Does the Frobenius coin problem require the denominations to be pairwise relatively prime?

Question: In the Frobenius Coin problem (or Chicken McNugget theorem) for $n>2$, do the numbers have to be pairwise relatively prime, or just relatively prime in totality?
Comment: Only relatively primein totality, for them to cover all values from some point on. The last uncovered value is denoted $g(a_1,...,a_n)$ and called the Frobenius number of the list of $a_k.$ There's something about this on wiki page for "coin problem".
Answer: They$\let\geq\geqslant\let\leq\leqslant$ need not be pairwise relatively prime. The reason why is essentially that Bézout's theorem works fine when we are only given that $\gcd(a_1,\ldots,a_n)=1$. Of course, it does not immediately follow that we can take the Bézout coefficients positive for sufficiently large numbers. Here's a quick way to see why:
Suppose we want to write $m\in\mathbb N$ as $x_1a_1+\cdots+x_na_n$ with $x_1,\ldots,x_n\geq0$. Bézout already gives us such $x_1,\ldots,x_n\in\mathbb Z$, but they can be negative. Now let $(q_k,r_k)$ be quotient and remainder when $x_k$ is divided by $\frac{a_1\cdots a_n}{a_k}$. Then
$$\begin{align*}
m &= \sum_{k=1}^nq_k(a_1\cdots a_n)+r_ka_k\\
&= (q_1+\cdots+q_n)\cdot a_1\cdots a_n+\sum_{k=1}^nr_ka_k.
\end{align*}$$
Because $r_k\leq\frac{a_1\cdots a_n}{a_k}-1$, we have $q_1+\cdots+q_n>0$ as soon as $m>\sum_{k=1}^na_k\left(\frac{a_1\cdots a_n}{a_k}-1\right)$.
Then
$$m=a_1(a_2\cdots a_n(q_1+\cdots+q_n)+r_1)+\sum_{k=2}^nr_ka_k$$
where all coefficients are non-negative.
Note: this technique allows to prove that
$$g(a_1,\ldots,a_n)\leq(n-1)a_1\cdots a_n-(a_1+\cdots+a_n).$$
This upperbound is sharp for $n=2$, but weak for $n>2$.


Configuring Iptables for cpumulti

Question: I'm using a VPS for Monero mining, but the cloud does not have DDoS protection, so I'm making iptable rules. A friend who knows how to mess with Linux (Ubuntu 16) made a configuration that he thinks is the best he has ever tested. But the configuration does not allow any data traffic to enter. With this the cpumulti does not connect to the pool. Does anyone here know of a rule that I can put that releases cpumulti? I already tried the pool doors and it will not.
I use the Wolf version ...
Anyone?
Answer: The miners use standard HTTP, and the pool will send information to the miner via the connection the miner itself initiated. This means you don't need any incoming rules for new connections. You will need to allow new outgoing connections to the port you want to mine on (this depends on your pool and chosen starting difficulty, see the "Getting started" page on the pool for details), and allow incoming data on the same connection.
Now I can't give iptables rules for this, but since it's a bog standard TCP duplex connection, you should be able to easily find one on the internet and adjust the port number.

Configuring Iptables for cpumulti


When buying and playing a Villa in Dominion do you in a sense get 3 buys for that turn?

Question: So I buy a Villa in my buy phase (buy #1), then I go back to my action phase. I play Villa and follow it with 2 actions, then proceed to my second buy phase with +1 treasure +1 buy (buy #2) from the Villa. As I go into this second buy phase do I get another free buy as I just started a new buy phase (buy #3)?
Answer: You don't get a new free Buy, sorry. Nice thinking though.
The base game rules do say that when you enter a Buy phase you get one default Buy, but the card-specific notes for the Villa in the Empires rules (page 11) clarify (or revise?) that you only get one default Buy in the entire turn, not one each buy phase:

If you buy Villa, that uses up your default Buy for the turn, however playing Villa will give you +1 Buy and so let you buy another card in your second Buy phase.

Another way to think about it might be that the game gives you +1 Buy as you start your turn, but not each Buy phase as the base rules might imply.
Once you re-enter the Buy phase you will have 1 Buy left from Villa itself, in addition to whatever other action cards you've played this turn, but not 1 free Buy from the game. From what you described you only have 2 Buys this turn.
Comment: That's what I thought. My wife argued that she got a new buy each buy phase and therefore got 3 buys. She got pissed off when I stated that I really don't think she was right. Thanks for clarifying!


VBA: Filling blank cells with the value above it plus one

Question: I have 5 sheets which have blank cells and I need to fill them up with the value above plus 1. For example: column A has 1,2, ,4,5 and I need a code that will make it 1,2,3,4,5
I have tried a code I found online but it just copies the value above it.
Sub FillBlanks()
Columns("A:A").Select
Selection.SpecialCells(xlCellTypeBlanks).Select
Selection.FormulaR1C1 = "=R[-1]C"
End Sub

I need to fill all the blanks.
Answer: You can do that without VBA.
Select the range, hit F5 to open the Go To dialog, click Special and in the next dialog tick Blanks and click OK. That will select all blank cells in the selected range.
Now, without changing the selection, type a = sign, then hit the up arrow on the keyboard, then type +1. Hold down the Ctrl key and hit Enter.

If you still want to use VBA, change the last line of code to
Selection.FormulaR1C1 = "=R[-1]C+1"

That will give you the same result as the manual approach.
Answer: Your program would be simpler, faster, and more efficient by avoiding the use of Select as much as possible. Here is a correct program in one line:
Sub FillBlanks()
Columns("A:A").SpecialCells(xlCellTypeBlanks).FormulaR1C1 = "=R[-1]C+1"
End Sub

To apply to all 5 sheets in your workbook:
Sub FillBlanks()
Dim ws as Worksheet, LastRow as Long
On Error Resume Next
For Each ws in ThisWorkbook.Worksheets
    LastRow = ws.Range("A" & ws.Rows.Count).End(xlUp).Row
    ws.Range("A1:A" & LastRow).SpecialCells(xlCellTypeBlanks).FormulaR1C1 = "=R[-1]C+1"
Next ws
End Sub


Index material in 2.8 (Cryptomatte)

Question: I have a lamp. Behind the glass is a source of light. I want to apply effects to the light source in the composer. Previously, this was done using a material index. In 2.8 this isn't possible, there is Cryptomatte. But the source of light is behind glass, so I can't pick it to get a number. What can I do?
Answer: This is not exactly how to do it, but you can try to reduce alpha transparency of your glass object and adjust your Alpha Threshold value on View Layer settings. Just after that you can use cryptomatte object to pick the light.

Index material in 2.8 (Cryptomatte)


Is it haram to listen Maher Zain's songs?

Question: I have been listening to Maher Zain (A Islamic music creator) since 2014. Through his whole career he made only Islamic music. His songs encourages people to follow the Islamic path. His all lyrics are praising to Allah & prophet Muhammad.
So is it haram to listen Maher Zain's songs ?
Comment: There's an entire Q/A for the permissibility of Music, which you can check out here: https://islam.stackexchange.com/a/77139/51636
Answer: His nasheeds have musical instruments in the background, however he has nasheeds that are just audio which you can listen to as an alternative but try to steer away from one's with music
Answer: If any song includes music, it will be haram. However, if it includes duff only, it will be mubah. And the music must not contain any haram ideas, meanings, and leading.
For a more detailed answer, read an article in Islamqa about it-
Is Music Haram? Fatwa no: 5000


Clean Install MacBook Pro

Question: I have a 13" MacBook Pro that Apple has lent me while my new 15" is being built and I need to restore it to the same condition as the day I received it from Apple. How do I do that?
Answer: You can do that by shutting down your computer, then when you turn it on press and hold command+option+R and wait a while (normally about 5 mins)
Once your in Internet Recovery go to disk utility and format your drive. After you have done that go to Install OS X and follow the instructions. This will create an clean install. Once you do that shutdown the computer and then you can give it back to them. Don't do the setup.

Clean Install MacBook Pro


Family tree design suggestions?

Question: I would like to design a family tree on my website.  How can this be done with jQuery or Ajax?  Any animated examples out there?
Comment: Let this be a call to action. JQFamTree! Let thee be!
Comment: if you are interested in genealogy, be aware there is move to start up a genealogy SE Q&A. Help it reach beta: http://area51.stackexchange.com/proposals/43502/genealogy-family-history?referrer=DIRpC-2QEpSJcDcQkP0RAg2
Answer: Use the Google Visualization API, it's well documented: http://code.google.com/apis/visualization/documentation/gallery/orgchart.html#Example
Comment: It seems that nodes can only be "one-to-may". You cannot be related with two parents
Comment: with Google Visualization API, can we have a Pop-Up on each of the node which would give more details about that node, either on mouse-over or on a click.
Answer: The following link will be helpful to share here as i applied every logic mentioned here but none works. at last i found this solution. It helped me build professional family tree via jquery and php
jTree Family Tree Script
Answer: Check www.geni.com. They use Flash, not JavaScript, but it's nice, animated and so on.
Answer: A quick look at the jQuery plugin site turned up Arrows & Boxes.  It looks like it does what you need.  If this one doesn't work out, there are probably a dozen others to try.
Answer: Have a look at my sample created using d3.js, mobile responsive.

Mouse scroll to zoom, draggable, with interactive tooltip
The 'Find' button to search any family member
'Reset' button to reset zoom & position

Able to display difficult relationships such as multiple marriages and marriages between family members. Created using d3.js

Family tree design suggestions?


"We shape clay into a pot, but it is the emptiness inside that holds whatever we want."- Lao Tzu.What does this mean?

Question:
We shape clay into a pot, but it is the emptiness inside that holds
  whatever we want. (Daodejing 11)

What does this mean?
Why does the emptiness hold the things we want?
Comment: suppose the pot is filled with water — where is that water? it is in space — what space? the space inside the pot.
Answer: One English edition is Smith, Trey; Paul, Alex: Around the Tao in 80 Days. 2009. The title alludes to the famous book of Jules Verne and also to the 81(!) Chapters of the Dao De Jing.
The book authored by Smith and Paul is a nice translation and introduction. It stays on a middle path between the trivial on one hand and excessive pensiveness on the other.
Chapter 11 is entitled by the editors
Much Ado About Nothing:

We join spokes together in a wheel,
  but is the center hole
  that makes the wagon move.
We shape clay into a pot,
  but it is the emptiness inside
  that holds whatever we want.
We hammer wood for a house,
  but is the inner space
  that makes it livable.
We work with being,
  but non-being is what we use.

