What do "finite" and "non-finite" mean in linguistics?

Question: What do "finite" and "non-finite" mean in linguistics? I know that they occur in other languages and in some cases not only in verbs.
Comment: I have never encountered the term _finite_ used in grammar for anything but verb inflection. Never nouns, and always morphological inflection. In English grammar there is a big distinction between finite verbs (present and past tense forms) and non-finite verbs (participles, gerunds, and infinitives). But that's just **English** grammar.
Comment: OK, I'd go with that; like transitivity, a clausal property. Just not finite nouns.
Comment: @jlawler There are definitely grammars of English, well known ones, for example *CaGEL* (Huddleston & Pullum, 2002), or *Oxford Modern English Grammar* which consider finiteness and non-finiteness properties of **clauses** rather than (necessarily) verbs. One reason for this is the presumption that any fully and well-formed sentence must be a finite clause, whereas the verb-forms therein may appear in both finite and non-finite clauses. So, for example, those grammars recognise a single plain form of the verb appearing in both imperatives and subjunctives (finite), and also 'bare infinitives'.
Comment: @jlawler Where the latter are definitely non-finite.
Comment: While "finite" isn't used for nouns, it's possible you're getting confused by "definite" which is.
Answer: In traditional grammar a finite form of a verb is a fully specified verb form according to all verbal categories relevant to the specific language, like voice, aspect, mood, tense, person, or number.
Non-finite verb forms are underspecified in this respect, leaving out some of the categories required for a finite verb form (typically tense, person and number). Examples of non-finite verb form include infinitives, gerunds, participles, or the Latin gerundive. Languages vary in the number of non-finite verb forms they have, and there are languages not having them at all.
Comment: The first paragraph seems a little too strict here – a finite form is specified according to _those categories that exist in the language_ out of voice, aspect, etc. There are many languages whose finite forms do not specify aspect or person, for example. @Araucaria From memory, I don't think Greenlandic (and hence presumably also other Inuit languages) has non-finite verb forms. It has a 'participial' form, but that's actually a finite form used in subordination.
Comment: @Araucaria Back home now, I just checked in Michael Fortescue's grammar of West Greenlandic, which proves me wrong: the nominalising suffix _-niq_ converts a finite verbal clause of any complexity to a noun phrase to be assigned case, possession, etc., and used in subject/object/other-nominal position. In doing so, the marking of mood, person and number is removed from the verbal form, so Greenlandic does have one non-finite form, though as far as I can tell, just the one.
Comment: I never knew that. What is a language that has no non-finite forms?
Comment: @JanusBahsJacquet Should I take that to mean that Greenlandic has verb forms that are used in both finite and non-finite clauses (like, arguably, some English verb forms)?
Comment: @Araucaria-hehim No, I think rather it has no non-finite clauses, only finite ones. But my days of studying Greenlandic are fifteen years behind me, so I may be misremembering something.
Comment: Another answer with very good comments ... I will make a question out of this: https://linguistics.stackexchange.com/q/46570/9781


Logistic Regression (Multi-class)

Question: I have a problem when I run Logistic Regression on a dataset I have modelled.
Every time I run the algorithm, it always gives me the same prediction accuracy.
Does that make sense?
Any help would be much appreciated.
Thank you in advance!
Comment: Algorithms that get different results each run are *non-deterministic*. Is logistic regression deterministic? Why or why not?
Comment: Why would you expect the results to be different?
Comment: To be honest this is my first implementation of a Machine Learning model and it is my final year project for my bachelor's degree. I have seen many tutorials online and when they run the algorithms they get different percentage in their accuracy in each run. Does that mean the algorithms do not converge in these examples and that in my model it converges? My data set has around 300 data entries with 92 features.
Answer: tl;dr There is no randomness in any step of this procedure so you should always get the same result.
Longer version
To add a little more explanation (although @Sycorax hints at the reason), let's just understand what's going on from a high level. A little debugging can go a long way. Since this is tagged with sci-kit, I'll assume you're familiar with sci-kit idioms.
I imagine you have a model (clf) fitted on a training set (X_train, y_train) and are predicting some testing set (X_test). Then you compare your predicted values (y_pred) against a target (y_test).
In this case, if we assume that the training and testing set are held constant every time you run your model, then the only things that can change are clf and y_pred. So instead of questioning why the accuracy remains unchanged, we can go upstream a bit and ask why the model and its output don't change.
First of all, the logistic regression equation looks like this:
$$P(Y_i=1 | \mathbf{X}_{i}) = \text{logit}^{-1}(\bf{\beta} \cdot \mathbf{X}_{i})$$
The only way that the output $P(Y_i=1 | \mathbf{X}_{i})$ (aka y_pred) can remain the same from run to run is if $\beta$ remains the same from run to run, because we know that $\mathbf{X}_{i}$ (aka X_test) doesn't change. There is no randomness in this equation.
Therefore we just need to understanding if $\beta$ will remain the same from run to run, given the same training input X_train, y_train. Note that clf is basically just a set of $\beta$'s.
To solve for $\beta$, note that we have to solve for the $\beta$ that minimizes the likelihood function, which is a joint probability distribution (which is easily solvable since we assume every observation is IID). This procedure, which is common in statistics and machine learning, is known as Maximum Likelihood Estimation. This is what happens when you run clf.fit(X_train, y_train) and get a set of coef_ ($\beta$'s).
Since there is no closed form solution for $\beta$, we need to find an algorithm to do the trick. For this type of problem (Logistic Regression is an example of a Generalized Linear Model) we use an algorithm called Iteratively Re-weighted Least Squares. There is a lot of content on this site related to this topic. The form of IRWLS is:
$${\displaystyle \mathbf {w} _{k+1}=\left(\mathbf {X} ^{T}\mathbf {S} _{k}\mathbf {X} \right)^{-1}\mathbf {X} ^{T}\left(\mathbf {S} _{k}\mathbf {X} \mathbf {w} _{k}+\mathbf {y} -\mathbf {\boldsymbol {\mu }} _{k}\right)}$$
Each of the terms on the right hand side are constant, that is, not random. For more information on what they stand for, see here. The algorithm stops when some tolerance has been achieved. This could be a small change in $\mathbf{w}$ or a small change in your target.
As you can see, there is no reason why this algorithm shouldn't converge to the same value every time (save perhaps for potential overflow errors on some runs).
And that's why you keep getting the same prediction accuracy.
Finally, convince yourself this is what's expected using sklearn's sample code:
from sklearn import datasets, neighbors, linear_model

digits = datasets.load_digits()
X_digits = digits.data
y_digits = digits.target

n_samples = len(X_digits)

X_train = X_digits[:int(.9 * n_samples)]
y_train = y_digits[:int(.9 * n_samples)]
X_test = X_digits[int(.9 * n_samples):]
y_test = y_digits[int(.9 * n_samples):]
logistic = linear_model.LogisticRegression()

for i in range(10):
    print('LogisticRegression score: %f' % logistic.fit(X_train, y_train).score(X_test, y_test))

Logistic Regression (Multi-class)


Good ways to improve rep without asking and answering questions?

Question: I am new to this account as I lost my login to both my old account and its email. I am trying to get back to the level I was before, and get back to my old privileges, but I need questions or to give answers, both of which are slow right now. Are there any ways I can get rep from doing things other than asking and answering questions?
Comment: SE can probably help you recover your original account,  [send them an email](https://gaming.meta.stackexchange.com/contact). Out of curiosity what was your original account?
Comment: Related [help center](https://gaming.stackexchange.com/help/whats-reputation). Anyway, if your old account is on the question-ban and you created this new account to ask a question, then you're in danger of getting suspended for avoiding the ban though.
Comment: Oh wow, now that I think about it I don't remember the name exactly. It was Mr followed by summodd amount of underscores. I do remember my email, though!
Comment: @Robotnik Im pretty sure I couldn't ask questions any more cuz people didn't read one of mine through and I couldn't fix it anyway so... I guess this is good!
Comment: @antimo while that is a benefit to creating this account, it was not made to swerve the curve. I lost my login info and the email account for it was long gone.
Answer: There is a help page for this.
The literal answer to your question is suggested edits (which give +2 reputation if accepted).  But it may well be easier to ask questions.


How to view the code for a certain page?

Question: Google is indexing pages that I used like a year ago and now they are 404. I want to add a noindex tag to them, but can't figure out how to open the code for a desired page so I can put in the tag. In addition, should I do anything with those 404 pages so I have a better seo ?
Answer: If they are 404, you can't put a noindex on them! You can put rel=nofollow on the links that link to the removed pages.
It also helps to have a sitemap so that Google can track changes more easily.


Can super Buddhists eat bread?

Question: Bread has flour and yeast. Therefore, a scientist can say that it is both an animal and a vegetable grain. Is there anything wrong with eating bread?
Answer: To be honest, my ego is completely confused. Still, for the sake of satisfying it.
Can super Buddhists eat bread?
If by super buddhists, you mean as someone of so high calibur that s/he will be aware of the presence of any tiniest living organism whether it's yeast or something else-- No, that venerable one won't eat cause it's killing.
Is there anything wrong with eating bread?
Sorry, I don't know.
But atleast, I can give metta to self and others. :)
With Metta.
May all the tiny living beings that I ate unintentionally till now be free from their suffering. May I reach to the level of venerable one to identify any living microorganism with mind. May I be free from my remorse of eaten yeast. May they pardon me.
Answer: No.
According to Buddhism, you required only to not to kill.
If someone or something is killed unintentionally it will not amount to killing

Can super Buddhists eat bread?


Is this a correct traditional grip?

