured value equals 1
circ.x(1).c_if(cr[0], 1)
# Apply Y-gate to second qubit if the measured value equals 0
circ.y(1).c_if(cr[0], 0)

The circuit looks like:

If, however, you mean classical operations, then you can do something like that:
# This function will be called if the measured value of first qubit equals 0
def func_0(bit_string):
    print('In func_0 =>', bit_string)

# This function will be called if the measured value of first qubit equals 1
def func_1(bit_string):
    print('In func_1 =>', bit_string)

# Specify how many times you want to run your circuit:
shots = 10

result = backend.run(circ, shots = shots, memory = True).result()
readouts = result.get_memory()

for bit_string in readouts:
    # Check the value of first qubit.
    # Note that Qiskit uses little-endian bit ordering
    if bit_string[1] == '1':
        func_1(bit_string)
    else:
        func_0(bit_string)

Comment: So If  want to use some other functions that i built in python, I have to just see weather measured quantum states are $\left|0\right> $ or $\left|1\right> $ then I have to pass in to two different functions based on $\left|0\right> $ or $\left|1\right> $  in python.(from there its pure classical) I just need to see the qubits measured are either 0 or 1.
Comment: I'm not sure I understand you well. Could you update your question and add some code to demonstrate what you are trying to do?
Comment: I believe OP is trying to trigger python functions rather than conditionally apply gates, they require `m = circ.measure(...)` which they can use in a python if condition `if m == 0`
Comment: Exactly same but for quantum register suppose if I measure a two qubit state  and found result is  $\left|01\right>$  then I have to check those qubits are either 00 or 01 or10 or11, and make them as input  for  some other functions that are classical based on first qubit is zero  $\left|0\right> or 1 $\left|1\right>$ I  need to  pass to different functions.
Comment: I'm still not sure whether I understand you well. Check my updated answer and let me know if it does not answer your question.