Translation due to Stephen Mitchell.
Putting in parallel the verses of your post one recognizes three well known, concrete examples illustrating the general, but abstract claim in the end.
Concerning the interpretation of the abstract claim the editors quote the following interpretation of Marc Watts:
The strategic advantage of recognizing the value of space is not only practical, however, because the bowl, representing space, is also a metaphor for the vessel of consciousness, and what is true of a ceramic bowl is also true of the mind - it works best when empty.
Answer: On a trivial level, it's saying something self-evident.
Bowls and pots are useful because they are objects fashioned to contain things.
For instance, this morning, I ate a bowl of cereal, but the bowl only works because it can hold things, but it can hold things because it as a space.
What it means a on deeper level is going to be open to debate.  The Daodejing is a constructed text. It's not the continuous sayings of anyone and Laozi is probably not a historical person. So, we have to ask what this meant to the original writer and to the compiler. As to the original author, I've got no idea.
As to the compiler, the text may have been compiled as a kind of counter-text to either Mohism (sometimes called "legalism") or Ruism ("Confucianism") which suggest a different vision of the Tao. For those views, the Tao is going to be or involve some human project and its completion. In this context, the point may be that the Tao is not to be found in the positive construction but in the space it opens for freedom (possibly wuwei).
This would put the compilation at this point partially in line with the Zhuangzi as the value of non-action and deformity over and against ideals of the individual and the state.
Working with the basic framework of the yin-yang from the I Ching (accepted by all major schools by the time there are major schools), it's an assertion that the Tao is not merely composed in the positive and actual but in the negative passive and non-actual.
Most of this is regrettably speculative but there's not much else to go on.
Answer: Like Socrates' dialogues and Zen koans, this passage presents a paradox as a way of guiding the reader away from superficial beliefs and easy conclusions, and towards a more profound mode of thought.
The specific idea here is that we think of a pot as a valuable material object, made out of ceramics.  But a pot-sized lump of solid ceramic material wouldn't be very valuable at all.  It's actually the empty space inside the pot that makes it usable.  Yet, the paradox is that there is empty space all around us.  How is the same empty space made valuable by being inside the pot, and yet the pot is made valuable by enclosing the empty space?
On one level, pondering this guides us towards viewing other places in life where similar counterintuitive principles might be at work (for one example, the concept of the "empty center" --meaning that the apparent center of power was actually powerless --was foundational to traditional Japanese politics).  At a deeper level, however, the goal is to invert our entire conventional way of thinking.  Philosophical aphorisms of this sort are always intended as gateways, not as destinations.
Answer: The simplest possible explanation seems to be that without that 'space' or 'nothingness' inside, the pot would not have the capacity or potential to hold anything.
I'm equivocating between space and nothingness here, as I read something recently that suggested the former reading was a better reading; another reading might be to read space as place.
Undoubtedly, it requires a clearer reading of the canon of the Tao, to come to a proper understanding what the term means.
Answer: The emptiness (or void) is a key concept of Taoism which is hard to translate without losing some important aspects.
The Taoist void is not something which "miss", or an absence of something, it is a "space of possibilities". So what is important into a pot is not it's shape or material it is made of, but only the space that may be filled with something.
The Dao also takes the example of a house : an emptiness inside walls. The inside of the house is what matters because it permits its usage and allow possibilities to flourish.
Answer: It is from chapter 11.

三十辐共一毂,当其无,有车之用。埏埴以为器,当其无,有器之用。凿户牖以为室,当其无,有室之用。故有之以为利,无之以为用。

Due to the inherent turbidity of Chinese language, it is very difficult to decipher this piece of aphorism; as of today, any interpretation is good interpretation. Roughly speaking, it illustrated the relation between 有 (sounds exactly like "yo") and 无 (sounds exactly like "woo").
有: have,     presence, existence,     the quality of there is.

无: not have, absence,  non-existence, the quality of there isn't.

There is a another distinction between 利 (/lee/) and 用 (/yeong/), which is pretty much lost in modern usage.
    利: the means, the instrument.
    用: the end, the usage.
The morale is something like this:
有 is the 利; 无 is the 用.

or
What is there provides the means; what is not there provides purpose.
Or:
Where there is something, this something is for employment; where there is nothing, this nothingness serves the purpose.
There is no much in it as far as I can tell. What is interesting is that his reasoning is inductive: from statements about wheels, pots, houses to a general statement about "there is" and "there isn't." Another interesting point is his conception of two universals: the quality of 有 (there is) and the quality of 无 (there isn't.)

“We shape clay into a pot, but it is the emptiness inside that holds whatever we want.”- Lao Tzu.What does this mean?


What kind of oscillator is used for CMOS CPU clocks?

Question: Do they usually have a mono/bi-stable multivibrator that is activated a schmidt trigger when the computer is powered up? Or do they use ring oscillators? Or perhaps crystal oscillators.
Comment: A ring oscillator or multivibrator would never be accurate enough to run current high frequency computers. Temperature, voltage and humidity schmoo the output of those types of oscillators too much.
Answer: Typically, a CPU will be driven by a clock generator, which is a crystal oscillator and a PLL. The PLL will be configurable (sometimes dynamically configurable). The CPU itself will typically have an internal clock multiplier, causing the CPU to run at a multiple of the system buss clock frequency.
As a result, there are often two ways to increase or decrease CPU clock speed (if enabled): the front-side bus speed can be changed via the clock generator, causing the entire buss and CPU to change speeds; or the CPU multiplier can be changed, which changes the relationship between the FSB and the CPU internals.
Systems designed for low power consumption will often be able to decrease the clock speed (via the clock generator) of the entire system when system load is low in order to save power, and then increase clock speed when more performance is desired.
As an aside, it's worth pointing out that it is very difficult to design an accurate, stable ring oscillator. Because a ring oscillator relies on propagation delay, it is very sensitive to temperature and voltage changes of the silicon (as well as other changes). In fact, it is possible to use ring oscillators as temperature sensors or even pressure sensors!.


Can I keep data into qubit and teleport?

Question: I was reading about teleportation I have some question about it. Can I keep normalized data (some customized data) on probability amplitudes (which are complex numbers) of a qubit (Alice's side)?  Then after teleporting this qubit can I retrieve  custom data on the receiving side (called as Bob's side)? Is this possible scenario or not? Is there any Qiskit code running on quantum computer available for this?
Answer: Yes, you can send normalized data across participants assuming you can convert them to probability amplitudes. To give a quick example, consider this single-qubit state:
$$|\psi\rangle= \alpha|0\rangle + \beta|1\rangle$$
Where $\alpha$ and $\beta$ are normalized data ($\alpha^{2} + \beta^{2} = 1$) that Alice is trying to send to Bob.
Then the following steps are to be followed by them:

Alice and Bob create an entangled pair of qubits and each holds one part of it. Usually, this is done via $|\phi^{+}\rangle = \frac{1}{\sqrt{2}}(|00\rangle + |11\rangle)$ which is one of the four bell's state. The rest of the step assumes we use $|\phi^{+}\rangle$ to pass $|\psi\rangle$ from Alice to Bob.

Alice applies Controlled-Not gate where the target is the qubit from the Bell's state that Alice holds and control is $|\psi\rangle$.

Hadamard gate is applied on $|\psi\rangle$. Then the two qubits that Alice holds are measured. (Don't forget that $|\psi\rangle$ in our example is a single-qubit state)

The two states that Alice sees is then classically communicated to Bob. (In our case it can either be 00, 01, 10 or 11)

And depending on the results that Alice communicates with him, Bob does the following on his part of the entangled state(which essentially is a single qubit):
(a) If 00, Apply Identity gate.
(b) If 01, Apply X gate.
(c) If 10, Apply Z gate.
(d) If 11, Apply Z gate followed by X gate.

The result of the above computations would be that Alice will lose her $|\psi\rangle$ and Bob's entangled part will now be equal to $|\psi\rangle$. Note that they both cannot keep $|\psi\rangle$ because of the No-Cloning Theorem.

While the above example is for a single-qubit case, the same logic applies for multiple qubit cases, you could pack your normalized data into a unitary matrix and then convert it to a gate.
However, you would need to repeat the experiment more times in order to retrieve the data from the amplitude states (In the above example, you would get $|0\rangle$ with $\alpha^2$ probability). Here's the qiskit implementation of it.
Comment: I am seeing unitary gates. It's seems like we have to give angels theta and phi as input. If I want to give a  input like 1 +4i ,2+3i  as alpha and beta how can I get angels? And in qiskit I am seeing the circuit always initiate from state  zero. Thank you responding.
Comment: A generalized Unitary gate takes three angles, $\theta$ $\phi$ and $\lambda$ and it is denoted by `U3` gate in qiskit. You would need to convert complex numbers in their [polar form](https://people.math.carleton.ca/~kcheung/math/notes/MATH1107/wk02/02_polar_form.html#:~:text=A%20complex%20number%20z%20in,number%20for%20every%20integer%20k.) to determines the angles. Following this way will be tedious since you would need to figure out $\theta$ $\phi$ and $\lambda$ via comparison, a better way could be directly feeding the matrix and let qiskit convert it into the gate.
Comment: Doing that requires you to make a unitary matrix on the normalized data(data in your example is not normalized). You can make any random matrix into a unitary matrix by doing [Schmidt decomposition](https://math.stackexchange.com/questions/2162190/how-to-convert-a-random-matrix-to-unitary-matrix). And finally you would have to do some post-processing to get back the original (pre-Schmidt) values.
Comment: can anyone give an example for converting complex $\alpha$ and $\beta$ into a unitary matrix? for example, I have normalized $\alpha$ and$\beta$ as (0.24506+0.9633i,0.0046238+0.10943i)  how can I convert this into a unitary gate and use it in qiskit? Thank You.


Does Grignard reagent on reaction with PbCl2 give PbR4 and not PbR2?

Question: I was told by my teacher that $\ce{RMgX}$ forms $\ce{PbR4}$ when it reacts with either $\ce{PbCl2/PbCl4}$ the later case is clear to me but why does $\ce{PbCl2}$ forms a compound of the form $\ce{PbR4}$.
Comment: Note with very bulky side groups Pb(II) compounds can be isolated, e.g. https://pubs.acs.org/doi/10.1021/om990614g https://pubs.acs.org/doi/10.1021/om9708337
Comment: What the teacher said when you had asked him/her? If one says something it need not to be true, even if it is said by a teacher.
Comment: PbCl4 "is best stored under pure sulfuric acid at -80 °C in the dark." (Wikipedia)
Comment: @IanBush "The compound is in effect the first dialkylead(II) species to be structurally characterized". Cool! It took way longer than it should have been given the first organolead compound was synthesized in 1858 ;)
Answer: More is involved here than the simple nucleophilic exchange normally associated with Grignard reagents. Essentially, the proposed dialkyl lead disproportionates with displacement of metallic lead. According to bionity com, the main reactions with both organolithium and Grignard reagents bring about this disproportionation:

Lead(II) chloride is the main precursor for organometallic derivatives of lead. The usual alkylating agents are employed, including Grignard reagents and organolithium compounds[1]:
$\ce{2 PbCl2 + 4 RLi -> R4Pb + 4 LiCl + Pb}$
$\ce{2 PbCl2 + 4 RMgBr -> R4Pb + Pb + 4 MgBrCl}$
$\ce{3 PbCl2 + 6 RMgBr → R3Pb-PbR3 + Pb + 6 MgBrCl}$
Notice how these reactions produce derivatives that are more similar to organosilicon compounds, i.e. that Pb(II) tends to disproportionate upon alkylation.