Question: I know I put the stick on my ring finger but the exact joint that I'm supposed to have it on confuses me as I was told to do this, but it is slightly painful and my ring finger slides around a lot.
Comment: @89f3a1c  this is what is known in some of the math and software SE sites as an "x/y question" , meaning what the OP literally asked and what he actually needs are two different things. And both those things are worth answering.
Answer: Hi and welcome to the music stack exchange. The short answer for you is, yes that is a form of the traditional grip

also known as orthodox grip or conventional grip and, to a lesser
  extent, the jazz grip.

The longer and somewhat less convenient answer is that you could still be "doing it wrong" potentially... there are correct and incorrect ways to strike a drum with this grip. You can be holding the stick incorrectly still. And, you may or may not be playing with too much tension in your wrists and/or fingers.
This really isn't the place to ask in the sense that no one here can examine how you are implementing the technique... You could potentially post more pics and a video of how you are playing in order to get a little better feedback. But, you are much better off to get one or more lessons on rudiments before proceeding with techniques that you are unfamiliar with. At very least, do some Youtube research to help get you started:
Answer: Any grip is a fulcrum, and the most important part is to grab the stick well, usually with index finger and thumb, as in the picture. That is the balance point of the fulcrum. And this applies to traditional, matched grip, and every grip. You should have it with pressure, it also will give you information on how is vibrating the stick.

I recommend you to master first the matched grip, as it is more natural. People who play traditional grip don't do this because they are good players, they do because the instrument needs it. The situations when you need the traditional grip are when playing in a marching band and the drum is not horizontal and when playing with brushes.
In a traditional grip you should grab well the fulcrum, with index and thumb. Between 3/4 and 2/3 of the lenght of the stick, where you find the balance point of the fulcrum. The stick lays back between the middle and ring finger.
There is a lot of work when mastering any grip, you should do exercises with fingers, with smaller sticks, in a lot of positions to make the fulcrum work.
More information:

How to hold a drum stick
The traditional grip
[Video] Gordy Knutson video series on mastering stick technique, check them!
[Video] Stephen Taylor debate between traditional an matched grip
[Video] Developing a killer traditional grip, by Rob Brown

Is this a correct traditional grip?


Integrate $\exp (iz^2)$ using contour integration

Question: Question:
Show that
$$\lim_{R\rightarrow \infty} \int_{-R}^Re^{iz^2}dz = \sqrt \pi e^{i\pi/4} + \mathcal O \bigg(\frac 1R \bigg)$$
by using contour integration

Attempt:
First I observed that
$$\int_{-R}^Re^{iz^2}dz =2\int_0^Re^{iz^2}dz$$
So I chose the contour $\Gamma_R = \gamma_1 * \gamma_2 * \gamma_3$ where
\begin{alignat}{2}
\gamma_1(t) & = Re^{it} \qquad & t \in \Big[0,\frac \pi 2\Big] \\
\gamma_2(t) & = (R-t)e^{i\pi/4} \qquad & t \in [0,R] \\
\gamma_3(t) & = t \qquad & t \in [0,R]
\end{alignat}
which is a sector of radius $R$ and angle $\pi /4$.
The integrand $e^{iz^2}$ is an entire function, so by Cauchy's Theorem we have
$$\int_{\Gamma_R}e^{iz^2}dz \equiv 0$$
for all $R$. Moreover, I was able to estimate the integral along the arc $\gamma_1$ as
$$\bigg|\int_{\gamma_1} e^{iz^2}dz \bigg| \leq \mathcal O\bigg(\frac 1R \bigg) \qquad \text{as } R\rightarrow \infty$$
However, I am stuck with the integral along $\gamma_2$:
\begin{align}
\int_{\gamma_2}e^{iz^2}dz & = \int_0^R \exp \Big(i{\underbrace{\big[(R-t)e^{i\pi/4}\big]}_{\gamma_2(t)}}^2\Big) \cdot -e^{i\pi/4}dt \\
& = -e^{i\pi/4}\int_0^R\exp\big(-(R-t)^2\big)dt \\
& = -e^{i\pi/4}\int_0^R\exp\big(-t^2\big)dt \\
& = ?
\end{align}
How should I proceed? (I feel like I have already gone wrong somewhere)
Comment: Probably you have misprinted in definition of $\gamma_1$.
Answer: In fact you have already done it as
$$
\int_0^\infty \exp (-t^2)dt=\frac {\sqrt\pi}2.
$$
Quite surely the value of this integral was assumed to be known.


Changing the layout of the top menu to match stackoverflow?

Question: This may sound very weird but I like the style and layout of stackoverflow's menu at the top, with a search centered and other menus to the right side. Is there a way to apply this to the rest of the stackExchange or at least this stack?
Comment: Not sure how it relates to Beta sites, though I suspect they're "in line" for the update as well. In any case, it seems that Stack Exchange intends to have the top bar of Stack Overflow as the standard for all sites eventually. Even on Area 51! See the [answer here](https://meta.stackoverflow.com/a/350666/7412956)
Answer: Whilst we are still in beta for this stack exchange we are unable to change our layout.
But rest assured as soon as we get out of beta we will all pitch together to make a layout fitting for the site
Answer: It sounds like you're asking about the top bar, where the inbox, achievements, and links like "review" and "help" are.  Stack Overflow changed that all around; it doesn't look like the other sites on the network.  That's not part of a site's design; that's baked into the SE code, currently only on SO and its meta.  I believe they intend to roll out something like that across the network at some point in the future, but I suspect it'll be a while.  (Some of the links on SO are only on SO, like Documentation and Careers, so they'll at least need to change that.  But I think they'll probably use SO's users to work out bugs and analyze how people are using it differently before they broaden it.)
Comment: I've gotten very use to it and hoped it would be rolled out throughout SE cause currently, the search bar is on the right instead of centered, the index stuff is on the left instead of the right... it really confuses me sometimes. Thanks for the answer. I guess I'll just have to wait and hope for the best!


locally conformally flat manifold

Question: A Riemannian manifold $(M,g)$ is locally conformally flat if it is locally conformal to $\mathbb{R}^n$ with the flat metric. I learn that Weyl tensor of a locally conformally flat manifold must vanish. I would like to ask: Is there any example of manifold $M$ such that it cannot be equipped with a metric $g$ with $(M,g)$ being locally flat? Is there any topological restriction on locally confomrally flat manifolds? Is there any classification theorem for locally conformally flat manifolds?
Comment: Small nitpick: the Weyl tensor is the obstruction to local conformal flatness only in dimension $> 3$. In dimension 3, the obstruction is measured by the Cotton-York tensor and in dimension 2 all surfaces are locally conformally flat due to the existence of isothermal coordinates.
Answer: The simplest example is $S^n$, it is locally conformally flat with the standard metric,
and is not flat for obvious reasons.
While flat manifolds are precisely quotients of $\mathbb R^n$ by discreet group of isometries, one should not expect to have a classification of conformally flat manifolds in higher dimensions. For example, already in dimension $4$ it was proven by Kapovich in
M. Kapovich. Conformally flat metrics on 4-manifolds. J. Differential
Geom. 66 (2004), no. 2, 289–301,
that arbitrary finitely presented group can be a subgroup of a fundamental group of a conformally flat manifold.
The article of Kapovich is and from its introduction you will learn a lot on the question.  $4$-dimensional manifolds with LCF structure have zero signature, in dimension $3$ it is known that some manfiolds don't admit conformally flat structure, first example was constructed in W. Goldman, Conformally flat manifolds with nilpotent holonomy and the uniformization problem for $3$-manifolds, Transactions
of AMS 278 (1983).
One more remark -- all hyperbolic manifolds (of constant negative sectional curvature) are all conformally flat. A connected sum of two conformally flat manifolds is conformally flat and so this already gives you a large collection of examples.
Answer: A simple obstruction is this:  No compact (without boundary), simply-connected $n$-manifold that is not diffeomorphic to the $n$-sphere carries a locally conformally flat structure.  The reason is that the developing map construction shows that any locally conformally flat metric $g$ on a simply-connected $M^n$ is, up to a conformal factor, the pullback of the standard metric on $S^n$ under some immersion $\phi:M^n\to S^n$.  If $M$ is also compact without boundary, then $\phi$ is a covering map and, hence, a diffeomorphism.
Comment: @Renato: Yes, that is the correct conclusion.  A simply-connected, closed (= compact without boundary) conformal $n$-manifold that is (locally) conformally flat is globally conformally equivalent to $S^n$.  However, the above argument only applies when $n>2$.  When $n=2$, the statement is true, but it doesn't follow from any developing map argument; when $n=2$, one has to appeal to the uniformization theorem.
Comment: Does it follow from this that any locally conformally flat metric $g$ on a simply-connected closed manifold $M$ is "globally" conformally equivalent to a round sphere? (This statement, where "locally" and "globally" are a bit fuzzy, can be found in http://en.wikipedia.org/wiki/Conformally_flat_manifold, and I basically wanted to check that the conclusion is not only that the metrics are locally conformally equivalent, but actually conformally equivalent). In particular, if $g$ is a metric on $S^n$ not conformal to the round metric, then it is not locally conformally flat.
Answer: Another topological obstruction by Kuiper,1950 is the following:
Universal cover of a compact, LCF space with an infinite Abelian
fundamental group must be $\mathbb R^n$ or $\mathbb R \times \mathbb S^{n−1}$.
Using this, for example you can show that $\mathbb S^2\times \mathbb T^2$ does not admit any LCF metric.
See the following for references and introduction to the subject:
Kalafat, M. - Locally conformally flat and self-dual structures on simple 4-manifolds. Proceedings of the Gökova Geometry-Topology Conference 2012, 111–122, Int. Press, Somerville, MA, 2013.

locally conformally flat manifold


Do I need a wooden frame for my plexiglas shelf door?