The "inert pair" effect in heavy $p$-block elements becomes less prominent when the heavy atom is attached to less electronegative ligands that favor covalent instead of ionic bonding (in this case, by exchanging chlorine for alkyl groups), so the higher oxidation states ($+4$ in tetraalkyl lead $+3$ in hexaalkyl dilead) become more favorable in such situations.
Cited Reference

Housecrift, Catherine and Sharpe, A.G.. Inorganic Chemistry (2nd edition). Pearson College Div (January 1, 2005), p. 524.
Answer: Note that the dialkyl/diaryl lead(II) derivatives are still an intermediate products before getting disproportionated.

Simple dialkyl- and diaryl-lead(II) derivatives cannot be isolated because of their facile disproportionation to elemental lead and hexaorganodilead compounds. Nevertheless, they are presumably the initial products of the reaction of lead(II) chloride with organolithium or Grignard reagents. A deep brown–black reaction mixture which exhibits reactions attributable to the presence of diphenyllead can be obtained from the reaction of lead(II) chloride with exactly two moles of phenylmagnesium bromide in ether at −20 °C (the reported isolation of diphenyllead as a red solid by Krause and Reissaus is most probably in error). Thus addition of water to the freshly prepared "diphenyllead" solution produces lead(II) oxide and benzene, whilst iodine affords lead(II) iodide and iodobenzene together with a small amount of diphenyllead diiodide. Reaction with phenyllithium gives triphenyllead lithium. Disproportionation occurs on allowing the solution to warm, and hexaphenyldilead and lead metal result.

Source: P.G. Harrison, Comprehensive Organometallic Chemistry, 1982 (Sciencedirect Link)


During installation of the Tor browser a unique asymmetric key pair is created and stored. Is this stored on the HDD/SSD and used repeatedly?

Question: I would like to know where the unique asymmetric key pair is stored following installation of the Tor browser.  Is it stored in the HDD/SSD and used repeatedly or in RAM and changed for each browsing session?
Comment: I should add that these keys are stored in a 'secure vault' on disk. But what disk. Thinking on 'disk' suggests permanent storage
Answer: Nothing is ever "installed" from the Tor Browser that is why it comes in an archive.
Where did this information come from saying that anything is "installed" from decompressing an archive?
Comment: educational text namely the following. 'During installation of the Tor browser the user's browser creates a unique asymmetric key pair and these keys are stored in a secure vault on the user's disk.'
Comment: @StewartBovis do you have links or anything else to the source? quoting false things once more, doesn't make it better.
Comment: Nothing that can be shared unfortunately DJCrashdummy


Compensation for an NFL draftee not signing?

Question: What happens to the team when an NFL draftee doesn't sign with a team?
Do they get some sort of compensation for the lost pick?
Answer: Broadly, no: there is no specific compensation for failing to sign a rookie.  It doesn't really happen, due to the rookie contracts being strictly defined; Bo Jackson is the only actual unsigned drafted player of note in recent memory (he refused to sign with Tampa Bay due to them allegedly sabotaging his NCAA eligibility, and played the year in MLB for the Kansas City Royals, before being drafted the following year by the L.A. Raiders).
From the 2020 NFL Collective Bargaining Agreement, the following is from Article 6 (covering the draft):

If a Drafted Rookie has not signed a Player Contract during the period from the date of such Draft to the thirtieth day prior to the first game of the regular season: (i) the Club that drafted the player may not thereafter trade to another Club either its exclusive negotiating rights to such player or any Player Contract that it signs with such player for the player's initial League Year; and (ii) the Club that drafted the player is the only Club with which the player may sign a Player Contract until the day of the Draft in the subsequent League Year, at which time such player is eligible to be drafted in the subsequent League Year's Draft by any Club except the Club that drafted him in the initial Draft.

There is additional language in there, but nothing about compensatory picks or similar; Appendix V covers compensatory picks in general, but none are awarded by rookies failing to sign.
Comment: You forget John Elway and Eli Manning. Both did get signed but there was a big threat of their not signing and a trade to other teams to get them to sign.
Comment: I did not forget either one!  They both *did* sign, hence they were not considered as "failing to sign".
Comment: I'm sure Joe and @Thad_The_Man know this, but for other readers- the two quarterbacks mentioned forced trades of their rights and signed with other teams.


Whats the best way to disinfect a package for covid19?

Question: Whats the safest way to decontaminate packages/electronics from China?  Checking with my shipper they don't bother yet. We just got a new SATA controller from China. Not having any alcohol we used vodka to wipe down the controller and disinfect the cords (touch)areas. MAS-airlines is using a solution of hydrogen peroxide & water to spray everything including your luggage. It turns everything a dingy yellowish color.  Of course we wore protective clothing, gloves, mask & goggles when we went on our vodka binge, it dries clear and leaves no ugly residue.
Comment: How was it shipped? Air or surface?
Answer: The UK's National Health Service webpage Coronavirus (COVID-19) says:

How coronavirus is spread
Because it's a new illness, we do not know exactly how coronavirus spreads from person to person.
Similar viruses are spread in cough droplets.
It's very unlikely it can be spread through things like packages or food.

Their advice seems contradictory: if they don't know exactly how the virus is spread, how can they say it is unlikely to be spread by packages?

If you are using standard supermarket vodka to disinfect, be aware that it is (in UK) only about 35% or 40% (ethyl) alcohol.
This page suggests that you need 70% ethyl alcohol to disinfect, so standard vodka may not be good enough.
And this page suggests that 70% alcohol is more effective than 99%, because water is needed as part of the disinfecting process.
Comment: RE "Their advice seems contradictory: if they don't know exactly how the virus is spread, how can they say it is unlikely to be spread by packages?" because all viruses are similar. If most viruses can not be spread by some method it likely that this virus can not be spread that way.  Also if packages from china spread the infection, it would have shown up in the US by now, with clear indications.
Comment: I would not trust this advice. WHO said it can live up to 24-hrs on cardboard or paper. We know now it's just not an air-born virus. China went as  far as spraying peoples homes, the sewer, and everything people touch...now what about those public libraries?
Answer: The safest way is to put the package in quarantine; in a warm and dry location for 14 days.

But how long can the new coronavirus linger on surfaces, anyway? The short answer is, we don't know. But if this new coronavirus resembles other human coronaviruses, such as its "cousins" that cause SARS and MERS, it can stay on surfaces —  such as metal, glass or plastic — for as long as nine days, according to a new study. (In comparison, flu viruses can last on surfaces for only about 48 hours.) source

.

The first section of the new paper focuses on how long coronaviruses can survive on inanimate surfaces, such as tables and door handles. The authors show that, depending on the material and the conditions, human coronaviruses can remain infectious from 2 hours to 9 days.
At temperatures of around 4°C or 39.2oF, certain versions of the coronavirus could remain viable for up to 28 days. At temperatures of 30–40°C (86–104°F), coronaviruses tended to persist for a shorter time.
"Human coronaviruses can remain infectious on inanimate surfaces at room temperature for up to 9 days. At a temperature of 30°C [86°F] or more, the duration of persistence is shorter. Veterinary coronaviruses have been shown to persist even longer for 28 d[ays]." Source

Edit March 15 2020: Many sources are now saying COVID 19 can only live about 3 days on surfaces.
Comment: Ha! Same thought. Seems your sources are a bit more conservative, though. As your post is clearly better, I'll happily remove mine and upvote yours instead.
Comment: Air born Virus can be killed with ultra-violet  lamps. Why isn't anyone deploying these? We used them at the chicken farm to kill bird-flu in the 80s. It just works.


Where does Embryo Implantation occur?

Question: Where does the embryo get implanted? If it is in the uterus side wall, why is the embryo shown hanging from top in some pictures?
Answer: According to Minami et al. (2003)1 (open access) the early gestational sac can be located by ultrasound, and usually is high in the uterus, more often on the left or right than in the middle.  They provide an illustration of the distribution.

 1. Minami, S., Ishihara, K. and Araki, T., 2003. Determination of blastocyst implantation site in spontaneous pregnancies using three-dimensional transvaginal ultrasound. Journal of Nippon Medical School, 70(3), pp.250-254.

Where does Embryo Implantation occur?


How to orient the camera to show the object exactly in the same way your eyes are looking at it

Question: Do you know if there is a way to align automatically the camera to the user persp view that I have at a certain moment,so that the camera can view exactly what I see in that persp view ? For example,let's see the image below. I want to orient automatically the camera on the x;y axis and with the right rotation needed to show the object exactly how my eyes are looking at it. Thanks.

Answer: Having your Camera selected press CtrlAltNumpad 0.

When objects are clipped you need to increase Camera Clipping range in Camera tab (you will need to have Camera selected):
Comment: like this ? https://drive.google.com/file/d/0B_vrhf_PTNauSkRVTmhEMlp3bTQ/ ; I did it what you explained,but the camera does not look exactly what I want.
Comment: I think that your edit does not look complete for me,because I'm not able to understand what to do.
Comment: @Marietto this one should be better. You can always look to Blender Docs if you are new in Blender: https://docs.blender.org/manual/en/dev/render/cycles/camera.html
Comment: no,I'm not completely new in blender,but don't give me the blender docs,because it's the most annoying way to learn blender. instead,I'm more satisfied if you want to give me a small video tutorial.
Comment: now I can see your edit...
Comment: now I understood your answer. ok. it works. thanks.
Comment: @Marietto, glad that I could help. Remember that video tutorials or any full blown tutorials aren't welcome here as well as external sources as answers.


What is this random light in my engine bay near my front passenger wheel well?

Question: I was replacing my headlights on my 2008 Honda Civic EX coupe and found this light bulb (I think?) plugged into a wire in my engine bay between the wheel well liner and my right headlight. It seems to have the same tabs as the housing for my low beams, but the bulbs look nothing alike. My high beams, fog lights, and turn signals all have bulbs installed. What is this?
Comment: Where do the wires let it reach to?  Does it look like it should be at the headlight?
Comment: Was the light mounted to anything or just hanging there? When you turn on your headlights, highs or lows, fog lamps, turn signals, etc. does it light up?
Answer: It sure looks like a FOG LAMP that has been removed from its housing.
If this car has fog lamps, see if the one nearest this is missing its bulb.  It may also be a side marker lamp or other lamp that has been pulled out and neglected to be replaced.
Look in the area for a lamp holder that is missing its lamp.


Eagle: Connect polygons / ground planes

Question: How can I connect polygons 1 and 2 together? It tried to make a trace + vias between them, but Eagle won't let me create a trace on a polygon.
Comment: Are they assigned to the same net?
Comment: Is there an airwire between them?
Comment: Yes, there's an airwire between them.
Answer: You should be able to create vias in the polygons, name them to match the names of the polygons, and then connect with a trace. If a conductor (via or trace) does not have the same name as the fill (polygon here), then Eagle will add space to prevent the signals from shorting together, as happened with the CSN via towards the side of your picture.
You could do this with just appropriately named traces too, but I don't see how you can do it without vias in this image.
As this answer implies, both polygons need to have the same name to be connected.
To do this without adding the via, you can add an arbitrary trace by going into Route mode and ctl-clicking inside the polygon. That method can be a bit wonky, so it might be easier to add the vias, make the trace, then remove the vias.
Comment: I just added a paragraph at the end to answer this. Short answer is ctl-click should work, but I would add the vias, make the trace, then remove the vias.
Comment: Thanks! Giving the vias the appropriate name (GND) worked. But what about another scenario in which I don't need vias? If I select the "Route"-Tool and click inside a polygon like in the picture above, it does not create a trace / nothing happens.
Answer: Two option:
Give the two polygons the same name.  That way Eagle knows they are the same net, and will allow you to directly route other traces of the same net to them.  This includes a trace between the two polygons.
Give them different names, then connect those two nets with some kind of part in the schematic.  I have a library of "shorts" for this purpose.  They are parts that just end up being a connection in the schematic, but allow the nets on either side to be distinct.  This can be useful, for example, for funneling all the power current for some section thru a particular point you can choose during layout.
Answer: You can connect these two polygone by adding a via and a trace on the TOP layer. To do so, add a via on each polygon and name them "GND" or the name of the polygone surface.
It is maybe possible to redesign a part of the PCB in order to avoid this durty solution.
Another way to solve your problem could be to make a route across the resistor between the pad. To achieve this you may need to edit the PCB properties, or resistor pad's shape.

Eagle: Connect polygons / ground planes


WPFToolkit.DLL indicate WPF app?

Question: Would the presence of WPFToolkit.dll in an application's folder indicate that it is a WPF app?
Answer: Yes, if it`s a desktop application, WPFToolkit.dll library may suggest that it`s WPF application.
If it was not copied or added as project reference by mistake, of course. And if that`s not an WinForms app using some WPF elements. And if that`s not some random library that author chose to name this way.
Anyways, that`s probably an WPF app alright.
Answer: As icebat said, it probably is.
Though you can use Process Explorer to see if the WPFToolkit.dll is loaded by the application while it's up to be sure.

WPFToolkit.DLL indicate WPF app?


Why is my bitlocker data drive unlocked for a few seconds after boot?

Question: To specify: why is the data on my bitlocker encrypted drive available for a few seconds after logging in? After a few seconds the system 'notices' the drives are bitlocker encrypted and need to be unlocked first by entering passwords. Why are the drives in an unlocked state for a few seconds?
These are aspects of the situation:
- I do not use auto-unlock.
- I have experienced this behaviour with a 128bit encrypted drive as well with a 256bit encrypted drive.
- Running Windows 8.1 Pro
- If I lock the drives before shutting down (manage-bde [...]), this does not happen. (But why should this be required?)
- Some fixed drives are mistakenly perceived as a Bitlocker on the Go Drive. (Removable)
- The system does not have a TPM chip.
- Opening Windows Explorer window and navigating within such a drive is sometimes possible if one is quick enough. The script however is quick enough.
Looking forward to any insight into this weird behaviour of my OS and bitlocker.
If anyone has a solution, besides manually locking the drives before shutdown, I am all ears!
Details:
How I noticed:
I use a script launched when logging in that checks if a folder on a encrypted drive is available, if it is, it launches certains apps that require data on the drive, if it isn't available (because I haven't unlocked the drive) it waits. I noticed it sometimes launched apps before I got to unlocking the drive; I changed the script to open a txt located on the drive in notepad and voila: next reboot the txt file appeared just before the system 'realizes' the drives are bitlocker protected. Obviously I cannot edit and save the file in this stage anymore (though I expect the script could), but I don't expect nor want any files to be readable after logging in BEFORE I unlock the bitlocker protected drive.
Answer: The bitlocker service might not be active yet, thus the computer thinks that it is not locked. So when the service starts, the computer then will realise that the drive should be lock, thus the drive is then locked.
Comment: That would not explain why i have read/write permissions on the drive. I could actually open a file from the drive. I shouldn't have access; the locked state of the drive is not depended on the state of a service.


NTFS permissions lost at root level

Question: I noticed that I don't have a+x permissions on one of the drives/partitions (which I had a couple of days back; I don't know how I lost them). However, to get something done, I tried creating a folder in that drive from the terminal as superuser, using this command:
> cd /media/progyadeep/New Volume        ##New Volume is the drive

> sudo mkdir "NEW"

but I can't. I see this error message:
mkdir: cannot create directory '/media/progyadeep/New Volume/NEW':
Read-only file system

I even tried opening an explorer window with
sudo -i nautilus

but I can't create files/folders even from the GUI opened as superuser.
WHY?
How can I fix this issue? How did Ubuntu become so desperate as to cheat even the superuser??
EDIT 1
This question was identified as a possible duplicate of this question: Lost all permissions to my NTFS partition. However, the main problem is that I can't regain permissionsusing the method shown there. As pointed out by someone in the comments, the drive being write protected might be building up an entirely different issue over here which didn't arise in the other question.
EDIT 2
As asked for by @wjandrea, here's the output of sudo lsblk:
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 931.5G  0 disk
├─sda4   8:4    0 138.6G  0 part /
├─sda2   8:2    0   128M  0 part
├─sda9   8:9    0   7.9G  0 part [SWAP]
├─sda7   8:7    0  10.5G  0 part
├─sda5   8:5    0   625G  0 part /media/progyadeep/New Volume
├─sda3   8:3    0 147.5G  0 part /media/progyadeep/OS
├─sda1   8:1    0   500M  0 part /boot/efi
├─sda8   8:8    0   1.1G  0 part
└─sda6   8:6    0   450M  0 part

EDIT 3
Here's the output of mount -l, as asked for by @dessert:
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=4012328k,nr_inodes=1003082,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,size=806920k,mode=755)
/dev/sda4 on / type ext4 (rw,relatime,errors=remount-ro,data=ordered)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd cgroups-agent,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
efivarfs on /sys/firmware/efi/efivars type efivarfs (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=29,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=1915)
mqueue on /dev/mqueue type mqueue (rw,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
/dev/sda3 on /media/progyadeep/OS type fuseblk (ro,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other,blksize=4096) [OS]
/dev/sda1 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=iso8859-1,shortname mixed,errors=remount-ro) [ESP]
/dev/sda5 on /media/progyadeep/New Volume type fuseblk (ro,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other,blksize=4096) [New Volume]
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=806920k,mode=700,uid=1000,gid=1000)
gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)

Comment: it sure looks like you've got the drive/device mounted as read-only.  type in `mount` & you'll likely discover its (ro)
Comment: Possible duplicate of [Lost all permissions to my NTFS partition](https://askubuntu.com/questions/86124/lost-all-permissions-to-my-ntfs-partition)
Comment: Do we speak about a usb drive/stick, sd card or an internal hdd here? The former sometimes have a little switch to enable read-only access. Your output of `lsblk` is really weird: most of these partitions don't seem to be mounted, and most importantly none at `/media/progyadeep/New Volume`. Was it mounted when you executed the command? Could you give us the output of `mount -l` please?
Comment: @guiverc I did have some mounting issues recently. Should I change something in `/etc/fstab/` to mount it as `-rw`? Because `-rw` doesn't seem to work with the `mount` command in the terminal for me.
Comment: it's write protected, first remove the write protection from the drive
Comment: @SurajKumar I tried removing the write protection with: `sudo hdparm /dev/sda3/` and it said: `readonly = off`. However, upon trying to remount in `-rw` mode, I failed again.
Comment: It might help if you post the output from `sudo lsblk`
Comment: @dessert I'm sorry about the output of `lsblk`; I've corrected it. And I've added the output of `mount -l` as well.
Comment: @dessert AND I'm TALKING ABOUT INTERNAL HARD DRIVE.
Comment: As suspected, `/dev/sda5` is mounted read-only. Try to remount it read-write: `sudo mount -o rw,remount /dev/sda5`
Comment: @dessert Did that. This is the output: `mount: /media/progyadeep/New Volume not mounted or bad option

       In some cases useful info is found in syslog - try
       dmesg | tail or so.`
Answer:
Read-only file system

This most likely happened because of some problem on the drive. Most systems use errors=remount-ro (in case of errors, remount as read-only) on local filesystems to prevent data damage and/or loss. Therefore there may be a problem with the drive itself. Check for data loss, because (at least in my experience) this often happens as a drive is failing. Even remount-ro can't stop the drive itself failing. If this is the case, you might need this: Get Your Data Back with Linux-Based Data Recovery Tools
If your hard drive is not failing, I can only suggest checking hardware all along the line or looking at /var/log/kern.log or dmesg for any specific details on the filesystem. I can't think of any other reason for it mounting as read-only.
Comment: My laptop is new so I doubt if my HDD is failing. And I'm new to linux so I could only see greek when I opened `kern.log` or `dmesg`. Maybe those will make sense to you. Take a look: **(1)** [`dmesg`](https://pastebin.com/Pv0QUhkA) **(2)** [`kern.log`](https://pastebin.com/Z1ewwSvC)
Answer: Answering my own question
After solutions suggested by different people failed to fix the issue, I went deep into research and finally found out why the things that should have worked didn't work in my case is because there was some problem on my hard drive that was caused due to Windows (yes, I have both OS's installed). (Thanks to Stephen Angelico's answer for it really helped to find out the real problem. +1! ) So what I did was used the command ntfsfix that supposedly cleared those files (or something like that) that stopped ubuntu from modifying things. I fixed that issue with
sudo ntfsfix /dev/sda5

After this, I opened up /etc/fstab in gedit and simply changed the value -ro, beside /dev/sda3, to -rw and simply mounted using
sudo mount -a

After a shutdown, I have regained -rw/a+x permissions on the drive at user level.