Question: I'm making a plexiglass shelf door (2 actually). Dimensions are 3500x7500x3. And I don't know if I need a frame for that. I wanted to attach it with 2 [that thing that lets you open doors] and one magnet on the other side.
Comment: What are those dimensions?  Assuming millimeters, are you trying to make a door that is 3.5m x 7.5m ?  Because that's like "large garage door" big.
Comment: oups. I added an extra 0 at  the end. it's 35x75 cm
Comment: You should edit the original question to clarify that; include units as well.
Answer: Plexiglas can be fairly flexible, unless you get thicker (more expensive)  sheets. If you're happy with how it looks/feels, then you could mount it directly... but glass is more commonly used "bare" this way due to its greater rigidity.
Comment: Given the updated dimensions in the answer, I'd say that without a frame would be way to "floppy" for me.  the height of 75cm is a lot of room for flex.
Comment: You should wait and give others a chance to agree or disagree with me before awarding me the check; someone else may (probably will) write a better answer. You can move the check later, of course, but awarding it too soon tends to discourage other answerers.
Answer: I had a plexiglas desktop, about 5mm thick, the longest edge being around 75cm. Even at this thickness, it does bend. On the other hand, if you're making doors which are to be in an upright position, the balance point is completely different. You say that you're planning on attaching it with two hinges, and at length 75cm, thickness 3mm, it does sound risky to me. 3mm thick is simply very vulnerable so if any twisting pressure gets exerted to it due to balance point, it could start to crack from any which point where you drilled holes for attaching the hinges. I would either choose a far thicker plexi, or a little bit thicker one with more than 2 hinges, or just play safe by making a frame and attaching the hinges and handles into that. Plexiglas doesn't take twisting too well.


Install MySQL using MacPorts or Mac OS X binary package?

Question: Is there any advantage in using one over the other? Should I use the vendor provided PKG file or use the Darwin Ports version? Is there a general rule of thumb for deciding how to install a package?
Answer: I would use the vendor provided package just because of support.  I have found that when I have issues with darwinports it is much harder to find support than with PKG based installs.
Answer: Use macports ( darwinports renamed ) .
You get a stock install that is in /opt/local.
Your toolchain built with this is very similar to the classic /usr/local toolchain you would get ordinarily in linux.  You know exactly how it's installed, and it pulls in dependencies automatically, and more to the point, it's quick to build the thing from source with any modern mac and when that is done then everything you need to build upon whatever it is is there, since you have the source.
port sync && port -d install mysql5 +server
if it's the first time using macports, run that at night and in the a.m. it'll be done.  Next time you wont need to build so much.  The system rewards constant use.
Answer: I've used the vendor-provided package to install MySQL on OS X.  It was fast and easy.  For general-purpose MySQL usage, I don't see why anyone would do it any other way.
Answer: I generally prefer using MacPorts to install software, but in the case of MySQL, I found it much easier to use the vendor-supplied installer. Less compile time (obviously), and it included tools that made configuration much easier.
Answer: I usually prefer to use a package from my package manager (though I use fink...). I have found that integration/dependency problems are more common and more severe than my bug-fix problems.
But, a lot will depend on the package maintainer, so YMMV.
Answer: I wouldn't use MacPorts or Fink for any critical apps.  Especially if you're using Leopard.
Perhaps it's just me, but I've had about a 50-50 success rate in installing apps using MacPorts and Fink.


I live in Bulgaria. Should I worry about a patent that has been granted in the USA?

Question: I want to implement, in my app, a technique that has been patented in the USA. I live in Bulgaria. Do I need permission from the patent owner?
Comment: Do you plan to make your app available worldwide (eg on the net) or just in Bulgaria? And (relevant in practice though not in theory) do you plan to charge for your app or just give it away?
Comment: @TimLymington: Worldwide. And I'm giving the app away for free so far, but I may start charging for it in the future.
Answer: Bulgaria is one of many countries in which intellectual property can be protected with a single international patent filing, in lieu of a Bulgarian specific filing. In generally, you should assume that any patented idea likely to have international application, such as Internet based software, which is patented in the U.S. is also the subject of international patent protection, unless you specifically know that this is not the case. Virtually all patent lawyers know how to make this filing and most would recommend doing so in this case.
So, yes, it is something you should worry about, and the better practice, by far, would be to obtain permission from the patent owner if the app is likely to have any meaningful commercial value.
Now, if you were sued, there is a good chance that it would be in Bulgarian courts under Bulgarian patent law, which may be somewhat less harsh in some respects like damages awards than U.S. patent law. But, the basis for patent liability for an infringement in Bulgaria would be very similar.
Comment: The single universal application (PCT application) does start the application process in 140+ countries but to continue the application in any of those countries requires paperwork, fees and engaging a Bulgarian patent practitioner for that country. When it comes choosing counties to enter into the national stage an applicant will make cost/benefit tradeoffs that are very rarely going to suggest pursuing a Bulgarian patent.
Comment: Also worth recognizing that the fact that the app programmer lives in Bulgaria does not necessarily mean that Bulgarian law applies or is important. For example, if the app distributed via the Apple app store, California law probably governs most of the important questions and the amounts payable to the programmer from the Apple app store could be garnished in the US.
Answer: Patents are territorial. A U.S. patent gives its owner the right to control who can make, sell, offer for sale, import or use the invention in the U.S. It may be that a counterpart application has been filed or even granted in Bulgaria or other countries.


Why are complex basis functions not used in electronic structure calculations?

Question: I've noticed while reading about Hartree-Fock in Modern Quantum Chemistry (Szabo and Ostlund) that most basis sets use only real basis functions. What I'm wondering is why aren't complex basis functions used? I might be mistaken, but from my experience it seems as though integration on the complex plane would have a lot of convenient properties that would make computations easier. Put another way, are complex basis functions not used because of some difficultly in implementation or is it because of difficulty in interpretation of properties like the molecular orbitals?
Comment: I have found a recent [article](https://www.ncbi.nlm.nih.gov/pubmed/25662632) that discusses using complex basis functions that might offer some insight, but I currently don't have access to it. Even if there are some cases where it is used, I'm interested in why it wouldn't be the standard approach.
Comment: "(...) integration on the complex plane would have a lot of convenient properties that would make computations easier." Could you give us some examples?
Comment: @pentavalent I guess I was thinking about it the wrong way in my explanation. It in most cases wouldn't make things easier to compute, but it does open up a wider array of functions to describe an orbital, which might allow fewer basis functions to be used to obtain an accurate description. I'm not certain this would necessarily be useful, but one could also potentially take advantage of path independence of complex integration to solve certain integral. But I admit, its purely speculation on my part whether these properties would be of any use in practice.
Comment: Also, I read a bit of that article and found this [book](https://books.google.com/books?id=6yao2_wubdwC&pg=PA188&lpg=PA188&dq=siegert+energy&source=bl&ots=dn3yMW0HUe&sig=b106xlynJAb6SZsvaLuoxqyQKUA&hl=en&sa=X&ved=0ahUKEwjQvNLXq-PSAhVCLmMKHY1yCb0Q6AEINTAD#v=onepage&q=siegert%20energy&f=false) which discusses using complex basis sets for a specific type of problem. It seems in both cases that complex wavefunctions are used because they allow one to obtain eigenvalues of an analytically extended Hamiltonian and that these eigenvalues are useful in the context of resonance scattering.
Answer: The basic answer is rather simple: In the non-relativistic limit it is just not necessary. There is no complex operator and hence nothing which could change the complex component of your basis functions. Using complex basis functions would only double the required work (i.e., computer time). There are very efficient schemes in order to calculate the standard integrals (McMurchie-Davidson, Obara-Saika, ...). I don't think that the representability of MOs is a reason for using real basis functions, since, strictly speaking, you can interprete only the square of the MOs and not their amplitude.
However, there are situations, where your MOs can be complex. This can happen when you have a complex operator in your equation. An example are the Pauli spin matrices of which $\sigma_y$ has only an imaginary compound. They occur, e.g., the Dirac equation (see here one formulation where they explicitly state the incorporation of the Pauli matrices). Complex MOs can be obtained either by using complex basis functions and real MO coefficients or by using real basis functions with complex coefficients. Starting from a non-relativistic implementation it might be simpler just to keep your basis functions real and to choose the MO coefficients complex.
Comment: @Tyberius : If you multiply two real numbers, you basically have one operation: $A*B$. If you instead multiply two complex numbers $(A+iC)*(B+iD)$ you end up with $A*B - C*D + i ( A*D +  B*C)$. In this case you would increase thenumber of operations by a factor of 6. So, the "double" was maybe not correct. Indeed, for GHF calculations, as they pop up in relativistic QC, one has to drop the spin symmetry. I.e., the orbitals are spinors which contain $\alpha$, as well as $\beta$ components. Hence you loose the blockdiagonal nature of many operators' matrix representation.
Comment: I haven't had much experience with the particular algorithms used to compute the integrals in these calculations so thank you for introducing them. I'm curious about one point in your answer: why would using complex basis functions "double" the work required? Does it eliminate certain symmetries that allow less integrals to be computed or do these efficient algorithms either not work or work less effectively for complex functions?


webform module in drupal

Question: I've installed the webform module in my drupal site and want to configure it so that the submission limitation is by email instead of cookies. I dont want users who have already submitted to submit twice if their email is in the system. Is there a way to do that? Would I Have to create a new module for this? If so, how do I communicate my new module with the webform module? Or would editing this webform module be the solution (which I dont think is a good idea in case I have to upgrade it and lose the changes I've done).
Please help. Thanks.
Answer: You can use the webform validation   to create a rule that compares the e-mailaddress with all e-mailaddresses in the table where the webform data is stored (you will have to look it up but I believe it is the email field in the webform_emails table).
Or you can create a custom module depending on webform_validation to compare data, there is a similar issue in the issues..
Comment: How would I create a rule that checks the values in the email field when the validation rules are very limited? The ones provided are

webform module in drupal


How to only make one trip when carrying groceries

Question: Whenever I go shopping, I have to go back and forth between the car and the kitchen 4 or 5 times. I sometimes use my hands and arms to carry the bags, and I'm able to get six or seven, but usually I have water cases and sometimes loose cans too. I've also tried using a laundry basket, but usually I have too many groceries. Is there any other life hack I can use so that I can carry all of my groceries, bags, water cases, and cans, inside my house in one trip?
Comment: My mom's hack? Get the kids to carry it in. ;P
Comment: @MaxD, just do not use throw-away plastic bags...
Comment: If one laudry basket is too small, why not take two or three of them? Better to carry than bags and doesn't waste plastic every time.
By the way, if your groceries don't fit in a single laundry basket, aren't they just too heavy to carry them comfortably in one trip?
Answer: Cheap aluminum carabiners are what I use; they're available in different sizes for about $1 or less (you don't need the expensive ones for climbing). Not only can they grab eight or  more plastic bags to carry them, but they keep the bags from spilling their contents in the trunk. For individual items, keep some bags in the car.
Comment: Terrific suggestion!  I will definitely try this one myself - thanx!
Comment: I feel this is the only answer that addresses the 'lifehack' part of the question, and could be varied to use things from around the house .
Answer: Rule #1: bag everything. doubled.
A trick I've used, although this won't work up flights of stairs, is to put all bag handles over a broom handle. Just be sure not to tilt the broom in a way that allows bags to fall off the open end.
Comment: Why double-bag stuff? Just use decent quality canvas or cotton reusable bags instead
Comment: absolutely, i live in a city and do not have a car and have to carry all my bags from the store to my building and up three flights of steps. it is completely impossible without double bagging
Comment: @NickC Canvas and other reusable bags are certainly a valid answer. There are several answers mentioning canvas and other reusable solutions below, oft praising their increased capacity. If you see an answer similar to yours, feel free to edit it to add some more details.
Answer: I've used a medium-large sized backpack to lug groceries in the absence of available transportation.  A large backpack can easily fit in a weeks worth of groceries safely.
A bonus is the environmental friendless of not needing any bags (and cost saving if you live in a place that charges extra for grocery bags).
Below is an image of a smallish pack that illustrates the point.

(source: outdoorgearlab.com)
Comment: The backpack in the picture is very small and this doesn't improve the efficiency of really much of anything with only that small amount of groceries. Yes, if you use a backpack in addition to carrying other bags in with your arms there are obvious advantages of being able to bring more with you. Also please consider the risks of [reusable bags](http://www.bloomberg.com/bw/articles/2013-01-15/paper-or-plastic-or-deadly-food-borne-pathogens) for groceries.
Comment: I usually shop by bike once a week for a 2-people household. I use a big backpack (double the size of Minnows picture), two bikerack bags and up to two cloth bags. I put heavy items such as juice in the backpack and lighter items in the bags. I can carry all that inside in a single trip. Now if I need to get milk or water, those come in sizes that don't fit in the backpack, so they go on the rack and I have to carry them in my hands while carrying the hopefully light bikerack bags and cloth bags too. If I have to get milk and water, I walk the bike and do two trips inside so I try to avoid it.
Answer: I've lived on the third floor of apartment building before with no elevator, so making one trip was a priority because who wants to climb those stairs over again or go outside in the cold/heat again.
Some things I would do to hopefully make this happen are :

never say paper when they ask paper or plastic
ask to double bag them all or double bag them all yourself (avoid potential broken bag causing another trip to retrieve what fell)
bag the milk cartons, orange juice cartons, 2 liter sodas, etc (bag everything)
don't overbuy
don't buy 12 pack/ 24 pack boxes of soda/whatever (if you must have soda, buy a 2 liter, and gallon jug for water)

This above procedure has worked really well for me in the past. This procedure's success will be dependent on how may bags you have, how heavy they all are, and your arm length and strength. I've surprised my self a few times in just how many bags I carried up in one trip. There's been times where I could only lift the bags like 2 inches above the ground, or where I've had to let them rest on the ground for a while and then get moving again. But remember, pain is gain.
Now lets say you don't take the advice above and buy a couple 24 packs of soda and a couple 24 packs of water bottles. There isn't really much of a lifehack short of building your own conveyor belt system from your car to the kitchen. If you have say, a sloped cement/patio leading into your home where you can enter without any steps, then you could possibly use a wheelbarrow or similar and pile up everything on that and make one trip inside the house. But then you're stuck with the wheelbarrow inside your home and would have to make another trip to bring it back out. So other than that, you could use a big plastic bin, but it'll likely be too heavy for one person, but two people could probably lift it.
Comment: if you insist on buying packs of water/soda you can always just remove them from packaging at the store (the store will dispose of the refuse) and bag them like up like everything else :)
Comment: @celeriko never seen that done before, but that's a brilliant idea! I'm sure the stores are trembling in fear of the thought that general public hears about that idea.
Comment: Use sturdy re-usable bags instead of two or more layers of thin plastic.
Answer: Get some reusable bags. I have the ones below and they are fantastic. They have nice big handles. I do not have to worry about them ripping. Plus they are better for the environment! Two ore three of these can fit a weeks+ worth of grocery's.
Comment: Agreed. Ikea has giant, sturdy bags well-suited for this. In my country, any supermarket will sell you big reusable grocery bags for E 1-2 apiece, and they last several years.
Comment: There's a non-working link to https://pbs.twimg.com/media/Bwel3b9IQAE83Qj.jpg at the end of that post.
Answer: Use a folding shopping cart, which you can keep in the trunk/back or behind a seat. You could combine it with the carabiners that @DrMoishe Pippik mentioned above, so you can hang bags (or other things with handles) off the side, and in the front, if the cart can't carry anything.
If you have stairs to go up, get one that can climb stairs. They have three wheels in a triangular formation on each side. And if you get tired because you are moving four or five loads of groceries all at once, get one with a seat so you can sit and take a break. :D
Answer: Get a cardboard box from the super market.
Most supermarkets I've found will happily give you a banana box or similar cardboard box for free. (Ask the person stocking the produce section).
You can then fit several shopping bags worth of groceries in the one banana box, so long as you are strong enough to carry it.
Answer: I know what you mean - I seem to lug my work stuff, my own bag, a few shopping bags and they all bang together as I try to get up the steep stairs - I am thinking of a small suitcase, the type you take on board planes with wheels and handle, and a large strong backpack that will be comfortable on my back and not make me fall backwards!!! - will look daft but as I am middle aged I can use my age and the fact I also have a disability as an excuse anyway - I try to shop every couple of days instead of one big shop to help ease the load of it all - maybe in a few years time I will pay to put a chair lift in for at least for my shopping to get a ride up - lol
Answer:
Put one or more (plastic, cardboard, wood) boxes with handles in your trunk that you can put the groceries in directly (or the bags). Has the extra advantage that your trunk does not get messed up if some carton breaks and spills.
I once lived in the forth floor and eliminated lugging bottles of liquid altogether. If your tap water is safe to drink and tastes ok, see if you can substitute at least some of your liquids with tap water. You may also use a water filter to filter it. Use any of the following water enhancers for variations in taste:

tea (e.g. herbal tea)
put the tap water in a water pitcher and add any of the following: fresh mint, freshly sliced ginger, slices of organic lemon or orange. Adds a wonderful fresh flavor to the water. It also costs less in the long run.
just a spritzer of some juice you like
Answer: I have large reusable bags in my car. When I come out of a store, I put the smaller full plastic grocery bags into the larger bags. This means I usually only have two larger bags to carry inside. The larger bags have bigger cloth handles that are easy to hold. And, if I have to put them down for some reason, I know the inside bags have extra protection from moisture or something else on the ground.
I also have two larger insulated reusable bags in my car. So, if what I've purchased needs to be kept cool, I slip the smaller bags with what needs to be kept cool inside those larger insulated bags.
I have also thought about getting a lightweight grocery cart. But, I'm not at that stage yet. There are a lot to choose from.
The previous suggestion for using luggage with wheels is a good one. If you don't want to use something you already own because you like it too much, take a trip to a Goodwill Store or Salvation Army/Thrift shop and see what's there
Answer: I use this basket with wheels

This way you can easily carry a lot of stuff and it also has a divider in order to keep fragile objects at the top for them not to be crushed by the weight of others or if you want certain groceries to be away from others.
Answer: You could use luggage, e.g. a large suitcase or trunk that has wheels, and load the groceries into the luggage while in the boot of the car.
Answer: A little while ago I bought this:

It's a nylon strap that keeps your bags together. It's called Grocery Gripps and it's actually very comfortable and lightweight. I'd highly recommend it.
This is their website I think: grocerygripps.com
Answer: when I return home from shopping I go inside my condo and get my large suitcase that has wheels.  I take it to the car and fill it up with the water I buy, bags of groceries etc....it's heavy and rolls along really well...once I reach the stairs I use the long suitcase handle and roll/pull it up 1 step at a time until I reach the top. I unload it and go back for another load.  This and grocery delivery are the best options I have found so far.
Comment: That answer has already been given.
Answer: I know this is an old question, but I have a very useful method I've been using since I lived in a 3rd floor apartment.
I stick my whole hand completely through the handles of all the bags I want to carry, then open my hand wide to keep them from slipping off again.  For larger hauls, I grab the last 1-3 handles that are hanging down around my wrist, which helps keep them from swinging so much as well as locking any bags on my arm, preventing them from sliding off.
I will sometimes grab the handle of something else I need to carry in, like the milk jug or a case of pop, letting that lock in all the bags around my wrist/arm.
To be clear, I have my arm hanging down by my side as I walk.  This allows the bags to creep up my arm, sometimes up to my elbow, rather than pom pom around my hands, allowing me to go through doors a little easier.
This puts the strain of carrying more on your arm and wrist, rather than your fingers and thumb.  Your full arm and wrist are much stronger than your fingers.  It also helps prevent the bags from creasing your fingers in painful ways.  To be clear, this can still press against your wrist and arm in uncomfortable ways.
This method puts more strain on your shoulder, as you are able to carry more bags, so remember to keep your bag hauling to what you can actually carry safely.
I generally do this with a single arm, so I have my keys and maybe 1-2 things in my other hand.