Point to be noted
Although I have fixed the permission issue on one of the drives, I still haven't been able to solve it on the Windows' OS drive. When I tried ntfsfix on the Windows OS drive, I saw the following error message:
sudo umount -a
sudo ntfsfix /dev/sda3

Mounting volume... Windows is hibernated, refused to mount.
FAILED
Attempting to correct errors...
Processing $MFT and $MFTMirr...
Reading $MFT... OK
Reading $MFTMirr... OK
Comparing $MFTMirr to $MFT... OK
Processing of $MFT and $MFTMirr completed successfully.
Setting required flags on partition... OK
Going to empty the journal ($LogFile)... OK
Windows is hibernated, refused to mount.
Remount failed: Operation not permitted

I have shut down windows several times but I keep on seeing this message.

EDIT
As suggested by @Stephen Angelico, Windows 10 has the "fast boot" option enabled by default which causes it to actually hibernate every time we click on "shut down". After disabling the fast boot from the control panel, I rebooted into ubuntu and did the same operations on the Windows OS drive as I did in the other drive and successfully mounted it with -rw permissions.
Comment: @StephenAngelico All I needed was a google search on "How to disable fast boot on WIndows 10". Tada!!
Comment: The problem with the Windows drive is that Windows 10 by default will in fact hibernate instead of shutting down, despite the label saying "Shut down". This can be fixed by disabling fast boot in Windows (sorry but I don't know how), but of course this will impact boot times to Windows.

NTFS permissions lost at root level


blender timeline in seconds instead of frames

Question: I would like to have the time line and key frames be in seconds instead of frames. When I animate something at 30 fps and then decided to change it to 60 fps the animation will play at twice the speed.
Answer: Press Ctrl + T with your mouse inside the timeline. This toggles that view. Do that and the timeline will depict parts in frames instead of seconds. This is useful for if you want it to be in seconds.
It can also be accessed via the view menu.

Of course, there are times when one is preferable over the other.
Answer: Leave your mouse cursor over the timeline panel and use Ctrl+T on Windows and Linux or Cmd+T on Mac. If you repeat it, you toggle back to the frame numbers.


OSX Sierra Notes & Reminders sync disabled

Question: On all my other devices(iPhone, iPad, another Macbook) I am able to sync my iCloud notes just fine. For some reason my work's Macbook on Sierra is unable to sync and the checkbox is completely disabled. Any ideas of how I can get around this?
Comment: Is this locked-down from your company?  Also, are you using the same Apple ID on all the devices?
Comment: Same Apple ID. Find My Mac has always been locked down but on El Capitan I was able to sync just fine. I suppose it's possible the company upped their game and blocked these apps for Sierra. I can't see any reason behind blocking a productivity apps from syncing though.
Comment: Usually, I only see these setting disabled if something is blocking their access.  If you log into iCloud.com with the same Apple ID does it work (probably will because it works on your other devices but it's worth a check)?  Also, have you tried logging out and back in to iCloud on this machine?
Answer: Check for a MacOS update, if you have one do it. If not then continue below.

Does your work MacBook have any work-installed profiles in your system preferences?
A lot of times companies don't allow certain features to be accessed. If there is a profile or a preference there that isnt a default preference then it was installed.
If you don't have any profiles or special preferences then I would check to see if you can access www.icloud.com and see if you can visit the site on your work MacBook. If you can then great, if not then its likely that the server is blocked, which means that it is either blocked from the network.
If none of the above apply, then there are 2 things that you can do to test and see if its a software issue.

Sign out of iCloud and then sign back in and see if the issue continues.
Try it in safe mode to see if there is something else that could be preventing it.
Create a new user account on that MacBook and sign into iCloud with the same Apple ID account. See if the issue continues.

If they still don't work with either of those troubleshooting steps then you need to backup the Mac with Time Machine and then the next step is to re-install MacOS and then once its been installed, try it again. It should work if none of the above did.


How will the uncertainty principle broaden emission spectrums?

Question: I have been told in a lecture that the broadening of peaks detected from photon emission in a hydrogen lamp is due to the uncertainty principle, but can't work out how it does or find any equation involving the width of peaks.
Answer: I am copying this because it has the main reasons of line broadening:

A spectral line emitted by an atom or molecule ....has a finite width and there are three distinct physical processes which contribute to this broadening.

This gives the connection between the uncertainty principle that you are asking:

The energy levels between which the transition takes place have a natural width, which arises from the reaction of the radiation field on matter. This means that an atom has a finite time in any level before spontaneous decay takes place.

So it uses the time energy Heisenberg uncertainty.

Also the emitting atom may be moving in the line of sight, which produces an apparent change in the line frequency through the Doppler effect. Finally, broadening of the spectral line is caused by the interaction of the emitting atom with surrounding particles in the plasma. Thus a detailed analysis of line shapes can yield much information on the density, temperature and motion of plasmas, whether they are high density plasma created in the laboratory, or the lower density plasma of interest in astrophysics, such as the solar corona or the interstellar medium.

Usually it is the other reasons that give the broadening, as the natural line widths are very small:
Here is a description of how this natural width comes about, at page 3.
Answer: The equation you are looking for, that is linking the emission linewidth to the lifetime of a state, is the time-energy uncertainty relation. This relation can be written as
$$ \sigma_E \frac{\sigma_B}{\left|\frac{d\langle\hat{B}\rangle}{dt}\right|} \ge \frac{\hbar}{2} $$
where $\sigma_E$ is the standard deviation of the energy (Hamiltonian) operator and the fraction, that has the dimension of a time, is the lifetime of the considered state with respect to a certain observable, that is defined as the time interval in which the expectation value of the given observable changes in an appreciable way.
As an example, consider an atom that is somehow excited to an electronic excited state: after some time, it will return to its ground state and, in doing this, a photon will be emitted. According to the previous equation, the smaller the time interval in which the said atom will remain in its excited state, the larger will be the uncertainty on the energy of this excited state and, as a consequence, the higher will be the uncertainty on the energy of the emitted photon. This actually links the width of the considered emission peak to the lifetime of the excited state involved. Another consequence is that only quantum states with an infinite lifetime will have a precise value of the energy.
In spectroscopy, we are thus talking of natural (line) broadening when the emission spectrum is broadened as a consequence of the energy-time uncertainty relation. However, this is only one possible source of line broadening and sometimes it can only give rise to negligible effects.
Sources:

Wikipedia page for "Uncertainty principle" and links therein
Wikipedia page for "Spectral line", in particular with respect to natural broadening


Why LED reversed bias voltage cannot be measured?

Question: As I have just found out, typical LED does not behave similarly to standard diode when measuring reversed bias voltage. On typical diode, you can measure reverse bias voltage about .3 to .6V, but not on LED. I have read you can measure it using constant current source, but why? What is the physical principle behind this?
Comment: Those sound like forward bias voltages to me...
Answer: LEDs behave electrically like other types of diodes, just with different parameters. They can be modeled reasonably well by the Shockley diode equation with a series resistor.

Regular diodes tend to have a reverse breakdown in the 50V-1000V range, LEDs it's on the lower end of that range. Usually we don't use LEDs reverse biased except to stand off a few volts in multiplexed circuits, so the specs tend to be very loose (maybe a 5V spec on an LED that can withstand 50V or 100V of reverse bias).
Regular diodes have a forward voltage of 0.6V or so at currents of mA, with LEDs it's more like 1V-3.5V (the lower values for IR LEDs, the higher for UV).
The ideality factor n tends to be around 2 for regular diodes, and it can be quite different for LEDs.
Answer: Sorry, but you're wrong.
The forward and reverse bias voltages and currents can be measured on an LED as easily as they can on any other diode, and all that's needed is a voltmeter, an ammeter and a voltage source.
In 2, the voltmeter is a balanced bridge which draws no current.
Comment: Or perhaps "the voltmeter must be a balanced bridge so that no current is drawn"?
Comment: Perhaps, but for the utmost in accuracy - and confusion-  "In 2, 'V' is a [potentiometer](http://en.wikipedia.org/wiki/Potentiometer_(measuring_instrument))" works best
Answer: I assume you are having trouble measuring the forward voltage with your DMM Diode function.  Some DMM's have enough compliance to measure LED's and some don't.  So you could try another  DMM.  If not follow EM-fields idea and just use your power supply on the bench.  Put some series resistance (maybe 1k ohm) before the LED to limit the current... and as Sphero said you will be measuring the forward voltage at only one current.
The reverse voltage of an LED is another story.. as Spehro said numbers in the 50 - 100 V range are common.  (Again a series resistor will be needed so as to not damage the LED.)  You can do some fun things with a reverse biased LED.  (Link on request.)
Comment: *I* am interested in that link about reverse biased LED  applications :-)
Comment: @LorenzoDonati, Well first I found that this only works (at low voltage.) with the GaP red LED's from here. https://www.purdyelectronics.com/pdf/LED-SFC.pdf AND113R or AND114R (the clear 113 is better.)  Reverse bias to ~25V and it's a sinlge photon detector. (with kinda terrible efficiency.) See here, http://teachspin.com/newsletters/TeachSpin_MAY13FINALFOR%20WEB.pdf


What is this "justified" text technique called?

Question: You usually see this technique on infographics and brochures, and sometimes magazines:
Comment: Sometimes, some words are rotated and still readable
Answer: I don't know if there is a universal term for this. However, I have seen the term slab text used to describe it (not to be confused with slab serif).
I also can't tell you the origin of the technique, however it was very popular during the wood type era...perhaps due to wood type becoming plentiful and more available in a variety of styles and sizes.

(Note the alternate 'A' and 'N' in the 'A NOVELTY' line to 'cheat' the line to full width)

For what it's worth, the example image you provided looks really nice, but I think is a good example of where not to use it: when creating info graphs. It's very much a way to make type more of a visual decoration, which is great for a poster, but isn't really a good way to a readable explanation of complex data. My two cents.
Answer: This style is also called justified
Justified
The start and end of text lines are both aligned to the left and right.
While justified alignment looks clean because it fits neatly into a box, it can also be hard to read because there is less visual cue between the termination of a text line. Variances in spacing can appear between words in order to keep the lines even.
The size variations in words is called typography. Designers achieve this kind of style using various techniques as kerning, tracking and changing the size of the words.


Two POE devices on One Ethernet Cable via a Y splitter

Question: Is it possible to run two PoE devices at the same time off of 1 ethernet cable from a PSE? Assuming that the ethernet cable is run through some sort of custom splitter  connector to both PoE Devices.
Comment: Will both use the ethernet cable for data? Is this "proper" PoE or just some proprietary pseudo-PoE PSE?
Answer: The POE specification does not allow for Y-splitters. Y-splitters do not follow the ethernet specifications either, and are a hack, it degrades your signal on the data lines.
If you used a Y-spliiter the PSE can't determine what class of load it has, and you also run the risk of overloading the rated current in the cable with two devices.
Don't use Y-splitters.
Answer: Don't split the Ethernet cable as already answered. Ethernet is a point to point connection and does not support Y-connectors under any circumstance.
However it is perfectly legal (in spec) to power two or more devices from your PSE. The PSE reflects the output Class to the source quite correctly.
Things to note:

The ground for the PSE may not be the ground for the POE source (typically you may see a bridge rectifier on the POE receiver
It is more challenging to ensure overload protection for each of your endpoint devices.
Without per port over-current protections fault in one device may impact operation in the other. This may occur if you unplug/re-plug a device due to the input capacitor.


Unable to access System storage error (ps4)

Question: Recently, I got my hands onto a ps4. The problem is, when I started it said "Cannot start the ps4. Please insert a USB drive with the 5.55 or higher reinstall files."
I did that and put it in. After it initialized, it got 20% of the way before stating "Cannot access the system storage. E-(something, will edit with code)"
I was ticked now. The heck?
All the tutorials on the web relate to a different error, thus I don't think they can help.
Can someone explain what's going on, and a way to FIX it?
Comment: Sounds like there's a problem with the HDD. If you have an old HDD lying around, (or an old SSD), I'd replace the PS4 HDD with it and try again.
Answer: Getting "Cannot access the system storage" while initializing the PS4 System Software usually means that the hard drive sectors are no longer readable.
As Nolonar points out in the comments, you should try to get a new 2.5' SATA drive that can be either an HDD or SDD and see if the system software can be installed that way.


HEVC 10 bit streaming to full HD TV

Question: I have a low power desktop (ASRock Mod 1150 H97M with integrated graphics, Intel Pentium G3258 CPU, 1920*1200 monitor, Windows 10) which acts as a media server in my home. My TV is Sony/Android TV/ 55 inch/full HD (kdl55w805C). I have Virgin fibre 350mbps connection, and both TV and desktop is physically connected to the Virgin Wi-Fi router through cat 6 cable.
I have movies/videos stored in the desktop. In the TV I use Kodi to watch the movies which is shared in the desktop.
All good until I recently came across a movie which is 4K HEVC 10bit. Kodi in my TV just refused to open the file. Since my TV is only full HD and the processor in TV is presumably not up to decode HEVC it is understandable. So my next target is to somehow use the desktop to process the video and stream to the TV.
When opening the video file, Windows 10 movies asked me to buy an HEVC decoder from store -which I did. After this (to my surprise) my relatively weak computer played the movie in the computer without any noticeable issues! However when I try to cast the movie to the TV, it just failed. The TV showed "unsupported video error". I tried using Windows Media Player, but the result was same — it can play the movie in computer but casting to TV failed.
This got me a bit confused. I thought when casting/streaming, the computer decodes the video and sends the decoded signals to the player. So when the TV is saying unsupported video what does that mean?
I tried VLC, but it cannot even play the video in the computer.
Tried Plex making the computer the Plex server. The TV Plex app can show all 1080p videos beautifully, but the HEVC playing failed. I tried playing the HEVC file using the Plex server in my Samsung S8 smartphone (which is 4K) and it played it without any issues. My question here is which device is decoding the HEVC file? Plex media server in the desktop or the playing device?
How can I solve this issue? Getting a dedicated graphics card(with HEVC decoding) is going to solve the problem? I am doubtful if it is because my system is able to play the video using Windows Media Player so it has the processing power to decode the video. But still it failed to cast to the TV.
Any insights are much appreciated
Answer: Video streamed across a network is always compressed. Even if you are only streaming what your TV is capable of, with a low film/cinema frame rate of 24 fps, that's 1920 pixels wide * 1080 pixels high * 24 bits per pixel * 24 frames per second = about 1.2 gigabits per second, which is more bandwidth than most consumers have on their home networks, wired or wireless.
Uncompressed 4K UHD (2160p) with 10 bits-per-RGB-color-channel at a high frame rate like 60fps approaches 15 gigabits per second.
So you need a casting solution that will decode HEVC, downsample/convert from 2160p and 10-bit color to 1080p and 8-bit color, and recompress as something like H.264 AVC that your TV probably understands, and cast that to the TV. That seems like a lot of work, and not something I would expect any free video player to automatically do on the fly.
Comment: Actually Emby server (free) does that - transcoding on demand - when properly configured.

HEVC 10 bit streaming to full HD TV


Was any of the movies based off anything from the manga?

Question: In regards to the Bleach Movies (Memories of Nobody, Diamond Dust Rebellion, Fade to Black and Hell Verse) were any of them based off anything from the Manga? or are they just as much filler as the Bount Arc?
Answer: Speaking to two of those movies, I don't recall any distinct plot-advancing points within them.  They explored some different concepts related to the Bleach universe (such as "Blanks" in Memories of Nobody, and the King's Seal in The Diamond Dust Rebellion), but to my recollection, there wasn't anything that was specifically canonical that the movies were based on.
Comment: I recall a certain very popular bleach manga reviewer had a short rant like talk about how Kubo made Memories of Nobody pseudo canon by introducing Blanks and the whole realm they live in canon through a description. Though, that was all we got, Just like the Hell verse where we had canonical confirmation Hell exists in the bleach verse, but all we got was to see the door pull someone in. The bleach movie about hell took its own liberties for everything else.
Answer: Memories of Nobody is pseudo-canon, showcasing real lore elements but depicting non-canon events.
All canonical lore facts introduced in Memories of Nobody are summed in the Bleach Fandom Wiki's article on the Valley of Screams. The manga indeed confirmed in Chapter 625 that Valleys of Screams do exist ; although, contrary to the MoN movie, there are several Valleys of Screams. This is a slight lore disparity, but the general concept from the movie can be accepted as canonical : there exists pockets of space between dimensions made out of lost souls' raw spiritual energy. The Blanks entities have not been confirmed as canonical, as is Senna's existence.
Diamond Dust Rebellion is entirely non-canonical.
The Oin artifact at the core of the movie is entirely non-canonical (canonically speaking, there isn't even a "Royal Family" that could have created or possessed the artifact).
Likewise, the idea of twin Zanpakutōs is wholly impossible and directly goes against the very nature of Zanpakutos. As explained in chapters 523 to 529, shinigamis-in-training are given Asauchis, blank Zanpakutōs designed to develop themselves as such :

"All Shinigami must spend every waking moment with their own Asauchi, and as they progress in their training, they slowly and methodically imprint the essence of their soul into their Asauchi. This is how they guide and mold their own unique Zanpakutō."

This directly goes against the idea of twin Zanpakutōs developing naturally.
I haven't seen Fade to Black, although a quick cursory search indicates there are no canonical concepts introduced within the movie ; neither does it bases itself upon Rukia's actual story. If someone familiar with the movie could second this analysis, I would be quite appreciative.
Hell Verse takes place in a non-canonical version of Hell
Hell Verse's production was relatively troubled, as Kubo himself asked to be removed from the movie's credits. He felt his contribution and ideas were actively ignored by the movie's producers and directors. This intense rejection from Kubo does mean that Hell Verse is fully non-canonical and even goes directly against Tite Kubo's very own ideas. The tie-in chapter "imaginary number 01. the unforgivens" should also be non-canonical.
Tite Kubo left a message in the Japanese DVD box of Hell Verse, detailing his troubles with the movie's production. Here's an unofficial translation by Andygoesrawr from r/Bleach :

In this movie I was credited as "Executive Director". However honestly speaking, for the DVD version I want that title to be removed. I already asked them to do so. This is because I feel I didn't participate enough in the production of this movie to warrant such a title.I already had this feelings since the premier of the theatre version, however when I met with the producer staff to persuade them, the movie was already in the editing process so it couldn't be removed.
I had a meeting with the scriptwriter - I think it was in the year preceding the movie premiere, in early summer.The meeting was incandescent, and we discussed ideas until nearly dawn. The scriptwriter took careful notes of the ideas that I had contributed jointly during the meeting. The response was that we were able to come up with some very interesting stuff. I had the feeling that before winter at the latest the scenario would be completed - but in the end, the scenario was sent to me only in the spring of the year of the movie premiere. Furthermore, the scenario didn't contain any of the ideas of the meeting... apparently, the notes taken at that time were not transmitted to the director and to the other members of the staff.
Later on, we had some trouble with the production department agreeing to some changes decided by the scriptwriter, and the scriptwriter worked hard with the changes that were made - but unfortunately, there was no more time. The fact that characters that first made their entry in the original work like Ichigo, Kokutou and Shuuren had a very Bleach-like feeling is thanks to all of the seiyuu that gave them their voices, and to all of the staff that drew them.
Once again, thank you from the bottom of my heart.


Color Logic problem 3

Question: Find the rule specified in the image below. Make sure the rule fully satisfies.

 Part two and one
Comment: Are each line verifying the logic independently?
Comment: Are these all coming from the same caterpillar logic app?
Comment: @boboquack No, it's not.
Answer: I don't know if it's the rule, but I found a rule that satisfies both the true and false examples:

 If you divide the line in half, each half has at least one full light-blue square
Comment: @Orphevs I don't think rounding applies, CaptainPlanet says "one **XXXX** xxxxx-xxxx square" where **XXXX** is the key word here.
Comment: @boboquack - nice inline spoilering, though it took me more than one re-read to get it :-)
Comment: Depending on how you handle rounding, your approach won't work correctly with False (2) and (3).
Answer: How about

 Each line must have at least 2 blue square with a limit of 2 consecutive color
Comment: False 2,3, and 7 match this rule though, meaning it cant be that.
Answer: I think this pretty much fits:

 If there are more lightblue squares, than other colored ones in a line, the next line must be longer than the actual line, otherwise the next line must be 1 square shorter.
Comment: For these types of rule puzzles, I believe the lines need to be analyzed independently (that is, the rule needs to apply to each line in a vacuum)
Answer: The rules are:

 There must be more than one blue square in a line, each half of a line containing atleast one blue square, and
 not more than two blue squares should come together in a line.
Comment: @Jon.G just glue the rules with _**and**_...
Comment: IMHO rule 3. follows from 1. unless you meant 'each half'.
Comment: I believe the idea is there is only **one** rule
Answer:
Rows of length two (2) cannot contain an orange square.
Comment: This does not provide an answer to the question. Once you have sufficient [reputation](https://puzzling.stackexchange.com/help/whats-reputation) you will be able to [comment on any post](https://puzzling.stackexchange.com/help/privileges/comment); instead, [provide answers that don't require clarification from the asker](https://meta.stackexchange.com/questions/214173/why-do-i-need-50-reputation-to-comment-what-can-i-do-instead). - [From Review](/review/low-quality-posts/35405)
Comment: @BeastlyGerbil If you consider the true and false as total grids that follow the rules, rather than collections of rows that each follow the rule, then this answer does identify one of the many, many possible rules to distinguish the grids. You could also view the question slightly differently as "do all rows in this group pass the rule?", in which case one failure would fail the whole category. Either way, this makes sense to me as a full answer, given that the question isn't explicit about how to interpret the grids. Admission: I made the same mistake initially.
Comment: @BeastlyGerbil actually, logically this is a 100% airtight answer. You obviously have no sense of humour.