Can I back-up individual games rather than my entire hardrive?

Question: I have a downloaded copy of P.T. on my PS4 and want to save just P.T. onto a USB drive. Is there a way I can just back-up P.T. without having to uninstall every other game on my PS4's harddrive?
Answer: According to this post, unfortunately, it looks like you cannot only backup a single game. You can backup saves, though.

In theory, you can use an External Hard Drive to do a complete system backup. This complete backup will actually back up games themselves, as well as updates, downloads, game saves, system settings, etc. However, the only utility of this is to restore the backup.
You can't use this to extract a single game off and install it another PS4. Also, whenever you do a restore, it will completely wipe what is on the PS4 at the time. So this should ONLY be used for the sole purpose of backing up your entire PS4 in case of system failure, getting a new PS4, or before you send it off to get repaired.

It seems like this is to prevent copies of downloaded games from being distributed illegally.
Answer: Note that there's an option called Extended Storage available for some time now. While not technically being a backup, you can move apps between disks, freeing up space from the main drive. Only PlayStation systems will be able to read those files, which means you can't share storage between PC and your PlayStation system. Other PS4 systems will work just fine, but only if the app is was purchased for the logged-in account.


How soon after baking can you refrigerate freshly made fruit pies?

Question: How soon after baking a fresh fruit custard pie can I refrigerate it? Must it be at room temperature before it's put in the fridge?
Answer: EDIT: Although the question title says "fruit pies," the question specifies a "fruit custard pie."  The following answer relates to custard pies and other pies containing fillings with eggs and/or milk.  Actual plain "fruit pies" generally contain enough sugar to prevent rapid spoilage and therefore often do not require refrigeration.  If you do plan to refrigerate a plain fruit pie, there's no significant advantage to getting it into the fridge quickly.

Pies do not have to come down to room temperature before refrigeration.  In fact, most food safety organizations recommend the same general policy for egg-based and dairy-based pies as they do for other foods: don't leave leftovers out for more than 2 hours after cooking.  See, for example, recommendations here:

Foods which contain eggs and milk, with high moisture content, must be
  kept refrigerated, as bacteria love to grow in these foods. Failing to
  put that pie back into the refrigerator before it has remained on the
  counter for more than 2 hours can make a very merry celebration for
  the bacteria, but not so good for friends and family.

So, 2 hours should be a maximum before refrigeration.
As for recommendations about the appropriate time to let cool at room temperature, see here, for example, which states:

Cool cream pies at room temperature for only  30 minutes after you
  take them out  of the oven.
After 30 minutes, put them in the refrigerator  to complete the
  cooling and to keep them  cold.

While it says "cream pies" here, the guidelines above in that link imply that such guidelines also relate to custard and pumpkin pies.  (The first link above also says the same thing about pumpkin pies.)
Basically, the only reason to keep a dairy-based or egg-based pie out of the refrigerator after removing from the oven is to allow cooking and setting to continue.  Many custard pies will continue to set a bit while cooling, and putting them in the refrigerator immediately might "shock" them and disrupt this process of solidification.  Changes in humidity levels and condensation might also have unpredictable effects on the pie surface while it is very hot.
(As for concerns about putting hot food in the fridge, see links to food safety organizations on the subject in my answer here.  Basically, you shouldn't put a hot or warm pie near anything that's very perishable in the fridge.  Otherwise, you're safer getting it in the fridge as soon as it has stablized after cooking, which shouldn't take more than 30 minutes or so.)
Answer: Basically you want to avoid heating up the contents of your refrigerator. That's pretty much the only concern, protecting your other food items.
How long it will take a given pie to cool depends on a lot of factors, but I'd say wait half an hour minimum after pulling from the oven.
It will still be warm at that point, but probably not enough to appreciably warm your fridge.


Secure Hash Function based on AES

Question: How secure would a hash function be which appends an extra block of 16 zeroed out bytes to the end of the message and then AES-encrypts it with a well-known password (say the first 128 bits of pi) using cipher-block-chaining and then XORs all the encrypted blocks together?
Comment: You can build a MAC with a similar technique ([CBC-MAC](http://en.wikipedia.org/wiki/CBC-MAC)) but building a good hash function is harder.
Comment: For SHA-3 candidates using AES or similar parts see e.g. [this paper](http://crypto.rd.francetelecom.com/sha3/AES/paper).
Answer: Not at all secure; generating preimages would be trivial.  Here's a demonstration with a three-block message:
Here is your suggested method (limited to three block messages):
$E_0 = Encrypt( IV \oplus P_0 )$
$E_1 = Encrypt( E_0 \oplus P_1 )$
$E_2 = Encrypt( E_1 \oplus P_2 )$
$E_3 = Encrypt( E_2 \oplus 0 )$
$Hash = E_0 \oplus E_1 \oplus E_2 \oplus E_3$
(with the key for Encrypt and the IV fixed).
Here's how you could find a message $(P_0, P_1, P_2)$ that hashes to a preselected value $Hash$:

Select an arbitrary value for $P_2$ (which may include the trailing padding for the last block)
Select an arbitrary value for $E_2$.
Compute $E_3 = Encrypt( E_2 \oplus 0 )$, $E_1 = Decrypt(E_2) \oplus P_2$ and $E_0 = Hash \oplus E_1 \oplus E_2 \oplus E_3$
Compute $P_0 = IV \oplus Decrypt( E_0 )$ and $P_1 = Decrypt(E_1) \oplus E_0$

You're done: $(P_0, P_1, P_2)$ hashes to preselected value; it's easy to see that hashing this value will cause the internal $E_0, E_1, E_2, E_3$ values that we have selected, and that exclusive-oring them will produce the preselected hash.
Comment: @Thomas, no, that's not likely to be enough. Lots of people have studied how to build a hash function out of AES, and the consensus view is: it's not a very promising direction.  You're probably not going to get something of adequate strength out of AES (at least, not something simple and as fast as AES).  We could spend all day going back with various proposed schemes and showing how they're broken, but let's jump past all that to the bottom line: this is not a promising direction to build a hash function.
Comment: Yes of course.  I forgot it's easy to decrypt arbitrary strings of bytes in AES.  But of course if the plain-text and cipher lengths are always the same than this has to be true
Comment: @dspyz: actually, it's not true that plaintext and ciphertext lengths are the same implies that the function must be easily invertible.  If we consider SHA-256 restricted to 256 bit input strings, well, the input and the output are the same size; however, inverting it is somewhat difficult.
Comment: Would adding a feedforward step to the AES permutation function like so $\mathrm{Encrypt}(X) = E(X) \oplus X$ fix this vulnerability?
Answer: In addition, you would want to use at least 256 bits of "state" for an iterated 128 bit hash function due to the existence of generic attacks to produce state collusions. You might want to google for "wide pipe construction" or "random sponge function".

Secure Hash Function based on AES


How can I create a Windows password reset disk on Mac?

Question: I have installed a dual-system on my Mac: Windows and Mac. Unfortunately, I forgot the password to login Windows OS and cannot access it. Is there any possible way to create a Windows password reset disk on MacOS,so that I could crack Windows password without reinstall?
Answer: Use Hiren's Boot CD. it have a password deleter. you can download it for free and just need to burn it to a CD.
Answer: The password reset disk could only be created from the Control Panel inside the Windows system. You can boot into MacOS and download the ISO image of Offline NT Password & Registry Editor, then burn the CD using the built-in Disk Utility tool. Or create a bootableb USB with the freeware UNetbootin.
Answer: You need to create the password reset disk while you still know the password, unfortunately. But there are other ways to rescue your Windows environment.


how do i get my stolen phone& pictures back?

Question: On 7 july 15 someone broke in my house and stole my galaxy note 3 it did not have service it has been disconnect for about 6mo now i would like to get my phone back because it had picture of me and my dad who died the day after father day this past june & other family pictures that can not be replaced.how do i go about getting those back?
Comment: Afraid there's not much we can do about here. Being disconnected for half a year, I see no way how you could locate it. Apart from which, the thief most likely already factory-reset the device to sell it. Sorry for these bad news.
Comment: Sure he could. That doesn't make it much likely the police dept will restore the data the thief most likely already purged – provided they even find the device.
Comment: @Izzy he could file a complain in the local police dept.
Answer: I'm very sorry for what happened, but there isn't much that can be done.
You can only get your photos back if you had backed them up.
Try to remember if you had copied them to your PC, pendrive or CD.
Or if you had shared it with someone who might still have them.
If you had shared it in apps like hangouts then they will be backed up by google+ photos. And if you had set photos to back up all your images you can retrieve them easily by opening your account in another device. Every thing will be stored safe in google's servers.
Or probably you would have them on your Google Drive, Dropbox or any other cloud service.
And also, if you had your whole phone backed up by your google account (every time you log in to a google in your phone, google askes you if you want to back up your phone), then you can get back all your stuff like contacts and bookmarks back by logging in a different phone.
Hope this helps


What kind of philosophical questions are transcendental philosophical questions?

Question: There are a lot of different philosophical questions and I'm interested in knowing what kind of questions are asked in or what kind of questions does transcendental philosophy try to answer. I've tried looking but I can't seem to find the answer anywhere.
Comment: With *transcendental philosophy* do you mean [this](https://en.wikipedia.org/wiki/Transcendental_philosophy) ?
Answer: "Trancendental" is a term used to characterize Kant's epistemology. Kant gives his definition in Critique of Pure Reason (CPR):

I call all knowledge transcendental which deals not so much with objects as with our manner of knowing objects insofar as this manner is to be possible a priori. (B25)

The Kantian term trascendental means to refer to the conditions of the possibility of a science or of a priori knowledge.
The term must not be confused with the term transcendent, which means to surmount our empirical experience.
Answer: TL;DR: The question that asks what the conditions of the possibility of our reference to objects are. There is only one question in transcendental philosophy, but for aspects or classes of objects it may have to be answered differently.
I would like to make another answer as a sort of appendix to what @JoWehler wrote, based on his letter to Herz in 1772 in addition to CPR, because it is easy to think that one understands what Kant means and what the problem transcendental philosophy tries to answer is, but another thing to actually understand the whole depth of it. As this question is so important and so very underestimated, it will become quite a long answer.
I will translate the letters by myself.
First approach towards the question
The question as asked already occured nine years before CPR and seems rather innocent (Ak. 10:130.6-8):

Ich frug mich nemlich selbst: auf welchem Grunde beruhet die Beziehung desienigen, was man in uns Vorstellung nennt, auf den Gegenstand?"
I asked myself: What is the reason for the relation of what we inside us call representation [Vorstellung] to its object?

Another way to put it, as we will see, is this: How can it be that we think to have representations that actually represent objects? But this is not about the objects of sensual experience, as he continues (lines 8-12):

Enthält die Vorstellung nur die Art, wie das subiect von dem Gegenstande afficirt wird, so ists leicht einzusehen, wie er diesem als eine Wirkung seiner Ursache gemäß sey und wie diese Bestimmung unsres Gemüths etwas vorstellen d. i. einen Gegenstand haben könne.
If the representation only contains the manner in which the subject is effected by the object, it is easy to understand how it, as an effect, corresponds to its cause and how this determination of our mind can represent something, i.e. have an object.

This means he actually takes this to be trivial as there is a causal relation between objects and our sensual representation of them. (Spoiler: Only in the sense of the manifold of intuition).
The other unproblematic case would be if we had an intellect that is productive, an intellectus archetypus, like described in the lines 18-21:

wenn das, was in uns Vorstellung heißt, in Ansehung des obiects activ wäre, d. i. wenn dadurch selbst der Gegenstand hervorgebracht würde, wie man sich die Göttliche Erkentnisse als die Urbilder der Sachen vorstellet, so würde auch die Conformitaet derselben mit den obiecten verstanden werden können.
If that what in us is called representation would be active in respect to the object, i.e. if the object would be produced by it, like divine cognition is thought to be the archetypes of things, the conformity of representations with the objects could be understood, too.

But as finite beings, we have a problem
Now, what Kant is thinking about is a third class of representations as a problem, like also expressed in this letter already (Ak. 10:131.1-10), but it is better put and adressed in CPR, A 92-93/B 124-126 (Cambridge Edition p. 224). I will quote almost the whole paragraph and make comments to make clear where and why a problem occurs:

There are only two possible cases in which synthetic representation and its objects can come together, necessarily relate to each other, and, as it were, meet each other: Either if the object alone makes the representation possible, or if the representation alone makes the object possible.

This corresponds exactly the two cases formulated nine years earlier.

If it is the first, then this relation is only empirical, and the representation is never possible a priori. And this is the case with appearance in respect of that in it which belongs to sensation [i.e. the beforementioned manifold!].

If we talk about sensual representation, it clearly isn't a priori and thus to some extend arbitrary.

But if it is the second, then since representation in itself (for we are not here talking about its causality by means of the will) does not produce its objects as far as its existance is concerned, the representation is still determinant of the object a priori if it is possible through it alone to cognize something as an object.

First, we are here not talking about the divine intellect, but an intellect as ours, a finite one (as becomes clear within further quotes). Therefore the representation does "not produce its objects as far as its existance".
He here restates the problem as follows: Before even being able to produce something by (or after, through the will) thinking it, it has a priori to be thought as object. The problematic relation would therefore be a relation a priori between a representation and an object by virtue of being an object at all:

But there are two conditions under which alone the cognition of an object is possible: first, intuition, through which it is given, but only as appearance; second, concept, through which an object is thought that corresponds to this inuition.

We cannot go depper into why he is able to say this here, just take it for granted for now. It follows from our finite understanding.

It is clear from what has been said above, however, that the first condition, namely that under which alone objects can be intuited, in fact does lie in the mind a priori as the ground of the form of objects. All appearances therefore necessarily agree with this formal condition of sensibility, because only through it can they appear, i.e. be empirically intiuted and given

He here refers to his Transcendental Aesthetics, where he showed space and time as forms of intuition. Now, as objects are given through intuition only, they underlie the same forms. In this sense space and time are the conditions of the possibility of our reference to objects insofar they are given by intuition.

The question now is wether a priori concepts do not also precede, as conditions under which alone something can be, if not untuited, nevertheless thought as object in general, for then all empirical cognition of objects is necessarily in accord with such concepts, since without their presupposition nothing is possible as object of experience.

The question is therefore here for "conditions under which alone something can be [...] thought as object in general":

For they [the concepts *a priori, i.e. the categories of pure understanding] then are related necessarily and a priori to objects of experience, since only by means of them can any object of experience be thought at all.

Where does it get us?
Taken this way,

the transcendental aesthetics are about the conditions of the possibility of our reference to objects insofar they have corresponding intuitions (the forms of intuition, space and time, are the answer),

the transcendental analytic about the conditions of the possibility of our reference to objects insofar they are represented as objects at all (the categories of pure understanding),

and the transcendental dialectics (not mentioned here) about the conditions of the possibility of our reference to objects that do not have a corresponding intuition and are nevertheless necessary (the ideas of pure reason, whose relation to their objects is inexplicable).


Entire apple seedling was eaten, but miraculously came back as two. Now what?

Question: At the beginning of the pandemic, house bound, I decided I wanted to try germinating apple seeds from fruits I had consumed. After a dormancy, one of the seeds actually sprouted and I was obsessed with caring for it. It got about 6 or 7 inches tall, was transplanted into a bigger pot, and moved outside where it continued to grow. One morning going out to my car, I saw that some creature had chewed through the base of the tree and just discarded it on the ground beside. Panicked, I put my sweet little friend in water, hoping to save it, but it was no use. I was so upset I couldn't even move or empty the pot it had been in. As a matter of fact, I probably left it for a month. But then, the craziest thing happened: the root must have been very established, and the darn thing re-sprouted!! Not one, but TWO trees from that root. I call it my 'Lazarus' tree. But now what? Do I leave the twins conjoined? Should I prune one whole half of this little tree? I have it inside under a grow-light at the moment to protect from outside critters and the impending frost. I live in USDA hardiness zone 6b. Do I leave it under light or put it in my basement for dormancy?
Comment: It's not really a miracle. In the wild, tiny trees get trodden on and broken, or eaten, all the time. That's why if they are growing in the ground, the roots start growing faster than the top. In a pot there might not be enough room for that. If the top was 6 inches tall it really should have been in a pot with at least 12 inches depth of soil.
Answer: Great story! And great name for an apple: Lazarus.
Since you have critters outside, I would leave both sprouts for now. Until it gets big enough to not be eaten by animals anymore (do you know what animal?), you have more chance with 2 spouts instead of just one.
I don't know what kind of apple you had, but most apple trees can survive hardiness zone 6b. So I don't think it needs to be inside for frost. But I understand that you are afraid that it will be damaged again by animals. So if you keep it indoors, you can use grow light until it loses it leaves. Without leaves it doesn't need light anymore of course.
I hope in some years you'll have good tasting "Lazarus" apples!
Comment: If you keep it warm indoors, it won't go dormant for the winter, won't lose its leaves, and will probably die before spring. Get it outside in the cold weather where it belongs - preferably planted in the ground so the roots can grow wide and deep, not it a little pot.
Comment: When you follow alephzero's advice. protect the little guy with a cylinder of hardware cloth (hardware cloth is actually a steel mesh of quarter-inch squares that nothing can chew through). Buy a three-foot high roll, cut about 18 inches off and roll it into a cylinder, then tie the ends together with twist-ties. Hammer a stake into the ground next to the tree and twist-tie the cylinder to it. If you can, sink the cylinder into the soil by a couple of inches or heap soil around it on the outside so that voles can't get under it. You can leave this on year-round until the tree is bigger.


What is the simplest way to create a precipitation reaction at home?

Question: What is the easiest way to create a precipitation reaction at home, preferably with easily retrievable chemicals?
I need this because I'm making a video for my film education.
Answer: Here's one easy way :
Make a solution of salt ($\ce{NaCl}$) in water, and another solution of Silver Nitrate ($\ce{AgNO_3}$), which you can buy easily) in water.
Upon mixing the two, $\ce{AgCl}$ (Silver chloride, a white compound) will instantly precipitate.
Comment: Silver chloride is white. The grey colour is due to elemental silver (which AgCl is reduced to)
Comment: Silver nitrate is expensive, and not easy to buy without legal authorization. Furthermore, its solutions makes dark spots on skin and clothes, that appears only on the following day. But this spot is impossible to clean.
Answer: For a low-hazard experiment with standard household materials, some variation of the following should work:
Chemicals:

$\ce{CaCl2}$ : Available as a type of ice melt (e.g., this)
Acetic acid : White distilled vinegar
$\ce{NaHCO3}$ : Baking soda

Procedure:

Dilute the vinegar in water, at about $1$ part vinegar to $10$ parts water.
Add a small handful of the $\ce{CaCl2}$ and stir to dissolve.
In a separate container, mix $\sim 1~\mathrm{Tbsp}$ baking soda in $1~ \mathrm{cup}$ lukewarm water
If all of the baking soda dissolves, keep adding more until it won't dissolve further.
Let the baking soda solids settle to the bottom of the container, then carefully pour the liquid into a clear container, suitable for the demonstration.