Color Logic problem 3


How can I compare two algorithms using their Big-Oh complexities?

Question: I have two recursive algorithms to solve a particular problem. I have calculated their time complexities as $O(n^2\times\log n)$ and $O(n^{2.32})$. I need to find which algorithm is better in terms of time complexity. I tried plotting graphs but two functions seem to be going together.
Comment: `logn` is not in the power of `n`. It's multiplied to `n^2`.
Comment: Ok, I edited your question to make the formulas clearer.
Answer: You will need to compare the rate of change for both functions. This can be accomplished by taking the derivative of both functions:
$$ O_1'(n^2 log(n)) = \frac{d}{dn} n^2 log(n) = n + 2n × log(n) $$
$$ O_2'(n^{2.32}) = \frac{d}{dn} n^{2.32} = 2.32n^{1.32} $$
Plot these derivatives and compare the graphs. If they still seem too close, continue to take higher order derivatives such as $\frac{d^2O}{dn^2}$, $\frac{d^3O}{dn^3}$, etc. Eventually, you will notice a clear difference in the rate of change.
For those who don't have access to plotting software, you can evaluate the slope of the tangent line for an arbitrarily large n-value:
$$ O_1'(10^6)=\frac{d}{dn} n^2log(n)\bigg|_{n=10^6} = 10^6 + 2(10^6) × log(10^6) ≈ 2.8631 × 10^7$$
$$ O_2'(10^6)=\frac{d}{dn} n^{2.32}\bigg|_{n=10^6} = 2.32(10^6)^{1.32} ≈ 1.9296 × 10^8$$
This means, for $n=10^6$, $O_1$'s tangent line @ $(10^6, y_1)$ would result for some equation:
$$y - y_1 = (2.8631 × 10^7)(x - 10^6) $$
and $O_2$'s tangent line would result in:
$$y - y_1 = (1.9296 × 10^8)(x - 10^6) $$
Now, the answer is clear: $O(n^{2.32})$ has a much more steeper rate of growth than $O(n^2log(n))$ for large values of $n > 10^6$. Conclusion: $O(n^2log(n))$ is more efficient than its counterpart.
Answer: I see, that answer is done and accepted, but let me share some thoughts:
Short answer: knowing only upper bounds it's impossible to compare algorithms. We can compare upper bounds, but this doesn't give answer to algorithms relation.
Long answer: assume we have $f\in O(n^2\log n)$ and $g \in O(n^{2.32})$. Because $\exists N \in \mathbb{N}$ such that for $n > N$ holds $n^2\log n<n^{2.32}$, then $ O(n^2\log n)\subset O(n^{2.32})$, so knowing only $g \in O(n^{2.32})$ does not gives warranty, that it is not in $ O(n^2\log n)$ also.
Let me bring analogy: if $x<5$ and $y<10$, then we cannot say how $x$ and $y$ are related to each other, without additional info. For example both variants $x=1,y=2$ and $x=2,y=1$ satisfies given conditions.
Answer: $O(n^{2.32})$ is kind of unusual. Do you have a mathematical proof for this, or is it an estimated based on observations? In that case, you can't draw any conclusions from it.
Big-Oh is an upper bound. So first you need to check what is the actual behaviour. If an algorithm  runs in $O(n)$ then it is correct (but not very useful) to say it runs in $O(n^{2.32})$, so check that first.
If both are strict upper bounds (so the algorithms are not $o(n^2 \log n)$ and not $o(n^{2.32})$) with a little o, then the second algorithm will be slower at least for some cases if n is large. If it was $\theta$ then it would be the case for all large n.
In practice, if you want to decide which algorithm to use after you implemented them both, you would measure their execution time for their typical inputs, and find the average time and the worst time. As long as the worst time is acceptable, you'd take whichever one takes less time on average for your inputs. For example, if you need to sort a million arrays of size 10 containing almost sorted, the Big-O of the sorting algorithm is irrelevant; what counts is the average sorting time for arrays of size 10 that are almost sorted.
Quite often the execution time for small n is "fast enough". In that case you will care for cases where one or both of the algorithms are not "fast enough". So if the usual case is "fast enough", you worry more about the unusual, very large cases.
Another problem happens when the average time is low and the worst case should be very rare, but is very slow. In that case an adversary might give you inputs that run very slow. For example, Quicksort is typically fast, but for every deterministic implementation, an adversary can prepare inputs of size n that take O(n^2) time. They will never happen in practice, only when created by an adversary.
Comment: Actually, It's 2^(log 5), base 2. Thank you for your answer
Answer: $O(n^2\log n)$ is better, since $\lim_{n \to \infty} {n^2\log n \over n^{2.32}} = 0$.
Answer: If this is a recursive algorithm, and you want it fast: Calculate the exact runtime for both algorithms for small n. Then algorithm A doesn't recursively call A for smaller n, but the faster of algorithm A and algorithm B. And you will have a base case for small n that is calculated without recursion. Consider that one as well. This may give you overall the fastest algorithm, especially if one algorithm is inferior until n gets quite large.
For recursive algorithms, the execution time often doesn't grow smoothly with n, so you might end up with a table telling you for which n the base case is fastest, for which case A is fastest, and for which case B is fastest.


Using Squeak from a shell

Question: Can I launch Squeak as a REPL (no GUI), where I can enter and evaluate Smalltalk expressions? I know the default image don't allow this. Is there any documentation on how to build a minimum image that can be accessed from a command-line shell?
Answer: Here is a (hackish) solution:
First, you need OSProcess, so run this in a Workspace:
Gofer new squeaksource:'OSProcess'; package:'OSProcess';load.

Next, put this in the file repl.st:
OSProcess thisOSProcess stdOut
  nextPutAll: 'Welcome to the simple Smalltalk REPL';
  nextPut: Character lf; nextPut: $>; flush.
[ |input|
  [ input := OSProcess readFromStdIn.
    input size > 0 ifTrue: [
      OSProcess thisOSProcess stdOut
        nextPutAll: ((Compiler evaluate: input) asString;
        nextPut: Character lf; nextPut: $>; flush
    ]
  ] repeat.
]forkAt: (Processor userBackgroundPriority)

And last, run this command:
squeak -headless path/to/squeak.image /absolute/path/to/repl.st

You can now have fun with a Smalltalk REPL. Dont forget to type in the command:
Smalltalk snapshot:true andQuit:true

if you want to save your changes.
Now, onto the explanation of this solution:
OSProcess is a package that allows to run other processes, read from stdin, and write to stdout and stderr. You can access the stdout AttachableFileStream with OSProcess thisOSProcess (the current process, aka squeak).
Next, you run an infinite loop at userBackgroundPriority (to let other processes run). In this infinite loop, you use Compiler evaluate: to execute the input.
And you run this in a script with a headless image.
Answer: As of Pharo 2.0 (and 1.3/1.4 with the fix described below), there are no more hacks necessary. The following snippet will turn your vanilla Pharo image into a REPL server...
From https://gist.github.com/2604215:
"Works out of the box in Pharo 2.0. For prior versions (definitely works in 1.3 and 1.4), first file in https://gist.github.com/2602113"

| command |
[
    command := FileStream stdin nextLine.
    command ~= 'exit' ] whileTrue: [ | result |
        result := Compiler evaluate: command.
        FileStream stdout nextPutAll: result asString; lf ].

Smalltalk snapshot: false andQuit: true.

If you want the image to always be a REPL, put the code in a #startup: method; otherwise, pass the script at the command line when you want REPL mode, like:
"/path/to/vm" -headless "/path/to/Pharo-2.0.image" "/path/to/gistfile1.st"

Answer: Please visit:
http://map.squeak.org/package/2c3b916b-75e2-455b-b25d-eba1bbc94b84
and Run Smalltalk on server without GUI?
Comment: This doesn't really answer the question. The first link is basically unrelated to the question. The second is to a question about server operation. But this question, as I understand it, is about running Squeak like `irb` or `python` so that it interacts with the terminal on stdin and stdout.
Answer: The project http://www.squeaksource.com/SecureSqueak.html includes a REPL package that may provide much of what you are looking for.
Comment: Oh and the first link in Friedrich's response includes reference to ExternalCommandShell which sounds like it provides similar functionality.
Comment: More information about REPLServer from SecureSqueak can be found at http://gulik.pbworks.com/w/page/7760030/REPLServer .

Using Squeak from a shell


Should we merge the tags "school" and "education"?

Question: The tags on this question made me think about this.

Is there any difference in meaning between the two words, or are they actually synonyms?
If they are synonyms then which one should be the tag and which one the synonym?
Answer: I see them as related, with some overlap, but distinct.
To me, education refers to anything related to teaching, whether it is classroom learning, homeschooling, social skills/manners, or helping a child pursue a particular topic that is of interest to them.  It covers everything directly related to the process of learning, both formal and informal.
I see school as referring to the specific structure of formalized education, with a focus more on the environment than the actual process of learning.
Questions on education would be "how do I teach my child the importance of proper grammar?" or "my child is having problems learning how to read; how do I help them?" or "when is it the right time to teach a child not to interrupt?".
Questions on school would be "I have a problem with a teacher; how do I address it?" or "how do you determine which is a better school environment between these choices?" or "my child is being bullied in class; how do I work with the staff to fix this?" or "what types of resources should I have on hand when setting up a classroom environment at home?"
Comment: Your differentiation makes sense. We should edit the tag descriptions to make it more evident. I'm going to take a stab at it some time.


Asuras/Rakshasas who became good?

Question: There were some Rakshasas like Vibhishana who were noble.
Were there any Asuras/Rakshasas who were initially evil but eventually became good i.e moved to the side of Dharma?
Comment: [Maareecha](http://www.valmikiramayan.net/utf8/aranya/sarga37/aranya_37_frame.htm) is another one.
Comment: Can you count Mahabali, The anonymous bramharakshas of Nampaduvan at Thirukurungudi & Gadodhgajan in it? @sv AFAIK, Mareecha advised the dharmic way, but didn't move as per the question. Just want to learn by asking questions..
Comment: Well Hidimbi,the wife of Pandava Bhima,is one of them.I heard that due to her penance,she became a goddess.Sachi,wife of Indra,is also another demoness as she was the daughter of Paolouman(I think I spelt the name wrongly),the Asura king.And Mandodari,queen of Rakshasas.
Comment: How are Raakshasa  evil ay first place? You know that even Devas can produce obstruction in tasks, it is called "Deva Badhaa" (obstruction madr by Devas). All Devas and Asuras are initially Dharmic , or evil, or good or bad or enlighten. Even Asuras practice Yoga and Devas play mischief
Comment: @AnuragSingh, if you have ever read Ramayana or Mahabharatha you'll know that Raakshasas often disrupted yajnas & yagas, killed and ate rishis and saadhus. How many Devas indulged in such behavior? Please keep your 'postmodernist' thinking out.
Comment: Yes and if you read Scriptures you will see how each time Indra produces obstacles for Munis, Vasus stole KaamaDhenu cow, Brihaspati forced his younger brother wife for intercourse, and then curses the baby in womb to be blind, Chandra abducted Taaraa, Brihaspati fooling the Yoga doing Asuras by becoming Shukracharya @Bharat
Answer: 1)Vibhishana
2)Mahabali
3)Hidimbi
4)Sachi
5)Mandodari
Are there any more?
Comment: Prahlada of course
Comment: Mandodari? Was she even a Raakshasa?
Comment: https://timesofindia.indiatimes.com/city/varanasi/Ravana-was-a-Brahmin-from-Ghaziabad-Subramanian-Swamy/articleshow/45663447.cms                       Ravana and Mandodari from UP, India Brahmins as per above report Subramania swamy.
Comment: Prahlada was an asura, but he was saintly and noble from the first :-)
Answer: Asuras/Rakshasas/Daityas/Danavas who were initially evil but eventually became good i.e moved to the side of Dharma?

Hidimva or Hidimbi or Hidimbā

She is mentioned as the female cannibal in The Mahabharata, Book 1: Adi Parva: Hidimva-vadha Parva: Section CLIV.

But after marrying Bhima she became good. As per this wiki, currently there are a few temples dedicated to Hidimbā Devi.

Malyavan

Initially, Malyavan (Ravana's maternal grandfather's brother) was king of Lanka. He was not good to the deities, sages, and ascetics. When they complained about Malyavan and other Rakshas to Vishnu, Malyavan attacked on Devas with his brothers Mali and Sumali where Mali was killed by Vishnu and other two left Lanka and started living in Rasatala. Later on Kubera started living in Lanka till Ravana took it from him. -UTTARA KANDA of Valmiki Ramayana

But in Rama-Ravana war, Malyavan preaches Ravana. -Yuddha Kanda - Sarga 35 of Valmiki Ramayana

Bāṇāsura: Story is given in Śrīmad-Bhāgavatam (Bhāgavata Purāṇa) » Canto 10 .63

Mahishasura: In his another birth, Mahishasura worshipped Bhadrakali for attain salvation. Kalika Purana was mentioned that.

Asuras/Rakshasas/Daityas/Danavas who were of virtuous nature:

Shachi (queen of Indra), the daughter of Asura Pulaman (as per Mahabharata)

Bali Maharaj (as per most of the Puranas)

Prahlad (as per most of the Puranas)

Prahoti (as per Ramayana)

Vibhishana (as per Ramayana)

Vajrang, Diti's son and TARAKASUR's father (as per Shiva Purana)

Mandodari, daughter of Maya Danava (as per Ramayana)
Comment: You should add chapter name because links may be dead some day. It happened many times. Don't worry about some comments saying chapter name is inconsistent. Just add the chapter name you found.
Answer: http://www.sacred-texts.com/hin/m03/m03273.htm

Brahma then addressed Vibhishana, 'O my son, I am much pleased with thee! Ask any boon thou pleasest!' Thereupon, Vibhishana replied, 'Even in great danger, may I never swerve from the path of righteousness, and though ignorant, may I, O adorable Sire, be illumined with the light of divine knowledge!' And Brahma replied, 'O scourge of thy enemies, as thy soul inclines not to unrighteousness although born in the Rakshasa race, I grant thee immortality!'

Vibhishna asked Brahma that he should always be righteous and have the light of divine knowledge. Brahma was so pleased that in addition, he even bestowed immortality upon him.
Answer: The obvious interpretation of the Shiva Purana is Vajrāṅga is an Asura who stopped being evil on his own. However, technically the only verse he is referred to as an Asura could be interpreted as giving up his Asura form.
https://www.wisdomlib.org/hinduism/book/shiva-purana-english/d/doc226078.html
https://www.wisdomlib.org/hinduism/book/shiva-purana-sanskrit/d/doc389737.html
Answer: There are many. Some of them are as follows.:

Andhaka became Bhringi.

Banasura became a Shiva Gana though later slain by Goddess Kanya Kumari.

3 Sons of Yagna Varaha Vishnu viz Suvrtta, Kanaka, Ghora became 3 sacred fire after their death by Lord Sharabha.

Mahabali became Chiranjeevi and Virochana died by giving his head as a charity to Indra.

Prahlada later slayed by Indra.

Ghatotkach died while saving the life if Arjuna from Karna.

Surapadma became the peacock of Lord Kartikeya.

Krauncha aka Mushakasura became the Mouse of Lord Ganesha.

And so on.
I hope this helps. Prd..
Answer: One must have more patience to hear the answer that follows:
<code>     BAD CANT ADVICE BAD
</code>
NEITHER ASURAAS NOR RAAKSHASAAS were/are good. They committed attrocities to such extent that they were driven away from Divine paths in Universe from ages.
Prahlaada or Vibheeshana or others were not ASURA janmaas but MAANAVA janmaas to give last chance to their relatives that "they cannot impact so many living beings on Earth just because they are powerful by unjust ways for which there were no competitors".
To warn Asura, there must be a Maanavas (from whom Manu Dharma originated) to understand Divine qualities & Demonaic bad deeds.

Asuras/Rakshasas who became good?


android sizing resolution

Question: consideration notes: extending SurfaceView, implementing SurfaceHolder.Callback, and loading in bitmap(.png) images to render the canvas (9x9 grid).
I am trying to get the system to resize the images for me so that I don't have to manually create up-to 4 copies of everything (even 3*77 bitmaps is bad overhead [and yes I need all 77 potentially]) I would prefer just having 77 image files in res/drawables(not all of them will be drawn at any given time; at most maybe 38, but needs to be dynamicly capable to change them out).
Q1: how do I get the system to resize the images without doing the white space thing that android.develop talks about for .9.png (considering that all of my grid images have black borders, and need to butt-up together)?
Q2: is there a unifying screen proportionality (4:3, 5:4) that I can fall back on so that diagonal lines don't look really bad?
Answer: A1:
<code>Bitmap b= BitmapFactory.decodeResource(context.getResources(), R.drawable.b);
b=Bitmap.createScaledBitmap(b,newWidth, newHeight, true);
</code>
A2: i don't think so

android sizing resolution


Securing an SVN only server

Question: Everything's running off of self-secured https. Aside from setting up user authentication, what steps should I take to be sure we're secured?
Comment: Which platform are you running it on? Apache? SVNSRV? Unix? Linux? Windows?
Comment: We shouldn't have to assume anything. Besides, assumption is the mother of all stuff-ups.
Comment: @Farseeker, the mention of https seems to strongly imply that Apache is being used.
Comment: Better safe than sorry... I've wasted a lot of time answering a question based on an incorrect assumption to just have to delete it later.
Answer:
Audit your OS patches, make sure you are running the latest security fixes
Shutdown unneeded services, perform an external nmap scan to make sure you aren't running anything you don't need
Secure your webserver! Here is one such article for apache https://web.archive.org/web/1/http://blogs.techrepublic%2ecom%2ecom/10things/?p=477
Use LDAP or another extenral authentication mechanism (over SSL)
Enforce password strength and rotation policies
(if appropriate) set-up path level access

Subversion as a daemon is rather trusting itself and hands most of the fine-grained user-permissions back into the realm of apache. Can you tell us more about your exact scenario, are you offering this subversion server to public use?
When you say "self-secured" https, you mean a self-signed certificate? If so look at how you are distributing either that certificate or the CA and ensure that that path is secure in itself.
Comment: All good tips that can be applied to any operating system
Comment: If this is for internal users and you are not already behind a corporate firewall (and maybe even if you are) consider running a local firewall. Presumably the only thing you need is 443 and possibly 22 for ssh.
Answer: Self-signed is not security; an attacker can generate their own self signed credentials and MiTM to the real server. This leaves the user unsure of who they're really talking to, unless you preshare the public key.
One specific step to take on SVN+WebDAV: make sure the authorization and authentication files are not within the docroot tree. You don't want to hand out something like that for people to beat on, esp if you use md5 for htaccess or something equally broken.

Securing an SVN only server


Examples of p-adic representations

Question: When reading the books or papers on p-adic Hodge theory, non trivial example of p-adic representation seems to be only the example of Tate curves. To be sure, I had read the very readable introduction by L.Berger and there are some calculations for elliptic curves by ($\varphi$, Fil)-modules. But, are there more concrete examples (coming from given equations) which one can calculate by hand(s)?
Answer: Not sure what you mean by "coming from given equations". If you're looking for concrete examples, you can start with abelian representations of $G_K = Gal(K^{alg}/K)$ where $K$ is a finite extension of $Q_p$. Choose a Lubin-Tate character $\chi_K : G_K \to O_K^\times$ and see what kinds of representations you can get by looking at $\eta \circ \chi_K$ where $\eta : O_K^\times \to O_L^\times$ is a character, with $L/K$ a finite extension, and you map $O_L^\times \to GL_d(Z_p)$ using a basis of $O_L$. What Hodge-Tate-Sen weights can you get this way? Then what extensions can there be between such representations? Even the abelian representations can teach you quite a bit.
Comment: Thank you very much. To be sure, they are just abelian representations but I can study lots. What kinds of references do you recommend for the Lubin-Tate characters?
Answer: Any $p$-adic modular form has a $p$-adic representation and any classical modular form has p-adic reprsentation such that it is potentially semi-stable at $p$.
Generally, any proper smooth scheme $X$ over $\mathbb{Q}$ yields a $p$-adic representation given by the action of $G_\mathbb{Q}$ on the $p$-adic etale cohomology $H^{i}(X\times \overline{\mathbb{Q}}, \mathbb{Z}_p) \otimes \mathbb{Q}_p$, and it is always potentially semi-stable at $p$.
Comment: Everyone knows that. And then??
Comment: Example of what ??  there is a lot of examples of $(\varphi,\Gamma)$-module but what do you mean by $(\varphi, Fil)$? what is $Fil$?

Examples of p-adic representations