For the demonstration, add the $\ce{CaCl2}$/vinegar solution drop-by-drop to the bicarbonate solution. If I've thought this through properly, a white $\ce{CaCO3}\!\left(\mathrm s\right)$ precipitate should hopefully form as each drop is added.
To note, I specified the dilute vinegar solution to try to avoid premature precipitation of $\ce{Ca(OH)2}$.  If the demonstration solution fizzes too much when adding the drops of $\ce{CaCl2}$/vinegar solution, or if no precipitate forms at all, you could try eliminating the vinegar (skip step $1$) and just dissolve the $\ce{CaCl2}$ in tap water.
Comment: Use washing soda instead of baking soda.  You are more guaranteed to get the calcium carbonate by adding a normal carbonate instead of a bicarbonate.
Comment: Indeed, @OscarLanzi, I tried this myself with bicarb, and it didn't really work. I'll have to try it again with the washing soda.
Answer: Mix solutions of washing soda (Na2CO3) and Epsom Salt (MgSO4) to get a precipitate of magnesium carbonate (MgCO3).
Comment: As per [magnesium carbonate](https://en.wikipedia.org/wiki/Magnesium_carbonate), this actually produces a hydrated complex of magnesium hydroxide and magnesium carbonate. From the same wiki article, mixing solutions of sodium bicarbonate ("baking soda") and magnesium sulfate (the typical hydrated form is "Epsom salt") produces magnesium carbonate.
Answer: For an experiment of some practical value, try Epsom salt solution plus soapy water.  Explain that the Epsom salt contains magnesium which is a source of water hardness and show what happens when you add the "hard water" to the soapy solution.  Ewww!  Now students will know why water softening is important.
Comment: But hard water is good!
Answer: Prepare a solution of table salt in boiling water until no more salt will dissolve. You can then transfer the solution to a different container and allow for the solution to cool. The salt should precipitate out. You should get about 10% of the total salt to precipitate out on cooling.
Answer: Because to precipitate means to come out of solution, this word is commonly used in weather, chemistry and even in biology. For a science experiment that is safe for the kids and amazing for adults I recommend DNA extraction. Strawberry DNA extraction to be more precise, follow the online instructions to make a strawberry smoothie. Mix with the extraction buffer (soap and table salt), and save the last and final step for the demonstration. Describe the experiment to the kids or do it with them, once you add the chilled rubbing alcohol to the strawberry wash the strawberry DNA will precipitate out!
Enjoy, Mr. R
Answer: The easiest way to make precipitation is using washing powder and water and then mixing it with baking powder and water. When they are mixed together the mixture goes from clear to cloudy and becomes hard water.


Is the Canon 650D still a good choice?

Question: I am planning on getting my first DSLR soon. I'm torn between the 1300D and 650D because they are about the same price right now. I love the fact that the 650D has a movable touchscreen and a mic input, but I'm not sure if buying a nearly 7-year-old model over the 2016 1300D is a good idea. So what would be better more features but older sensor or new sensor but fewer features? (I know the 1300D has wifi capabilities. but I value that less than the movable screen. But I have never owned a DSLR so if wifi is crazy useful and I don't realize it please tell me.)
Comment: Canon (not the brand) questions dont have an objective answer. Youre going to have personal tastes that affect your decisions someone else cannot account for or will find less important.
Comment: Don't stress too hard about what to get as your first DSLR body. You'll replace sooner or later it if it is really holding you back. Follow the link Philip Kendall posted above to help you think through the decision.
Comment: I was more looking for some information on whether I will have problems that I can't foresee because I don't have a lot of experience when buying an older model.
Comment: Have a look at this if you're thinking of buying a used camera. https://photo.stackexchange.com/questions/1776/what-should-i-look-out-for-when-buying-a-second-hand-dslr-body and keep in mind people were once making great pictures with none of the features we have now.
Answer: The Canon Rebel T4i/650D was released in 2012.  Just because a digital camera is X number of years old - does not mean that the images it will produce are any worse then the day that it came out.
The question is really down to what features you consider necessary and what your budget (for the camera body) is - neither of which we can answer for you.
The two specific models that you provided as examples are very similar.  The differences in the sensor are not relevant to someone buying a DSLR for the first time - some would argue this all day long, but to me its simply not an issue.  I would expect that you can find a lightly used or at a minimum a well discounted Canon Rebel T4i/650D due to its age - so for that reason it seems like an easy answer to me.  Since I don't know the features that are most important to you beyond an articulating touch screen and mic-input, I'd say figure that out and you have your answer.

Is the Canon 650D still a good choice?


How do I transfer documents from Google Apps to another Google Account outside of that organization?

Question: I have a Google Apps account as part of my school, but I'm going to be graduating shortly. I want to transfer ownership of my documents to my personal Google Drive account. However, when I do so from the sharing dialog, it tells me that I can only transfer ownership of documents to other people inside of my domain. I don't need changes to sync back to my old Apps account, as that will be deleted.
Is there any way to do this?
Answer: The easiest way to do this without manually share each document or folder with another account, is to make use of Google Takeout (if enabled by your Google Apps-Administrator) to export your Google Drive-content.
Refer to Download your data: FAQ for more information about Google Takeout.
Answer: I've managed to get this to work without wasting my bandwidth. My issue was I had about 750GB in an unlimited Google Drive account on one domain but I had to switch off the domain onto a new account, under a different domain. I didn't want to download 750GB just to upload it again and cripple my network for a few days.
I found this Reddit post which mentions a tool called rclone which is available on mostly every platform. If you have OSX brew you can simply brew install rclone.
Once you have rclone installed you need to do the following:

Share your large folder to your new Google Drive account. You don't have to be the owner on your new account. From the shared tab of the web client, add your big folder of stuff to your drive. This should add a linked folder to your root dictionary of your drive.
Setup your NEW drive account in rclone by running rclone config. Choose n for new remote, and then 7 for Google Drive account. These are subject to change so read the list please. Roll through the config. You shouldn't have to type in anything except a name for the account and it should launch your browser to authenticate. Choose the right account.Follow the menu to exit config
Now let's build the command to copy all of our stuff using the API. rclone is very nice to us since it obeys API and retries until it copies everything. Here is a skeleton command: rclone copy name_of_your_NEW_drive:"sharedFolderName" name_of_your_NEW_drive:"aDifferentSharedFolderName"

Some important things to note about the command:

You need to name your destination folder something different than the input. This is as easy as just adding copy or whatever
You can do cross account transfer however this means you will be downloading files which is not what I wanted.

The command will run for quite a while because as the rclone docs state the API limits to 2 files per seconds assuming no overhead. If you have a ton of files (versus five 1TB files..) this will take quite a while but it'll be faster and cleaner than downloading it. rclone will periodically update you on the progress and if you set this up right it should say
Transferred:      0 Bytes (0 Bytes/s)
which means that you are not downloading any data!

This works far more reliably than some of the Google App Scripts which, to be frank, failed for half of my files while rclone duplicated this for me in just under an hour. When it completes the command should just exit so if you want to just paste in another command after to notify you I'd recommend it.
Answer: Well, 7 years old post, sorry for being too late.
I was searching for a way to solve this problem as I had to keep the link of the file the same.
The solution that I found is to create a shared drive (Not just a shared folder. Click here for more).

Create a shared drive in your organization (School). Sadly personal accounts can not create these sort of drives, not every organization has the right to do this (Click here for more).

You might also look into making an organization yourself that has the right to make shared drives. (In 2021 it requires Business Standard and it is $12USD/user/month currently. You can cancel it, but one payment is neccessary. Click here for more). With that you can bypass your organization admins too, as you will be the one to set the rules for that.

School accounts are able to create shared drives. If you are unable to create one, ask your administrators for help.

Move your files into the shared drive with your organization account.

Give manager access for your personal account.

Move your files into your drive with your personal account.

With that you can transfer those files into your account and keep the link too.
This only works if you can create shared drives or your admin can and willing to help you with that OR if you are willing to pay.
Answer: It is not possible to share the Google doc outside of domain
As workaround,Please follow the steps
(i) select the Google doc you need to share and then click on the more icon  and then chose the download button with your desired format.
(ii) Now go to the other domain and open the Google drive,Click upload and then select desired files by browsing the computer.Once it is selected,It would be uploaded


Is it possible to completely disable Universal Access zoom shortcuts? [Solved]

Question: I am able to assign an additional shortcut to zoom in and out using the System Settings > Keyboard > Universal Access > Magnifier Zoom In/Out options, but regardless of what I set there, the shortcuts Meta+= and Meta+- still zoom in and out.
It's conflicting with a shortcut in another program.
Answer: I discovered a workaround via this answer to a related question.
First, use gsettings to find the internal configuration setting we wish to change:
gsettings list-recursively | grep -i zoom
# ...
# org.pantheon.desktop.gala.keybindings zoom-out ['<Super>minus', '<Super>KP_Subtract']
# org.pantheon.desktop.gala.keybindings zoom-in ['<Super>plus', '<Super>KP_Add']
# ...

Then, change the individual setting as necessary. In my case:
gsettings set org.pantheon.desktop.gala.keybindings zoom-out "[]"
gsettings set org.pantheon.desktop.gala.keybindings zoom-in "[]"

Then you should be able to use the built in elementaryOS settings for the shortcut you want.
It seems like this may be a bug in ElementaryOS. https://github.com/elementary/switchboard-plug-keyboard/issues/31?_pjax=%23js-repo-pjax-container


Minimum slope for rolled asphalt roof

Question: Have a overhang / leantoo built off the garage that was never completed and covered with a tarp. I've stripped the rotten plywood off and have new OSB to install. The slope is 5" in a 12' run. A fraction more than 1/4" per 1'. My thought is to install a layer of felt paper then rolled asphalt nailed at the top edge and adhesive along the bottom??
Comment: There are roof underlayments that are tapered fiberboard that will change the pitch of the roof without adding a lot of weight and no need for framing. FWIW, the roof slope you have is at the minimum slope acccepted by the UBC, so I just seen on this website    http://www.epsindustry.org/roofing-systems/tapered-roofing-systems   I need to mention, your proposed idea for the roofing will not hold up. Neoprene, hot mop or torch apply at the least. PVC as mentioned below sounds intriguing, although I have never known of it...
Answer: I don't think what you are proposing will work. Asphalt rolled roofing is NOT waterproof. Sealing at the joints and eave will stop wind blown rain, but standing water will saturate the paper and it will leak. (The paper is not UV resistant either.)
I wouldn't use a "peel and stick" membrane either, like Grace "Ice and Water Shield", because they can only be used on slopes down to 2:12. (...plus they have no UV protection.)
I'd use an PVC membrane. I would not use an EPDM membrane. The main difference is that EPDM's seams are chemically sealed and PVC seams are heat welded together. The EPDM seams can breakdown over time.
...but back to your question, No, I would not use roll roofing sealed with mastic.
Comment: Trying to incorporate this into my understanding of roofing, does "roll roofing" have mineral grains on the surface intended to be exposed to the sun?
Comment: Hmmm... I think of "roll roofing" as anything that is a building paper or felt, (asphalt impregnated.) Some is solid and some is perforated (to help absorb asphalt).  Roofing systems have various components, like: nailable base sheet, layers of felt, cap, etc.  Cap sheets can be smooth or granular. However, all the components are applied into a layer of asphalt, coal tar or mastic. In my opinion, that system is nearly impossible to install correctly...there are always voids in the asphalt or mastic...and that leads to roofing failures.  @JimStewart That's a long-winded answer...
Answer: I'm guessing that the reason your not going to torch it down is your uncomfortable with fire?  If so then I would contact a roofing supply and get a two part roll roofing system that has a nail base.  It essentially has a sheet you nail down then a sheet you glue down ontop or some systems even include a peel off backing to be applied to the nailed base. And are very easy to apply if instructions are followed correctly.  Oh and minimal slope for most rolled roofing products is 1/12

Minimum slope for rolled asphalt roof


How to get string address by coordinates?

Question: How to get string address by coordinates? I am using gmaps.js  3rd party API. Is there someone how was working with it? I want to get string addresses, and I know coordinates.
UPD. Actually I know about google maps standart tutorials, the question is how to pick up the data using gmaps.js. I know for sure that this data can be taken.
Answer: I do not know if it's supported by gmaps.js, but basically you are searching for "reverse geocoding"
EDIT:
Unfortunately there is no "direct" support in gmaps.js for (reverse) geocoding, but you can still use google geocoding in gmap.js (in a mixed way):

<code>
var opt = {
    lat : 40.714224,
    lng : -73.961452,
    callback : function(results, status) {
        if (status == google.maps.GeocoderStatus.OK) {
            console.log(results[1].formatted_address);
        }
    }
}

GMaps.geocode(opt);
</code>
Answer: I think you can get the help at https://developers.google.com/maps/documentation/geocoding/  OR https://developers.google.com/places/documentation/
These links are google tutorials for google geocoding API.


Convert from VMDK to OVF

Question: How can I convert a VMDK to OVF?
Answer: The VMDK file is the actual virtual disk, an ovf file is just a settings file (plain text), that VMWare products (like ESXi Server) and other virtualization software (like Virtualbox) can use when importing the VM.
You may have an existing settings file (like a .vmx) which you can convert into ovf format using VMware's tool 'ovftool':
http://communities.vmware.com/community/vmtn/vsphere/automationtools/ovf
There's quite a lot of options, which are detailed here in the user guide:
http://www.vmware.com/support/developer/ovf/ovf20/ovftool_201_userguide.pdf
Comment: Example use: ovftool mymachine.vmx mymachine.ovf
Comment: BTW, ovftool's src and/or destination VM locations CAN be on remote ESX(i) hosts! :)
Comment: Haven't tried this yet but while importing into AWS I am guessing, its going to help me. I will post my findings when done
Answer: You can use VMware's Workstation Pro or thier OVF tool.  In Workstation, load the VM then under file menu, select export to OVF.  Be aware this can take a long time.
VMware's OVF Tools is a command line option.

Convert from VMDK to OVF


What's the difference between "over and over again" and "again and again"?

Question: What's the difference between "over and over again" and "again and again"? Are there any subtle hues in meaning?
Answer: Perhaps "over and over again" has a slightly more negative connotation, in that the repetitive behavior is both undesirable and unnecessary.
But the difference is very subtle, and either expression would serve in the majority of situations.


Is my network being sniffed?

Question: Is there any way to find out if someone who is connected to my network is sniffing packets?
There is a way with nmap if his card is in promiscuous mode but what if it is passive?
Answer: The thing about passive sniffing is that you don't get other people's network traffic unless you're either in a position to see that traffic due to network topology (e.g. you're sniffing a trunk port) or are doing network spoofing (e.g. ARP spoofing) that causes packets to be sent to your device.
If they're doing the latter, you just need to look out for ARP spoofing attacks. Many IDS solutions have features that can detect ARP spoofing. A really low-quality cheap way to catch rogue devices is to just look for packets coming from MAC addresses you don't recognise. Better solutions match up the known MAC addresses to physical ports and devices, so that unusual routing can be spotted quickly.
I can't think of any way to detect entirely passive sniffing per se, but it would certainly be possible to probe for rogue devices on your network by doing ARP scans, DHCP probes, or application-layer broadcasts (e.g. on 192.168.x.255) and looking for responses from devices that you don't recognise.
Comment: On a wireless network all data transmitted can be sniffed without detection. The only concern is if the attacker can get around the encryption...
Comment: A sniffing device can be entirely passive, either through a modified stack or through a read-only [Ethernet cable](http://www.tamos.com/htmlhelp/monitoring/read_onlycables.htm).
Comment: It can, but it would have to be sniffing on a line that already has traffic going down it. If that line is connected to a port that only has the sniffing device connected, or if you're on a wireless network, you'll get no data.
Comment: +1 for read only ethernet cable! never heard of something like that.
Comment: Other than what @Polynomial said about only seeing whats passing. I would make the additional point that if you are upstream (Victim A and B are connected to a switch and your reading on the upstream side of that switch) you wont see any traffic that goes directly between them (eg. you might see the DNS lookup where they find each other, but not the file transfer between them.) By contrast, You Victim A and B are all on a hub (not recommended since switches have gotten much less expensive) you could see everything that is said between them and what goes upstream...and what comes back down..ALL
Answer: Leaving aside physical attacks like cable splicing and wiretapping, there are a couple ways to find traffic sniffers. One way, as already mentioned by @Polynomial, is to detect the traffic tampering that is required in order to direct useful (i.e. other people's) traffic to the sniffer. An example program that does this is arpwatch.
Another detection mechanism is using probes to determine if the host's interface is in promiscuous mode. Nmap has a script, sniffer-detect which can do this, but there are other programs as well.
Answer: There is always the possibility that a sniffer can be deployed on the local machine to sniff the network, it will narrow the traffic to just the local host but is a effective if a targeted attack is in progress to monitor a specific person and/or host of interest.
This can be somewhat hard to detect in some cases due to this type of sniffing being passive in nature, maybe even cloaked by root-kits etc.
Answer: I want to look into this in a little more details, but I recall a networking friend of mine once told me about an advanced "Fluke Tool" that could detect the distance of a cable and anything physically on the wire. This is not using network traffic, but something way down in the physical layer, etc. I would imagine if you knew your before state you could scan for any changes in physical connections (on a wired network) on a periodic basis and this might show rogue connections. On a large network, this sound a bit unpractical though.
A better way of going about this may be to assume you are being tapped at the physical level and to use IPSec, VPN, etc so that the unauthorized connection is only capturing encrypted data. For a malicious insider, if it's company owned equipment, hopefully you have the system admin tools, policies, etc to lock down software and to prevent promiscuous mode (I believe on Windows you need admin level to enter promiscuous mode).
Comment: The device you're describing is called a time domain reflectometer.

Is my network being sniffed?


Simple question about pre/post hard fork of July 2016

Question: I have searched the messages and, while I did find some info on the hard fork, I didn't see my answer.  I believe it is because it is such a simple question.  Thank you for any clarification you can provide!
I am a novice regarding cryptocurrency in general.  If you owned 50 Ethereum prior to the hard fork in July 2016, would those 50 coins be considered ETH or Classic?  I have read some conflicting articles trying to figure this out myself.  Some say that Classic forked off ETH to remain "pure"; thus, I would think the 50 would be considered ETH.  I read a different article saying that the Classic remained "pure" and ETH forked off it, meaning the original 50 would be Classic.  Now, reading some message threads on here, it seems to be that the fork gave owners the same of each ETH and Classic; therefore, you would have 50 of each.  I sincerely hope someone can answer this for me.  Thank you again!
Answer:
it seems to be that the fork gave owners the same of each ETH and Classic; therefore, you would have 50 of each

Correct. A snapshot was taken of the world state, and all accounts and their balances were duplicated to the new ETC chain. You would have had both 50 ETH and 50 ETC.